Dqn/dqn.h

////////////////////////////////////////////////////////////////////////////////
// Dqn.h Usage
////////////////////////////////////////////////////////////////////////////////
/*
	#define DQN_IMPLEMENTATION       // Enable the implementation

	// Define this wherever you want access to DQN code that uses the platform.
	#define DQN_PLATFORM_HEADER      // Enable function prototypes for xplatform/platform code

	// NOTE: For platform code, it's one or the other or you will get compilation problems.
	// Define this in ONE and only ONE file to enable the implementation of platform code.
	// On Win32 you must link against user32.lib
	#define DQN_WIN32_IMPLEMENTATION // Enable Win32 Code, but only if _WIN32 or _WIN64 is already defined. Also requires DQN_IMPLEMENTATION.
	#define DQN_UNIX_IMPLEMENTATION  // Enable Unix Code, but only if __linux__ is already defined. Also requires DQN_IMPLEMENTATION.

	#define DQN_MAKE_STATIC          // Make all functions be static
	#include "dqn.h"
 */

// Conventions
// All data structures fields are exposed by default, with exceptions here and there. The rationale
// is I rarely go into libraries and start changing values around in fields unless I know the
// implementation OR we're required to fill out a struct for some function.

// Just treat all struct fields to be internal and read-only unless explicitly stated otherwise.

////////////////////////////////////////////////////////////////////////////////
// Table Of Contents #TOC #TableOfContents
////////////////////////////////////////////////////////////////////////////////
// You can search by #<entry> to jump straight to the section.
// The first match is the public API, the next matche(s) are the implementation

// #Portable Code
// #DqnAssert    Assertions
// #DqnMem       Memory Allocation
// #DqnMemAPI    Custom memory API for Dqn Data Structures
// #DqnMemStack  Memory Allocator, Push, Pop Style
// #DqnString    String library
// #DqnArray     Dynamic Array using Templates
// #DqnHash      Hashing using Murmur
// #DqnHashTable Hash Tables using Templates
// #DqnMath      Simple Math Helpers (Lerp etc.)
// #DqnV2        2D  Math Vectors
// #DqnV3        3D  Math Vectors
// #DqnV4        4D  Math Vectors
// #DqnMat4      4x4 Math Matrix
// #DqnRect      Rectangles
// #DqnChar      Char  Operations (IsDigit(), IsAlpha() etc)
// #DqnStr       Str   Operations (Str_Len(), Str_Copy() etc)
// #DqnWChar     WChar Operations (IsDigit(), IsAlpha() etc)
// #DqnRnd       Random Number Generator (ints and floats)
// #Dqn_*        Utility code, (qsort, quick file reading)

// #XPlatform (Win32 & Unix)
// #DqnFile      File I/O (Read, Write, Delete)
// #DqnTimer     High Resolution Timer
// #DqnLock      Mutex Synchronisation
// #DqnJobQueue  Multithreaded Job Queue
// #DqnAtomic    Interlocks/Atomic Operations
// #DqnPlatform  Common Platform API helpers

// #Platform
// - #Win32Platform
//   - #DqnWin32     Common Win32 API Helpers

// #External Code
// #DqnIni       Simple INI Config File API (Public Domain lib by Mattias Gustavsson)
// #DqnSprintf   Cross-platform Sprintf Implementation (Public Domain lib stb_sprintf)

// TODO
// - Memory debugging
//   - Total allocated memory vs freed memory to track leaked allocations
//
// - QuickSort version for classes that implement a less than operator
//
// - DqnMemStack
//   - Allow 0 size memblock stack initialisation/block-less stack for situations where you don't
//     care about specifying a size upfront
//   - Default block size for when new blocks are required
//
// - Win32
//   - Get rid of reliance on MAX_PATH
//
// - Make lib compile and run on Linux with GCC using -03
// - Make DqnV* operations be static to class for consistency?

////////////////////////////////////////////////////////////////////////////////
// Preprocessor Checks
////////////////////////////////////////////////////////////////////////////////
// This needs to be above the portable layer so  that, if the user requests
// a platform implementation, platform specific implementations in the portable
// layer will get activated.
#if (defined(_WIN32) || defined(_WIN64))
	#define DQN_IS_WIN32 1
#elif defined(__linux__)
	#define DQN_IS_UNIX 1
#endif

#if defined(DQN_IS_WIN32) && defined(DQN_WIN32_IMPLEMENTATION)
	#define DQN_XPLATFORM_LAYER 1
	#define DQN_WIN32_PLATFORM 1
#elif defined(DQN_IS_UNIX) && defined(DQN_UNIX_IMPLEMENTATION)
	#define DQN_XPLATFORM_LAYER 1
	#define DQN_UNIX_PLATFORM 1
#endif

////////////////////////////////////////////////////////////////////////////////
// #Portable Code
////////////////////////////////////////////////////////////////////////////////
#ifndef DQN_H
#define DQN_H

#ifdef DQN_MAKE_STATIC
	#define DQN_FILE_SCOPE static
#else
	#define DQN_FILE_SCOPE
#endif

#include <stdint.h> // For standard types
#include <stddef.h> // For standard types
#include <string.h> // memmove
#include <float.h>
#define LOCAL_PERSIST static
#define FILE_SCOPE    static

typedef uint64_t u64;
typedef uint32_t u32;
typedef uint16_t u16;
typedef uint8_t  u8;

typedef int64_t i64;
typedef int32_t i32;
typedef int16_t i16;
typedef int8_t  i8;

typedef double f64;
typedef float  f32;

#define DQN_F32_MIN -FLT_MAX

#define DQN_TERABYTE(val) (DQN_GIGABYTE(val) * 1024LL)
#define DQN_GIGABYTE(val) (DQN_MEGABYTE(val) * 1024LL)
#define DQN_MEGABYTE(val) (DQN_KILOBYTE(val) * 1024LL)
#define DQN_KILOBYTE(val) ((val) * 1024LL)

#define DQN_ALIGN_POW_N(val, align) ((((size_t)val) + ((size_t)align-1)) & (~(size_t)(align-1)))
#define DQN_ALIGN_POW_4(val)        DQN_ALIGN_POW_N(val, 4)

#define DQN_INVALID_CODE_PATH 0
#define DQN_CHAR_COUNT(charArray) DQN_ARRAY_COUNT(charArray) - 1
#define DQN_ARRAY_COUNT(array) (sizeof(array) / sizeof(array[0]))

#define DQN_PI 3.14159265359f
#define DQN_SQUARED(x) ((x) * (x))
#define DQN_ABS(x) (((x) < 0) ? (-(x)) : (x))
#define DQN_DEGREES_TO_RADIANS(x) ((x * (DQN_PI / 180.0f)))
#define DQN_RADIANS_TO_DEGREES(x) ((x * (180.0f / DQN_PI)))

#define DQN_MAX(a, b) ((a) < (b) ? (b) : (a))
#define DQN_MIN(a, b) ((a) < (b) ? (a) : (b))
#define DQN_SWAP(type, a, b) do { type tmp = a; a = b; b = tmp; } while(0)

////////////////////////////////////////////////////////////////////////////////
// #DqnAssert Public API - Assertions
////////////////////////////////////////////////////////////////////////////////
// DQN_ASSERT() & DQN_ASSERT_MSG() will hard break the program but it can be
// disabled in DqnAssertInternal() for release whilst still allowing the assert
// expressions to be evaluated and instead send diagnostics to console.

// NOTE: "## __VA_ARGS__" is a GCC hack. Zero variadic arguments won't compile
// because there will be a trailing ',' at the end. Pasting it swallows it. MSVC
// implicitly swallows the trailing comma.

// returns: If the expr was true or not.
#define DQN_ASSERT(expr)               DqnAssertInternal(expr, __FILE__, __LINE__, #expr, nullptr)
#define DQN_ASSERT_MSG(expr, msg, ...) DqnAssertInternal(expr, __FILE__, __LINE__, #expr, msg, ## __VA_ARGS__)

// Usage example. This protects code against asserts that should fire in release
// mode by still letting the expression evaluate and the ability to redirect
// the code flow to some recovery path.
#if 0
	int *mem = (int *)malloc(sizeof(*mem));
	if (DQN_ASSERT_MSG(mem, "Not enough memory for malloc")) {
	    // success
	} else {
	    // failed
	}
#endif

// Internal implementation should not be used as the macro above will handle it, but is required in
// header for visibility to external functions calling it.
// returns: If the expr was true or not.
DQN_FILE_SCOPE bool DqnAssertInternal(const bool result, const char *const file, const i32 lineNum,
                                      const char *const expr, const char *const msg, ...);

// Hard assert causes an immediate program break at point of assertion by trying
// to modify the 0th mem-address.
#define DQN_ASSERT_HARD(expr) if (!(expr)) { *((int *)0) = 0; }

// Assert at compile time by making a type that is invalid depending on the expression result
#define DQN_COMPILE_ASSERT(expr)                DQN_COMPILE_ASSERT_INTERNAL(expr, __COUNTER__)
#define DQN_COMPILE_ASSERT_INTERNAL(expr, guid) typedef char DqnCompileAssertInternal_##guid[((int)(expr)) * 2 - 1];

////////////////////////////////////////////////////////////////////////////////
// #DqnMem Public API - Memory Allocation
////////////////////////////////////////////////////////////////////////////////
// TODO(doyle): Use platform allocation, fallback to malloc if platform not defined
DQN_FILE_SCOPE void *DqnMem_Alloc  (const size_t size);
DQN_FILE_SCOPE void *DqnMem_Calloc (const size_t size);
DQN_FILE_SCOPE void  DqnMem_Clear  (void *const memory, const u8 clearValue, const size_t size);
DQN_FILE_SCOPE void *DqnMem_Realloc(void *memory, const size_t newSize);
DQN_FILE_SCOPE void  DqnMem_Free   (void *memory);
DQN_FILE_SCOPE void  DqnMem_Copy   (void *const dest, void *const src, const i64 numBytesToCopy);
DQN_FILE_SCOPE void *DqnMem_Set    (void *const dest, u8 value, const i64 numBytesToSet);
DQN_FILE_SCOPE void *DqnMem_Set64  (void *const dest, u8 value, const i64 numBytesToSet);

////////////////////////////////////////////////////////////////////////////////
// #DqnMemAPI Public API - Custom memory API for Dqn Data Structures
////////////////////////////////////////////////////////////////////////////////
// You only need to care about this API if you want to use custom mem-alloc routines in the data
// structures! Otherwise it already has a default one to use.

// How To Use:
// 1. Implement the allocator function, where DqnMemAPI::Request will tell you the request.
//    - (NOTE) The callback should return the resulting data into DqnMemAPI::Result
// 2. Create a DqnMemAPI struct with a function ptr to your allocator
//    - (OPTIONAL) Set the user context to your book-keeping/mem allocating service
// 3. Initialise any data structure that supports a DqnMemAPI with your struct.

// That's it! Done :) Of course, changing memAPI's after initialisation is invalid since the
// pointers belonging to your old routine may not be tracked in your new memAPI. So you're at your
// own discretion there.

class DqnMemAPI
{
public:
	enum Type
	{
		Invalid,
		Alloc,
		Calloc,
		Realloc,
		Free
	};

	struct Request
	{
		void *userContext;
		Type type;
		union {
			// DqnMemAPI::Type::Alloc / DqnMemAPI::Type::Calloc
			struct
			{
				bool clearToZero;
				size_t requestSize;
			};

			// DqnMemAPI::Type::Free
			struct
			{
				void *ptrToFree;
				size_t sizeToFree;
			};

			// DqnMemAPI::Type::Realloc
			struct
			{
				size_t newRequestSize;
				void *oldMemPtr;
				size_t oldSize;
			};
		};
	};

	typedef u8 *Allocator(DqnMemAPI::Request request);

	static Request RequestRealloc(const DqnMemAPI memAPI, void *const oldMemPtr, size_t const oldSize, size_t const newSize);
	static Request RequestAlloc  (const DqnMemAPI memAPI, size_t const size, const bool clearToZero = true);
	static Request RequestFree   (const DqnMemAPI memAPI, void *const ptrToFree, size_t const sizeToFree);

	bool IsValid() const { return (callback != nullptr); }

	Allocator *callback;
	void      *userContext;
};

DQN_FILE_SCOPE DqnMemAPI DqnMemAPI_HeapAllocator ();
DQN_FILE_SCOPE DqnMemAPI DqnMemAPI_StackAllocator(struct DqnMemStack *const stack);

////////////////////////////////////////////////////////////////////////////////
// #DqnMemStack Public API - Memory Allocator, Push, Pop Style
////////////////////////////////////////////////////////////////////////////////
// DqnMemStack is an memory allocator in a stack like, push-pop style. It pre-allocates a block of
// memory at init and sub-allocates from this block to take advantage of memory locality.

// When an allocation requires a larger amount of memory than available in the block then the
// MemStack will allocate a new block of sufficient size for you in DqnMemStack_Push(..). This DOES
// mean that there will be wasted spaceat the end of each block and is a tradeoff for memory
// locality against optimal space usage.

// How To Use:
// 1. Create a DqnMemStack struct and pass it into an initialisation function
//    - InitWithFixedMem() allows you to pass in your own memory which is
//      converted to a memory block. This disables dynamic allocation.
//      NOTE: Space is reserved in the given memory for MemStackBlock metadata.

//    - InitWithFixedSize() allows you to to disable dynamic allocations and
//      sub-allocate from the initial MemStack allocation size only.

// 2. Use DqnMemStack_Push(..) to allocate memory for use.
//    - "Freeing" memory is dealt by creating temporary MemStacks or using the
//      BeginTempRegion and EndTempRegion functions. Specifically freeing
//      individual items is typically not generalisable in this scheme.

struct DqnMemStack
{
	enum Flag
	{
		IsNotExpandable       = (1 << 0),
		// NOTE(doyle): Required to indicate we CAN'T free this memory when free is called.
		IsFixedMemoryFromUser = (1 << 1),
	};

	// Blocks are freely modifiable if you want fine grained control. Size value and memory ptr should
	// NOT be modified directly, only indirectly through the regular API.
	struct Block
	{
		// The raw memory block, size and used count
		u8 *memory;
		size_t size;
		size_t used;

		// The allocator uses a linked list approach for additional blocks beyond capacity
		Block *prevBlock;
	};

	DqnMemAPI  memAPI;          // Allocation scheme
	Block     *block;           // The memory block allocated for the stack
	u32        flags;           // Bits set from enum Flag
	i32        tempRegionCount;

	// Allocations are address aligned to this value. Not modifiable as popping uses this to realign ptrs
	u32 byteAlign;

	// -- Initialisation API
	// Uses fixed memory given by user. All allocations from the MemStack will be suballocated from the
	// given memory. Allocations fail after the MemStack becomes full.
	// stack:     Pass in a pointer to a zero cleared DqnMemStack struct.
	// mem:       Memory to use for the memory stack
	// byteAlign: Set the alignment of memory addresses for all allocated items from the memory stack.
	// return:    FALSE if args are invalid, or insufficient memSize.
	bool InitWithFixedMem(u8 *const mem, size_t const memSize, u32 const byteAlign_ = 4);

	// The memory stack uses 1 initial allocation from the DqnMem_Alloc(). No further allocations are
	// made. All allocations are suballocated from the first allocation.
	// size: The amount of memory to allocate. Size gets aligned to the next "byteAlign"ed value.
	bool InitWithFixedSize(size_t const size, bool const zeroClear, u32 const byteAlign_ = 4, DqnMemAPI const memAPI_ = DqnMemAPI_HeapAllocator());

	// Dynamically expandable stack. Akin to DqnMemStack_InitWithFixedSize() except if the MemStack does
	// not have enough space for allocation it will automatically attach another MemBlock using
	// DqnMem_Calloc().
	bool Init(size_t const size, bool const zeroClear, u32 const byteAlign_ = 4, DqnMemAPI const memAPI_ = DqnMemAPI_HeapAllocator());

	// -- Memory API
	// Allocate memory from the MemStack.
	// size:   "size" gets aligned to the byte alignment of the stack.
	// return: nullptr if out of space OR stack is using fixed memory/size OR stack full and platform malloc fails.
	void *Push(size_t size);

	// Frees the given ptr. It MUST be the last allocated item in the stack, fails otherwise.
	bool  Pop (void *const ptr, size_t size);

	// Frees all blocks belonging to this stack.
	void  Free();

	// Frees the specified block belonging to the stack.
	// return: FALSE if block doesn't belong this into calls DqnMem_Free() or invalid args.
	bool  FreeMemBlock(Block *memBlock);

	// Frees the last-most memory block. If last block, free that block making the MemStack blockless.
	// Next allocate will attach a block.
	bool  FreeLastBlock();

	// Reset the current memory block usage to 0.
	void  ClearCurrBlock(bool const zeroClear);

	// -- Temporary Regions API
	// region: Takes pointer to a zero-cleared DqnMemStackTempRegion struct.
	// return: FALSE if arguments are invalid.
	struct DqnMemStackTempRegion TempRegionBegin();
	void                         TempRegionEnd  (DqnMemStackTempRegion region);

	// -- Scoped Temporary Regions API
	struct DqnMemStackTempRegionGuard TempRegionGuard();

	// -- Advanced API
	// These are useful for forcing a new block to be used. AllocateCompatibleBlock() will fail if the
	// supplied stack has flags set such that the stack is not allowed to have new blocks.
	Block *AllocateCompatibleBlock(size_t size, bool const zeroClear);
	bool   AttachBlock            (Block *const newBlock);
	bool   DetachBlock            (Block *const detachBlock);

	// (IMPORTANT) Should only be used to free blocks that haven't been attached! Attached blocks should
	// be freed using DqnMemStack_FreeMemBlock().
    void   FreeDetachedBlock      (Block *memBlock);
};

////////////////////////////////////////////////////////////////////////////////
//  DqnMemStack Temporary Regions
////////////////////////////////////////////////////////////////////////////////
// Lets the programmer mark a begin/end region in which all the memory allocated from the MemStack
// will be reverted upon reaching the DqnMemStackTempRegion_End() call. This includes the reverting
// of additional MemBlocks allocated in a dynamic stack and all other various MemStack configs.

// TODO(doyle): Look into a way of "preventing/guarding" against anual calls to free/clear in temp
// regions
typedef struct DqnMemStackTempRegion
{
	// The stack associated with this TempRegion
	DqnMemStack *stack;

	// Store memBlock state to revert back to on DqnMemStackTempRegion_End()
	DqnMemStack::Block *startingBlock;
	size_t used;
} DqnMemStackTempRegion;

// Region guard automatically starts a region on construction and ends a region on destruction.
struct DqnMemStackTempRegionGuard
{
	// stack: Takes a pointer to a pre-existing and already initialised stack
	DqnMemStackTempRegionGuard(DqnMemStack *const stack);
	~DqnMemStackTempRegionGuard();

private:
	DqnMemStackTempRegion memRegion;
};

////////////////////////////////////////////////////////////////////////////////
// #DqnString Public API - String library
////////////////////////////////////////////////////////////////////////////////
// String allocates +1 extra byte for the null-terminator to be completely compatible with
// C style strings, but this is not reflected in the capacity or len, and is hidden from the user.

// NOTE: Pasting tokens doesn't do anything with preprocessor directives IF the preprocessor finds
//       a stringify or paste operation (# or ##) so we need this level of indirection.
#define DQN_TOKEN_COMBINE(x, y) x ## y
#define DQN_TOKEN_COMBINE2(x, y) DQN_TOKEN_COMBINE(x, y)

// Usage: DqnString example = DQN_STRING_LITERAL(example, "hello world");
#define DQN_STRING_LITERAL(srcVariable, literal)                                                   \
	DQN_STRING_LITERAL_INTERNAL1(srcVariable, literal, DQN_TOKEN_COMBINE2(dqnstring_, __COUNTER__))

class DqnString
{
public:
	char *str;
	i32 len; // Len of the string in bytes not including null-terminator
	i32 max; // The maximum capacity not including space for null-terminator.
	DqnMemAPI memAPI;

	bool InitSize(const i32 size, DqnMemStack *const stack);
	bool InitSize(const i32 size, const DqnMemAPI api = DqnMemAPI_HeapAllocator());

	bool InitFixedMem(char *const memory, const i32 sizeInBytes);

	bool InitLiteral(char const *const cstr, DqnMemStack *const stack);
	bool InitLiteral(char const *const cstr, DqnMemAPI const api = DqnMemAPI_HeapAllocator());

	bool InitLiteral(char const *const cstr, i32 const lenInBytes, DqnMemStack *const stack);
	bool InitLiteral(char const *const cstr, i32 const lenInBytes, DqnMemAPI const api = DqnMemAPI_HeapAllocator());

	bool InitWLiteral(const wchar_t *const cstr, DqnMemStack *const stack);
	bool InitWLiteral(const wchar_t *const cstr, const DqnMemAPI api = DqnMemAPI_HeapAllocator());

	bool InitLiteralNoAlloc(char *const cstr, i32 cstrLen = -1);

	bool Expand(const i32 newMax);

	bool Sprintf(char const *fmt, ...);
	bool Append (DqnString const strToAppend, i32 bytesToCopy = -1);
	bool Append (char const *const cstr     , i32 bytesToCopy = -1);
	void Clear  ();
	bool Free   ();

	// The function automatically null-terminates the output string.
	// bufSize: The size of the buffer in wchar_t characters.
	// return: -1 if invalid, or if bufSize is 0 the required buffer length in wchar_t
	// characters
	i32 ToWCharUseBuf(wchar_t *const buf, const i32 bufSize);

	// returns a malloc() string, needs to be freed using free(..);
	wchar_t *ToWChar(DqnMemAPI api = DqnMemAPI_HeapAllocator());
};

// returns: Initialised string,
DQN_FILE_SCOPE DqnString DqnString_(i32 const len, DqnMemAPI    const api = DqnMemAPI_HeapAllocator());
DQN_FILE_SCOPE DqnString DqnString_(i32 const len, DqnMemStack *const stack);

DQN_FILE_SCOPE DqnString DqnString_(DqnMemAPI    const api = DqnMemAPI_HeapAllocator());
DQN_FILE_SCOPE DqnString DqnString_(DqnMemStack *const stack);

// NOTE: First level of indirection needs to turn the combined dqnstring_(guid) into a name. Otherwise
//       each use of literalVarName will increment __COUNTER__
#define DQN_STRING_LITERAL_INTERNAL1(srcVariable, literal, literalVarName)                         \
	DQN_STRING_LITERAL_INTERNAL2(srcVariable, literal, literalVarName)

#define DQN_STRING_LITERAL_INTERNAL2(srcVariable, literal, literalVarName)                         \
	{};                                                                                            \
	char literalVarName[] = literal;                                                               \
	srcVariable.InitLiteralNoAlloc(literalVarName, DQN_CHAR_COUNT(literalVarName))

////////////////////////////////////////////////////////////////////////////////
// #DqnArray Public API - CPP Dynamic Array with Templates
////////////////////////////////////////////////////////////////////////////////
#define DQN_FOR_ARRAY(indexName, arrayPtr)                                                         \
	for (auto indexName = 0; indexName < (arrayPtr)->count; indexName++)

template <typename T>
struct DqnArray
{
	// Function pointers to custom allocators
	DqnMemAPI memAPI;

	// Array state
	i64 count;
	i64 max;
	T   *data;

	T &operator[](i32 x) { return this->data[x]; }

	// API
	bool  Init        (const i64 size, DqnMemStack *const stack);
	bool  Init        (const i64 size, DqnMemAPI api = DqnMemAPI_HeapAllocator());
	bool  Free        ();
	bool  Resize      (const i64 newMax);
	bool  Grow        ();
	T    *Push        (const T *item, const i64 num);
	T    *Push        (const T item);
	T    *Insert      (const T item, i64 index);
	void  Pop         ();
	T    *Get         (const i64 index);
	void  Clear       (const bool clearMemory = false);
	bool  Remove      (const i64 index);
	bool  RemoveStable(const i64 index);
	void  RemoveStable(i64 *indexList, const i64 numIndexes);
};

template <typename T>
DQN_FILE_SCOPE DqnArray<T> DqnArray_(i64 const size,
                                     DqnMemAPI const api = DqnMemAPI_HeapAllocator())
{
	DqnArray<T> result;
	bool init = result.Init(size, api);
	DQN_ASSERT_HARD(init);
	return result;
}

template <typename T>
DQN_FILE_SCOPE DqnArray<T> DqnArray_(i64 const size, DqnMemStack *const stack)
{
	DqnArray<T> result = DqnArray_<T>(size, DqnMemAPI_StackAllocator(stack));
	return result;
}

template <typename T>
DQN_FILE_SCOPE DqnArray<T> DqnArray_(DqnMemAPI const api = DqnMemAPI_HeapAllocator())
{
	DqnArray<T> result = DqnArray_<T>(0, api);
	return result;
}

template <typename T>
DQN_FILE_SCOPE DqnArray<T> DqnArray_(DqnMemStack *const stack)
{
	DqnArray<T> result = DqnArray_<T>(0, stack);
	return result;
}

template <typename T>
bool DqnArray<T>::Init(i64 const size, DqnMemStack *const stack)
{
	bool result = false;
	if (stack)
	{
		result = this->Init(size, DqnMemAPI_StackAllocator(stack));
	}

	return result;
}

template <typename T>
bool DqnArray<T>::Init(i64 const size, DqnMemAPI const api)
{
	DQN_ASSERT_HARD(size >= 0);

	if (size > 0)
	{
		i64 allocateSize        = size * sizeof(T);
		DqnMemAPI::Request info = DqnMemAPI::RequestAlloc(api, allocateSize, /*zeroClear*/ false);
		this->data              = (T *)api.callback(info);
		if (!this->data) return false;
	}

	this->memAPI = api;
	this->count  = 0;
	this->max    = size;
	return true;
}

// Implementation taken from Milton, developed by Serge at
// https://github.com/serge-rgb/milton#license
template <typename T>
bool DqnArray<T>::Free()
{
	if (this->data)
	{
		// TODO(doyle): Right now we assume free always works, and it probably should?
		i64 sizeToFree = this->max * sizeof(T);
		DqnMemAPI::Request info =
		    DqnMemAPI::RequestFree(this->memAPI, this->data, sizeToFree);
		this->memAPI.callback(info);
		this->data = nullptr;

		this->count = 0;
		this->max   = 0;
		return true;
	}

	return false;
}

template <typename T>
bool DqnArray<T>::Resize(i64 newMax)
{
	if (!this->data)            return false;
	if (!this->memAPI.callback) return false;

	i64 oldSize = this->max * sizeof(T);
	i64 newSize = newMax * sizeof(T);

	DqnMemAPI::Request info;
	if (oldSize == 0)
	{
		info = DqnMemAPI::RequestAlloc(this->memAPI, newSize, /*zeroClear*/ false);
	}
	else
	{
	    info = DqnMemAPI::RequestRealloc(this->memAPI, this->data, oldSize, newSize);
	}

	u8 *result = this->memAPI.callback(info);
	if (result)
	{
		this->data = (T *)result;
		this->max  = newMax;
		return true;
	}
	else
	{
		return false;
	}
}

template <typename T>
bool DqnArray<T>::Grow()
{
	if (!this->data) return false;

	const f32 GROWTH_FACTOR = 2.0f;
	i64 newMax              = (i64)(this->max * GROWTH_FACTOR);
	if (newMax == this->max) newMax++;

	bool result = this->Resize(newMax);
	return result;
}

template <typename T>
T *DqnArray<T>::Push(const T *item, const i64 num)
{
	i64 newSize = this->count + num;
	if (!this->data || newSize > this->max)
	{
		if (!this->Grow()) return nullptr;
	}

	for (auto i = 0; i < num; i++)
	{
		this->data[this->count++] = item[i];
	}

	DQN_ASSERT(this->count <= this->max);
	T *result = this->data + (this->count - 1);
	return result;
}

template <typename T>
T *DqnArray<T>::Push(const T item)
{
	T* result = this->Push(&item, 1);
	return result;
}

template <typename T>
T *DqnArray<T>::Insert(const T item, i64 index)
{
	if (index >= this->count)
	{
		T *result = this->Push(item);
		return result;
	}

	index       = DQN_MAX(index, 0);
	i64 newSize = this->count + 1;
	if (!this->data || newSize > this->max)
	{
		if (!this->Grow()) return nullptr;
	}

	this->count++;
	for (auto i = this->count - 1; (i - 1) >= index; i--)
	{
		this->data[i] = this->data[i - 1];
	}

	this->data[index] = item;
	T *result         = this->data + index;

	DQN_ASSERT(this->count < this->max);
	return result;
}

template <typename T>
void DqnArray<T>::Pop()
{
	if (this->count == 0) return;
	this->count--;
}

template <typename T>
T *DqnArray<T>::Get(const i64 index)
{
	T *result = nullptr;
	if (index >= 0 && index <= this->count) result = &this->data[index];
	return result;
}

template <typename T>
void DqnArray<T>::Clear(bool clearMemory)
{
	if (clearMemory)
	{
		i64 sizeToClear = sizeof(T) * this->count;
		DqnMem_Clear(this->data, 0, sizeToClear);
	}
	this->count = 0;
}

template <typename T>
bool DqnArray<T>::Remove(const i64 index)
{
	if (index >= this->count) return false;

	bool firstElementAndOnlyElement = (index == 0 && this->count == 1);
	bool isLastElement              = (index == (this->count - 1));
	if (firstElementAndOnlyElement || isLastElement)
	{
		this->count--;
		return true;
	}

	this->data[index] = this->data[this->count - 1];
	this->count--;
	return true;
}

template <typename T>
bool DqnArray<T>::RemoveStable(const i64 index)
{
	if (index >= this->count) return false;

	bool firstElementAndOnlyElement = (index == 0 && this->count == 1);
	bool isLastElement              = (index == (this->count - 1));
	if (firstElementAndOnlyElement || isLastElement)
	{
		this->count--;
		return true;
	}

	i64 itemToRemoveByteOffset         = index * sizeof(T);
	i64 oneAfterItemToRemoveByteOffset = (index + 1)  * sizeof(T);
	i64 lastItemByteOffset             = this->count * sizeof(T);
	i64 numBytesToMove                 = lastItemByteOffset - oneAfterItemToRemoveByteOffset;

	u8 *bytePtr = (u8 *)this->data;
	u8 *dest    = &bytePtr[itemToRemoveByteOffset];
	u8 *src     = &bytePtr[oneAfterItemToRemoveByteOffset];
	memmove(dest, src, numBytesToMove);

	this->count--;
	return true;
}

template <typename T>
void DqnArray<T>::RemoveStable(i64 *indexList, const i64 numIndexes)
{
	if (numIndexes == 0 || !indexList) return;

	// NOTE: Sort the index list and ensure we only remove indexes up to the size of our array
	Dqn_QuickSort<i64>(indexList, numIndexes);

	i64 arrayHighestIndex = this->count - 1;
	i64 realCount         = numIndexes;
	if (indexList[numIndexes - 1] > arrayHighestIndex)
	{
		i64 realNumIndexes =
		    Dqn_BSearch(indexList, numIndexes, arrayHighestIndex, Dqn_BSearchBound_Lower);
		// NOTE: If -1, then there's no index in the indexlist that is within the range of our array
		// i.e. no index we can remove without out of array bounds access
		if (realNumIndexes == -1)
			return;

		if (indexList[realNumIndexes] == arrayHighestIndex)
		{
			realCount = realNumIndexes++;
		}
		else
		{
			realCount = realNumIndexes += 2;
		}
		realCount = DQN_MIN(numIndexes, realCount);
	}

	if (realCount == 1)
	{
		this->RemoveStable(indexList[0]);
	}
	else
	{
		i64 indexListIndex  = 0;
		i64 indexToCopyTo   = indexList[indexListIndex++];
		i64 indexToCopyFrom = indexToCopyTo + 1;
		i64 deadIndex       = indexList[indexListIndex++];

		bool breakLoop = false;
		for (;
		     indexToCopyFrom < this->count;
		     indexToCopyTo++, indexToCopyFrom++)
		{
			while (indexToCopyFrom == deadIndex)
			{
				deadIndex = indexList[indexListIndex++];
				indexToCopyFrom++;

				breakLoop |= (indexToCopyFrom >= this->count);
				breakLoop |= (indexListIndex > realCount);
				if (breakLoop) break;
			}
			if (breakLoop) break;

			this->data[indexToCopyTo] = this->data[indexToCopyFrom];
		}

		for (; indexToCopyFrom < this->count; indexToCopyTo++, indexToCopyFrom++)
		{
			this->data[indexToCopyTo] = this->data[indexToCopyFrom];
		}

		this->count -= realCount;
		DQN_ASSERT(this->count >= 0);
	}
}

////////////////////////////////////////////////////////////////////////////////
// #DqnHash Public API
////////////////////////////////////////////////////////////////////////////////
DQN_FILE_SCOPE u32 DqnHash_Murmur32Seed(void const *data,  size_t len, u32 seed);
DQN_FILE_SCOPE u64 DqnHash_Murmur64Seed(void const *data_, size_t len, u64 seed);

DQN_FILE_SCOPE inline u32 DqnHash_Murmur32(void const *data, size_t len)
{
	return DqnHash_Murmur32Seed(data, len, 0x9747b28c);
}

DQN_FILE_SCOPE inline u64 DqnHash_Murmur64(void const *data, size_t len)
{
	return DqnHash_Murmur64Seed(data, len, 0x9747b28c);
}

////////////////////////////////////////////////////////////////////////////////
// #DqnHashTable Public API - Hash Tables using Templates
////////////////////////////////////////////////////////////////////////////////
template <typename T>
struct DqnHashTable
{
	struct Entry
	{
		DqnString key;
		T data;
		Entry *next;
	};

	DqnMemAPI memAPI;

	Entry **entries;
	i64 numEntries;

	Entry *freeList;      // Entries which are allocated and can be reused are stored here.
	i64 numFreeEntries;

	i64 *usedEntries;     // Tracks the indexes used in the entries.
	i64 usedEntriesIndex;

	bool Init(i64 const numTableEntries = 1024, DqnMemAPI const api = DqnMemAPI_HeapAllocator());

	// keyLen: Len of string not including null-terminator, if -1, utf8 strlen will be used to determine length.
	// return: Pre-existing entry if it exists, otherwise a nullptr.
	Entry *Get(DqnString key);
	Entry *Get(char const *const key, i32 keyLen = -1);

	// keyLen: Len of string not including null-terminator, if -1, utf8 strlen will be used to determine length.
	// entryAlreadyExisted: Pass in a bool that indicates true if a new entry was created, or false
	//                      if the entry already existed.
	// return: Pre-existing entry if it exists, otherwise create a new entry suitable for key.
	//         nullptr if out of memory.
	Entry *Make(DqnString key,                          bool *entryAlreadyExisted = nullptr);
	Entry *Make(char const *const key, i32 keyLen = -1, bool *entryAlreadyExisted = nullptr);

	// keyLen: Len of string not including null-terminator, if -1, utf8 strlen will be used to determine length.
	void Remove(DqnString key);
	void Remove(char const *const key, i32 keyLen = -1);

	void Free  ();

	// num: If num is positive, allocate num entries to free list.
	//      If num is negative, remove num entries from free list.
	bool AddNewEntriesToFreeList(i64 num);

	// newNumEntries: If different from numEntries, reallocate the table and rehash all entries in the table.
	bool ChangeNumEntries(i64 newNumEntries);
};

template <typename T>
bool DqnHashTable<T>::Init(i64 const numTableEntries, DqnMemAPI const api)
{
	size_t arrayOfPtrsSize             = sizeof(*this->entries) * numTableEntries;
	DqnMemAPI::Request arrayOfPtrsInfo = DqnMemAPI::RequestAlloc(api, arrayOfPtrsSize);
	u8 *arrayOfPtrs                    = api.callback(arrayOfPtrsInfo);
	if (!arrayOfPtrs) return false;

	size_t usedEntriesSize             = sizeof(*this->usedEntries) * numTableEntries;
	DqnMemAPI::Request usedEntriesInfo = DqnMemAPI::RequestAlloc(api, usedEntriesSize);
	u8 *usedEntriesPtr                 = api.callback(usedEntriesInfo);
	if (!usedEntriesPtr)
	{
		DqnMemAPI::Request freeInfo =
		    DqnMemAPI::RequestFree(api, arrayOfPtrs, arrayOfPtrsSize);
		api.callback(freeInfo);
		return false;
	}

	this->memAPI           = api;
	this->entries          = (Entry **)arrayOfPtrs;
	this->numEntries       = numTableEntries;
	this->freeList         = nullptr;
	this->numFreeEntries   = 0;
	this->usedEntries      = (i64 *)usedEntriesPtr;
	this->usedEntriesIndex = 0;

	return true;
}

template <typename T>
typename DqnHashTable<T>::Entry *DqnHashTableInternal_AllocateEntry(DqnHashTable<T> *table)
{
	DqnMemAPI::Request info =
	    DqnMemAPI::RequestAlloc(table->memAPI, sizeof(DqnHashTable<T>::Entry));
	auto *result = (DqnHashTable<T>::Entry *)table->memAPI.callback(info);

	if (!result->key.InitSize(0, table->memAPI))
	{
		DQN_ASSERT_MSG(DQN_INVALID_CODE_PATH, "Out of memory error");
		DqnMemAPI::RequestFree(table->memAPI, result, sizeof(DqnHashTable<T>::Entry));
		return nullptr;
	}

	return result;
}

template <typename T>
FILE_SCOPE typename DqnHashTable<T>::Entry *
DqnHashTableInternal_GetFreeEntry(DqnHashTable<T> *table)
{
	DqnHashTable<T>::Entry *result = {};
	if (table->freeList)
	{
		result          = table->freeList;
		table->freeList = table->freeList->next;
		table->numFreeEntries--;
	}
	else
	{
		DQN_ASSERT(table->numFreeEntries == 0);
		result = DqnHashTableInternal_AllocateEntry(table);
	}

	return result;
}

template <typename T>
FILE_SCOPE inline i64 DqnHashTableInternal_GetHashIndex(DqnHashTable<T> *table,
                                                        char const *const key, i32 keyLen)
{
	u64 hash      = DqnHash_Murmur64(key, keyLen);
	i64 hashIndex = hash % table->numEntries;
	return hashIndex;
}

FILE_SCOPE inline i64 DqnHashTableInternal_GetHashIndex(i64 numEntries, char const *const key,
                                                        i32 keyLen)
{
	u64 hash      = DqnHash_Murmur64(key, keyLen);
	i64 hashIndex = hash % numEntries;
	return hashIndex;
}

template <typename T>
typename DqnHashTable<T>::Entry *
DqnHashTableInternal_FindMatchingKey(typename DqnHashTable<T>::Entry *entry, char const *const key,
                                     i32 keyLen,
                                     typename DqnHashTable<T>::Entry **prevEntry = nullptr)
{
	for (;;)
	{
		if (entry->key.len == keyLen && DqnStr_Cmp(entry->key.str, key) == 0)
		{
			return entry;
		}

		if (entry->next == nullptr) break;
		if (prevEntry) *prevEntry = entry;

		entry = entry->next;
	}

	return nullptr;
}

template <typename T>
DQN_FILE_SCOPE inline typename DqnHashTable<T>::Entry *
DqnHashTableInternal_Get(DqnHashTable<T> *table, char const *const key, i32 keyLen, i64 hashIndex)
{
	DqnHashTable<T>::Entry *entry  = table->entries[hashIndex];
	if (entry)
	{
		DqnHashTable<T>::Entry *matchingEntry = DqnHashTableInternal_FindMatchingKey<T>(entry, key, (i64)keyLen);
		if (matchingEntry) return matchingEntry;
	}

	return nullptr;
}

template <typename T>
typename DqnHashTable<T>::Entry *DqnHashTable<T>::Get(char const *const key, i32 keyLen)
{
	if (keyLen == -1) DqnStr_LenUTF8((u32 *)key, &keyLen);
	i64 hashIndex = DqnHashTableInternal_GetHashIndex(this, key, keyLen);
	Entry *result = DqnHashTableInternal_Get(this, key, keyLen, hashIndex);
	return result;
}

template <typename T>
typename DqnHashTable<T>::Entry *DqnHashTable<T>::Get(DqnString key)
{
	Entry *result = this->Get(key.str, key.len);
	return result;
}

template <typename T>
typename DqnHashTable<T>::Entry *DqnHashTable<T>::Make(char const *const key, i32 keyLen,
                                                       bool *entryAlreadyExisted)
{
	// NOTE: Internal_Get() function because we want a way to allow re-using the hashIndex
	if (keyLen == -1) DqnStr_LenUTF8((u32 *)key, &keyLen);

	i64 hashIndex        = DqnHashTableInternal_GetHashIndex(this, key, keyLen);
	Entry *existingEntry = DqnHashTableInternal_Get(this, key, keyLen, hashIndex);

	if (entryAlreadyExisted) *entryAlreadyExisted = true;
	if (existingEntry) return existingEntry;

	Entry *newEntry = DqnHashTableInternal_GetFreeEntry(this);
	if (newEntry)
	{
		if (entryAlreadyExisted) *entryAlreadyExisted = false;

		// If entry for hashIndex not used yet, mark it down as a used slot.
		if (!this->entries[hashIndex])
		{
			i64 index = Dqn_BSearch(this->usedEntries, this->usedEntriesIndex, hashIndex,
			                        Dqn_BSearchBound_Lower);
			i64 indexToEndAt              = index;
			if (index == -1) indexToEndAt = 0;

			this->usedEntriesIndex++;
			for (i64 i = this->usedEntriesIndex; i > indexToEndAt; i--)
				this->usedEntries[i] = this->usedEntries[i - 1];

			this->usedEntries[indexToEndAt] = hashIndex;
		}

		newEntry->key.InitSize(keyLen, this->memAPI);
		newEntry->key.Append(key, keyLen);
		newEntry->next           = this->entries[hashIndex];
		this->entries[hashIndex] = newEntry;

		return newEntry;
	}
	else
	{
		DQN_ASSERT_MSG(DQN_INVALID_CODE_PATH, "DqnHashTable_Get() failed: Out of memory.");
		return nullptr;
	}
}

template <typename T>
typename DqnHashTable<T>::Entry *DqnHashTable<T>::Make(DqnString key, bool *entryAlreadyExisted)
{
	Entry *result = this->Make(key.str, key.len, entryAlreadyExisted);
	return result;
}

template <typename T>
void DqnHashTable<T>::Remove(char const *const key, i32 keyLen)
{
	if (keyLen == -1) DqnStr_LenUTF8((u32 *)key, &keyLen);

	i64 hashIndex = DqnHashTableInternal_GetHashIndex(this, key, keyLen);
	Entry *entry  = this->entries[hashIndex];

	// TODO(doyle): This is wrong, doesn't update before pointers
	if (entry)
	{
		Entry prevEntry_;

		Entry *prevEntry = &prevEntry_;
		Entry *entryToFree =
		    DqnHashTableInternal_FindMatchingKey<T>(entry, key, (i64)keyLen, &prevEntry);
		if (entryToFree)
		{
			if (entryToFree == entry)
			{
				// Unique entry, so remove this index from the used list as well.
				i64 indexToRemove = Dqn_BSearch(this->usedEntries, this->usedEntriesIndex,
				                                hashIndex, Dqn_BSearchBound_Lower);

				for (i64 i = indexToRemove; i < this->usedEntriesIndex - 1; i++)
					this->usedEntries[i] = this->usedEntries[i + 1];

				this->usedEntriesIndex--;
			}

			if (prevEntry)
			{
				prevEntry->next = nullptr;
			}

			entryToFree->key.Clear();
			entryToFree->data = {};
			entryToFree->next = this->freeList;

			this->freeList = entryToFree;
			this->numFreeEntries++;
		}
	}
}

template <typename T>
void DqnHashTable<T>::Remove(DqnString key)
{
	Entry result = this->Remove(key.str, key.len);
}

template <typename T>
void DqnHashTable<T>::Free()
{
	size_t const ENTRY_SIZE = sizeof(*this->entries);
	for (i64 i = 0; i < usedEntriesIndex; i++)
	{
		i64 indexToFree    = usedEntries[i];
		Entry *entryToFree = *(this->entries + indexToFree);

		entryToFree->key.Free();
		DqnMemAPI::Request info =
		    DqnMemAPI::RequestFree(this->memAPI, entryToFree, ENTRY_SIZE);
		this->memAPI.callback(info);
	}

	// Free usedEntries list
	{
		size_t sizeToFree = sizeof(*this->usedEntries) * this->numEntries;
		DqnMemAPI::Request info =
		    DqnMemAPI::RequestFree(this->memAPI, this->usedEntries, sizeToFree);
		this->memAPI.callback(info);
	}

	// Free freeList
	{
		Entry *entry = this->freeList;
		while (entry)
		{
			Entry *entryToFree = entry;
			entry              = entry->next;

			entryToFree->key.Free();
			DqnMemAPI::Request info = DqnMemAPI::RequestFree(this->memAPI, entryToFree, ENTRY_SIZE);
			this->memAPI.callback(info);
		}
	}

	// Free the array of ptrs
	{
		size_t sizeToFree = ENTRY_SIZE * this->numEntries;
		DqnMemAPI::Request info =
		    DqnMemAPI::RequestFree(this->memAPI, this->entries, sizeToFree);
		this->memAPI.callback(info);
	}

}

template <typename T>
bool DqnHashTable<T>::AddNewEntriesToFreeList(i64 num)
{
	if (num < 0)
	{
		num = DQN_ABS(num);
		for (i64 i = 0; i < num; i++)
		{
			Entry *entryToFree = this->freeList;
			if (entryToFree)
			{
				this->freeList             = entryToFree->next;
				DqnMemAPI::Request info = DqnMemAPI::RequestFree(
				    this->memAPI, entryToFree, sizeof(*this->freeList));
				this->memAPI.callback(info);
			}
		}

		this->numFreeEntries -= num;
	}
	else
	{
		for (i64 i = 0; i < num; i++)
		{
			Entry *newEntry = DqnHashTableInternal_AllocateEntry(this);
			if (!newEntry) return false;

			newEntry->next = this->freeList;
			this->freeList = newEntry;
		}

		this->numFreeEntries += num;
	}

	DQN_ASSERT(this->numFreeEntries >= 0);
	return true;
}

template <typename T>
bool DqnHashTable<T>::ChangeNumEntries(i64 newNumEntries)
{
	if (newNumEntries == this->numEntries) return true;

	Entry **newEntries    = {};
	size_t newEntriesSize = sizeof(*this->entries) * newNumEntries;

	i64 *newUsedEntries       = {};
	size_t newUsedEntriesSize = sizeof(*this->usedEntries) * newNumEntries;
	i64 newUsedEntriesIndex   = 0;

	// NOTE: If you change allocation order, be sure to change the free order.
	// Allocate newEntries
	{
		DqnMemAPI::Request info = DqnMemAPI::RequestAlloc(this->memAPI, newEntriesSize);
		u8 *newEntriesPtr       = this->memAPI.callback(info);
		if (!newEntriesPtr) return false;

		newEntries = (Entry **)newEntriesPtr;
	}

	// Allocate usedEntries
	{
		DqnMemAPI::Request info = DqnMemAPI::RequestAlloc(this->memAPI, newUsedEntriesSize);
		u8 *usedEntriesPtr      = this->memAPI.callback(info);

		if (!usedEntriesPtr)
		{
			DqnMemAPI::Request freeInfo =
			    DqnMemAPI::RequestFree(this->memAPI, newEntries, newEntriesSize);
			this->memAPI.callback(freeInfo);
			return false;
		}

		newUsedEntries = (i64 *)usedEntriesPtr;
	}

	for (i64 i = 0; i < this->usedEntriesIndex; i++)
	{
		i64 usedIndex   = this->usedEntries[i];
		Entry *oldEntry = this->entries[usedIndex];

		while (oldEntry)
		{
			i64 newHashIndex = DqnHashTableInternal_GetHashIndex(newNumEntries, oldEntry->key.str,
			                                                     oldEntry->key.len);
			Entry *entryToAppendTo = newEntries[newHashIndex];

			if (entryToAppendTo)
			{
				while (entryToAppendTo->next)
					entryToAppendTo = entryToAppendTo->next;

				entryToAppendTo->next = oldEntry;
			}
			else
			{
				newEntries[newHashIndex]              = oldEntry;
				newUsedEntries[newUsedEntriesIndex++] = newHashIndex;
			}

			oldEntry = oldEntry->next;
		}
	}

	// Free the old entry list
	{
		size_t freeSize = sizeof(*this->entries) * this->numEntries;
		DqnMemAPI::Request info =
		    DqnMemAPI::RequestFree(this->memAPI, this->entries, freeSize);
		this->memAPI.callback(info);
	}

	// Free the old used entry list
	{
		size_t freeSize = sizeof(*this->usedEntries) * this->numEntries;
		DqnMemAPI::Request info =
		    DqnMemAPI::RequestFree(this->memAPI, this->usedEntries, freeSize);
		this->memAPI.callback(info);
	}

	this->entries          = newEntries;
	this->numEntries       = newNumEntries;
	this->usedEntries      = newUsedEntries;
	this->usedEntriesIndex = newUsedEntriesIndex;

	return true;
}

////////////////////////////////////////////////////////////////////////////////
// #DqnMath Public API - Simple Math Helpers
////////////////////////////////////////////////////////////////////////////////
DQN_FILE_SCOPE f32 DqnMath_Lerp  (f32 a, f32 t, f32 b);
DQN_FILE_SCOPE f32 DqnMath_Sqrtf (f32 a);
DQN_FILE_SCOPE f32 DqnMath_Clampf(f32 val, f32 min, f32 max);

////////////////////////////////////////////////////////////////////////////////
// #DqnV2 Public API - 2D Math Vectors
////////////////////////////////////////////////////////////////////////////////
union DqnV2i
{
	struct { i32 x, y; };
	struct { i32 w, h; };
	struct { i32 min, max; };
	i32 e[2];

};

union DqnV2
{
	struct { f32 x, y; };
	struct { f32 w, h; };
	struct { f32 min, max; };
	f32 e[2];
};

DQN_FILE_SCOPE DqnV2 DqnV2_(f32 xy);
DQN_FILE_SCOPE DqnV2 DqnV2_(f32 x, f32 y);
DQN_FILE_SCOPE DqnV2 DqnV2_(i32 x, i32 y);
DQN_FILE_SCOPE DqnV2 DqnV2_(DqnV2i a);

DQN_FILE_SCOPE DqnV2 DqnV2_Add     (DqnV2 a, DqnV2 b);
DQN_FILE_SCOPE DqnV2 DqnV2_Sub     (DqnV2 a, DqnV2 b);
DQN_FILE_SCOPE DqnV2 DqnV2_Scalei  (DqnV2 a, i32 b);
DQN_FILE_SCOPE DqnV2 DqnV2_Scalef  (DqnV2 a, f32 b);
DQN_FILE_SCOPE DqnV2 DqnV2_Hadamard(DqnV2 a, DqnV2 b);
DQN_FILE_SCOPE f32   DqnV2_Dot     (DqnV2 a, DqnV2 b);
DQN_FILE_SCOPE bool  DqnV2_Equals  (DqnV2 a, DqnV2 b);

DQN_FILE_SCOPE f32   DqnV2_LengthSquared(const DqnV2 a, const DqnV2 b);
DQN_FILE_SCOPE f32   DqnV2_Length       (const DqnV2 a, const DqnV2 b);
DQN_FILE_SCOPE DqnV2 DqnV2_Normalise    (const DqnV2 a);
DQN_FILE_SCOPE bool  DqnV2_Overlaps     (      DqnV2 a,       DqnV2 b);
DQN_FILE_SCOPE DqnV2 DqnV2_Perpendicular(const DqnV2 a);

DQN_FILE_SCOPE DqnV2 DqnV2_ResizeKeepAspectRatio(DqnV2 srcSize, DqnV2 targetSize);
DQN_FILE_SCOPE DqnV2 DqnV2_ConstrainToRatio     (DqnV2 dim, DqnV2 ratio); // Resize the dimension to fit the aspect ratio provided. Downscale only.

inline bool operator>(DqnV2 const &a, DqnV2 const &b)
{
	bool result = (a.x > b.x) && (a.y > b.y);
	return result;
}

inline bool operator<(DqnV2 const &a, DqnV2 const &b)
{
	bool result = (a.x < b.x) && (a.y < b.y);
	return result;
}

inline bool operator<=(DqnV2 const &a, DqnV2 const &b)
{
	bool result = (a.x <= b.x) && (a.y <= b.y);
	return result;
}

inline bool operator>=(DqnV2 const &a, DqnV2 const &b)
{
	bool result = (a.x >= b.x) && (a.y >= b.y);
	return result;
}

DQN_FILE_SCOPE inline DqnV2  operator- (DqnV2  a, DqnV2 b) { return      DqnV2_Sub     (a, b);  }
DQN_FILE_SCOPE inline DqnV2  operator+ (DqnV2  a, DqnV2 b) { return      DqnV2_Add     (a, b);  }
DQN_FILE_SCOPE inline DqnV2  operator* (DqnV2  a, DqnV2 b) { return      DqnV2_Hadamard(a, b);  }
DQN_FILE_SCOPE inline DqnV2  operator* (DqnV2  a, f32   b) { return      DqnV2_Scalef  (a, b);  }
DQN_FILE_SCOPE inline DqnV2  operator* (DqnV2  a, i32   b) { return      DqnV2_Scalei  (a, b);  }
DQN_FILE_SCOPE inline DqnV2 &operator*=(DqnV2 &a, DqnV2 b) { return (a = DqnV2_Hadamard(a, b)); }
DQN_FILE_SCOPE inline DqnV2 &operator*=(DqnV2 &a, f32   b) { return (a = DqnV2_Scalef  (a, b)); }
DQN_FILE_SCOPE inline DqnV2 &operator*=(DqnV2 &a, i32   b) { return (a = DqnV2_Scalei  (a, b)); }
DQN_FILE_SCOPE inline DqnV2 &operator-=(DqnV2 &a, DqnV2 b) { return (a = DqnV2_Sub     (a, b)); }
DQN_FILE_SCOPE inline DqnV2 &operator+=(DqnV2 &a, DqnV2 b) { return (a = DqnV2_Add     (a, b)); }
DQN_FILE_SCOPE inline bool   operator==(DqnV2  a, DqnV2 b) { return      DqnV2_Equals  (a, b);  }

// DqnV2i
DQN_FILE_SCOPE DqnV2i DqnV2i_(i32 x_, i32 y_);
DQN_FILE_SCOPE DqnV2i DqnV2i_(f32 x_, f32 y_);
DQN_FILE_SCOPE DqnV2i DqnV2i_(DqnV2 a);

DQN_FILE_SCOPE DqnV2i DqnV2i_Add     (DqnV2i a, DqnV2i b);
DQN_FILE_SCOPE DqnV2i DqnV2i_Sub     (DqnV2i a, DqnV2i b);
DQN_FILE_SCOPE DqnV2i DqnV2i_Scalei  (DqnV2i a, i32 b);
DQN_FILE_SCOPE DqnV2i DqnV2i_Scalef  (DqnV2i a, f32 b);
DQN_FILE_SCOPE DqnV2i DqnV2i_Hadamard(DqnV2i a, DqnV2i b);
DQN_FILE_SCOPE f32    DqnV2i_Dot     (DqnV2i a, DqnV2i b);
DQN_FILE_SCOPE bool   DqnV2i_Equals  (DqnV2i a, DqnV2i b);

DQN_FILE_SCOPE inline DqnV2i  operator- (DqnV2i  a, DqnV2i b) { return      DqnV2i_Sub     (a, b);  }
DQN_FILE_SCOPE inline DqnV2i  operator+ (DqnV2i  a, DqnV2i b) { return      DqnV2i_Add     (a, b);  }
DQN_FILE_SCOPE inline DqnV2i  operator* (DqnV2i  a, DqnV2i b) { return      DqnV2i_Hadamard(a, b);  }
DQN_FILE_SCOPE inline DqnV2i  operator* (DqnV2i  a, f32    b) { return      DqnV2i_Scalef  (a, b);  }
DQN_FILE_SCOPE inline DqnV2i  operator* (DqnV2i  a, i32    b) { return      DqnV2i_Scalei  (a, b);  }
DQN_FILE_SCOPE inline DqnV2i &operator*=(DqnV2i &a, DqnV2i b) { return (a = DqnV2i_Hadamard(a, b)); }
DQN_FILE_SCOPE inline DqnV2i &operator-=(DqnV2i &a, DqnV2i b) { return (a = DqnV2i_Sub     (a, b)); }
DQN_FILE_SCOPE inline DqnV2i &operator+=(DqnV2i &a, DqnV2i b) { return (a = DqnV2i_Add     (a, b)); }
DQN_FILE_SCOPE inline bool    operator==(DqnV2i  a, DqnV2i b) { return      DqnV2i_Equals  (a, b);  }

////////////////////////////////////////////////////////////////////////////////
// #DqnV3 Public API - 3D Math Vectors
////////////////////////////////////////////////////////////////////////////////
union DqnV3
{
		struct { f32 x, y, z; };
		DqnV2 xy;
		struct { f32 r, g, b; };
		f32 e[3];
};

union DqnV3i
{
	struct { i32 x, y, z; };
	struct { i32 r, g, b; };
	i32 e[3];
};

// DqnV3
DQN_FILE_SCOPE DqnV3 DqnV3_(f32 xyz);
DQN_FILE_SCOPE DqnV3 DqnV3_(f32 x, f32 y, f32 z);
DQN_FILE_SCOPE DqnV3 DqnV3_(i32 x, i32 y, i32 z);

DQN_FILE_SCOPE DqnV3 DqnV3_Add     (DqnV3 a, DqnV3 b);
DQN_FILE_SCOPE DqnV3 DqnV3_Sub     (DqnV3 a, DqnV3 b);
DQN_FILE_SCOPE DqnV3 DqnV3_Scalei  (DqnV3 a, i32 b);
DQN_FILE_SCOPE DqnV3 DqnV3_Scalef  (DqnV3 a, f32 b);
DQN_FILE_SCOPE DqnV3 DqnV3_Hadamard(DqnV3 a, DqnV3 b);
DQN_FILE_SCOPE f32   DqnV3_Dot     (DqnV3 a, DqnV3 b);
DQN_FILE_SCOPE bool  DqnV3_Equals  (DqnV3 a, DqnV3 b);
DQN_FILE_SCOPE DqnV3 DqnV3_Cross   (DqnV3 a, DqnV3 b);

DQN_FILE_SCOPE DqnV3 DqnV3_Normalise    (DqnV3 a);
DQN_FILE_SCOPE f32   DqnV3_Length       (DqnV3 a, DqnV3 b);
DQN_FILE_SCOPE f32   DqnV3_LengthSquared(DqnV3 a, DqnV3 b);

DQN_FILE_SCOPE inline DqnV3  operator- (DqnV3  a, DqnV3 b) { return      DqnV3_Sub     (a, b);           }
DQN_FILE_SCOPE inline DqnV3  operator+ (DqnV3  a, DqnV3 b) { return      DqnV3_Add     (a, b);           }
DQN_FILE_SCOPE inline DqnV3  operator+ (DqnV3  a, f32   b) { return      DqnV3_Add     (a, DqnV3_(b));   }
DQN_FILE_SCOPE inline DqnV3  operator* (DqnV3  a, DqnV3 b) { return      DqnV3_Hadamard(a, b);           }
DQN_FILE_SCOPE inline DqnV3  operator* (DqnV3  a, f32   b) { return      DqnV3_Scalef  (a, b);           }
DQN_FILE_SCOPE inline DqnV3  operator* (DqnV3  a, i32   b) { return      DqnV3_Scalei  (a, b);           }
DQN_FILE_SCOPE inline DqnV3  operator/ (DqnV3  a, f32   b) { return      DqnV3_Scalef  (a, (1.0f/b));    }
DQN_FILE_SCOPE inline DqnV3 &operator*=(DqnV3 &a, DqnV3 b) { return (a = DqnV3_Hadamard(a, b));          }
DQN_FILE_SCOPE inline DqnV3 &operator*=(DqnV3 &a, f32   b) { return (a = DqnV3_Scalef  (a, b));          }
DQN_FILE_SCOPE inline DqnV3 &operator*=(DqnV3 &a, i32   b) { return (a = DqnV3_Scalei  (a, b));          }
DQN_FILE_SCOPE inline DqnV3 &operator-=(DqnV3 &a, DqnV3 b) { return (a = DqnV3_Sub     (a, b));          }
DQN_FILE_SCOPE inline DqnV3 &operator+=(DqnV3 &a, DqnV3 b) { return (a = DqnV3_Add     (a, b));          }
DQN_FILE_SCOPE inline bool   operator==(DqnV3  a, DqnV3 b) { return      DqnV3_Equals  (a, b);           }

DQN_FILE_SCOPE DqnV3i DqnV3i_(i32 x, i32 y, i32 z);
DQN_FILE_SCOPE DqnV3i DqnV3i_(f32 x, f32 y, f32 z);

////////////////////////////////////////////////////////////////////////////////
// #DqnV4 Public API - 4D Math Vectors
////////////////////////////////////////////////////////////////////////////////
union DqnV4
{
	struct { f32 x, y, z, w; };
	DqnV3 xyz;
	DqnV2 xy;

	struct { f32 r, g, b, a; };
	DqnV3 rgb;

	f32    e[4];
	DqnV2 v2[2];
};

DQN_FILE_SCOPE DqnV4 DqnV4_();
DQN_FILE_SCOPE DqnV4 DqnV4_(f32 xyzw);
DQN_FILE_SCOPE DqnV4 DqnV4_(f32 x, f32 y, f32 z, f32 w);
DQN_FILE_SCOPE DqnV4 DqnV4_(i32 x, i32 y, i32 z, i32 w);
DQN_FILE_SCOPE DqnV4 DqnV4_(DqnV3 a, f32 w);

DQN_FILE_SCOPE DqnV4 DqnV4_Add     (DqnV4 a, DqnV4 b);
DQN_FILE_SCOPE DqnV4 DqnV4_Sub     (DqnV4 a, DqnV4 b);
DQN_FILE_SCOPE DqnV4 DqnV4_Scalef  (DqnV4 a, f32 b);
DQN_FILE_SCOPE DqnV4 DqnV4_Scalei  (DqnV4 a, i32 b);
DQN_FILE_SCOPE DqnV4 DqnV4_Hadamard(DqnV4 a, DqnV4 b);
DQN_FILE_SCOPE f32   DqnV4_Dot     (DqnV4 a, DqnV4 b);
DQN_FILE_SCOPE bool  DqnV4_Equals  (DqnV4 a, DqnV4 b);

DQN_FILE_SCOPE inline DqnV4  operator- (DqnV4  a, DqnV4 b) { return      DqnV4_Sub     (a, b);            }
DQN_FILE_SCOPE inline DqnV4  operator+ (DqnV4  a, DqnV4 b) { return      DqnV4_Add     (a, b);            }
DQN_FILE_SCOPE inline DqnV4  operator+ (DqnV4  a, f32   b) { return      DqnV4_Add     (a, DqnV4_(b));    }
DQN_FILE_SCOPE inline DqnV4  operator* (DqnV4  a, DqnV4 b) { return      DqnV4_Hadamard(a, b);            }
DQN_FILE_SCOPE inline DqnV4  operator* (DqnV4  a, f32   b) { return      DqnV4_Scalef  (a, b);            }
DQN_FILE_SCOPE inline DqnV4  operator* (DqnV4  a, i32   b) { return      DqnV4_Scalei  (a, b);            }
DQN_FILE_SCOPE inline DqnV4 &operator*=(DqnV4 &a, DqnV4 b) { return (a = DqnV4_Hadamard(a, b));           }
DQN_FILE_SCOPE inline DqnV4 &operator*=(DqnV4 &a, f32   b) { return (a = DqnV4_Scalef  (a, b));           }
DQN_FILE_SCOPE inline DqnV4 &operator*=(DqnV4 &a, i32   b) { return (a = DqnV4_Scalei  (a, b));           }
DQN_FILE_SCOPE inline DqnV4 &operator-=(DqnV4 &a, DqnV4 b) { return (a = DqnV4_Sub     (a, b));           }
DQN_FILE_SCOPE inline DqnV4 &operator+=(DqnV4 &a, DqnV4 b) { return (a = DqnV4_Add     (a, b));           }
DQN_FILE_SCOPE inline bool   operator==(DqnV4 &a, DqnV4 b) { return      DqnV4_Equals  (a, b);            }

////////////////////////////////////////////////////////////////////////////////
// #DqnMat4 Public API - 4x4 Math Matrix
////////////////////////////////////////////////////////////////////////////////
typedef union DqnMat4
{
	// TODO(doyle): Row/column instead? More cache friendly since multiplication
	// prefers rows.
	DqnV4 col[4];
	f32   e[4][4]; // Column/row
} DqnMat4;

DQN_FILE_SCOPE DqnMat4 DqnMat4_Identity    ();

DQN_FILE_SCOPE DqnMat4 DqnMat4_Orthographic(f32 left, f32 right, f32 bottom, f32 top, f32 zNear, f32 zFar);
DQN_FILE_SCOPE DqnMat4 DqnMat4_Perspective (f32 fovYDegrees, f32 aspectRatio, f32 zNear, f32 zFar);
DQN_FILE_SCOPE DqnMat4 DqnMat4_LookAt      (DqnV3 eye, DqnV3 center, DqnV3 up);

DQN_FILE_SCOPE DqnMat4 DqnMat4_Translate3f (f32 x, f32 y, f32 z);
DQN_FILE_SCOPE DqnMat4 DqnMat4_TranslateV3 (DqnV3 vec);
DQN_FILE_SCOPE DqnMat4 DqnMat4_Rotate      (f32 radians, f32 x, f32 y, f32 z);
DQN_FILE_SCOPE DqnMat4 DqnMat4_Scale       (f32 x, f32 y, f32 z);
DQN_FILE_SCOPE DqnMat4 DqnMat4_ScaleV3     (DqnV3 scale);
DQN_FILE_SCOPE DqnMat4 DqnMat4_Mul         (DqnMat4 a, DqnMat4 b);
DQN_FILE_SCOPE DqnV4   DqnMat4_MulV4       (DqnMat4 a, DqnV4 b);

////////////////////////////////////////////////////////////////////////////////
// #DqnRect Public API - Rectangles
////////////////////////////////////////////////////////////////////////////////
class DqnRect
{
public:
	DqnV2 min;
	DqnV2 max;

	f32   GetWidth ()                                    const { return max.w - min.w; }
	f32   GetHeight()                                    const { return max.h - min.h; }
	DqnV2 GetSize  ()                                    const { return max - min;     }
	void  GetSize  (f32 *const width, f32 *const height) const;
	DqnV2 GetCenter()                                    const;

	DqnRect ClipRect (DqnRect const clip) const;
	DqnRect Move     (DqnV2   const shift)  const;
	bool    ContainsP(DqnV2   const p)      const;
};

DQN_FILE_SCOPE DqnRect DqnRect_(DqnV2 origin, DqnV2 size);
DQN_FILE_SCOPE DqnRect DqnRect_(f32 x, f32 y, f32 w, f32 h);
DQN_FILE_SCOPE DqnRect DqnRect_(i32 x, i32 y, i32 w, i32 h);

////////////////////////////////////////////////////////////////////////////////
// #DqnChar Public API - Char Operations
////////////////////////////////////////////////////////////////////////////////
DQN_FILE_SCOPE char DqnChar_ToLower   (char c);
DQN_FILE_SCOPE char DqnChar_ToUpper   (char c);
DQN_FILE_SCOPE bool DqnChar_IsDigit   (char c);
DQN_FILE_SCOPE bool DqnChar_IsAlpha   (char c);
DQN_FILE_SCOPE bool DqnChar_IsAlphanum(char c);

DQN_FILE_SCOPE char *DqnChar_SkipWhitespace(char *ptr);

// TODO(doyle): this is NOT UTF8 safe
// ch:        Char to find
// len:       The length of the string stored in ptr, (doesn't care if it includes null terminator)
// lenToChar: The length to the char from end of the ptr, i.e. (ptr + len)
// return:    The ptr to the last char, null if it could not find.
DQN_FILE_SCOPE char *DqnChar_FindLastChar  (char *ptr, char const ch, i32 len, u32 *const lenToChar);

// returns: The value to advance the ptr by, this can be different from the line
//          length if there are new lines or leading whitespaces in the next line
DQN_FILE_SCOPE i32   DqnChar_GetNextLine (char const *ptr, i32 *lineLength);

////////////////////////////////////////////////////////////////////////////////
// #DqnStr Public API - Str Operations
////////////////////////////////////////////////////////////////////////////////
// numBytesToCompare: If -1, cmp runs until \0 is encountered.
// return: 0 if equal. 0 < if a is before b, > 0 if a is after b
DQN_FILE_SCOPE i32 DqnStr_Cmp(char const *const a, char const *const b, i32 numBytesToCompare = -1, bool ignoreCase = false);

// return: String length not including the nullptr terminator. 0 if invalid args.
DQN_FILE_SCOPE i32 DqnStr_Len    (char const *const a);
DQN_FILE_SCOPE i32 DqnStr_LenUTF8(u32 const *const a, i32 *const lenInBytes = nullptr);

// Get the String length starting from a, up to and not including the first delimiter character.
DQN_FILE_SCOPE i32 DqnStr_LenDelimitWith(char *const a, char const delimiter);

// return: The dest argument, nullptr if args invalid (i.e. nullptr pointers or numChars < 0)
DQN_FILE_SCOPE char *DqnStr_Copy(char *const dest, char const *const src, i32 const numChars);

DQN_FILE_SCOPE void DqnStr_Reverse(char *const buf, u32 const bufSize);

// return: Number of bytes in codepoint, 0 if *a becomes invalid or end of stream.
DQN_FILE_SCOPE i32 DqnStr_ReadUTF8Codepoint(u32 const *const a, u32 *outCodepoint);

// return: The offset into the src to first char of the found string. Returns -1 if not found
DQN_FILE_SCOPE i32   DqnStr_FindFirstOccurence(char const *const src, i32 const srcLen, char const *const find, i32 const findLen, bool ignoreCase = false);
// return: Helper function that returns the pointer to the first occurence, nullptr if not found.
DQN_FILE_SCOPE char *DqnStr_GetFirstOccurence(char *const src, i32 const srcLen, char *const find, i32 const findLen, bool ignoreCase = false);
DQN_FILE_SCOPE bool  DqnStr_HasSubstring     (char const *const src, i32 const srcLen, char const *const find, i32 const findLen, bool ignoreCase = false);

#define DQN_32BIT_NUM_MAX_STR_SIZE 11
#define DQN_64BIT_NUM_MAX_STR_SIZE 21
// Return the len of the derived string. If buf is nullptr and or bufSize is 0 the function returns the
// required string length for the integer
// TODO NOTE(doyle): Parsing stops when a non-digit is encountered, so numbers with ',' don't work atm.
DQN_FILE_SCOPE i32   Dqn_I64ToStr(i64 const value, char *const buf, i32 const bufSize);
DQN_FILE_SCOPE i64   Dqn_StrToI64(char const *const buf, i64 const bufSize);
// WARNING: Not robust, precision errors and whatnot but good enough!
DQN_FILE_SCOPE f32   Dqn_StrToF32(char const *const buf, i64 const bufSize);

// Both return the number of bytes read, return 0 if invalid codepoint or UTF8
DQN_FILE_SCOPE u32 Dqn_UCSToUTF8(u32 *const dest, u32 const character);
DQN_FILE_SCOPE u32 Dqn_UTF8ToUCS(u32 *const dest, u32 const character);

////////////////////////////////////////////////////////////////////////////////
// #DqnWChar Public API - WChar Operations
////////////////////////////////////////////////////////////////////////////////
DQN_FILE_SCOPE bool     DqnWChar_IsDigit(wchar_t const c);
DQN_FILE_SCOPE wchar_t  DqnWChar_ToLower(wchar_t const c);

DQN_FILE_SCOPE wchar_t *DqnWChar_SkipWhitespace(wchar_t *ptr);
DQN_FILE_SCOPE wchar_t *DqnWChar_FindLastChar  (wchar_t *ptr, const wchar_t ch, i32 len, u32 *const lenToChar);
DQN_FILE_SCOPE i32      DqnWChar_GetNextLine   (const wchar_t *ptr, i32 *lineLength);

DQN_FILE_SCOPE i32  DqnWStr_Cmp               (wchar_t const *const a, const wchar_t *const b);
DQN_FILE_SCOPE i32  DqnWStr_FindFirstOccurence(wchar_t const *const src, i32 const srcLen, wchar_t const *const find, i32 const findLen);
DQN_FILE_SCOPE bool DqnWStr_HasSubstring      (wchar_t const *const src, i32 const srcLen, wchar_t const *const find, i32 const findLen);
DQN_FILE_SCOPE i32  DqnWStr_Len               (wchar_t const *const a);
DQN_FILE_SCOPE i32  DqnWStr_LenDelimitWith    (wchar_t const *const a, wchar_t const delimiter);
DQN_FILE_SCOPE void DqnWStr_Reverse           (wchar_t *const buf, u32 const bufSize);

DQN_FILE_SCOPE i32  Dqn_WStrToI32(wchar_t const *const buf, i32 const bufSize);
DQN_FILE_SCOPE i32  Dqn_I32ToWStr(i32 value, wchar_t *buf, i32 bufSize);

////////////////////////////////////////////////////////////////////////////////
// #DqnRnd Public API - Random Number Generator
////////////////////////////////////////////////////////////////////////////////
// PCG (Permuted Congruential Generator) Random Number Generator
class DqnRndPCG
{
public:
	u64 state[2];

	void Init        ();          // Uses rdstc to create a seed
	void InitWithSeed(u32 seed);

	u32 Next ();                 // return: A random number  N between [0, 0xFFFFFFFF]
	f32 Nextf();                 // return: A random float   N between [0.0, 1.0f]
	i32 Range(i32 min, i32 max); // return: A random integer N between [min, max]
};

DQN_FILE_SCOPE DqnRndPCG DqnRndPCG_();         // Uses rdtsc to create a seed
DQN_FILE_SCOPE DqnRndPCG DqnRndPCG_(u32 seed);

////////////////////////////////////////////////////////////////////////////////
// #Dqn_* Public API
////////////////////////////////////////////////////////////////////////////////

template <typename T>
using Dqn_QuickSortLessThanCallback = bool (*)(const T *const , const T *const);

template <typename T>
DQN_FILE_SCOPE void Dqn_QuickSort(T *const array, const i64 size,
                                  Dqn_QuickSortLessThanCallback<T> IsLessThan)
{
	if (!array || size <= 1 || !IsLessThan) return;

#if 1
	// Insertion Sort, under 24->32 is an optimal amount
	const i32 QUICK_SORT_THRESHOLD = 24;
	if (size < QUICK_SORT_THRESHOLD)
	{
		i32 itemToInsertIndex = 1;
		while (itemToInsertIndex < size)
		{
			for (i32 checkIndex = 0; checkIndex < itemToInsertIndex; checkIndex++)
			{
				if (!IsLessThan(&array[checkIndex], &array[itemToInsertIndex]))
				{
					T itemToInsert = array[itemToInsertIndex];
					for (i32 i   = itemToInsertIndex; i > checkIndex; i--)
						array[i] = array[i - 1];

					array[checkIndex] = itemToInsert;
					break;
				}
			}
			itemToInsertIndex++;
		}

		return;
	}
#endif

	DqnRndPCG state; state.Init();

	auto lastIndex      = size - 1;
	auto pivotIndex     = (i64)state.Range(0, (i32)lastIndex);
	auto partitionIndex = 0;
	auto startIndex     = 0;

	// Swap pivot with last index, so pivot is always at the end of the array.
	// This makes logic much simpler.
	DQN_SWAP(T, array[lastIndex], array[pivotIndex]);
	pivotIndex = lastIndex;

	// 4^, 8, 7, 5, 2, 3, 6
	if (IsLessThan(&array[startIndex], &array[pivotIndex])) partitionIndex++;
	startIndex++;

	// 4, |8, 7, 5^, 2, 3, 6*
	// 4, 5, |7, 8, 2^, 3, 6*
	// 4, 5, 2, |8, 7, ^3, 6*
	// 4, 5, 2, 3, |7, 8, ^6*
	for (auto checkIndex = startIndex; checkIndex < lastIndex; checkIndex++)
	{
		if (IsLessThan(&array[checkIndex], &array[pivotIndex]))
		{
			DQN_SWAP(T, array[partitionIndex], array[checkIndex]);
			partitionIndex++;
		}
	}

	// Move pivot to right of partition
	// 4, 5, 2, 3, |6, 8, ^7*
	DQN_SWAP(T, array[partitionIndex], array[pivotIndex]);
	Dqn_QuickSort(array, partitionIndex, IsLessThan);

	// Skip the value at partion index since that is guaranteed to be sorted.
	// 4, 5, 2, 3, (x), 8, 7
	i32 oneAfterPartitionIndex = partitionIndex + 1;
	Dqn_QuickSort(array + oneAfterPartitionIndex, (size - oneAfterPartitionIndex), IsLessThan);
}

template <typename T>
DQN_FILE_SCOPE void Dqn_QuickSort(T *const array, const i64 size)
{
	if (!array || size <= 1) return;

#if 1
	// Insertion Sort, under 24->32 is an optimal amount
	const i32 QUICK_SORT_THRESHOLD = 24;
	if (size < QUICK_SORT_THRESHOLD)
	{
		i32 itemToInsertIndex = 1;
		while (itemToInsertIndex < size)
		{
			for (i32 checkIndex = 0; checkIndex < itemToInsertIndex; checkIndex++)
			{
				if (!(array[checkIndex] < array[itemToInsertIndex]))
				{
					T itemToInsert = array[itemToInsertIndex];
					for (i32 i   = itemToInsertIndex; i > checkIndex; i--)
						array[i] = array[i - 1];

					array[checkIndex] = itemToInsert;
					break;
				}
			}
			itemToInsertIndex++;
		}

		return;
	}
#endif

	DqnRndPCG state; state.Init();

	auto lastIndex      = size - 1;
	auto pivotIndex     = (i64)state.Range(0, (i32)lastIndex); // TODO(doyle): RNG 64bit
	auto partitionIndex = 0;
	auto startIndex     = 0;

	// Swap pivot with last index, so pivot is always at the end of the array.
	// This makes logic much simpler.
	DQN_SWAP(T, array[lastIndex], array[pivotIndex]);
	pivotIndex = lastIndex;

	// 4^, 8, 7, 5, 2, 3, 6
	if (array[startIndex] < array[pivotIndex]) partitionIndex++;
	startIndex++;

	// 4, |8, 7, 5^, 2, 3, 6*
	// 4, 5, |7, 8, 2^, 3, 6*
	// 4, 5, 2, |8, 7, ^3, 6*
	// 4, 5, 2, 3, |7, 8, ^6*
	for (auto checkIndex = startIndex; checkIndex < lastIndex; checkIndex++)
	{
		if (array[checkIndex] < array[pivotIndex])
		{
			DQN_SWAP(T, array[partitionIndex], array[checkIndex]);
			partitionIndex++;
		}
	}

	// Move pivot to right of partition
	// 4, 5, 2, 3, |6, 8, ^7*
	DQN_SWAP(T, array[partitionIndex], array[pivotIndex]);
	Dqn_QuickSort(array, partitionIndex);

	// Skip the value at partion index since that is guaranteed to be sorted.
	// 4, 5, 2, 3, (x), 8, 7
	i32 oneAfterPartitionIndex = partitionIndex + 1;
	Dqn_QuickSort(array + oneAfterPartitionIndex, (size - oneAfterPartitionIndex));
}

template <typename T>
using Dqn_BSearchLessThanCallback = bool (*)(const T&, const T&);

template <typename T>
using Dqn_BSearchEqualsCallback   = bool (*)(const T&, const T&);

enum Dqn_BSearchBound
{
	Dqn_BSearchBound_Normal, // Return the index of the first item that matches the find value
	Dqn_BSearchBound_Lower,  // Return the index of the first item lower than the find value
	Dqn_BSearchBound_Higher, // Return the index of the first item higher than the find value

	Dqn_BSearchBound_NormalLower,  // Return the index of the matching item if not found the first item lower
	Dqn_BSearchBound_NormalHigher, // Return the index of the matching item if not found the first item higher
};

// bound: The behaviour of the binary search,
// return: -1 if element not found, otherwise index of the element.
//         For higher and lower bounds return -1 if there is no element higher/lower than the
//         find value (i.e. -1 if the 0th element is the find val for lower bound).
template <typename T>
DQN_FILE_SCOPE i64 Dqn_BSearch(T *const array, i64 const size, T const &find,
                               Dqn_BSearchEqualsCallback<T> const Equals,
                               Dqn_BSearchLessThanCallback<T> const IsLessThan,
                               Dqn_BSearchBound const bound = Dqn_BSearchBound_Normal)
{
	if (size == 0 || !array) return -1;

	i64 start = 0;
	i64 end   = size - 1;
	i64 mid   = (i64)((start + end) * 0.5f);

	while (start <= end)
	{
		if (Equals(array[mid], find))
		{
			if (bound == Dqn_BSearchBound_Normal ||
			    bound == Dqn_BSearchBound_NormalLower ||
			    bound == Dqn_BSearchBound_NormalHigher)
			{
				return mid;
			}
			else if (bound == Dqn_BSearchBound_Lower)
			{
				// NOTE: We can always -1 because at worst case, 0 index will go to -1 which is
				// correct behaviour.
				return mid - 1;
			}
			else
			{
				if ((mid + 1) >= size) return -1;
				return mid + 1;
			}
		}
		else if (IsLessThan(array[mid], find)) start = mid + 1;
		else                                   end   = mid - 1;
		mid = (i64)((start + end) * 0.5f);
	}

	if (bound == Dqn_BSearchBound_Normal)
	{
		return -1;
	}
	if (bound == Dqn_BSearchBound_Lower || bound == Dqn_BSearchBound_NormalLower)
	{
		if (IsLessThan(find, array[mid])) return -1;
		return mid;
	}
	else
	{
		if (IsLessThan(array[mid], find)) return -1;
		return mid;
	}
}

DQN_FILE_SCOPE i64 Dqn_BSearch(i64 *const array, i64 const size, i64 const find,
                               Dqn_BSearchBound const bound = Dqn_BSearchBound_Normal);
#endif  /* DQN_H */

////////////////////////////////////////////////////////////////////////////////
// #XPlatform (Win32 & Unix) Public API
////////////////////////////////////////////////////////////////////////////////
// Functions in the Cross Platform are guaranteed to be supported in both Unix
// and Win32

// NOTE(doyle): DQN_PLATFORM_HEADER is enabled by the user to have the function prototypes be
// visible. DQN_PLATFORM_H is like a normal header guard that ensures singular declaration of
// functions.
#ifdef DQN_PLATFORM_HEADER

#ifndef DQN_PLATFORM_H
#define DQN_PLATFORM_H

#if defined(DQN_IS_WIN32)
	#define WIN32_LEAN_AND_MEAN 1
	#include <Windows.h>

#elif defined(DQN_IS_UNIX)
	#include <pthread.h>
	#include <semaphore.h>

#endif
////////////////////////////////////////////////////////////////////////////////
// XPlatform > #DqnFile Public API - File I/O
////////////////////////////////////////////////////////////////////////////////
struct DqnFile
{
	enum PermissionFlag
	{
		FileRead  = (1 << 0),
		FileWrite = (1 << 1),
		Execute   = (1 << 2),
		All       = (1 << 3)
	};

	enum class Action
	{
		OpenOnly,         // Only open file if it exists. Fails and returns false if file did not exist or could not open.
		CreateIfNotExist, // Try and create file. Return true if it was able to create. If it already exists, this fails.
		ClearIfExist,     // Clear the file contents to zero if it exists. Fails and returns false if file does not exist.
		ForceCreate,      // Always create, even if it exists
	};

	u32     flags;
	void   *handle;
	size_t  size;

	// If raiiCleanup is true, close() is called in the destructor on scope exit. Can be changed at
	// any point by user.
	bool    raiiCleanup;
	DqnFile (bool const raiiCleanup = false);
	~DqnFile();

	// NOTE: W(ide) versions of functions only work on Win32, since Unix is already UTF-8 compatible.

	// Open a handle for file read and writing. Deleting files does not need a handle. Handles should be
	// closed before deleting files otherwise the OS may not be able to delete the file.
	// return: FALSE if invalid args or failed to get handle (i.e. insufficient permissions)
	bool   Open (const char    *const path, u32 const flags_, Action const action);
	bool   OpenW(const wchar_t *const path, u32 const flags_, Action const action);

	// fileOffset: The byte offset to starting writing from.
	// return:     The number of bytes written. 0 if invalid args or it failed to write.
	size_t Write(u8 const *const buf, size_t const numBytesToWrite, size_t const fileOffset);

	// return: The number of bytes read. 0 if invalid args or it failed to read.
	size_t Read (u8 *const buf, size_t const numBytesToRead);

	// File close invalidates the handle after it is called.
	void   Close();

	// Read the entire file at path into the given buffer. To determine the necessary buffer size, use GetFileSize()
	// buf:       The buffer to put data into.
	// bufSize:   The size of the given buffer.
	// bytesRead: Pass in a pointer to a size_t to get how many bytes of the buffer was
	//            used. Will be valid only if function returns true. This is basically the return value
	//            of Read()
	// return:    FALSE if insufficient bufferSize OR file access failure OR invalid args (i.e nullptr)
	static bool ReadEntireFile (char    const *const path, u8 *const buf, size_t const bufSize, size_t &bytesRead);
	static bool ReadEntireFileW(wchar_t const *const path, u8 *const buf, size_t const bufSize, size_t &bytesRead);

	// bufSize: Pass in ref to a size_t to fill out with the size of the returned buffer. Holds invalid data
	//          if the returned ptr is null.
	// returns: nullptr if file could not be read, malloc failed or string.
	//          Free the buffer using the memAPI, if default heap allocator, this is just free().
	static u8 *ReadEntireFileSimple (char    const *const path, size_t &bufSize, DqnMemAPI const memAPI = DqnMemAPI_HeapAllocator());
	static u8 *ReadEntireFileSimpleW(wchar_t const *const path, size_t &bufSize, DqnMemAPI const memAPI = DqnMemAPI_HeapAllocator());

	// size: Pass in a pointer to a size_t where the file size gets put into. It holds invalid data if
	// function returns false.
	static bool GetFileSize (char    const *const path, size_t &size);
	static bool GetFileSizeW(wchar_t const *const path, size_t &size);

	// NOTE: You can't delete a file unless the handle has been closed to it on Win32.
	static bool Delete (char    const *const path);
	static bool DeleteW(wchar_t const *const path);

	// numFiles: Pass in a ref to a i32. The function fills it out with the number of entries.
	// return:   An array of strings of the files in the directory in UTF-8. The directory lisiting is
	//           allocated with malloc and must be freed using free() or the helper function ListDirFree()
	static char **ListDir    (char const *const dir, i32 &numFiles);
	static void   ListDirFree(char **fileList,       i32 const numFiles);
};

////////////////////////////////////////////////////////////////////////////////
// XPlatform > #DqnTimer Public API - High Resolution Timer
////////////////////////////////////////////////////////////////////////////////
DQN_FILE_SCOPE f64  DqnTimer_NowInMs();
DQN_FILE_SCOPE f64  DqnTimer_NowInS ();

////////////////////////////////////////////////////////////////////////////////
// XPlatform > #DqnLock Public API - Mutex Synchronisation
////////////////////////////////////////////////////////////////////////////////
typedef struct DqnLock
{
#if defined(DQN_IS_WIN32)
	CRITICAL_SECTION win32Handle;

#elif defined(DQN_IS_UNIX)
	pthread_mutex_t unixHandle;

#else
	#error Unknown platform

#endif

	// Win32 only, when trying to acquire a locked lock, it is the number of spins permitted
	// spinlocking on the lock before being blocked. Set before init if you want a different value.
	u32 win32SpinCount = 16000;

	bool Init   ();
	void Acquire();
	void Release();
	void Delete ();

	// Create a lock guard on the lock this is invoked on.
	struct DqnLockGuard LockGuard();
} DqnLock;

// Lock guard automatically acquires a lock on construction and releases the associated lock on
// destruction. If the lock is unable to be acquired, the program blocks at construction until it
// can.
struct DqnLockGuard
{
	// lock: Takes a pointer to a pre-existing and already initialised lock
	// bool: Pass in (optionally) a pointer to a bool which returns whether a lock was successful.
	// FALSE if lock is nullptr.
	 DqnLockGuard(DqnLock *const lock_, bool *const succeeded);
	~DqnLockGuard();

private:
	DqnLock *lock;
};

// lock: Pass in a pointer to a default DqnLock struct.
//       In Win32, you may optionally change the win32Spincount.
DQN_FILE_SCOPE bool DqnLock_Init   (DqnLock *const lock);
DQN_FILE_SCOPE void DqnLock_Acquire(DqnLock *const lock);
DQN_FILE_SCOPE void DqnLock_Release(DqnLock *const lock);
DQN_FILE_SCOPE void DqnLock_Delete (DqnLock *const lock);

////////////////////////////////////////////////////////////////////////////////
// XPlatform > #DqnJobQueue Public API - Multithreaded Job Queue
////////////////////////////////////////////////////////////////////////////////
// DqnJobQueue is a platform abstracted "lockless" multithreaded work queue. It will create threads
// and assign threads to complete the job via the job "callback" using the "userData" supplied.

// Usage
// 1. Prepare your callback function for threads to execute following the 'DqnJob_Callback' function
//    signature.
// 2. Create a job queue with DqnJobQueue_InitWithMem()
// 3. Add jobs with DqnJobQueue_AddJob() and threads will be dispatched automatically.

// When all jobs are sent you can also utilise the main executing thread to complete jobs whilst you
// wait for all jobs to complete using DqnJobQueue_TryExecuteNextJob() or spinlock on
// DqnJobQueue_AllJobsComplete(). Alternatively you can combine both for the main thread to help
// complete work and not move on until all tasks are complete.

typedef struct DqnJobQueue DqnJobQueue;

typedef void   DqnJob_Callback(DqnJobQueue *const queue, void *const userData);
typedef struct DqnJob
{
	DqnJob_Callback *callback;
	void            *userData;
} DqnJob;

typedef struct DqnJobQueue
{
	// JobList Circular Array, is setup in Init()
	DqnJob *jobList;
	u32     size;

	// NOTE(doyle): Modified by main+worker threads
	i32   volatile jobToExecuteIndex;
	i32   volatile numJobsToComplete;

#if defined(DQN_IS_WIN32)
	void *semaphore;

#elif defined(DQN_IS_UNIX)
	sem_t semaphore;

#else
	#error Unknown platform

#endif

	// NOTE: Modified by main thread ONLY
	i32 volatile jobInsertIndex;

	bool Init             (DqnJob *const jobList_, const u32 jobListSize, const u32 numThreads);
	bool AddJob           (const DqnJob job);

    void BlockAndCompleteAllJobs();
	bool TryExecuteNextJob();
	bool AllJobsComplete  ();
} DqnJobQueue;

// TODO(doyle): Queue delete, thread delete

// queue:       Pass a pointer to a zero cleared DqnJobQueue struct
// jobList:     Pass in a pointer to an array of DqnJob's
// jobListSize: The number of elements in the jobList array
// numThreads:  The number of threads the queue should request from the OS for working on the queue
// return:      FALSE if invalid args i.e. nullptr ptrs or jobListSize & numThreads == 0
DQN_FILE_SCOPE bool DqnJobQueue_Init(DqnJobQueue *const queue, const DqnJob *const jobList,
                                     const u32 jobListSize, const u32 numThreads);

// return: FALSE if the job is not able to be added, this occurs if the queue is full.
DQN_FILE_SCOPE bool DqnJobQueue_AddJob(DqnJobQueue *const queue, const DqnJob job);

// Helper function that combines TryExecuteNextJob() and AllJobsComplete(), i.e.
// complete all work before moving on. Does nothing if queue is nullptr.
DQN_FILE_SCOPE void DqnJobQueue_BlockAndCompleteAllJobs(DqnJobQueue *const queue);

// return: TRUE if there was a job to execute (the calling thread executes it). FALSE if it could
//         not get a job. It may return FALSE whilst there are still jobs, this means that another thread
//         has taken the job before the calling thread could and should NOT be used to determine if there
//         are any remaining jobs left. That can only be definitively known using
//         DqnJobQueue_AllJobsComplete(). This is typically combined like so ..
//         while (DqnJobQueue_TryExecuteNextJob(queue) || !DqnJobQueue_AllJobsComplete(queue));
//         Return FALSE also if queue is a nullptr pointer.
DQN_FILE_SCOPE bool DqnJobQueue_TryExecuteNextJob(DqnJobQueue *const queue);
DQN_FILE_SCOPE bool DqnJobQueue_AllJobsComplete  (DqnJobQueue *const queue);

////////////////////////////////////////////////////////////////////////////////
// XPlatform > #DqnAtomic Public API - Interlocks/Atomic Operations
////////////////////////////////////////////////////////////////////////////////
// All atomic operations generate a full read/write barrier. This is implicitly enforced by the
// OS calls, not explicitly in my code.

// swapVal:    The value to put into "dest", IF at point of read, "dest" has the value of "compareVal"
// compareVal: The value to check in "dest"
// return:     Return the original value that was in "dest"
DQN_FILE_SCOPE i32 DqnAtomic_CompareSwap32(i32 volatile *const dest, const i32 swapVal, const i32 compareVal);

// Add "value" to src
// return: The new value at src
DQN_FILE_SCOPE i32 DqnAtomic_Add32(i32 volatile *const src, const i32 value);

////////////////////////////////////////////////////////////////////////////////
// XPlatform > #DqnPlatform Public API - Common Platform API Helpers
////////////////////////////////////////////////////////////////////////////////
// Uses a single call to DqnMem_Calloc() and DqnMem_Free(). Not completely platform "independent" for Unix.
// numCores: numThreadsPerCore: Can be nullptr, the function will just skip it.
DQN_FILE_SCOPE void DqnPlatform_GetNumThreadsAndCores(u32 *const numCores, u32 *const numThreadsPerCore);

////////////////////////////////////////////////////////////////////////////////
// #Platform Public API
////////////////////////////////////////////////////////////////////////////////
// Functions here are only available for the #defined sections (i.e. all functions in
// DQN_WIN32_PLATFORM only have a valid implementation in Win32.

////////////////////////////////////////////////////////////////////////////////
// #Win32Platform Public API
////////////////////////////////////////////////////////////////////////////////
#if defined(DQN_IS_WIN32)
////////////////////////////////////////////////////////////////////////////////
// Platform > #DqnWin32 Public API - Common Win32 API Helpers
////////////////////////////////////////////////////////////////////////////////
#define DQN_WIN32_ERROR_BOX(text, title) MessageBoxA(nullptr, text, title, MB_OK);

// The function automatically null-terminates the output string.
// out:    A pointer to the buffer to receive the characters.
// outLen: The length/capacity of the buffer "out". If 0, the function returns the required length including null terminator.
// return: -1 if invalid, or if outLen is 0 the required buffer length.
DQN_FILE_SCOPE i32 DqnWin32_UTF8ToWChar(const char    *const in, wchar_t *const out, const i32 outLen);
DQN_FILE_SCOPE i32 DqnWin32_WCharToUTF8(const wchar_t *const in, char    *const out, const i32 outLen);

// "width" and "height" are optional and won't be used if not given by user.
// width & height: Pass in a pointer for function to fill out.
DQN_FILE_SCOPE void DqnWin32_GetClientDim     (const HWND window, LONG *const width, LONG *const height);
DQN_FILE_SCOPE void DqnWin32_GetRectDim       (const RECT rect,   LONG *const width, LONG *const height);

// Displays error in the format <errorPrefix>: <Win32 Error Message> in a Win32 Dialog Box.
// errorPrefix: The message before the Win32 error, can be nullptr
DQN_FILE_SCOPE void DqnWin32_DisplayLastError (const char *const errorPrefix);

// Asimilar to DqnWin32_DisplayLastError() a particular error can be specified in a Win32 Dialog Box.
DQN_FILE_SCOPE void DqnWin32_DisplayErrorCode (const DWORD error, const char *const errorPrefix);

// Output text to the debug console. For visual studio this is the output window and not the console.
// ...: Variable args alike printf, powered by stb_sprintf
DQN_FILE_SCOPE void DqnWin32_OutputDebugString(const char *const formatStr, ...);

// Get the full path of to the current processes executable, and return the char offset in the
// string to the last backslash, i.e. the directory.
// buf:    Filled with the path to the executable file.
// return: The offset to the last backslash. -1 if bufLen was not large enough or buf is null.
DQN_FILE_SCOPE i32  DqnWin32_GetEXEDirectory(char *const buf, const u32 bufLen);
#endif // DQN_IS_WIN32
#endif // DQN_PLATFORM_H
#endif // DQN_PLATFORM_HEADER


////////////////////////////////////////////////////////////////////////////////
// #External Code
////////////////////////////////////////////////////////////////////////////////
#ifndef DQN_INI_H
#define DQN_INI_H
////////////////////////////////////////////////////////////////////////////////
// #DqnIni Public API - Simple INI Config File API v1.1
////////////////////////////////////////////////////////////////////////////////
/*
TODO(doyle): Make my own for fun?
Public Domain library with thanks to Mattias Gustavsson
https://github.com/mattiasgustavsson/libs/blob/master/docs/ini.md

Examples
Loading an ini file and retrieving values

#define DQN_INI_IMPLEMENTATION
#include "ini.h"
#include <stdio.h>
#include <stdlib.h>

int main()
{
	FILE *fp = fopen("test.ini", "r");
	fseek(fp, 0, SEEK_END);
	int size = ftell(fp);
	fseek(fp, 0, SEEK_SET);
	char *data = (char *)malloc(size + 1);
	fread(data, 1, size, fp);
	data[size] = '\0';
	fclose(fp);

	DqnIni *ini = DqnIni_Load(data);
	free(data);
	int second_index   = DqnIni_FindProperty(ini, DQN_INI_GLOBAL_SECTION, "SecondSetting");
	char const *second = DqnIni_PropertyValue(ini, DQN_INI_GLOBAL_SECTION, second_index);
	int section        = DqnIni_FindSection(ini, "MySection");
	int third_index    = DqnIni_FindProperty(ini, section, "ThirdSetting");
	char const *third  = DqnIni_PropertyValue(ini, section, third_index);
	DqnIni_Destroy(ini);

	return 0;
}

Creating a new ini file
#define DQN_INI_IMPLEMENTATION
#include "ini.h"

#include <stdio.h>
#include <stdlib.h>

int main()
{
	DqnIni *ini = DqnIni_Create();
	DqnIni_PropertyAdd(ini, DQN_INI_GLOBAL_SECTION, "FirstSetting", "Test");
	DqnIni_PropertyAdd(ini, DQN_INI_GLOBAL_SECTION, "SecondSetting", "2");
	int section = DqnIni_SectionAdd(ini, "MySection");
	DqnIni_PropertyAdd(ini, section, "ThirdSetting", "Three");

	int size   = DqnIni_Save(ini, nullptr, 0); // Find the size needed
	char *data = (char *)malloc(size);
	size       = DqnIni_Save(ini, data, size); // Actually save the file
	DqnIni_Destroy(ini);

	FILE *fp = fopen("test.ini", "w");
	fwrite(data, 1, size, fp);
	fclose(fp);
	free(data);

	return 0;
}
*/

#define DQN_INI_GLOBAL_SECTION (0)
#define DQN_INI_NOT_FOUND (-1)

typedef struct DqnIni DqnIni;

DqnIni *DqnIni_Create(void *memctx);
DqnIni *DqnIni_Load  (char const *data, void *memctx);

int  DqnIni_Save   (DqnIni const *ini, char *data, int size);
void DqnIni_Destroy(DqnIni *ini);

int         DqnIni_SectionCount(DqnIni const *ini);
char const *DqnIni_SectionName (DqnIni const *ini, int section);

int         DqnIni_PropertyCount(DqnIni const *ini, int section);
char const *DqnIni_PropertyName (DqnIni const *ini, int section, int property);
char const *DqnIni_PropertyValue(DqnIni const *ini, int section, int property);

int DqnIni_FindSection (DqnIni const *ini, char const *name, int name_length);
int DqnIni_FindProperty(DqnIni const *ini, int section, char const *name, int name_length);

int  DqnIni_SectionAdd    (DqnIni *ini, char const *name, int length);
void DqnIni_PropertyAdd   (DqnIni *ini, int section, char const *name, int name_length, char const *value, int value_length);
void DqnIni_SectionRemove (DqnIni *ini, int section);
void DqnIni_PropertyRemove(DqnIni *ini, int section, int property);

void DqnIni_SectionNameSet  (DqnIni *ini, int section, char const *name, int length);
void DqnIni_PropertyNameSet (DqnIni *ini, int section, int property, char const *name, int length);
void DqnIni_PropertyValueSet(DqnIni *ini, int section, int property, char const *value, int length);

/**
Customization
-------------
### Custom memory allocators

To store the internal data structures, ini.h needs to do dynamic allocation by
calling `malloc`. Programs might want to keep track of allocations done, or use
custom defined pools to allocate memory from. ini.h allows for specifying custom
memory allocation functions for `malloc` and `free`.  This is done with the
following code:

    #define DQN_INI_IMPLEMENTATION
    #define DQN_INI_MALLOC( ctx, size ) ( my_custom_malloc( ctx, size ) )
    #define DQN_INI_FREE( ctx, ptr ) ( my_custom_free( ctx, ptr ) )
    #include "ini.h"

where `my_custom_malloc` and `my_custom_free` are your own memory
allocation/deallocation functions. The `ctx` parameter is an optional parameter
of type `void*`. When `DqnIni_Create` or `DqnIni_Load` is called, you can pass
in a `memctx` parameter, which can be a pointer to anything you like, and which
will be passed through as the `ctx` parameter to every
`DQN_INI_MALLOC`/`DQN_INI_FREE` call. For example, if you are doing memory
tracking, you can pass a pointer to your tracking data as `memctx`, and in your
custom allocation/deallocation function, you can cast the `ctx` param back to
the right type, and access the tracking data.

If no custom allocator is defined, ini.h will default to `malloc` and `free`
from the C runtime library.

### Custom C runtime function
The library makes use of three additional functions from the C runtime library,
and for full flexibility, it allows you to substitute them for your own.  Here's
an example:

    #define DQN_INI_IMPLEMENTATION
    #define DQN_INI_MEMCPY( dst, src, cnt ) ( my_memcpy_func( dst, src, cnt ) )
    #define DQN_INI_STRLEN( s ) ( my_strlen_func( s ) )
    #define DQN_INI_STRICMP( s1, s2 ) ( my_stricmp_func( s1, s2 ) )
    #include "ini.h"

If no custom function is defined, ini.h will default to the C runtime library equivalent.


DqnIni_Create
----------

    DqnIni* DqnIni_Create( void* memctx )

Instantiates a new, empty ini structure, which can be manipulated with other API
calls, to fill it with data. To save it out to an ini-file string, use
`DqnIni_Save`. When no longer needed, it can be destroyed by calling
`DqnIni_Destroy`.  `memctx` is a pointer to user defined data which will be
passed through to the custom DQN_INI_MALLOC/DQN_INI_FREE calls. It can be nullptr
if no user defined data is needed.


DqnIni_Load
--------

    DqnIni* DqnIni_Load( char const* data, void* memctx )

Parse the zero-terminated string `data` containing an ini-file, and create a new
DqnIni instance containing the data.  The instance can be manipulated with
other API calls to enumerate sections/properties and retrieve values. When no
longer needed, it can be destroyed by calling `DqnIni_Destroy`. `memctx` is
a pointer to user defined data which will be passed through to the custom
DQN_INI_MALLOC/DQN_INI_FREE calls. It can be nullptr if no user defined data is
needed.


DqnIni_Save
--------

    int DqnIni_Save( DqnIni const* ini, char* data, int size )

Saves an ini structure as a zero-terminated ini-file string, into the specified
buffer. Returns the number of bytes written, including the zero terminator. If
`data` is nullptr, nothing is written, but `DqnIni_Save` still returns the number
of bytes it would have written. If the size of `data`, as specified in the
`size` parameter, is smaller than that required, only part of the ini-file
string will be written. `DqnIni_Save` still returns the number of bytes it
would have written had the buffer been large enough.

DqnIni_Destroy
-----------

    void DqnIni_Destroy( DqnIni* ini )

Destroy an `DqnIni` instance created by calling `DqnIni_Load` or
`DqnIni_Create`, releasing the memory allocated by it. No further API calls are
valid on an `DqnIni` instance after calling `DqnIni_Destroy` on it.


DqnIni_SectionCount
-----------------

    int DqnIni_SectionCount( DqnIni const* ini )

Returns the number of sections in an ini file. There's at least one section in
an ini file (the global section), but there can be many more, each specified in
the file by the section name wrapped in square brackets [ ].


DqnIni_SectionName
----------------

    char const* DqnIni_SectionName( DqnIni const* ini, int section )

Returns the name of the section with the specified index. `section` must be
non-negative and less than the value returned by `DqnIni_SectionCount`, or
`DqnIni_SectionName` will return nullptr. The defined constant
`DQN_INI_GLOBAL_SECTION` can be used to indicate the global section.


DqnIni_PropertyCount
------------------

    int DqnIni_PropertyCount( DqnIni const* ini, int section )

Returns the number of properties belonging to the section with the specified
index. `section` must be non-negative and less than the value returned by
`DqnIni_SectionCount`, or `DqnIni_SectionName` will return 0. The defined
constant `DQN_INI_GLOBAL_SECTION` can be used to indicate the global section.
Properties are declared in the ini-file on he format `name=value`.


DqnIni_PropertyName
-----------------

    char const* DqnIni_PropertyName( DqnIni const* ini, int section, int property )

Returns the name of the property with the specified index `property` in the
section with the specified index `section`.  `section` must be non-negative and
less than the value returned by `DqnIni_SectionCount`, and `property` must be
non-negative and less than the value returned by `DqnIni_PropertyCount`, or
`DqnIni_PropertyName` will return nullptr. The defined constant
`DQN_INI_GLOBAL_SECTION` can be used to indicate the global section.


DqnIni_PropertyValue
------------------

    char const* DqnIni_PropertyValue( DqnIni const* ini, int section, int property )

Returns the value of the property with the specified index `property` in the
section with the specified index `section`.  `section` must be non-negative and
less than the value returned by `DqnIni_SectionCount`, and `property` must be
non-negative and less than the value returned by `DqnIni_PropertyCount`, or
`DqnIni_PropertyValue` will return nullptr. The defined constant
`DQN_INI_GLOBAL_SECTION` can be used to indicate the global section.


DqnIni_FindSection
----------------

    int DqnIni_FindSection( DqnIni const* ini, char const* name, int name_length )

Finds the section with the specified name, and returns its index. `name_length`
specifies the number of characters in `name`, which does not have to be
zero-terminated. If `name_length` is zero, the length is determined
automatically, but in this case `name` has to be zero-terminated. If no section
with the specified name could be found, the value `DQN_INI_NOT_FOUND` is
returned.


DqnIni_FindProperty
-----------------

    int DqnIni_FindProperty( DqnIni const* ini, int section, char const* name, int name_length )

Finds the property with the specified name, within the section with the
specified index, and returns the index of the property. `name_length` specifies
the number of characters in `name`, which does not have to be zero-terminated.
If `name_length` is zero, the length is determined automatically, but in this
case `name` has to be zero-terminated. If no property with the specified name
could be found within the specified section, the value `DQN_INI_NOT_FOUND` is
returned.  `section` must be non-negative and less than the value returned by
`DqnIni_SectionCount`, or `DqnIni_FindProperty` will return
`DQN_INI_NOT_FOUND`. The defined constant `DQN_INI_GLOBAL_SECTION` can be used
to indicate the global section.


DqnIni_SectionAdd
---------------

    int DqnIni_SectionAdd( DqnIni* ini, char const* name, int length )

Adds a section with the specified name, and returns the index it was added at.
There is no check done to see if a section with the specified name already
exists - multiple sections of the same name are allowed. `length` specifies the
number of characters in `name`, which does not have to be zero-terminated. If
`length` is zero, the length is determined automatically, but in this case
`name` has to be zero-terminated.


DqnIni_PropertyAdd
----------------
    
    void DqnIni_PropertyAdd( DqnIni* ini, int section, char const* name, int name_length, char const* value, int value_length )

Adds a property with the specified name and value to the specified section, and returns the index it was added at. There is no check done to see if a property
with the specified name already exists - multiple properties of the same name
are allowed. `name_length` and `value_length` specifies the number of characters
in `name` and `value`, which does not have to be zero-terminated. If
`name_length` or `value_length` is zero, the length is determined automatically,
but in this case `name`/`value` has to be zero-terminated. `section` must be
non-negative and less than the value returned by `DqnIni_SectionCount`, or the
property will not be added. The defined constant `DQN_INI_GLOBAL_SECTION` can be
used to indicate the global section.


DqnIni_SectionRemove
------------------

    void DqnIni_SectionRemove( DqnIni* ini, int section )

Removes the section with the specified index, and all properties within it.
`section` must be non-negative and less than the value returned by
`DqnIni_SectionCount`. The defined constant `DQN_INI_GLOBAL_SECTION` can be
used to indicate the global section. Note that removing a section will shuffle
section indices, so that section indices you may have stored will no longer
indicate the same section as it did before the remove. Use the find functions to
update your indices.


DqnIni_PropertyRemove
-------------------

    void DqnIni_PropertyRemove( DqnIni* ini, int section, int property )

Removes the property with the specified index from the specified section.
`section` must be non-negative and less than the value returned by
`DqnIni_SectionCount`, and `property` must be non-negative and less than the
value returned by `DqnIni_PropertyCount`. The defined constant
`DQN_INI_GLOBAL_SECTION` can be used to indicate the global section. Note that
removing a property will shuffle property indices within the specified section,
so that property indices you may have stored will no longer indicate the same
property as it did before the remove. Use the find functions to update your
indices.


DqnIni_SectionNameSet
--------------------

    void DqnIni_SectionNameSet( DqnIni* ini, int section, char const* name, int length )

Change the name of the section with the specified index. `section` must be
non-negative and less than the value returned by `DqnIni_SectionCount`. The
defined constant `DQN_INI_GLOBAL_SECTION` can be used to indicate the global
section. `length` specifies the number of characters in `name`, which does not
have to be zero-terminated. If `length` is zero, the length is determined
automatically, but in this case `name` has to be zero-terminated.


DqnIni_PropertyNameSet
---------------------

    void DqnIni_PropertyNameSet( DqnIni* ini, int section, int property, char const* name, int length )

Change the name of the property with the specified index in the specified
section. `section` must be non-negative and less than the value returned by
`DqnIni_SectionCount`, and `property` must be non-negative and less than the
value returned by `DqnIni_PropertyCount`. The defined constant
`DQN_INI_GLOBAL_SECTION` can be used to indicate the global section.  `length`
specifies the number of characters in `name`, which does not have to be
zero-terminated. If `length` is zero, the length is determined automatically,
	but in this case `name` has to be zero-terminated.


DqnIni_PropertyValueSet
----------------------

    void DqnIni_PropertyValueSet( DqnIni* ini, int section, int property, char const* value, int length  )

Change the value of the property with the specified index in the specified
section. `section` must be non-negative and less than the value returned by
`DqnIni_SectionCount`, and `property` must be non-negative and less than the
value returned by `DqnIni_PropertyCount`. The defined constant
`DQN_INI_GLOBAL_SECTION` can be used to indicate the global section.  `length`
specifies the number of characters in `value`, which does not have to be
zero-terminated. If `length` is zero, the length is determined automatically,
	but in this case `value` has to be zero-terminated.

**/
#endif // DQN_INI_H

#ifndef STB_SPRINTF_H_INCLUDE
#define STB_SPRINTF_H_INCLUDE
#define STB_SPRINTF_DECORATE(name) Dqn_##name

////////////////////////////////////////////////////////////////////////////////
// #DqnSprintf Public API - Cross-platform Sprintf Implementation
////////////////////////////////////////////////////////////////////////////////
/*
Public Domain library originally written by Jeff Roberts at RAD Game Tools
- 2015/10/20.  Hereby placed in public domain.
STB_Sprintf renamed to Dqn_Sprintf

FLOATS/DOUBLES:
===============
This code uses a internal float->ascii conversion method that uses doubles with
error correction (double-doubles, for ~105 bits of precision).  This conversion
is round-trip perfect - that is, an atof of the values output here will give you
the bit-exact double back.

One difference is that our insignificant digits will be different than with MSVC
or GCC (but they don't match each other either).  We also don't attempt to find
the minimum length matching float (pre-MSVC15 doesn't either).

If you don't need float or doubles at all, define STB_SPRINTF_NOFLOAT and you'll
save 4K of code space.

64-BIT INTS:
============
This library also supports 64-bit integers and you can use MSVC style or GCC
style indicators (%I64d or %lld).  It supports the C99 specifiers for size_t and
ptr_diff_t (%jd %zd) as well.

EXTRAS:
=======
Like some GCCs, for integers and floats, you can use a ' (single quote)
specifier and commas will be inserted on the thousands: "%'d" on 12345 would
print 12,345.

For integers and floats, you can use a "$" specifier and the number will be
converted to float and then divided to get kilo, mega, giga or tera and then
printed, so "%$d" 1000 is "1.0 k", "%$.2d" 2536000 is "2.53 M", etc. For byte
values, use two $:s, like "%$$d" to turn 2536000 to "2.42 Mi". If you prefer
JEDEC suffixes to SI ones, use three $:s: "%$$$d" -> "2.42 M". To remove the
space between the number and the suffix, add "_" specifier: "%_$d" -> "2.53M".

In addition to octal and hexadecimal conversions, you can print integers in
binary: "%b" for 256 would print 100.
*/

#if defined(__has_feature)
	#if __has_feature(address_sanitizer)
		#define STBI__ASAN __attribute__((no_sanitize("address")))
	#endif
#endif

#ifndef STBI__ASAN
	#define STBI__ASAN
#endif

#ifdef STB_SPRINTF_STATIC
	#define STBSP__PUBLICDEC static
	#define STBSP__PUBLICDEF static STBI__ASAN
#else
	#ifdef __cplusplus
		#define STBSP__PUBLICDEC extern "C"
		#define STBSP__PUBLICDEF extern "C" STBI__ASAN
	#else
		#define STBSP__PUBLICDEC extern
		#define STBSP__PUBLICDEF STBI__ASAN
	#endif
#endif

#include <stdarg.h>  // for va_list()

#ifndef STB_SPRINTF_MIN
	#define STB_SPRINTF_MIN 512 // how many characters per callback
#endif

#ifndef STB_SPRINTF_DECORATE
	#define STB_SPRINTF_DECORATE(name) stbsp_##name  // define this before including if you want to change the names
#endif

// Convert a va_list arg list into a buffer. vsnprintf always returns a zero-terminated string (unlike regular snprintf).
// return: The number of characters copied into the buffer
STBSP__PUBLICDEF int STB_SPRINTF_DECORATE(vsprintf) (char *buf, char const *fmt, va_list va);
STBSP__PUBLICDEF int STB_SPRINTF_DECORATE(vsnprintf)(char *buf, int count, char const *fmt, va_list va);

// Write format string to buffer. It always writes the whole string and appends a null.
// return: The number of characters copied into the buffer not including the null terminator.
STBSP__PUBLICDEF int STB_SPRINTF_DECORATE(sprintf) (char *buf, char const *fmt, ...);

// snprintf() always returns a zero-terminated string (unlike regular snprintf).
STBSP__PUBLICDEF int STB_SPRINTF_DECORATE(snprintf)(char *buf, int count, char const *fmt, ...);

// Convert into a buffer, calling back every STB_SPRINTF_MIN chars.
// Your callback can then copy the chars out, print them or whatever.
// This function is actually the workhorse for everything else.
// The buffer you pass in must hold at least STB_SPRINTF_MIN characters.
// You return the next buffer to use or 0 to stop converting
typedef char *STBSP_SPRINTFCB(char *buf, void *user, int len);
STBSP__PUBLICDEF int  STB_SPRINTF_DECORATE(vsprintfcb)(STBSP_SPRINTFCB* callback, void *user, char *buf, char const *fmt, va_list va);

// Set the comma and period characters to use.
STBSP__PUBLICDEF void STB_SPRINTF_DECORATE(set_separators)(char comma, char period);

#endif // STB_SPRINTF_H_INCLUDE

#ifdef DQN_IMPLEMENTATION
////////////////////////////////////////////////////////////////////////////////
//
// DQN_IMPLEMENTATION
//
////////////////////////////////////////////////////////////////////////////////
#include <math.h>    // TODO(doyle): For trigonometry functions (for now)
#include <stdlib.h>  // For calloc, malloc, free
#include <stdio.h>   // For printf

// NOTE: STB_SPRINTF is included when DQN_IMPLEMENTATION defined
// #define STB_SPRINTF_IMPLEMENTATION

// NOTE: DQN_INI_IMPLEMENTATION modified to be included when DQN_IMPLEMENTATION defined
// #define DQN_INI_IMPLEMENTATION
#define DQN_INI_STRLEN(s) DqnStr_Len(s)

////////////////////////////////////////////////////////////////////////////////
// #DqnAssert Implementation
////////////////////////////////////////////////////////////////////////////////
DQN_FILE_SCOPE bool DqnAssertInternal(const bool result, const char *const file, const i32 lineNum,
                                      const char *const expr, const char *const msg, ...)
{
	if (!(result))
	{
		const char *const formatStrNoMsg   = "DqnAssert() failed: %s|%d| (%s)\n";
		const char *const formatStrWithMsg = "DqnAssert() failed: %s|%d| (%s): %s\n";
		const char *const formatStr        = (msg) ? formatStrWithMsg : formatStrNoMsg;

		char userMsg[2048] = {};
		if (msg)
		{
			va_list argList;
			va_start(argList, msg);
			{
				u32 numCopied = Dqn_vsprintf(userMsg, msg, argList);
				DQN_ASSERT_HARD(numCopied < DQN_ARRAY_COUNT(userMsg));
			}
			va_end(argList);
		}

		printf(formatStr, file, lineNum, expr, userMsg);
		(*((i32 *)0)) = 0;
	}
	return result;
}

////////////////////////////////////////////////////////////////////////////////
// #DqnMemory Implementation
////////////////////////////////////////////////////////////////////////////////
// NOTE: All memory allocations in dqn.h go through these functions. So they can
// be rerouted fairly easily especially for platform specific mallocs.
DQN_FILE_SCOPE void *DqnMem_Alloc(const size_t size)
{
	void *result = malloc(size);
	return result;
}

DQN_FILE_SCOPE void *DqnMem_Calloc(const size_t size)
{
	void *result = calloc(1, size);
	return result;
}

DQN_FILE_SCOPE void DqnMem_Clear(void *const memory, const u8 clearValue, const size_t size)
{
	if (memory) memset(memory, clearValue, size);
}

DQN_FILE_SCOPE void *DqnMem_Realloc(void *memory, const size_t newSize)
{
	void *result = realloc(memory, newSize);
	return result;
}

DQN_FILE_SCOPE void DqnMem_Free(void *memory)
{
	if (memory) free(memory);
}

DQN_FILE_SCOPE void DqnMem_Copy(void *const dest, void *const src, const i64 numBytesToCopy)
{
	auto *to   = (u8 *)dest;
	auto *from = (u8 *)src;
	for (auto i = 0; i < numBytesToCopy; i++)
		to[i]   = from[i];
}

DQN_FILE_SCOPE void *DqnMem_Set(void *const dest, u8 value, const i64 numBytesToSet)
{
	auto *ptr = (u8 *)dest;
	for (auto i = 0; i < numBytesToSet; i++)
		ptr[i]  = value;

	return dest;
}

DQN_FILE_SCOPE void *DqnMem_Set64(void *const dest, u8 value, const i64 numBytesToCopy)
{
#if defined(DQN_WIN32_PLATFORM)
	u64 valueU64 = value;
	valueU64 |= valueU64 << 8;
	valueU64 |= valueU64 << 16;
	valueU64 |= valueU64 << 32;

	auto *const destU64      = (u64 *)dest;
	i64   const numU64ToCopy = numBytesToCopy / sizeof(u64);
	__stosq(destU64, valueU64, numU64ToCopy);

	const u64 remainingMask   = sizeof(u64) - 1;
	auto   *const destU8      = (u8 *)dest + (numBytesToCopy & ~remainingMask);
	u8      const valueU8     = value;
	size_t  const numU8ToCopy = numBytesToCopy & (remainingMask);
	__stosb(destU8, valueU8, numU8ToCopy);
#else
	DQN_ASSERT_HARD(DQN_INVALID_CODE_PATH)
#endif
	return dest;
};

////////////////////////////////////////////////////////////////////////////////
// #DqnMemAPIInternal Implementation
////////////////////////////////////////////////////////////////////////////////
FILE_SCOPE void DqnMemAPIInternal_ValidateRequest(DqnMemAPI::Request request)
{
	DQN_ASSERT_HARD(request.type != DqnMemAPI::Type::Invalid);

	switch(request.type)
	{
		case DqnMemAPI::Type::Alloc:
		{
			DQN_ASSERT_HARD(request.requestSize > 0);
		}
		break;

		case DqnMemAPI::Type::Realloc:
		{
			DQN_ASSERT_HARD(request.oldSize > 0);
			DQN_ASSERT_HARD(request.requestSize > 0);
			DQN_ASSERT_HARD(request.oldMemPtr);
		}
		break;

		case DqnMemAPI::Type::Free:
		{
			// nothing to validate
		}
		break;

		default:
		{
			DQN_ASSERT_HARD(DQN_INVALID_CODE_PATH);
		}
		break;
	}
}

FILE_SCOPE u8 *DqnMemAPIInternal_HeapAllocatorCallback(DqnMemAPI::Request request)
{
	DQN_ASSERT_HARD(!request.userContext);
	u8 *result = nullptr;

	DqnMemAPIInternal_ValidateRequest(request);
	switch(request.type)
	{
		case DqnMemAPI::Type::Alloc:
		{
			if (request.clearToZero)
			{
				result = (u8 *)DqnMem_Calloc(request.requestSize);
			}
			else
			{
				result = (u8 *)DqnMem_Alloc(request.requestSize);
			}
		}
		break;

		case DqnMemAPI::Type::Realloc:
		{
			result = (u8 *)DqnMem_Realloc(request.oldMemPtr, request.newRequestSize);
		}
		break;

		case DqnMemAPI::Type::Free:
		{
			DqnMem_Free(request.ptrToFree);
		}
		break;

		default:
		{
			DQN_ASSERT_HARD(DQN_INVALID_CODE_PATH);
		}
		break;
	}

	return result;
}

FILE_SCOPE u8 *DqnMemAPIInternal_StackAllocatorCallback(DqnMemAPI::Request info)
{
	DQN_ASSERT_HARD(info.userContext);
	DqnMemStack *const stack = static_cast<DqnMemStack *>(info.userContext);
	u8 *result               = nullptr;

	DqnMemAPIInternal_ValidateRequest(info);
	switch(info.type)
	{
		case DqnMemAPI::Type::Alloc:
		{
			result = (u8 *)stack->Push(info.requestSize);

			if (info.clearToZero)
			{
				DqnMem_Clear(result, 0, info.requestSize);
			}
		}
		break;

		case DqnMemAPI::Type::Realloc:
		case DqnMemAPI::Type::Free:
		{
			// IMPORTANT: This is a _naive_ realloc scheme for stack allocation.
			DqnMemStack::Block *block = stack->block;
			u8 *currUsagePtr        = (u8 *)(block->memory + block->used);
			u8 *checkPtr            = currUsagePtr - DQN_ALIGN_POW_N(info.oldSize, stack->byteAlign);

			if (info.type == DqnMemAPI::Type::Realloc)
			{
				// Last allocation, can safely allocate the remainder space.
				if (checkPtr == (u8 *)info.oldMemPtr || info.oldMemPtr == block->memory)
				{
					size_t remainingBytesToAlloc = info.newRequestSize - info.oldSize;
					DQN_ASSERT_HARD(remainingBytesToAlloc > 0);

					bool enoughSpace =
					    (currUsagePtr + remainingBytesToAlloc) < (block->memory + block->size);

					if (enoughSpace)
					{
						result       = (u8 *)info.oldMemPtr;
						u8 *startPtr = (u8 *)stack->Push(remainingBytesToAlloc);
						DQN_ASSERT_HARD(stack->block == block);

						if (info.clearToZero)
						{
							DqnMem_Clear(startPtr, 0, remainingBytesToAlloc);
						}

						return result;
					}

					// Else, last allocation but not enough space in block. Create a new block and
					// copy
					DqnMemStack::Block *newBlock =
					    stack->AllocateCompatibleBlock(info.newRequestSize, info.clearToZero);
					if (newBlock)
					{
						DqnMem_Copy(result, (u8 *)info.oldMemPtr, info.oldSize);
						stack->Pop(info.oldMemPtr, info.oldSize);

						stack->AttachBlock(block);
						result = stack->block->memory;
					}
				}
				else
				{
					// NOTE: Lost memory when this case occurs.
					result = (u8 *)stack->Push(info.newRequestSize);

					if (result)
					{
						DqnMem_Copy(result, (u8 *)info.oldMemPtr, info.oldSize);
					}
				}

				return result;
			}
			else
			{
				if (checkPtr == (u8 *)info.oldMemPtr)
					stack->Pop(info.oldMemPtr, info.oldSize);
			}
		}
		break;

		default:
		{
			DQN_ASSERT_HARD(DQN_INVALID_CODE_PATH);
		}
		break;
	}

	return result;
}

////////////////////////////////////////////////////////////////////////////////
// #DqnMemAPI Implementation
////////////////////////////////////////////////////////////////////////////////
DqnMemAPI::Request DqnMemAPI::RequestRealloc(DqnMemAPI const memAPI, void *const oldMemPtr,
                                             size_t const oldSize, size_t const newSize)
{
	DqnMemAPI::Request info = {};
	info.type               = Type::Realloc;
	info.userContext        = memAPI.userContext;
	info.newRequestSize     = newSize;
	info.oldMemPtr          = oldMemPtr;
	info.oldSize            = oldSize;

	return info;
}

DqnMemAPI::Request DqnMemAPI::RequestAlloc(DqnMemAPI const memAPI, size_t const size,
                                           bool const clearToZero)
{
	DqnMemAPI::Request result = {};
	result.type               = DqnMemAPI::Type::Alloc;
	result.userContext        = memAPI.userContext;
	result.clearToZero        = clearToZero;
	result.requestSize        = size;
	return result;
}

DqnMemAPI::Request DqnMemAPI::RequestFree(DqnMemAPI const memAPI, void *const ptrToFree,
                                          size_t const sizeToFree)
{
	DqnMemAPI::Request result = {};
	result.type               = DqnMemAPI::Type::Free;
	result.userContext        = memAPI.userContext;
	result.ptrToFree          = ptrToFree;
	result.sizeToFree         = sizeToFree;
	return result;
}

DQN_FILE_SCOPE DqnMemAPI DqnMemAPI_HeapAllocator()
{
	DqnMemAPI result   = {0};
	result.callback    = DqnMemAPIInternal_HeapAllocatorCallback;
	result.userContext = nullptr;
	return result;
}

DQN_FILE_SCOPE DqnMemAPI DqnMemAPI_StackAllocator(DqnMemStack *const stack)
{
	DQN_ASSERT_HARD(stack);
	DqnMemAPI result   = {0};
	result.callback    = DqnMemAPIInternal_StackAllocatorCallback;
	result.userContext = stack;
	return result;
}

////////////////////////////////////////////////////////////////////////////////
// #DqnMemStackInternal Implementation
////////////////////////////////////////////////////////////////////////////////
DQN_FILE_SCOPE DqnMemStack::Block *DqnMemStackInternal_AllocateBlock(u32 byteAlign, size_t size,
                                                                     bool const zeroClear,
                                                                     DqnMemAPI const &memAPI)
{
	if (!memAPI.callback) return nullptr;

	size_t alignedSize = DQN_ALIGN_POW_N(size, byteAlign);
	size_t totalSize   = alignedSize + sizeof(DqnMemStack::Block) + (byteAlign -1);

	// NOTE(doyle): Total size includes another (byteAlign-1) since we also want
	// to align the base pointer to memory that we receive.
	DqnMemAPI::Request request = DqnMemAPI::RequestAlloc(memAPI, totalSize, zeroClear);
	auto *result               = (DqnMemStack::Block *)memAPI.callback(request);
	if (!result) return nullptr;

	result->memory    = (u8 *)DQN_ALIGN_POW_N((u8 *)result + sizeof(*result), byteAlign);
	result->size      = alignedSize;
	result->used      = 0;
	result->prevBlock = nullptr;
	return result;
}

////////////////////////////////////////////////////////////////////////////////
// #DqnMemStack Initialisation Implementation
////////////////////////////////////////////////////////////////////////////////
DQN_FILE_SCOPE bool DqnMemStack::InitWithFixedMem(u8 *const mem, size_t const memSize,
                                                  u32 const byteAlign_)
{
	// TODO(doyle): Logging
	if (!mem) return false;

	if (!DQN_ASSERT_MSG(
	        memSize > sizeof(DqnMemStack::Block),
	        "memSize is insufficient to initialise a memstack, memSize: %d, requiredSize: %d",
	        memSize, sizeof(DqnMemStack::Block)))
	{
		return false;
	}

	this->block            = (DqnMemStack::Block *)mem;
	this->block->memory    = mem + sizeof(DqnMemStack::Block);
	this->block->used      = 0;
	this->block->size      = memSize - sizeof(DqnMemStack::Block);
	this->block->prevBlock = nullptr;
	this->memAPI           = {};
	this->flags = (DqnMemStack::Flag::IsFixedMemoryFromUser | DqnMemStack::Flag::IsNotExpandable);

	const u32 DEFAULT_ALIGNMENT = 4;
	this->tempRegionCount       = 0;
	this->byteAlign             = (byteAlign_ == 0) ? DEFAULT_ALIGNMENT : byteAlign_;

	DQN_ASSERT(!this->block->prevBlock);
	return true;
}

DQN_FILE_SCOPE bool DqnMemStack::InitWithFixedSize(size_t size, bool const zeroClear,
                                                   u32 const byteAlign_, DqnMemAPI const memAPI_)
{
	bool result = this->Init(size, zeroClear, byteAlign_, memAPI_);
	if (result)
	{
		this->flags |= DqnMemStack::Flag::IsNotExpandable;
		DQN_ASSERT(!this->block->prevBlock);
		return true;
	}

	return false;
}

DQN_FILE_SCOPE bool DqnMemStack::Init(size_t size, bool const zeroClear, u32 const byteAlign_, DqnMemAPI const memAPI_)
{
	if (!this || size < 0) return false;
	if (!DQN_ASSERT_MSG(!this->block, "MemStack has pre-existing block already attached"))
		return false;

	if (size == 0)
	{
		this->block = nullptr;
	}
	else
	{
		this->block = DqnMemStackInternal_AllocateBlock(byteAlign_, size, zeroClear, memAPI_);
		if (!DQN_ASSERT_MSG(this->block, "MemStack failed to allocate block, not enough memory"))
			return false;

		DQN_ASSERT(!this->block->prevBlock);
	}

	this->tempRegionCount = 0;
	this->byteAlign       = byteAlign_;
	this->flags           = 0;
	this->memAPI          = memAPI_;
	return true;
}

////////////////////////////////////////////////////////////////////////////////
// #DqnMemStack Push/Pop/Free Implementation
////////////////////////////////////////////////////////////////////////////////
DQN_FILE_SCOPE void *DqnMemStack::Push(size_t size)
{
	if (size == 0) return nullptr;

	size_t alignedSize = DQN_ALIGN_POW_N(size, this->byteAlign);
	if (!this->block || (this->block->used + alignedSize) > this->block->size)
	{
		size_t newBlockSize;

		// TODO(doyle): Allocate block size based on the aligned size or
		// a minimum block size? Not allocate based on the current block
		// size
		if (this->block)
			newBlockSize = DQN_MAX(alignedSize, this->block->size);
		else
			newBlockSize = alignedSize;

		DqnMemStack::Block *newBlock = this->AllocateCompatibleBlock(newBlockSize, true);
		if (newBlock)
		{
			bool blockAttachResult = this->AttachBlock(newBlock);
			// IMPORTANT(doyle): This should be impossible, considering that
			// AllocateCompatibleBlock checks the preconditions that the new
			// block should be able to be attached.

			// But if we somehow reach this, we need to free the block
			// otherwise memory is leaked.
			DQN_ASSERT_HARD(blockAttachResult);
		}
		else
		{
			// TODO: Better notifying to user, out of space in stack OR stack
			// is configured such that new blocks are not allowed.
			return nullptr;
		}
	}

	u8 *currPointer        = this->block->memory + this->block->used;
	u8 *alignedResult      = (u8 *)DQN_ALIGN_POW_N(currPointer, this->byteAlign);
	size_t alignmentOffset = (size_t)(alignedResult - currPointer);

	// NOTE(doyle): Since all stack can't change alignment once they've been
	// initialised and that the base memory ptr is already aligned, then all
	// subsequent allocations should also be aligned automatically.
	// TODO(doyle): In the future, do we want to allow arbitrary alignment PER
	// allocation, not per MemStack?
	DQN_ASSERT_HARD(alignmentOffset == 0);

	void *result = alignedResult;
	this->block->used += (alignedSize + alignmentOffset);
	DQN_ASSERT_HARD(this->block->used <= this->block->size);
	return result;
}

DQN_FILE_SCOPE bool DqnMemStack::Pop(void *const ptr, size_t size)
{
	if (!this->block) return false;
	u8 *currPtr = block->memory + block->used;
	if (DQN_ASSERT_MSG((u8 *)ptr >= block->memory && ptr < currPtr,
	                   "'ptr' to pop does not belong to current memStack attached block"))
	{
		size_t calcSize = (size_t)currPtr - (size_t)ptr;
		size_t sizeAligned = DQN_ALIGN_POW_N(size, this->byteAlign);

		if (calcSize == sizeAligned)
		{
			this->block->used -= sizeAligned;
			if (this->block->used == 0 && block->prevBlock)
			{
				bool result = this->FreeLastBlock();
				return result;
			}

			return true;
		}
	}

	return false;
}

DQN_FILE_SCOPE void DqnMemStack::Free()
{
	// NOTE(doyle): User is in charge of freeing this memory, so all we need to
	// do is clear the block.
	if (this->flags & DqnMemStack::Flag::IsFixedMemoryFromUser)
	{
		DQN_ASSERT_HARD(!this->block->prevBlock);
		this->ClearCurrBlock(false);
		return;
	}

	while (this->block)
		this->FreeLastBlock();

	// After a stack is free, we reset the not expandable flag so that if we
	// allocate on an empty stack it still works.
	this->flags &= ~DqnMemStack::Flag::IsNotExpandable;
}

DQN_FILE_SCOPE bool DqnMemStack::FreeMemBlock(DqnMemStack::Block *memBlock)
{
	if (!memBlock || !this->block) return false;
	if (this->flags & DqnMemStack::Flag::IsFixedMemoryFromUser) return false;

	DqnMemStack::Block **blockPtr = &this->block;

	while (*blockPtr && (*blockPtr) != memBlock)
		blockPtr = &((*blockPtr)->prevBlock);

	if (*blockPtr)
	{
		DqnMemStack::Block *blockToFree = *blockPtr;
		(*blockPtr)                     = blockToFree->prevBlock;
		DqnMem_Free(blockToFree);

		// No more blocks, then last block has been freed
		if (!this->block) DQN_ASSERT_HARD(this->tempRegionCount == 0);
		return true;
	}

	return false;
}

DQN_FILE_SCOPE bool DqnMemStack::FreeLastBlock()
{
	bool result = this->FreeMemBlock(this->block);
	return result;
}

DQN_FILE_SCOPE void DqnMemStack::ClearCurrBlock(bool const zeroClear)
{
	if (this->block)
	{
		this->block->used = 0;
		if (zeroClear)
		{
			DqnMem_Clear(this->block->memory, 0, this->block->size);
		}
	}
}

////////////////////////////////////////////////////////////////////////////////
// #DqnMemStackTempRegion Implementation
////////////////////////////////////////////////////////////////////////////////
DQN_FILE_SCOPE DqnMemStackTempRegion DqnMemStack::TempRegionBegin()
{
	DqnMemStackTempRegion result;
	result.stack         = this;
	result.startingBlock = this->block;
	result.used          = this->block->used;
	this->tempRegionCount++;

	return result;
}

DQN_FILE_SCOPE void DqnMemStack::TempRegionEnd(DqnMemStackTempRegion region)
{
	DqnMemStack *stack = region.stack;
	DQN_ASSERT(stack == this);

	while (this->block != region.startingBlock)
		this->FreeLastBlock();

	if (this->block)
	{
		DQN_ASSERT_HARD(this->block->used >= region.used);
		this->block->used = region.used;
	}

	this->tempRegionCount--;
	DQN_ASSERT_HARD(this->tempRegionCount >= 0);
}

DqnMemStackTempRegionGuard DqnMemStack::TempRegionGuard()
{
	return DqnMemStackTempRegionGuard(this);
}

DqnMemStackTempRegionGuard::DqnMemStackTempRegionGuard(DqnMemStack *const stack)
{
	this->memRegion = stack->TempRegionBegin();
}

DqnMemStackTempRegionGuard::~DqnMemStackTempRegionGuard()
{
	const DqnMemStackTempRegion &region = this->memRegion;
	DqnMemStack *const stack            = region.stack;
	stack->TempRegionEnd(region);
}

////////////////////////////////////////////////////////////////////////////////
// #DqnMemStack Advanced API Implementation
////////////////////////////////////////////////////////////////////////////////
DQN_FILE_SCOPE DqnMemStack::Block *DqnMemStack::AllocateCompatibleBlock(size_t size,
                                                                        bool const zeroClear)
{
	if (this->flags & DqnMemStack::Flag::IsFixedMemoryFromUser) return nullptr;
	if (this->flags & DqnMemStack::Flag::IsNotExpandable)       return nullptr;

	DqnMemStack::Block *memBlock =
	    DqnMemStackInternal_AllocateBlock(this->byteAlign, size, zeroClear, this->memAPI);
	return memBlock;
}

DQN_FILE_SCOPE bool DqnMemStack::AttachBlock(DqnMemStack::Block *const newBlock)
{
	if (!newBlock) return false;
	if (this->flags & DqnMemStack::Flag::IsFixedMemoryFromUser) return false;
	if (this->flags & DqnMemStack::Flag::IsNotExpandable)       return false;

	newBlock->prevBlock = this->block;
	this->block         = newBlock;
	return true;
}

DQN_FILE_SCOPE bool DqnMemStack::DetachBlock(DqnMemStack::Block *const detachBlock)
{
	if (!detachBlock) return false;
	if (this->flags & DqnMemStack::Flag::IsFixedMemoryFromUser) return false;
	if (this->flags & DqnMemStack::Flag::IsNotExpandable)       return false;

	DqnMemStack::Block **blockPtr = &this->block;
	while (*blockPtr && *blockPtr != detachBlock)
		blockPtr = &((*blockPtr)->prevBlock);

	if (*blockPtr)
	{
		*blockPtr = detachBlock->prevBlock;
		detachBlock->prevBlock = nullptr;
	}
	else
	{
		return false;
	}

	return true;
}

DQN_FILE_SCOPE void DqnMemStack::FreeDetachedBlock(DqnMemStack::Block *memBlock)
{
	if (!memBlock) return;
	DqnMem_Free(memBlock);
}

////////////////////////////////////////////////////////////////////////////////
// #DqnHash Implementation
////////////////////////////////////////////////////////////////////////////////
// Taken from GingerBill single file library @ github.com/gingerbill/gb
u32 DqnHash_Murmur32Seed(void const *data, size_t len, u32 seed)
{
	u32 const c1 = 0xcc9e2d51; u32 const c2 = 0x1b873593; u32 const r1 = 15;
	u32 const r2 = 13; u32 const m  = 5; u32 const n  = 0xe6546b64;

	size_t i, nblocks = len / 4;
	u32 hash = seed, k1 = 0;
	u32 const *blocks = (u32 const *)data;
	u8 const *tail    = (u8 const *)(data) + nblocks * 4;

	for (i = 0; i < nblocks; i++) {
		u32 k = blocks[i];
		k *= c1;
		k = (k << r1) | (k >> (32 - r1));
		k *= c2;

		hash ^= k;
		hash = ((hash << r2) | (hash >> (32 - r2))) * m + n;
	}

	switch (len & 3) {
	case 3: k1 ^= tail[2] << 16;
	case 2: k1 ^= tail[1] << 8;
	case 1: k1 ^= tail[0];

		k1 *= c1;
		k1 = (k1 << r1) | (k1 >> (32 - r1));
		k1 *= c2;
		hash ^= k1;
	}

	hash ^= len;        hash ^= (hash >> 16);
	hash *= 0x85ebca6b; hash ^= (hash >> 13);
	hash *= 0xc2b2ae35; hash ^= (hash >> 16);

	return hash;
}

u64 DqnHash_Murmur64Seed(void const *data_, size_t len, u64 seed)
{
	u64 const m = 0xc6a4a7935bd1e995ULL;
	i32 const r = 47;

	u64 h = seed ^ (len * m);

	u64 const *data = (u64 const *)data_;
	u8 const *data2 = (u8 const *)data_;
	u64 const *end  = data + (len / 8);

	while (data != end) {
		u64 k = *data++;
		k *= m; k ^= k >> r; k *= m;
		h ^= k; h *= m;
	}

	switch (len & 7) {
	case 7: h ^= (u64)(data2[6]) << 48;
	case 6: h ^= (u64)(data2[5]) << 40;
	case 5: h ^= (u64)(data2[4]) << 32;
	case 4: h ^= (u64)(data2[3]) << 24;
	case 3: h ^= (u64)(data2[2]) << 16;
	case 2: h ^= (u64)(data2[1]) << 8;
	case 1: h ^= (u64)(data2[0]);
		h *= m;
	};

	h ^= h >> r; h *= m; h ^= h >> r;
	return h;
}

////////////////////////////////////////////////////////////////////////////////
// #DqnMath Implementation
////////////////////////////////////////////////////////////////////////////////
DQN_FILE_SCOPE f32 DqnMath_Lerp(f32 a, f32 t, f32 b)
{
	/*
	    Linear blend between two values. We having a starting point "a", and
	    the distance to "b" is defined as (b - a). Then we can say

	    a + t(b - a)

	    As our linear blend fn. We start from "a" and choosing a t from 0->1
	    will vary the value of (b - a) towards b. If we expand this, this
	    becomes

	    a + (t * b) - (a * t) == (1 - t)a + t*b
	*/
	f32 result =  a + (b - a) * t;
	return result;
}

DQN_FILE_SCOPE f32 DqnMath_Sqrtf(f32 a)
{
	f32 result = sqrtf(a);
	return result;
}

DQN_FILE_SCOPE f32 DqnMath_Clampf(f32 val, f32 min, f32 max)
{
	if (val < min) return min;
	if (val > max) return max;
	return val;
}

////////////////////////////////////////////////////////////////////////////////
// #DqnV2 Implementation
////////////////////////////////////////////////////////////////////////////////
DQN_FILE_SCOPE DqnV2 DqnV2_(f32 xy)
{
	DqnV2 result = {xy, xy};
	return result;
}

DQN_FILE_SCOPE DqnV2 DqnV2_(f32 x, f32 y)
{
	DqnV2 result = {x, y};
	return result;
}

DQN_FILE_SCOPE DqnV2 DqnV2_(i32 x, i32 y)
{
	DqnV2 result = {(f32)x, (f32)y};
	return result;
}

DQN_FILE_SCOPE DqnV2 DqnV2_(DqnV2i a)
{
	DqnV2 result = {(f32)a.x, (f32)a.y};
	return result;
}

////////////////////////////////////////////////////////////////////////////////
// #DqnV2 Arithmetic Implementation
////////////////////////////////////////////////////////////////////////////////
DQN_FILE_SCOPE DqnV2 DqnV2_Add(DqnV2 a, DqnV2 b)
{
	DqnV2 result = {};
	for (u32 i = 0; i < DQN_ARRAY_COUNT(a.e); i++)
		result.e[i] = a.e[i] + b.e[i];

	return result;
}

DQN_FILE_SCOPE DqnV2 DqnV2_Sub(DqnV2 a, DqnV2 b)
{
	DqnV2 result = {};
	for (u32 i = 0; i < DQN_ARRAY_COUNT(a.e); i++)
		result.e[i] = a.e[i] - b.e[i];

	return result;
}

DQN_FILE_SCOPE DqnV2 DqnV2_Scalei(DqnV2 a, i32 b)
{
	DqnV2 result = {};
	for (u32 i = 0; i < DQN_ARRAY_COUNT(a.e); i++)
		result.e[i] = a.e[i] * b;

	return result;
}

DQN_FILE_SCOPE DqnV2 DqnV2_Scalef(DqnV2 a, f32 b)
{
	DqnV2 result = {};
	for (u32 i = 0; i < DQN_ARRAY_COUNT(a.e); i++)
		result.e[i] = a.e[i] * b;

	return result;
}

DQN_FILE_SCOPE DqnV2 DqnV2_Hadamard(DqnV2 a, DqnV2 b)
{
	DqnV2 result = {};
	for (u32 i = 0; i < DQN_ARRAY_COUNT(a.e); i++)
		result.e[i] = a.e[i] * b.e[i];

	return result;
}

DQN_FILE_SCOPE f32 DqnV2_Dot(DqnV2 a, DqnV2 b)
{
	/*
	   DOT PRODUCT
	   Two vectors with dot product equals |a||b|cos(theta)
	   |a|   |d|
	   |b| . |e| = (ad + be + cf)
	   |c|   |f|
	 */
	f32 result = 0;
	for (u32 i = 0; i < DQN_ARRAY_COUNT(a.e); i++)
		result += (a.e[i] * b.e[i]);

	return result;
}

DQN_FILE_SCOPE bool DqnV2_Equals(DqnV2 a, DqnV2 b)
{
	bool result = true;
	for (u32 i = 0; i < DQN_ARRAY_COUNT(a.e); i++)
		if (a.e[i] != b.e[i]) result = false;
	return result;
}

DQN_FILE_SCOPE f32 DqnV2_LengthSquared(const DqnV2 a, const DqnV2 b)
{
	f32 x_     = b.x - a.x;
	f32 y_     = b.y - a.y;
	f32 result = (DQN_SQUARED(x_) + DQN_SQUARED(y_));
	return result;
}

DQN_FILE_SCOPE f32 DqnV2_Length(const DqnV2 a, const DqnV2 b)
{
	f32 lengthSq = DqnV2_LengthSquared(a, b);
	if (lengthSq == 0) return 0;

	f32 result = DqnMath_Sqrtf(lengthSq);
	return result;
}

DQN_FILE_SCOPE DqnV2 DqnV2_Normalise(const DqnV2 a)
{
	f32 magnitude = DqnV2_Length(DqnV2_(0, 0), a);
	if (magnitude == 0) return DqnV2_(0.0f);

	DqnV2 result = a * (1.0f / magnitude);
	return result;
}

DQN_FILE_SCOPE bool DqnV2_Overlaps(DqnV2 a, DqnV2 b)
{
	bool result = false;

	f32 lenOfA = a.max - a.min;
	f32 lenOfB = b.max - b.min;

	if (lenOfA > lenOfB)
	{
		DqnV2 tmp = a;
		a         = b;
		b         = tmp;
	}

	if ((a.min >= b.min && a.min <= b.max) || (a.max >= b.min && a.max <= b.max))
	{
		result = true;
	}

	return result;
}

DQN_FILE_SCOPE DqnV2 DqnV2_Perpendicular(const DqnV2 a)
{
	DqnV2 result = DqnV2_(a.y, -a.x);
	return result;
}

DQN_FILE_SCOPE DqnV2 DqnV2_ResizeKeepAspectRatio(DqnV2 srcSize, DqnV2 targetSize)
{
	f32 ratioA   = srcSize.w / targetSize.w;
	f32 ratioB   = srcSize.h / targetSize.h;
	f32 ratio    = DQN_MIN(ratioA, ratioB);
	DqnV2 result = DqnV2_Scalef(targetSize, ratio);
	return result;
}

DQN_FILE_SCOPE DqnV2 DqnV2_ConstrainToRatio(DqnV2 dim, DqnV2 ratio)
{
	DqnV2 result                  = {0};
	f32 numRatioIncrementsToWidth  = (f32)(dim.w / ratio.w);
	f32 numRatioIncrementsToHeight = (f32)(dim.h / ratio.h);

	f32 leastIncrementsToSide =
	    DQN_MIN(numRatioIncrementsToHeight, numRatioIncrementsToWidth);

	result.w = (f32)(ratio.w * leastIncrementsToSide);
	result.h = (f32)(ratio.h * leastIncrementsToSide);
	return result;
}

////////////////////////////////////////////////////////////////////////////////
// #DqnV2i Implementation
////////////////////////////////////////////////////////////////////////////////
DQN_FILE_SCOPE DqnV2i DqnV2i_(i32 x, i32 y)
{
	DqnV2i result = {x, y};
	return result;
}

DQN_FILE_SCOPE DqnV2i DqnV2i_(f32 x, f32 y)
{
	DqnV2i result = {(i32)x, (i32)y};
	return result;
}

DQN_FILE_SCOPE DqnV2i DqnV2i_(DqnV2 a)
{
	DqnV2i result = {(i32)a.x, (i32)a.y};
	return result;
}

DQN_FILE_SCOPE DqnV2i DqnV2i_Add(DqnV2i a, DqnV2i b)
{
	DqnV2i result = {0};
	for (u32 i = 0; i < DQN_ARRAY_COUNT(a.e); i++)
		result.e[i] = a.e[i] + b.e[i];

	return result;
}

DQN_FILE_SCOPE DqnV2i DqnV2i_Sub(DqnV2i a, DqnV2i b)
{
	DqnV2i result = {0};
	for (u32 i = 0; i < DQN_ARRAY_COUNT(a.e); i++)
		result.e[i] = a.e[i] - b.e[i];

	return result;
}

DQN_FILE_SCOPE DqnV2i DqnV2i_Scalef(DqnV2i a, f32 b)
{
	DqnV2i result = {0};
	for (u32 i = 0; i < DQN_ARRAY_COUNT(a.e); i++)
		result.e[i] = (i32)(a.e[i] * b);

	return result;
}

DQN_FILE_SCOPE DqnV2i DqnV2i_Scalei(DqnV2i a, i32 b)
{
	DqnV2i result = {0};
	for (u32 i = 0; i < DQN_ARRAY_COUNT(a.e); i++)
		result.e[i] = a.e[i] * b;

	return result;
}

DQN_FILE_SCOPE DqnV2i DqnV2i_Hadamard(DqnV2i a, DqnV2i b)
{
	DqnV2i result = {0};
	for (u32 i = 0; i < DQN_ARRAY_COUNT(a.e); i++)
		result.e[i] = a.e[i] * b.e[i];

	return result;
}

DQN_FILE_SCOPE f32 DqnV2i_Dot(DqnV2i a, DqnV2i b)
{
	/*
	   DOT PRODUCT
	   Two vectors with dot product equals |a||b|cos(theta)
	   |a|   |d|
	   |b| . |e| = (ad + be + cf)
	   |c|   |f|
	 */
	f32 result = 0;
	for (u32 i = 0; i < DQN_ARRAY_COUNT(a.e); i++)
		result += (a.e[i] * b.e[i]);

	return result;
}

DQN_FILE_SCOPE bool DqnV2i_Equals(DqnV2i a, DqnV2i b)
{
	bool result = true;
	for (u32 i = 0; i < DQN_ARRAY_COUNT(a.e); i++)
		if (a.e[i] != b.e[i]) result = false;
	return result;
}

////////////////////////////////////////////////////////////////////////////////
// #DqnV3 Implementation
////////////////////////////////////////////////////////////////////////////////
DQN_FILE_SCOPE DqnV3 DqnV3_(f32 xyz)
{
	DqnV3 result = {xyz, xyz, xyz};
	return result;
}

DQN_FILE_SCOPE DqnV3 DqnV3_(f32 x, f32 y, f32 z)
{
	DqnV3 result = {x, y, z};
	return result;
}

DQN_FILE_SCOPE DqnV3 DqnV3_(i32 x, i32 y, i32 z)
{
	DqnV3 result = {(f32)x, (f32)y, (f32)z};
	return result;
}

DQN_FILE_SCOPE DqnV3 DqnV3_Add(DqnV3 a, DqnV3 b)
{
	DqnV3 result = {0};
	for (u32 i = 0; i < DQN_ARRAY_COUNT(a.e); i++)
		result.e[i] = a.e[i] + b.e[i];

	return result;
}

DQN_FILE_SCOPE DqnV3 DqnV3_Sub(DqnV3 a, DqnV3 b)
{
	DqnV3 result = {0};
	for (u32 i = 0; i < DQN_ARRAY_COUNT(a.e); i++)
		result.e[i] = a.e[i] - b.e[i];

	return result;
}

DQN_FILE_SCOPE DqnV3 DqnV3_Scalei(DqnV3 a, i32 b)
{
	DqnV3 result = {0};
	for (u32 i = 0; i < DQN_ARRAY_COUNT(a.e); i++)
		result.e[i] = a.e[i] * b;

	return result;
}

DQN_FILE_SCOPE DqnV3 DqnV3_Scalef(DqnV3 a, f32 b)
{
	DqnV3 result = {0};
	for (u32 i = 0; i < DQN_ARRAY_COUNT(a.e); i++)
		result.e[i] = a.e[i] * b;

	return result;
}

DQN_FILE_SCOPE DqnV3 DqnV3_Hadamard(DqnV3 a, DqnV3 b)
{
	DqnV3 result = {0};
	for (u32 i = 0; i < DQN_ARRAY_COUNT(a.e); i++)
		result.e[i] = a.e[i] * b.e[i];

	return result;
}

DQN_FILE_SCOPE f32 DqnV3_Dot(DqnV3 a, DqnV3 b)
{
	/*
	   DOT PRODUCT
	   Two vectors with dot product equals |a||b|cos(theta)
	   |a|   |d|
	   |b| . |e| = (ad + be + cf)
	   |c|   |f|
	 */
	f32 result = 0;
	for (u32 i = 0; i < DQN_ARRAY_COUNT(a.e); i++)
		result += (a.e[i] * b.e[i]);

	return result;
}

DQN_FILE_SCOPE bool DqnV3_Equals(DqnV3 a, DqnV3 b)
{
	bool result = true;
	for (u32 i = 0; i < DQN_ARRAY_COUNT(a.e); i++)
		if (a.e[i] != b.e[i]) result = false;
	return result;
}

DQN_FILE_SCOPE DqnV3 DqnV3_Cross(DqnV3 a, DqnV3 b)
{
	/*
	   CROSS PRODUCT
	   Generate a perpendicular vector to the 2 vectors
	   |a|   |d|   |bf - ce|
	   |b| x |e| = |cd - af|
	   |c|   |f|   |ae - be|
	 */
	DqnV3 result = {0};
	result.e[0] = (a.e[1] * b.e[2]) - (a.e[2] * b.e[1]);
	result.e[1] = (a.e[2] * b.e[0]) - (a.e[0] * b.e[2]);
	result.e[2] = (a.e[0] * b.e[1]) - (a.e[1] * b.e[0]);
	return result;
}

DQN_FILE_SCOPE DqnV3 DqnV3_Normalise(DqnV3 a)
{
	f32 length    = DqnMath_Sqrtf(DQN_SQUARED(a.x) + DQN_SQUARED(a.y) + DQN_SQUARED(a.z));
	f32 invLength = 1 / length;
	DqnV3 result  = a * invLength;

	return result;
}

DQN_FILE_SCOPE f32 DqnV3_LengthSquared(DqnV3 a, DqnV3 b)
{
	f32 x      = b.x - a.x;
	f32 y      = b.y - a.y;
	f32 z      = b.z - a.z;
	f32 result = (DQN_SQUARED(x) + DQN_SQUARED(y) + DQN_SQUARED(z));
	return result;
}

DQN_FILE_SCOPE f32 DqnV3_Length(DqnV3 a, DqnV3 b)
{
	f32 lengthSq = DqnV3_LengthSquared(a, b);
	if (lengthSq == 0) return 0;

	f32 result = DqnMath_Sqrtf(lengthSq);
	return result;
}

////////////////////////////////////////////////////////////////////////////////
// #DqnV3i Implementation
////////////////////////////////////////////////////////////////////////////////
DQN_FILE_SCOPE DqnV3i DqnV3i_(i32 x, i32 y, i32 z)
{
	DqnV3i result = {x, y, z};
	return result;
}

DQN_FILE_SCOPE DqnV3i DqnV3i_(f32 x, f32 y, f32 z)
{
	DqnV3i result = {(i32)x, (i32)y, (i32)z};
	return result;
}

////////////////////////////////////////////////////////////////////////////////
// #DqnV4 Implementation
////////////////////////////////////////////////////////////////////////////////
DQN_FILE_SCOPE DqnV4 DqnV4_(f32 xyzw)
{
	DqnV4 result = {xyzw, xyzw, xyzw, xyzw};
	return result;
}

DQN_FILE_SCOPE DqnV4 DqnV4_(f32 x, f32 y, f32 z, f32 w)
{
	DqnV4 result = {x, y, z, w};
	return result;
}

DQN_FILE_SCOPE DqnV4 DqnV4_(i32 x, i32 y, i32 z, i32 w)
{
	DqnV4 result = {(f32)x, (f32)y, (f32)z, (f32)w};
	return result;
}

DQN_FILE_SCOPE DqnV4 DqnV4_(DqnV3 a, f32 w)
{
	DqnV4 result = {a.x, a.y, a.z, w};
	return result;
}

////////////////////////////////////////////////////////////////////////////////
// #DqnV4 Arithmetic Implementation
////////////////////////////////////////////////////////////////////////////////
DQN_FILE_SCOPE DqnV4 DqnV4_Add(DqnV4 a, DqnV4 b)
{
	DqnV4 result = {0};
	for (u32 i = 0; i < DQN_ARRAY_COUNT(a.e); i++)
		result.e[i] = a.e[i] + b.e[i];

	return result;
}

DQN_FILE_SCOPE DqnV4 DqnV4_Sub(DqnV4 a, DqnV4 b)
{
	DqnV4 result = {0};
	for (u32 i = 0; i < DQN_ARRAY_COUNT(a.e); i++)
		result.e[i] = a.e[i] - b.e[i];

	return result;
}

DQN_FILE_SCOPE DqnV4 DqnV4_Scalei(DqnV4 a, i32 b)
{
	DqnV4 result = {0};
	for (u32 i = 0; i < DQN_ARRAY_COUNT(a.e); i++)
		result.e[i] = a.e[i] * b;

	return result;
}

DQN_FILE_SCOPE DqnV4 DqnV4_Scalef(DqnV4 a, f32 b)
{
	DqnV4 result = {0};
	for (u32 i = 0; i < DQN_ARRAY_COUNT(a.e); i++)
		result.e[i] = a.e[i] * b;

	return result;
}

DQN_FILE_SCOPE DqnV4 DqnV4_Hadamard(DqnV4 a, DqnV4 b)
{
	DqnV4 result = {0};
	for (u32 i = 0; i < DQN_ARRAY_COUNT(a.e); i++)
		result.e[i] = a.e[i] * b.e[i];

	return result;
}

DQN_FILE_SCOPE f32 DqnV4_Dot(DqnV4 a, DqnV4 b)
{
	/*
	   DOT PRODUCT
	   Two vectors with dot product equals |a||b|cos(theta)
	   |a|   |d|
	   |b| . |e| = (ad + be + cf)
	   |c|   |f|
	 */
	f32 result = 0;
	for (u32 i = 0; i < DQN_ARRAY_COUNT(a.e); i++)
		result += (a.e[i] * b.e[i]);

	return result;
}

DQN_FILE_SCOPE bool DqnV4_Equals(DqnV4 a, DqnV4 b)
{
	bool result = true;
	for (u32 i = 0; i < DQN_ARRAY_COUNT(a.e); i++)
		if (a.e[i] != b.e[i]) result = false;
	return result;
}

////////////////////////////////////////////////////////////////////////////////
// #DqnMat4 Implementation
////////////////////////////////////////////////////////////////////////////////
DQN_FILE_SCOPE DqnMat4 DqnMat4_Identity()
{
	DqnMat4 result = {0, 0, 0, 0};
	result.e[0][0] = 1;
	result.e[1][1] = 1;
	result.e[2][2] = 1;
	result.e[3][3] = 1;
	return result;
}

DQN_FILE_SCOPE DqnMat4 DqnMat4_Orthographic(f32 left, f32 right, f32 bottom, f32 top, f32 zNear,
                                            f32 zFar)
{
	DqnMat4 result = DqnMat4_Identity();
	result.e[0][0] = +2.0f / (right - left);
	result.e[1][1] = +2.0f / (top   - bottom);
	result.e[2][2] = -2.0f / (zFar  - zNear);

	result.e[3][0] = -(right + left)   / (right - left);
	result.e[3][1] = -(top   + bottom) / (top   - bottom);
	result.e[3][2] = -(zFar  + zNear)  / (zFar  - zNear);

	return result;
}

DQN_FILE_SCOPE DqnMat4 DqnMat4_Perspective(f32 fovYDegrees, f32 aspectRatio, f32 zNear, f32 zFar)
{
	f32 fovYRadians         = DQN_DEGREES_TO_RADIANS(fovYDegrees);
	f32 fovYRadiansOver2    = fovYRadians * 0.5f;
	f32 tanFovYRadiansOver2 = tanf(fovYRadiansOver2);
	f32 zNearSubZFar        = zNear - zFar;

	DqnMat4 result = DqnMat4_Identity();
	result.e[0][0] = 1.0f / (aspectRatio * tanFovYRadiansOver2);
	result.e[1][1] = 1.0f / tanFovYRadiansOver2;
	result.e[2][2] = (zNear + zFar) / zNearSubZFar;
	result.e[2][3] = -1.0f;
	result.e[3][2] = (2.0f * zNear * zFar) / zNearSubZFar;
	result.e[3][3] = 0.0f;

	return result;
}

DQN_FILE_SCOPE DqnMat4 DqnMat4_LookAt(DqnV3 eye, DqnV3 center, DqnV3 up)
{
	DqnMat4 result = {0, 0, 0, 0};

	DqnV3 f = DqnV3_Normalise(DqnV3_Sub(eye, center));
	DqnV3 s = DqnV3_Normalise(DqnV3_Cross(up, f));
	DqnV3 u = DqnV3_Cross(f, s);

	result.e[0][0] = s.x;
	result.e[0][1] = u.x;
	result.e[0][2] = -f.x;

	result.e[1][0] = s.y;
	result.e[1][1] = u.y;
	result.e[1][2] = -f.y;

	result.e[2][0] = s.z;
	result.e[2][1] = u.z;
	result.e[2][2] = -f.z;

	result.e[3][0] = -DqnV3_Dot(s, eye);
	result.e[3][1] = -DqnV3_Dot(u, eye);
	result.e[3][2] = DqnV3_Dot(f, eye);
	result.e[3][3] = 1.0f;
	return result;
}

DQN_FILE_SCOPE DqnMat4 DqnMat4_Translate3f(f32 x, f32 y, f32 z)
{
	DqnMat4 result = DqnMat4_Identity();
	result.e[3][0] = x;
	result.e[3][1] = y;
	result.e[3][2] = z;
	return result;
}

DQN_FILE_SCOPE DqnMat4 DqnMat4_TranslateV3(DqnV3 vec)
{
	DqnMat4 result = DqnMat4_Identity();
	result.e[3][0] = vec.x;
	result.e[3][1] = vec.y;
	result.e[3][2] = vec.z;
	return result;
}

DQN_FILE_SCOPE DqnMat4 DqnMat4_Rotate(f32 radians, f32 x, f32 y, f32 z)
{
	DqnMat4 result     = DqnMat4_Identity();
	f32 sinVal         = sinf(radians);
	f32 cosVal         = cosf(radians);
	f32 oneMinusCosVal = 1 - cosVal;

	DqnV3 axis = DqnV3_Normalise(DqnV3_(x, y, z));

	result.e[0][0] = (axis.x * axis.x * oneMinusCosVal) + cosVal;
	result.e[0][1] = (axis.x * axis.y * oneMinusCosVal) + (axis.z * sinVal);
	result.e[0][2] = (axis.x * axis.z * oneMinusCosVal) - (axis.y * sinVal);

	result.e[1][0] = (axis.y * axis.x * oneMinusCosVal) - (axis.z * sinVal);
	result.e[1][1] = (axis.y * axis.y * oneMinusCosVal) + cosVal;
	result.e[1][2] = (axis.y * axis.z * oneMinusCosVal) + (axis.x * sinVal);

	result.e[2][0] = (axis.z * axis.x * oneMinusCosVal) + (axis.y * sinVal);
	result.e[2][1] = (axis.z * axis.y * oneMinusCosVal) - (axis.x * sinVal);
	result.e[2][2] = (axis.z * axis.z * oneMinusCosVal) + cosVal;

	return result;
}

DQN_FILE_SCOPE DqnMat4 DqnMat4_Scale(f32 x, f32 y, f32 z)
{
	DqnMat4 result = {0, 0, 0, 0};
	result.e[0][0] = x;
	result.e[1][1] = y;
	result.e[2][2] = z;
	result.e[3][3] = 1;
	return result;
}

DQN_FILE_SCOPE DqnMat4 DqnMat4_ScaleV3(DqnV3 scale)
{
	DqnMat4 result = {0, 0, 0, 0};
	result.e[0][0] = scale.x;
	result.e[1][1] = scale.y;
	result.e[2][2] = scale.z;
	result.e[3][3] = 1;
	return result;
}

DQN_FILE_SCOPE DqnMat4 DqnMat4_Mul(DqnMat4 a, DqnMat4 b)
{
	DqnMat4 result = {0};
	for (u32 j = 0; j < 4; j++) {
		for (u32 i = 0; i < 4; i++)
		{
			result.e[j][i] = a.e[0][i] * b.e[j][0]
			               + a.e[1][i] * b.e[j][1]
			               + a.e[2][i] * b.e[j][2]
			               + a.e[3][i] * b.e[j][3];
		}
	}

	return result;
}

DQN_FILE_SCOPE DqnV4 DqnMat4_MulV4(DqnMat4 a, DqnV4 b)
{
	DqnV4 result = {0};
	result.x = (a.e[0][0] * b.x) + (a.e[1][0] * b.y) + (a.e[2][0] * b.z) + (a.e[3][0] * b.w);
	result.y = (a.e[0][1] * b.x) + (a.e[1][1] * b.y) + (a.e[2][1] * b.z) + (a.e[3][1] * b.w);
	result.z = (a.e[0][2] * b.x) + (a.e[1][2] * b.y) + (a.e[2][2] * b.z) + (a.e[3][2] * b.w);
	result.w = (a.e[0][3] * b.x) + (a.e[1][3] * b.y) + (a.e[2][3] * b.z) + (a.e[3][3] * b.w);

	return result;
}

////////////////////////////////////////////////////////////////////////////////
// #DqnRect Implementation
////////////////////////////////////////////////////////////////////////////////
DQN_FILE_SCOPE DqnRect DqnRect_(DqnV2 origin, DqnV2 size)
{
	DqnRect result;
	result.min = origin;
	result.max = result.min + size;

	DQN_ASSERT_HARD(result.min <= result.max);
	return result;
}

DQN_FILE_SCOPE DqnRect DqnRect_(f32 x, f32 y, f32 w, f32 h)
{
	DqnRect result;
	result.min = DqnV2_(x, y);
	result.max = DqnV2_(x + w, y + h);

	DQN_ASSERT_HARD(result.min <= result.max);
	return result;
}

DQN_FILE_SCOPE DqnRect DqnRect_(i32 x, i32 y, i32 w, i32 h)
{
	DqnRect result;
	result.min = DqnV2_(x, y);
	result.max = DqnV2_(x + w, y + h);

	DQN_ASSERT_HARD(result.min <= result.max);
	return result;
}

void DqnRect::GetSize(f32 *const width, f32 *const height) const
{
	DQN_ASSERT_HARD(this->min <= this->max);
	if (width) *width   = this->max.x - this->min.x;
	if (height) *height = this->max.y - this->min.y;
}

DqnV2 DqnRect::GetCenter() const
{
	DQN_ASSERT_HARD(this->min <= this->max);
	f32 sumX     = this->min.x + this->max.x;
	f32 sumY     = this->min.y + this->max.y;
	DqnV2 result = DqnV2_(sumX, sumY) * 0.5f;
	return result;
}

DqnRect DqnRect::ClipRect(const DqnRect clip) const
{
	DQN_ASSERT_HARD(this->min <= this->max);
	DQN_ASSERT_HARD(clip.min <= clip.max);
	DqnRect result = *this;

	DqnV2 clipSize = clip.GetSize();
	if (clip.min.x > this->min.x && clip.min.x < this->max.x)
	{
		if (clip.min.y > this->min.y && clip.min.y < this->max.y)
		{
			result.min = clip.min;
		}
		else if (clip.max.y > this->min.y)
		{
			result.min.x = clip.min.x;
		}
	}

	if (clip.max.x > this->min.x && clip.max.x < this->max.x)
	{
		if (clip.max.y > this->min.y && clip.max.y < this->max.y)
		{
			result.max = clip.max;
		}
		else if (clip.min.y < this->max.y)
		{
			result.max.x = clip.max.x;
		}
	}

	return result;
}

DqnRect DqnRect::Move(const DqnV2 shift) const
{
	DQN_ASSERT_HARD(this->min <= this->max);

	DqnRect result;
	result.min = this->min + shift;
	result.max = this->max + shift;
	return result;
}

bool DqnRect::ContainsP(const DqnV2 p) const
{
	DQN_ASSERT_HARD(this->min <= this->max);

	bool outsideOfRectX = false;
	if (p.x < this->min.x || p.x > this->max.w)
		outsideOfRectX = true;

	bool outsideOfRectY = false;
	if (p.y < this->min.y || p.y > this->max.h)
		outsideOfRectY = true;

	if (outsideOfRectX || outsideOfRectY) return false;

	return true;
}

////////////////////////////////////////////////////////////////////////////////
// #DqnChar Implementation
////////////////////////////////////////////////////////////////////////////////
DQN_FILE_SCOPE char DqnChar_ToLower(char c)
{
	if (c >= 'A' && c <= 'Z')
	{
		i32 shiftOffset = 'a' - 'A';
		return (c + (char)shiftOffset);
	}
	return c;
}

DQN_FILE_SCOPE char DqnChar_ToUpper(char c)
{
	if (c >= 'a' && c <= 'z')
	{
		i32 shiftOffset = 'a' - 'A';
		return (c - (char)shiftOffset);
	}
	return c;
}


DQN_FILE_SCOPE bool DqnChar_IsDigit(char c)
{
	if (c >= '0' && c <= '9') return true;
	return false;
}

DQN_FILE_SCOPE bool DqnChar_IsAlpha(char c)
{
	if ((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z')) return true;
	return false;
}

DQN_FILE_SCOPE bool DqnChar_IsAlphaNum(char c)
{
	if (DqnChar_IsAlpha(c) || DqnChar_IsDigit(c)) return true;
	return false;
}

DQN_FILE_SCOPE char *DqnChar_SkipWhitespace(char *ptr)
{
	while (ptr && (*ptr == ' ' || *ptr == '\r' || *ptr == '\n')) ptr++;
	return ptr;
}

DQN_FILE_SCOPE char *DqnChar_FindLastChar(char *ptr, const char ch, i32 len, u32 *const lenToChar)
{
	for (i32 i = len - 1; i >= 0; i--)
	{
		if (ptr[i] == ch)
		{
			if (lenToChar) *lenToChar = (u32)len - i;
			return &ptr[i];
		}
	}

	return nullptr;
}

DQN_FILE_SCOPE i32 DqnChar_GetNextLine(char *ptr, i32 *lineLength)
{
	i32 len = 0;
	ptr     = DqnChar_SkipWhitespace(ptr);

	// Advance pointer to first new line
	while (ptr && *ptr != 0 && *ptr != '\r' && *ptr != '\n')
	{
		ptr++;
		len++;
	}

	if (!ptr || *ptr == 0)
	{
		if (lineLength) *lineLength = len;
		return -1;
	}

	// Destroy all new lines
	i32 extraChars = 0;
	while (ptr && (*ptr == '\r' || *ptr == '\n' || *ptr == ' '))
	{
		*ptr = 0;
		ptr++;
		extraChars++;
	}

	if (lineLength) *lineLength = len;
	return len + extraChars;
}

////////////////////////////////////////////////////////////////////////////////
// #DqnStr Implementation
////////////////////////////////////////////////////////////////////////////////
DQN_FILE_SCOPE i32 DqnStr_Cmp(const char *const a, const char *const b, i32 numBytesToCompare, bool ignoreCase)
{
	if (!a && !b)               return -1;
	if (!a)                     return -1;
	if (!b)                     return -1;
	if (numBytesToCompare == 0) return -1;

	i32 bytesCompared = 0;
	char const *aPtr = a;
	char const *bPtr = b;

	if (ignoreCase)
	{
		while (DqnChar_ToLower((*aPtr)) == DqnChar_ToLower((*bPtr)))
		{
			if (!(*aPtr)) return 0;
			bytesCompared++;
			aPtr++;
			bPtr++;

			if (bytesCompared == numBytesToCompare) return 0;
		}
	}
	else
	{
		while ((*aPtr) == (*bPtr))
		{
			if (!(*aPtr)) return 0;
			bytesCompared++;
			aPtr++;
			bPtr++;

			if (bytesCompared == numBytesToCompare) return 0;
		}
	}

	return (((*aPtr) < (*bPtr)) ? -1 : 1);
}

DQN_FILE_SCOPE i32 DqnStr_Len(const char *const a)
{
	i32 result = 0;
	while (a && a[result]) result++;

	return result;
}

DQN_FILE_SCOPE i32 DqnStr_LenUTF8(const u32 *const a, i32 *const lenInBytes)
{
	i32 utf8Len        = 0;
	i32 utf8LenInBytes = 0;
	u8 *bytePtr        = (u8 *)a;
	while (true)
	{
		u32 codepoint           = 0;
		i32 numBytesInCodepoint = DqnStr_ReadUTF8Codepoint((u32 *)bytePtr, &codepoint);

		if (numBytesInCodepoint == 0) break;
		utf8Len++;
		bytePtr        += numBytesInCodepoint;
		utf8LenInBytes += numBytesInCodepoint;
	}

	if (lenInBytes) *lenInBytes = utf8LenInBytes;
	return utf8Len;
}

DQN_FILE_SCOPE i32 DqnStr_LenDelimitWith(const char *a, const char delimiter)
{
	i32 result = 0;
	while (a && a[result] && a[result] != delimiter) result++;
	return result;
}

DQN_FILE_SCOPE char *DqnStr_Copy(char *const dest, const char *const src, const i32 numChars)
{
	if (!dest) return nullptr;
	if (!src)  return nullptr;
	if (numChars < 0) return nullptr;

	for (i32 i  = 0; i < numChars; i++)
		dest[i] = src[i];

	return dest;
}

DQN_FILE_SCOPE i32 DqnStr_ReadUTF8Codepoint(const u32 *const a, u32 *outCodepoint)
{
	u8 *byte = (u8 *)a;
	if (a && byte[0])
	{
		i32 numBytesInChar = 0;
		u32 actualChar     = 0;

		if (byte[0] <= 128)
		{
			actualChar     = byte[0];
			numBytesInChar = 1;
		}
		else if ((byte[0] & 0xE0) == 0xC0)
		{
			// Header 110xxxxx 10xxxxxx
			actualChar     = ((u32)(byte[0] & 0x3F) << 6)
			               | ((u32)(byte[1] & 0x1F) << 0);
			numBytesInChar = 2;
		}
		else if ((byte[0] & 0xF0) == 0xE0)
		{
			// Header 1110xxxx 10xxxxxx 10xxxxxx
			actualChar     = ((u32)(byte[0] & 0x0F) << 12)
			               | ((u32)(byte[1] & 0x3F) << 6 )
			               | ((u32)(byte[2] & 0x3F) << 0 );
			numBytesInChar = 3;
		}
		else if ((byte[0] & 0xF8) == 0xF0)
		{
			// Header 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx
			actualChar = ((u32)(byte[0] & 0x07) << 18)
			           | ((u32)(byte[1] & 0x3F) << 12)
			           | ((u32)(byte[2] & 0x3F) << 6 )
			           | ((u32)(byte[3] & 0x3F) << 0 );
			numBytesInChar = 4;
		}
		else
		{
			// NOTE: Malformed utf8 stream
		}

		if (outCodepoint) *outCodepoint = actualChar;
		return numBytesInChar;
	}

	return 0;
}

DQN_FILE_SCOPE void DqnStr_Reverse(char *const buf, const u32 bufSize)
{
	if (!buf) return;
	i32 mid = bufSize / 2;

	for (i32 i = 0; i < mid; i++)
	{
		char tmp               = buf[i];
		buf[i]                 = buf[(bufSize - 1) - i];
		buf[(bufSize - 1) - i] = tmp;
	}
}

DQN_FILE_SCOPE i32 DqnStr_FindFirstOccurence(const char *const src, const i32 srcLen,
                                             const char *const find, const i32 findLen, bool ignoreCase)
{
	if (!src || !find)               return -1;
	if (srcLen == 0 || findLen == 0) return -1;
	if (srcLen < findLen)            return -1;

	for (i32 indexIntoSrc = 0; indexIntoSrc < srcLen; indexIntoSrc++)
	{
		// NOTE: As we scan through, if the src string we index into becomes
		// shorter than the substring we're checking then the substring is not
		// contained in the src string.
		i32 remainingLenInSrcStr = srcLen - indexIntoSrc;
		if (remainingLenInSrcStr < findLen) break;

		const char *srcSubStr = src + indexIntoSrc;
		if (DqnStr_Cmp(srcSubStr, find, findLen, ignoreCase) == 0)
		{
			return indexIntoSrc;
		}
	}

	// NOTE(doyle): We have early exit, if we reach here, then the substring was
	// not found.
	return -1;
}

DQN_FILE_SCOPE char *DqnStr_GetFirstOccurence(char *const src, i32 const srcLen, char *const find,
                                              i32 const findLen, bool ignoreCase)
{
	i32 offset = DqnStr_FindFirstOccurence(src, srcLen, find, findLen, ignoreCase);
	if (offset == -1) return nullptr;

	char *result = src + offset;
	return result;
}

DQN_FILE_SCOPE bool DqnStr_HasSubstring(char const *const src, i32 const srcLen,
                                        char const *const find, i32 const findLen, bool ignoreCase)
{
	if (DqnStr_FindFirstOccurence(src, srcLen, find, findLen, ignoreCase) == -1)
		return false;

	return true;
}

DQN_FILE_SCOPE i32 Dqn_I64ToStr(i64 const value, char *const buf, i32 const bufSize)
{
	bool validBuffer = true;
	if (!buf || bufSize == 0) validBuffer = false;

	if (value == 0)
	{
		if (validBuffer) buf[0] = '0';
		return 1;
	}
	
	i32 charIndex = 0;
	bool negative           = false;
	if (value < 0) negative = true;

	if (negative)
	{
		if (validBuffer) buf[charIndex] = '-';
		charIndex++;
	}

	bool lastDigitDecremented = false;
	i64 val = DQN_ABS(value);
	if (val < 0)
	{
		// TODO(doyle): This will occur if we are checking the smallest number
		// possible in i64 since the range of negative numbers is one more than
		// it is for positives, so ABS will fail.
		lastDigitDecremented = true;
		val                  = DQN_ABS(val - 1);
		DQN_ASSERT_HARD(val >= 0);
	}

	if (validBuffer)
	{
		if (lastDigitDecremented)
		{
			i64 rem = (val % 10) + 1;
			buf[charIndex++] = (u8)rem + '0';
			val /= 10;
		}

		while (val != 0 && charIndex < bufSize)
		{
			i64 rem          = val % 10;
			buf[charIndex++] = (u8)rem + '0';
			val /= 10;
		}

		// NOTE(doyle): If string is negative, we only want to reverse starting
		// from the second character, so we don't put the negative sign at the
		// end
		if (negative)
		{
			DqnStr_Reverse(buf + 1, charIndex - 1);
		}
		else
		{
			DqnStr_Reverse(buf, charIndex);
		}
	}
	else
	{
		while (val != 0)
		{
			val /= 10;
			charIndex++;
		}
	}

	return charIndex;
}

DQN_FILE_SCOPE i64 Dqn_StrToI64(char const *const buf, i64 const bufSize)
{
	if (!buf || bufSize == 0) return 0;

	i64 index = 0;
	while (buf[index] == ' ')
	{
		index++;
	}

	bool isNegative = false;
	if (buf[index] == '-' || buf[index] == '+')
	{
		if (buf[index] == '-') isNegative = true;
		index++;
	}
	else if (!DqnChar_IsDigit(buf[index]))
	{
		return 0;
	}

	i64 result = 0;
	for (auto i = index; i < bufSize; i++)
	{
		if (DqnChar_IsDigit(buf[i]))
		{
			result *= 10;
			result += (buf[i] - '0');
		}
		else
		{
			break;
		}
	}

	if (isNegative) result *= -1;

	return result;
}

DQN_FILE_SCOPE f32 Dqn_StrToF32(char const *const buf, i64 const bufSize)
{
	if (!buf || bufSize == 0) return 0;

	i64 index       = 0;
	bool isNegative = false;
	if (buf[index] == '-')
	{
		index++;
		isNegative = true;
	}

	bool isPastDecimal        = false;
	i64 numDigitsAfterDecimal = 0;
	i64 rawNumber             = 0;

	f32 digitShiftValue      = 1.0f;
	f32 digitShiftMultiplier = 0.1f;
	for (auto i = index; i < bufSize; i++)
	{
		char ch = buf[i];
		if (ch == '.')
		{
			isPastDecimal = true;
			continue;
		}
		// Handle scientific notation
		else if (ch == 'e')
		{
			bool digitShiftIsPositive = true;
			if (i < bufSize)
			{
				if (buf[i + 1] == '-') digitShiftIsPositive = false;
				DQN_ASSERT_HARD(buf[i + 1] == '-' || buf[i + 1] == '+');
				i += 2;
			}

			i32 exponentPow         = 0;
			bool scientificNotation = false;
			while (i < bufSize)
			{
				scientificNotation = true;
				char exponentCh    = buf[i];
				if (DqnChar_IsDigit(exponentCh))
				{
					exponentPow *= 10;
					exponentPow += (buf[i] - '0');
				}
				else
				{
					i = bufSize;
				}

				i++;
			}

			// NOTE(doyle): If exponent not specified but this branch occurred,
			// the float string has a malformed scientific notation in the
			// string, i.e. "e" followed by no number.
			DQN_ASSERT_HARD(scientificNotation);

			if (digitShiftIsPositive)
			{
				numDigitsAfterDecimal -= exponentPow;
			}
			else
			{
				numDigitsAfterDecimal += exponentPow;
			}
		}
		else if (DqnChar_IsDigit(ch))
		{
			numDigitsAfterDecimal += (i32)isPastDecimal;
			rawNumber *= 10;
			rawNumber += (ch - '0');
		}
		else
		{
			break;
		}
	}

	for (auto i = 0; i < numDigitsAfterDecimal; i++)
		digitShiftValue *= digitShiftMultiplier;

	f32 result = (f32)rawNumber;
	if (numDigitsAfterDecimal > 0) result *= digitShiftValue;
	if (isNegative) result *= -1;

	return result;
}

/*
	Encoding
	The following byte sequences are used to represent a character. The sequence
	to be used depends on the UCS code number of the character:

	The extra 1's are the headers used to identify the string as a UTF-8 string.
	UCS [0x00000000, 0x0000007F] -> UTF-8 0xxxxxxx
	UCS [0x00000080, 0x000007FF] -> UTF-8 110xxxxx 10xxxxxx
	UCS [0x00000800, 0x0000FFFF] -> UTF-8 1110xxxx 10xxxxxx 10xxxxxx
	UCS [0x00010000, 0x001FFFFF] -> UTF-8 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx
	UCS [0x00200000, 0x03FFFFFF] -> N/A   111110xx 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx
	UCS [0x04000000, 0x7FFFFFFF] -> N/A   1111110x 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx

	The xxx bit positions are filled with the bits of the character code number
	in binary representation. Only the shortest possible multibyte sequence
	which can represent the code number of the character can be used.

	The UCS code values 0xd800–0xdfff (UTF-16 surrogates) as well as 0xfffe and
	0xffff (UCS noncharacters) should not appear in conforming UTF-8 streams.
*/
DQN_FILE_SCOPE u32 Dqn_UCSToUTF8(u32 *const dest, const u32 character)
{
	if (!dest) return 0;

	u8 *bytePtr = (u8 *)dest;

	// Character is within ASCII range, so it's an ascii character
	// UTF Bit Arrangement: 0xxxxxxx
	// Character          : 0xxxxxxx
	if (character >= 0 && character < 0x80)
	{
		bytePtr[0] = (u8)character;
		return 1;
	}

	// UTF Header Bits    : 11000000 00xxxxxx
	// UTF Bit Arrangement: 000xxxxx 00xxxxxx
	// Character          : 00000xxx xxxxxxxx
	if (character < 0x800)
	{
		// Add the 2nd byte, 6 bits, OR the 0xC0 (11000000) header bits
		bytePtr[1] = (u8)((character >> 6) | 0xC0);

		// Add the 1st byte, 6 bits, plus the 0x80 (10000000) header bits
		bytePtr[0] = (u8)((character & 0x3F) | 0x80);

		return 2;
	}

	// UTF Header Bits     : 11100000 10000000 10000000
	// UTF Bit Arrangement : 0000xxxx 00xxxxxx 00xxxxxx
	// Character           : 00000000 xxxxxxxx xxxxxxxx
	if (character < 0x10000)
	{
		// Add the 3rd byte, 4 bits, OR the 0xE0 (11100000) header bits
		bytePtr[2] = (u8)((character >> 12) | 0xE0);

		// Add the 2nd byte, 6 bits, OR the 0x80 (10000000) header bits
		bytePtr[1] = (u8)((character >> 6) | 0x80);

		// Add the 1st byte, 6 bits, plus the 0x80 (10000000) header bits
		bytePtr[0] = (u8)((character & 0x3F) | 0x80);

		return 3;
	}

	// UTF Header Bits     : 11110000 10000000 10000000 10000000
	// UTF Bit Arrangement : 00000xxx 00xxxxxx 00xxxxxx 00xxxxxx
	// Character           : 00000000 00000xxx xxxxxxxx xxxxxxxx
	if (character < 0x110000)
	{
		// Add the 4th byte, 3 bits, OR the 0xF0 (11110000) header bits
		bytePtr[3] = (u8)((character >> 18) | 0xF0);

		// Add the 3rd byte, 6 bits, OR the 0x80 (10000000) header bits
		bytePtr[2] = (u8)(((character >> 12) & 0x3F) | 0x80);

		// Add the 2nd byte, 6 bits, plus the 0x80 (10000000) header bits
		bytePtr[1] = (u8)(((character >> 6) & 0x3F) | 0x80);

		// Add the 2nd byte, 6 bits, plus the 0x80 (10000000) header bits
		bytePtr[0] = (u8)((character & 0x3F) | 0x80);

		return 4;
	}

	return 0;
}

DQN_FILE_SCOPE u32 Dqn_UTF8ToUCS(u32 *const dest, const u32 character)
{
	if (!dest) return 0;

	const u32 HEADER_BITS_4_BYTES = 0xF0808080u;
	const u32 HEADER_BITS_3_BYTES = 0xE08080u;
	const u32 HEADER_BITS_2_BYTES = 0xC000u;
	const u32 HEADER_BITS_1_BYTE  = 0x80u;

	// UTF Header Bits     : 11110000 10000000 10000000 10000000
	// UTF Bit Arrangement : 00000xxx 00xxxxxx 00xxxxxx 00xxxxxx
	// UCS                 : 00000000 00000xxx xxxxxxxx xxxxxxxx
	if ((character & HEADER_BITS_4_BYTES) == HEADER_BITS_4_BYTES)
	{
		u32 utfWithoutHeader = HEADER_BITS_4_BYTES ^ character;

		u32 firstByte  = utfWithoutHeader & 0x3F;
		u32 secondByte = (utfWithoutHeader >> 8) & 0x3F;
		u32 thirdByte  = (utfWithoutHeader >> 16) & 0x3F;
		u32 fourthByte = utfWithoutHeader >> 24;

		u32 result =
		    (fourthByte << 18 | thirdByte << 12 | secondByte << 6 | firstByte);
		*dest = result;

		return 4;
	}

	// UTF Header Bits     : 11100000 10000000 10000000
	// UTF Bit Arrangement : 0000xxxx 00xxxxxx 00xxxxxx
	// UCS                 : 00000000 xxxxxxxx xxxxxxxx
	if ((character & HEADER_BITS_3_BYTES) == HEADER_BITS_3_BYTES)
	{
		u32 utfWithoutHeader = HEADER_BITS_3_BYTES ^ character;

		u32 firstByte  = utfWithoutHeader & 0x3F;
		u32 secondByte = (utfWithoutHeader >> 8) & 0x3F;
		u32 thirdByte  = utfWithoutHeader >> 16;

		u32 result = (thirdByte << 12 | secondByte << 6 | firstByte);
		*dest = result;

		return 3;
	}

	// UTF Header Bits    : 11000000 00xxxxxx
	// UTF Bit Arrangement: 000xxxxx 00xxxxxx
	// UCS                : 00000xxx xxxxxxxx
	if ((character & HEADER_BITS_2_BYTES) == HEADER_BITS_2_BYTES)
	{
		u32 utfWithoutHeader = HEADER_BITS_2_BYTES ^ character;

		u32 firstByte  = utfWithoutHeader & 0x3F;
		u32 secondByte = utfWithoutHeader >> 8;

		u32 result = (secondByte << 6 | firstByte);
		*dest = result;

		return 2;
	}

	// Character is within ASCII range, so it's an ascii character
	// UTF Bit Arrangement: 0xxxxxxx
	// UCS                : 0xxxxxxx
	if ((character & HEADER_BITS_1_BYTE) == 0)
	{
		u32 firstByte = (character & 0x3F);
		*dest         = firstByte;

		return 1;
	}

	return 0;
}

////////////////////////////////////////////////////////////////////////////////
// #DqnWChar Implementation
////////////////////////////////////////////////////////////////////////////////
DQN_FILE_SCOPE bool DqnWChar_IsDigit(const wchar_t c)
{
	if (c >= L'0' && c <= L'9') return true;
	return false;
}

DQN_FILE_SCOPE wchar_t DqnWChar_ToLower(const wchar_t c)
{
	if (c >= L'A' && c <= L'Z')
	{
		i32 shiftOffset = L'a' - L'A';
		return (c + (wchar_t)shiftOffset);
	}

	return c;
}

DQN_FILE_SCOPE wchar_t *DqnWChar_SkipWhitespace(wchar_t *ptr)
{
	while (ptr && (*ptr == ' ' || *ptr == '\r' || *ptr == '\n')) ptr++;
	return ptr;
}

DQN_FILE_SCOPE wchar_t *DqnWChar_FindLastChar(wchar_t *ptr, const wchar_t ch, i32 len, u32 *const lenToChar)
{
	for (i32 i = len - 1; i >= 0; i--)
	{
		if (ptr[i] == ch)
		{
			if (lenToChar) *lenToChar = (u32)len - i;
			return &ptr[i];
		}
	}

	return nullptr;
}

DQN_FILE_SCOPE i32 DqnWChar_GetNextLine(wchar_t *ptr, i32 *lineLength)
{
	i32 len = 0;
	ptr     = DqnWChar_SkipWhitespace(ptr);

	// Advance pointer to first new line
	while (ptr && *ptr != 0 && *ptr != '\r' && *ptr != '\n')
	{
		ptr++;
		len++;
	}

	if (!ptr || *ptr == 0) return -1;

	// Destroy all new lines
	i32 extraChars = 0;
	while (ptr && (*ptr == '\r' || *ptr == '\n' || *ptr == ' '))
	{
		*ptr = 0;
		ptr++;
		extraChars++;
	}

	if (lineLength) *lineLength = len;
	return len + extraChars;
}

////////////////////////////////////////////////////////////////////////////////
// #DqnWStr Implementation
////////////////////////////////////////////////////////////////////////////////
DQN_FILE_SCOPE i32 DqnWStr_Cmp(const wchar_t *const a, const wchar_t *const b)
{
	if (!a && !b) return -1;
	if (!a) return -1;
	if (!b) return -1;

	const wchar_t *aPtr = a;
	const wchar_t *bPtr = b;

	while ((*aPtr) == (*bPtr))
	{
		if (!(*aPtr)) return 0;
		aPtr++;
		bPtr++;
	}

	return (((*aPtr) < (*bPtr)) ? -1 : 1);
}

DQN_FILE_SCOPE i32 DqnWStr_FindFirstOccurence(const wchar_t *const src, const i32 srcLen,
                                                  const wchar_t *const find, const i32 findLen)
{
	if (!src || !find)               return -1;
	if (srcLen == 0 || findLen == 0) return -1;
	if (srcLen < findLen)            return -1;

	for (i32 indexIntoSrc = 0; indexIntoSrc < srcLen; indexIntoSrc++)
	{
		// NOTE: As we scan through, if the src string we index into becomes
		// shorter than the substring we're checking then the substring is not
		// contained in the src string.
		i32 remainingLenInSrcStr = srcLen - indexIntoSrc;
		if (remainingLenInSrcStr < findLen) break;

		const wchar_t *srcSubStr = &src[indexIntoSrc];
		i32 index = 0;
		for (;;)
		{
			if (DqnWChar_ToLower(srcSubStr[index]) ==
			    DqnWChar_ToLower(find[index]))
			{
				index++;
				if (index >= findLen || !find[index])
				{
					return indexIntoSrc;
				}
			}
			else
			{
				break;
			}
		}
	}

	// NOTE(doyle): We have early exit, if we reach here, then the substring was
	// not found.
	return -1;
}

DQN_FILE_SCOPE bool DqnWStr_HasSubstring(const wchar_t *const src, const i32 srcLen,
                                         const wchar_t *const find, const i32 findLen)
{
	if (DqnWStr_FindFirstOccurence(src, srcLen, find, findLen) == -1)
		return false;

	return true;
}

DQN_FILE_SCOPE i32 DqnWStr_Len(const wchar_t *const a)
{
	i32 result = 0;
	while (a && a[result]) result++;
	return result;
}

DQN_FILE_SCOPE i32 DqnWStr_LenDelimitWith(const wchar_t *a, const wchar_t delimiter)
{
	i32 result = 0;
	while (a && a[result] && a[result] != delimiter) result++;
	return result;
}

DQN_FILE_SCOPE void DqnWStr_Reverse(wchar_t *const buf, const u32 bufSize)
{
	if (!buf) return;
	i32 mid = bufSize / 2;

	for (i32 i = 0; i < mid; i++)
	{
		wchar_t tmp            = buf[i];
		buf[i]                 = buf[(bufSize - 1) - i];
		buf[(bufSize - 1) - i] = tmp;
	}
}

DQN_FILE_SCOPE i32 Dqn_WStrToI32(const wchar_t *const buf, const i32 bufSize)
{
	if (!buf || bufSize == 0) return 0;

	i32 index       = 0;
	bool isNegative = false;
	if (buf[index] == L'-' || buf[index] == L'+')
	{
		if (buf[index] == L'-') isNegative = true;
		index++;
	}
	else if (!DqnWChar_IsDigit(buf[index]))
	{
		return 0;
	}

	i32 result = 0;
	for (i32 i = index; i < bufSize; i++)
	{
		if (DqnWChar_IsDigit(buf[i]))
		{
			result *= 10;
			result += (buf[i] - L'0');
		}
		else
		{
			break;
		}
	}

	if (isNegative) result *= -1;

	return result;
}

DQN_FILE_SCOPE i32 Dqn_I32ToWstr(i32 value, wchar_t *buf, i32 bufSize)
{
	if (!buf || bufSize == 0) return 0;

	if (value == 0)
	{
		buf[0] = L'0';
		return 0;
	}
	
	// NOTE(doyle): Max 32bit integer (+-)2147483647
	i32 charIndex = 0;
	bool negative           = false;
	if (value < 0) negative = true;

	if (negative) buf[charIndex++] = L'-';

	i32 val = DQN_ABS(value);
	while (val != 0 && charIndex < bufSize)
	{
		i32 rem          = val % 10;
		buf[charIndex++] = (u8)rem + '0';
		val /= 10;
	}

	// NOTE(doyle): If string is negative, we only want to reverse starting
	// from the second character, so we don't put the negative sign at the end
	if (negative)
	{
		DqnWStr_Reverse(buf + 1, charIndex - 1);
	}
	else
	{
		DqnWStr_Reverse(buf, charIndex);
	}

	return charIndex;
}

////////////////////////////////////////////////////////////////////////////////
// #DqnString Impleemntation
////////////////////////////////////////////////////////////////////////////////
DQN_FILE_SCOPE DqnString DqnString_(i32 const len, DqnMemAPI const api)
{
	DqnString result;
	bool init = result.InitSize(len, api);
	DQN_ASSERT_HARD(init);
	return result;
}

DQN_FILE_SCOPE DqnString DqnString_(i32 const len, DqnMemStack *const stack)
{
	DqnString result = DqnString_(len, DqnMemAPI_StackAllocator(stack));
	return result;
}

DQN_FILE_SCOPE DqnString DqnString_(DqnMemAPI const api)
{
	DqnString result = DqnString_(0, api);
	return result;
}

DQN_FILE_SCOPE DqnString DqnString_(DqnMemStack *const stack)
{
	DqnString result = DqnString_(0, stack);
	return result;
}

bool DqnString::InitSize(const i32 size, DqnMemStack *const stack)
{
	bool result = this->InitSize(size, DqnMemAPI_StackAllocator(stack));
	return result;
}

bool DqnString::InitSize(const i32 size, const DqnMemAPI api)
{
	DQN_ASSERT(size >= 0);
	if (size < 0)
	{
		DqnString nullString = {};
		*this                = nullString;
		return false;
	}

	if (size > 0)
	{
		size_t allocSize        = sizeof(*(this->str)) * (size + 1);
		DqnMemAPI::Request info = DqnMemAPI::RequestAlloc(api, allocSize);
		this->str               = (char *)api.callback(info);

		if (!this->str)
		{
			return false;
		}
	}
	else // size == 0
	{
		this->str = nullptr;
	}

	this->max    = size;
	this->len    = 0;
	this->memAPI = api;
	return true;
}

bool DqnString::InitFixedMem(char *const memory, i32 const sizeInBytes)
{
	if (!memory || sizeInBytes == 0) return false;

	this->str    = (char *)memory;
	this->len    = 0;
	this->max    = sizeInBytes - 1;
	this->memAPI = {};

	return true;
}

bool DqnString::InitLiteral(char const *const cstr, DqnMemStack *const stack)
{
	bool result = this->InitLiteral(cstr, DqnMemAPI_StackAllocator(stack));
	return result;
}

bool DqnString::InitLiteral(char const *const cstr, i32 const lenInBytes, DqnMemStack *const stack)
{
	bool result = this->InitLiteral(cstr, lenInBytes, DqnMemAPI_StackAllocator(stack));
	return result;
}

bool DqnString::InitLiteral(char const *const cstr, i32 const lenInBytes, DqnMemAPI const api)
{
	if (lenInBytes < 0) return false;

	if (lenInBytes > 0)
	{
		size_t allocSize        = sizeof(*(this->str)) * (lenInBytes + 1);
		DqnMemAPI::Request info = DqnMemAPI::RequestAlloc(api, allocSize);

		this->str = (char *)api.callback(info);
		if (!this->str) return false;

		this->str[lenInBytes] = 0;
	}

	this->len             = lenInBytes;
	this->max             = lenInBytes;
	this->memAPI          = api;

	for (i32 i = 0; i < this->len; i++)
	{
		this->str[i] = cstr[i];
	}


	return true;
}

bool DqnString::InitLiteral(char const *const cstr, DqnMemAPI const api)
{
	i32 utf8LenInBytes = 0;
	DqnStr_LenUTF8((u32 *)cstr, &utf8LenInBytes);
	bool result = this->InitLiteral(cstr, utf8LenInBytes, api);
	return result;
}

bool DqnString::InitWLiteral(wchar_t const *const cstr, DqnMemStack *const stack)
{
	bool result = this->InitWLiteral(cstr, DqnMemAPI_StackAllocator(stack));
	return result;
}

bool DqnString::InitWLiteral(wchar_t const *const cstr, DqnMemAPI const api)
{
#if defined(DQN_IS_WIN32) && defined(DQN_WIN32_IMPLEMENTATION)
	i32 requiredLen = DqnWin32_WCharToUTF8(cstr, nullptr, 0);
	this->len = requiredLen - 1;

	size_t allocSize        = sizeof(*(this->str)) * (this->len + 1);
	DqnMemAPI::Request info = DqnMemAPI::RequestAlloc(api, allocSize);
	this->str               = (char *)api.callback(info);
	if (!this->str) return false;

	this->max    = this->len;
	this->memAPI = api;

	i32 convertResult = DqnWin32_WCharToUTF8(cstr, this->str, this->len + 1);
	DQN_ASSERT(convertResult != -1);

	this->str[this->len] = 0;
	return true;

#else
	DQN_ASSERT_HARD(DQN_INVALID_CODE_PATH);
	return false;

#endif
}

bool DqnString::InitLiteralNoAlloc(char *const cstr, i32 cstrLen)
{
	if (!cstr) return false;

	this->str = cstr;
	if (cstrLen == -1)
	{
		i32 utf8LenInBytes = 0;
		DqnStr_LenUTF8((u32 *)cstr, &utf8LenInBytes);
		this->len = utf8LenInBytes;
	}
	else
	{
		this->len = cstrLen;
	}

	this->max = this->len;

	return true;
}

bool DqnString::Expand(const i32 newMax)
{
	if (!this->memAPI.callback) return false;
	if (newMax < this->max)     return true;

	size_t allocSize           = sizeof(*(this->str)) * (newMax + 1);
	DqnMemAPI::Request info = {};

	if (this->str)
	{
		info = DqnMemAPI::RequestRealloc(this->memAPI, this->str, this->max, allocSize);
	}
	else
	{
		info = DqnMemAPI::RequestAlloc(this->memAPI, allocSize);
	}

	u8 *result = this->memAPI.callback(info);
	if (result)
	{
		this->str = (char *)result;
		this->max = newMax;
		return true;
	}

	return false;
}

DQN_FILE_SCOPE bool DqnStringInternal_Append(DqnString *const str, char const *const cstr,
                                             i32 const bytesToCopy)
{
	if (bytesToCopy <= 0)
	{
		return true;
	}

	// Check and reserve space if needed
	i32 totalLen = str->len + bytesToCopy;
	if (totalLen > str->max)
	{
		bool result = str->Expand(totalLen);
		if (!result) return false;
	}

	// Append
	for (i32 i = 0; i < bytesToCopy; i++) str->str[str->len + i] = cstr[i];

	str->len           = totalLen;
	str->str[totalLen] = 0;
	return true;
}

bool DqnString::Sprintf(char const *fmt, ...)
{
	static char tmp[STB_SPRINTF_MIN];
	auto PrintCallback = [](char *buf, void *user, int len) -> char *
	{
		(void)len; (void)user;
		return buf;
	};

	va_list argList;
	va_start(argList, fmt);
	{
		i32  const reqLen          = Dqn_vsprintfcb(PrintCallback, nullptr, tmp, fmt, argList);
		auto const remainingSpace  = this->max - this->len;
		if (reqLen > remainingSpace)
		{
			i32 const newMax = this->max + reqLen;
			if (!this->Expand(newMax))
			{
				return false;
			}
		}

		char *bufStart = this->str + this->len;
		i32 numCopied  = Dqn_vsprintf(bufStart, fmt, argList);
		this->len += numCopied;
		DQN_ASSERT_HARD(this->len <= this->max);
	}
	va_end(argList);

	return true;
}

bool DqnString::Append(char const *const cstr, i32 bytesToCopy)
{
	i32 cstrLen = 0;
	if (bytesToCopy == -1)
	{
		i32 utf8LenInBytes = 0;
		DqnStr_LenUTF8((u32 *)cstr, &utf8LenInBytes);
		cstrLen = utf8LenInBytes;
	}
	else
	{
		cstrLen = bytesToCopy;
	}

	bool result = DqnStringInternal_Append(this, cstr, cstrLen);
	return result;
}

bool DqnString::Append(DqnString const strToAppend, i32 bytesToCopy)
{
	i32 cstrLen = (bytesToCopy == -1) ? strToAppend.len : bytesToCopy;
	bool result = DqnStringInternal_Append(this, strToAppend.str, cstrLen);
	return result;
}

void DqnString::Clear()
{
	this->len    = 0;

	if (this->str)
	{
		this->str[0] = 0;
	}
}

bool DqnString::Free()
{
	if (this->str)
	{
		if (this->memAPI.callback)
		{
			DqnMemAPI::Request info =
			    DqnMemAPI::RequestFree(this->memAPI, this->str, this->len);
			this->memAPI.callback(info);

			this->str = nullptr;
			this->len = 0;
			this->max = 0;

			return true;
		}
	}

	return false;
}

i32 DqnString::ToWCharUseBuf(wchar_t *const buf, const i32 bufSize)
{
#if defined(DQN_IS_WIN32) && defined(DQN_WIN32_IMPLEMENTATION)
	i32 result = DqnWin32_UTF8ToWChar(this->str, buf, bufSize);
	return result;

#else
	DQN_ASSERT_HARD(DQN_INVALID_CODE_PATH);
	return -1;

#endif
}

wchar_t *DqnString::ToWChar(const DqnMemAPI api)
{
	// TODO(doyle): Should the "in" string allow specifyign len? probably
	// Otherwise a c-string and a literal initiated string might have different lengths
	// to wchar will produce an unintuitive output
#if defined(DQN_IS_WIN32) && defined(DQN_WIN32_IMPLEMENTATION)
	i32 requiredLenInclNull = DqnWin32_UTF8ToWChar(this->str, nullptr, 0);

	i32 allocSize           = sizeof(wchar_t) * requiredLenInclNull;
	DqnMemAPI::Request info = DqnMemAPI::RequestAlloc(api, allocSize);
	wchar_t *result         = (wchar_t *)api.callback(info);
	if (!result) return nullptr;

	DqnWin32_UTF8ToWChar(this->str, result, requiredLenInclNull);
	result[requiredLenInclNull - 1] = 0;
	return result;

#else
	DQN_ASSERT_HARD(DQN_INVALID_CODE_PATH);
	return nullptr;

#endif
}

////////////////////////////////////////////////////////////////////////////////
// #DqnRnd Implementation
////////////////////////////////////////////////////////////////////////////////
// Public Domain library with thanks to Mattias Gustavsson
// https://github.com/mattiasgustavsson/libs/blob/master/docs/rnd.md

// Convert a randomized u32 value to a float value x in the range 0.0f <= x
// < 1.0f. Contributed by Jonatan Hedborg

// NOTE: This is to abide to strict aliasing rules.
union DqnRndInternal_U32F32
{
	u32 unsigned32;
	f32 float32;
};

FILE_SCOPE f32 DqnRndInternal_F32NormalizedFromU32(u32 value)
{
	u32 exponent = 127;
	u32 mantissa = value >> 9;

	union DqnRndInternal_U32F32 uf;
	uf.unsigned32 = (exponent << 23 | mantissa);
	return uf.float32 - 1.0f;
}

FILE_SCOPE u64 DqnRndInternal_Murmur3Avalanche64(u64 h)
{
	h ^= h >> 33;
	h *= 0xff51afd7ed558ccd;
	h ^= h >> 33;
	h *= 0xc4ceb9fe1a85ec53;
	h ^= h >> 33;
	return h;
}

#if defined(DQN_UNIX_PLATFORM)
	#include <x86intrin.h> // __rdtsc
#endif

FILE_SCOPE u32 DqnRndInternal_MakeSeed()
{
#if defined(DQN_WIN32_PLATFORM) || defined(DQN_UNIX_PLATFORM)
	i64 numClockCycles = __rdtsc();
	return (u32)numClockCycles;
#elif __ANDROID__
	DQN_ASSERT_MSG(DQN_INVALID_CODE_PATH, "Android path not implemented yet");
	return 0;
#else
	DQN_ASSERT_MSG(DQN_INVALID_CODE_PATH, "Non Win32 path not implemented yet");
	return 0;
#endif
}

DQN_FILE_SCOPE DqnRndPCG DqnRndPCG_()
{
	DqnRndPCG result;
	result.Init();
	return result;
}

DQN_FILE_SCOPE DqnRndPCG DqnRndPCG_(u32 seed)
{
	DqnRndPCG result;
	result.InitWithSeed(seed);
	return result;
}

void DqnRndPCG::InitWithSeed(u32 seed)
{
	u64 value     = (((u64)seed) << 1ULL) | 1ULL;
	value         = DqnRndInternal_Murmur3Avalanche64(value);
	this->state[0] = 0U;
	this->state[1] = (value << 1ULL) | 1ULL;
	this->Next();
	this->state[0] += DqnRndInternal_Murmur3Avalanche64(value);
	this->Next();
}

void DqnRndPCG::Init()
{
	u32 seed = DqnRndInternal_MakeSeed();
	this->InitWithSeed(seed);
}

u32 DqnRndPCG::Next()
{
	u64 oldstate   = this->state[0];
	this->state[0] = oldstate * 0x5851f42d4c957f2dULL + this->state[1];
	u32 xorshifted = (u32)(((oldstate >> 18ULL) ^ oldstate) >> 27ULL);
	u32 rot        = (u32)(oldstate >> 59ULL);
	return (xorshifted >> rot) | (xorshifted << ((-(i32)rot) & 31));
}

f32 DqnRndPCG::Nextf()
{
	f32 result = DqnRndInternal_F32NormalizedFromU32(this->Next());
	return result;
}

i32 DqnRndPCG::Range(i32 min, i32 max)
{
	i32 const range = (max - min) + 1;
	if (range <= 0) return min;

	i32 const value = (i32)(this->Nextf() * range);
	i32 result      = min + value;
	return result;
}

////////////////////////////////////////////////////////////////////////////////
// #Dqn_* Implementation
////////////////////////////////////////////////////////////////////////////////
DQN_FILE_SCOPE i64 Dqn_BSearch(i64 *const array, i64 const size, i64 const find,
                               Dqn_BSearchBound const bound)
{
	if (size == 0 || !array) return -1;

	i64 start = 0;
	i64 end   = size - 1;
	i64 mid   = (i64)((start + end) * 0.5f);

	while (start <= end)
	{
		if (array[mid] == find)
		{
			if (bound == Dqn_BSearchBound_Normal ||
			    bound == Dqn_BSearchBound_NormalLower ||
			    bound == Dqn_BSearchBound_NormalHigher)
			{
				return mid;
			}
			else if (bound == Dqn_BSearchBound_Lower)
			{
				return mid - 1;
			}
			else
			{
				if ((mid + 1) >= size) return -1;
				return mid + 1;
			}
		}
		else if (array[mid] <  find) start = mid + 1;
		else                         end   = mid - 1;
		mid = (i64)((start + end) * 0.5f);
	}

	if (bound == Dqn_BSearchBound_Normal)
	{
		return -1;
	}
	if (bound == Dqn_BSearchBound_Lower || bound == Dqn_BSearchBound_NormalLower)
	{
		if (find < array[mid]) return -1;
		return mid;
	}
	else
	{
		if (find > array[mid]) return -1;
		return mid;
	}
}

////////////////////////////////////////////////////////////////////////////////
// #External Code
////////////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////
// #DqnSprintf Implementation - STB_Sprintf
////////////////////////////////////////////////////////////////////////////////
/*
Single file sprintf replacement.

Originally written by Jeff Roberts at RAD Game Tools - 2015/10/20.  Hereby
placed in public domain.

This is a full sprintf replacement that supports everything that the C runtime
sprintfs support, including float/double, 64-bit integers, hex floats, field
parameters (%*.*d stuff), length reads backs, etc.

Why would you need this if sprintf already exists?  Well, first off, it's *much*
faster (see below). It's also much smaller than the CRT versions
code-space-wise. We've also added some simple improvements that are super handy
(commas in thousands, callbacks at buffer full, for example). Finally, the
format strings for MSVC and GCC differ for 64-bit integers (among other small
things), so this lets you use the same format strings in cross platform code.

It uses the standard single file trick of being both the header file and the
source itself. If you just include it normally, you just get the header file
function definitions. To get the code, you include it from a C or C++ file and
define STB_SPRINTF_IMPLEMENTATION first.

It only uses va_args macros from the C runtime to do it's work. It does cast
doubles to S64s and shifts and divides U64s, which does drag in CRT code on most
platforms.

It compiles to roughly 8K with float support, and 4K without.  As a comparison,
when using MSVC static libs, calling sprintf drags in 16K.

PERFORMANCE vs MSVC 2008 32-/64-bit (GCC is even slower than MSVC):
===================================================================
"%d" across all 32-bit ints (4.8x/4.0x faster than 32-/64-bit MSVC)
"%24d" across all 32-bit ints (4.5x/4.2x faster)
"%x" across all 32-bit ints (4.5x/3.8x faster)
"%08x" across all 32-bit ints (4.3x/3.8x faster)
"%f" across e-10 to e+10 floats (7.3x/6.0x faster)
"%e" across e-10 to e+10 floats (8.1x/6.0x faster)
"%g" across e-10 to e+10 floats (10.0x/7.1x faster)
"%f" for values near e-300 (7.9x/6.5x faster)
"%f" for values near e+300 (10.0x/9.1x faster)
"%e" for values near e-300 (10.1x/7.0x faster)
"%e" for values near e+300 (9.2x/6.0x faster)
"%.320f" for values near e-300 (12.6x/11.2x faster)
"%a" for random values (8.6x/4.3x faster)
"%I64d" for 64-bits with 32-bit values (4.8x/3.4x faster)
"%I64d" for 64-bits > 32-bit values (4.9x/5.5x faster)
"%s%s%s" for 64 char strings (7.1x/7.3x faster)
"...512 char string..." ( 35.0x/32.5x faster!)
*/

#ifdef __GNUC__
	#pragma GCC diagnostic push
	#pragma GCC diagnostic ignored "-Wmisleading-indentation"
	#pragma GCC diagnostic ignored "-Wstrict-aliasing"
#endif

#include <stdlib.h>  // for va_arg()

#define stbsp__uint32 unsigned int
#define stbsp__int32 signed int

#ifdef _MSC_VER
#define stbsp__uint64 unsigned __int64
#define stbsp__int64 signed __int64
#else
#define stbsp__uint64 unsigned long long
#define stbsp__int64 signed long long
#endif
#define stbsp__uint16 unsigned short

#ifndef stbsp__uintptr 
#if defined(__ppc64__) || defined(__aarch64__) || defined(_M_X64) || defined(__x86_64__) || defined(__x86_64)
#define stbsp__uintptr stbsp__uint64
#else
#define stbsp__uintptr stbsp__uint32
#endif
#endif

#ifndef STB_SPRINTF_MSVC_MODE  // used for MSVC2013 and earlier (MSVC2015 matches GCC)
#if defined(_MSC_VER) && (_MSC_VER<1900)
#define STB_SPRINTF_MSVC_MODE
#endif
#endif

#ifdef STB_SPRINTF_NOUNALIGNED  // define this before inclusion to force stbsp_sprintf to always use aligned accesses
#define STBSP__UNALIGNED(code)
#else
#define STBSP__UNALIGNED(code) code
#endif

#ifndef STB_SPRINTF_NOFLOAT
// internal float utility functions
static stbsp__int32 stbsp__real_to_str( char const * * start, stbsp__uint32 * len, char *out, stbsp__int32 * decimal_pos, double value, stbsp__uint32 frac_digits );
static stbsp__int32 stbsp__real_to_parts( stbsp__int64 * bits, stbsp__int32 * expo, double value );
#define STBSP__SPECIAL 0x7000
#endif

static char stbsp__period='.';
static char stbsp__comma=',';
static char stbsp__digitpair[201]="00010203040506070809101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899";

STBSP__PUBLICDEF void STB_SPRINTF_DECORATE( set_separators )( char pcomma, char pperiod )
{
  stbsp__period=pperiod;
  stbsp__comma=pcomma;
}

#define STBSP__LEFTJUST 1
#define STBSP__LEADINGPLUS 2
#define STBSP__LEADINGSPACE 4
#define STBSP__LEADING_0X 8
#define STBSP__LEADINGZERO 16
#define STBSP__INTMAX 32
#define STBSP__TRIPLET_COMMA 64
#define STBSP__NEGATIVE 128
#define STBSP__METRIC_SUFFIX 256
#define STBSP__HALFWIDTH 512
#define STBSP__METRIC_NOSPACE 1024
#define STBSP__METRIC_1024 2048
#define STBSP__METRIC_JEDEC 4096

static void stbsp__lead_sign(stbsp__uint32 fl, char *sign)
{
  sign[0] = 0;
  if (fl&STBSP__NEGATIVE) {
    sign[0]=1;
    sign[1]='-';
  } else if (fl&STBSP__LEADINGSPACE) {
    sign[0]=1;
    sign[1]=' ';
  } else if (fl&STBSP__LEADINGPLUS) {
    sign[0]=1;
    sign[1]='+';
  }
}
  
STBSP__PUBLICDEF int STB_SPRINTF_DECORATE( vsprintfcb )( STBSP_SPRINTFCB * callback, void * user, char * buf, char const * fmt, va_list va )
{
  static char hex[]="0123456789abcdefxp";
  static char hexu[]="0123456789ABCDEFXP";
  char * bf;
  char const * f;
  int tlen = 0;

  bf = buf;
  f = fmt;
  for(;;)
  {
    stbsp__int32 fw,pr,tz; stbsp__uint32 fl;

    // macros for the callback buffer stuff
    #define stbsp__chk_cb_bufL(bytes) { int len = (int)(bf-buf); if ((len+(bytes))>=STB_SPRINTF_MIN) { tlen+=len; if (0==(bf=buf=callback(buf,user,len))) goto done; } }
    #define stbsp__chk_cb_buf(bytes) { if ( callback ) { stbsp__chk_cb_bufL(bytes); } }
    #define stbsp__flush_cb() { stbsp__chk_cb_bufL(STB_SPRINTF_MIN-1); } //flush if there is even one byte in the buffer
    #define stbsp__cb_buf_clamp(cl,v) cl = v; if ( callback ) { int lg = STB_SPRINTF_MIN-(int)(bf-buf); if (cl>lg) cl=lg; }

    // fast copy everything up to the next % (or end of string)
    for(;;)
    { 
      while (((stbsp__uintptr)f)&3)
      {
       schk1: if (f[0]=='%') goto scandd;
       schk2: if (f[0]==0) goto endfmt;
        stbsp__chk_cb_buf(1); *bf++=f[0]; ++f;
      } 
      for(;;)
      { 
        // Check if the next 4 bytes contain %(0x25) or end of string.
        // Using the 'hasless' trick:
        // https://graphics.stanford.edu/~seander/bithacks.html#HasLessInWord
        stbsp__uint32 v,c;
        v=*(stbsp__uint32*)f; c=(~v)&0x80808080;
        if (((v^0x25252525)-0x01010101)&c) goto schk1;
        if ((v-0x01010101)&c) goto schk2; 
        if (callback) if ((STB_SPRINTF_MIN-(int)(bf-buf))<4) goto schk1;
        *(stbsp__uint32*)bf=v; bf+=4; f+=4;
      }
    } scandd:

    ++f;

    // ok, we have a percent, read the modifiers first
    fw = 0; pr = -1; fl = 0; tz = 0;
    
    // flags
    for(;;)
    {
      switch(f[0])
      {
        // if we have left justify
        case '-': fl|=STBSP__LEFTJUST; ++f; continue;
        // if we have leading plus
        case '+': fl|=STBSP__LEADINGPLUS; ++f; continue; 
        // if we have leading space
        case ' ': fl|=STBSP__LEADINGSPACE; ++f; continue; 
        // if we have leading 0x
        case '#': fl|=STBSP__LEADING_0X; ++f; continue; 
        // if we have thousand commas
        case '\'': fl|=STBSP__TRIPLET_COMMA; ++f; continue; 
        // if we have kilo marker (none->kilo->kibi->jedec)
        case '$': 
            if (fl&STBSP__METRIC_SUFFIX)
            {
                if (fl&STBSP__METRIC_1024)
                {
                    fl|=STBSP__METRIC_JEDEC;
                }
                else
                {
                    fl|=STBSP__METRIC_1024;
                }
            }
            else
            {
                fl|=STBSP__METRIC_SUFFIX; 
            }
            ++f; continue; 
        // if we don't want space between metric suffix and number
        case '_': fl|=STBSP__METRIC_NOSPACE; ++f; continue;
        // if we have leading zero
        case '0': fl|=STBSP__LEADINGZERO; ++f; goto flags_done; 
        default: goto flags_done;
      }
    }
    flags_done:
   
    // get the field width
    if ( f[0] == '*' ) {fw = va_arg(va,stbsp__uint32); ++f;} else { while (( f[0] >= '0' ) && ( f[0] <= '9' )) { fw = fw * 10 + f[0] - '0'; f++; } }
    // get the precision
    if ( f[0]=='.' ) { ++f; if ( f[0] == '*' ) {pr = va_arg(va,stbsp__uint32); ++f;} else { pr = 0; while (( f[0] >= '0' ) && ( f[0] <= '9' )) { pr = pr * 10 + f[0] - '0'; f++; } } } 
    
    // handle integer size overrides
    switch(f[0])
    {
      // are we halfwidth?
      case 'h': fl|=STBSP__HALFWIDTH; ++f; break;
      // are we 64-bit (unix style)
      case 'l': ++f; if ( f[0]=='l') { fl|=STBSP__INTMAX; ++f; } break;
      // are we 64-bit on intmax? (c99)
      case 'j': fl|=STBSP__INTMAX; ++f; break; 
      // are we 64-bit on size_t or ptrdiff_t? (c99)
      case 'z': case 't': fl|=((sizeof(char*)==8)?STBSP__INTMAX:0); ++f; break; 
      // are we 64-bit (msft style)
      case 'I': if ( ( f[1]=='6') && ( f[2]=='4') ) { fl|=STBSP__INTMAX; f+=3; }
                else if ( ( f[1]=='3') && ( f[2]=='2') ) { f+=3; }
                else { fl|=((sizeof(void*)==8)?STBSP__INTMAX:0); ++f; } break;
      default: break;
    }

    // handle each replacement
    switch( f[0] )
    {
      #define STBSP__NUMSZ   512 // big enough for e308 (with commas) or e-307 
      char num[STBSP__NUMSZ]; 
      char lead[8]; 
      char tail[8]; 
      char *s;
      char const *h;
      stbsp__uint32 l,n,cs;
      stbsp__uint64 n64;
      #ifndef STB_SPRINTF_NOFLOAT      
      double fv; 
      #endif
      stbsp__int32 dp; char const * sn;

      case 's':
        // get the string
        s = va_arg(va,char*); if (s==0) s = (char*)"null";
        // get the length
        sn = s;
        for(;;)
        { 
          if ((((stbsp__uintptr)sn)&3)==0) break;
         lchk:
          if (sn[0]==0) goto ld;
          ++sn;
        }
        n = 0xffffffff;
        if (pr>=0) { n=(stbsp__uint32)(sn-s); if (n>=(stbsp__uint32)pr) goto ld; n=((stbsp__uint32)(pr-n))>>2; }
        while(n) 
        { 
          stbsp__uint32 v=*(stbsp__uint32*)sn;
          if ((v-0x01010101)&(~v)&0x80808080UL) goto lchk; 
          sn+=4; 
          --n;
        }
        goto lchk;
       ld:

        l = (stbsp__uint32) ( sn - s );
        // clamp to precision
        if ( l > (stbsp__uint32)pr ) l = pr;
        lead[0]=0; tail[0]=0; pr = 0; dp = 0; cs = 0;
        // copy the string in
        goto scopy;

      case 'c': // char
        // get the character
        s = num + STBSP__NUMSZ -1; *s = (char)va_arg(va,int);
        l = 1;
        lead[0]=0; tail[0]=0; pr = 0; dp = 0; cs = 0;
        goto scopy;

      case 'n': // weird write-bytes specifier
        { int * d = va_arg(va,int*);
        *d = tlen + (int)( bf - buf ); }
        break;

#ifdef STB_SPRINTF_NOFLOAT
      case 'A': // float
      case 'a': // hex float
      case 'G': // float
      case 'g': // float
      case 'E': // float
      case 'e': // float
      case 'f': // float
        va_arg(va,double); // eat it
        s = (char*)"No float";
        l = 8;
        lead[0]=0; tail[0]=0; pr = 0; dp = 0; cs = 0;
        goto scopy;
#else
      case 'A': // float
        h=hexu;  
        goto hexfloat;

      case 'a': // hex float
        h=hex;
       hexfloat: 
        fv = va_arg(va,double);
        if (pr==-1) pr=6; // default is 6
        // read the double into a string
        if ( stbsp__real_to_parts( (stbsp__int64*)&n64, &dp, fv ) )
          fl |= STBSP__NEGATIVE;
  
        s = num+64;

        stbsp__lead_sign(fl, lead);

        if (dp==-1023) dp=(n64)?-1022:0; else n64|=(((stbsp__uint64)1)<<52);
        n64<<=(64-56);
        if (pr<15) n64+=((((stbsp__uint64)8)<<56)>>(pr*4));
        // add leading chars
        
        #ifdef STB_SPRINTF_MSVC_MODE
        *s++='0';*s++='x';
        #else
        lead[1+lead[0]]='0'; lead[2+lead[0]]='x'; lead[0]+=2;
        #endif
        *s++=h[(n64>>60)&15]; n64<<=4;
        if ( pr ) *s++=stbsp__period;
        sn = s;

        // print the bits
        n = pr; if (n>13) n = 13; if (pr>(stbsp__int32)n) tz=pr-n; pr = 0;
        while(n--) { *s++=h[(n64>>60)&15]; n64<<=4; }

        // print the expo
        tail[1]=h[17];
        if (dp<0) { tail[2]='-'; dp=-dp;} else tail[2]='+';
        n = (dp>=1000)?6:((dp>=100)?5:((dp>=10)?4:3));
        tail[0]=(char)n;
        for(;;) { tail[n]='0'+dp%10; if (n<=3) break; --n; dp/=10; }

        dp = (int)(s-sn);
        l = (int)(s-(num+64));
        s = num+64;
        cs = 1 + (3<<24);
        goto scopy;

      case 'G': // float
        h=hexu;
        goto dosmallfloat;

      case 'g': // float
        h=hex;
       dosmallfloat:   
        fv = va_arg(va,double);
        if (pr==-1) pr=6; else if (pr==0) pr = 1; // default is 6
        // read the double into a string
        if ( stbsp__real_to_str( &sn, &l, num, &dp, fv, (pr-1)|0x80000000 ) )
          fl |= STBSP__NEGATIVE;

        // clamp the precision and delete extra zeros after clamp
        n = pr;
        if ( l > (stbsp__uint32)pr ) l = pr; while ((l>1)&&(pr)&&(sn[l-1]=='0')) { --pr; --l; }

        // should we use %e
        if ((dp<=-4)||(dp>(stbsp__int32)n))
        {
          if ( pr > (stbsp__int32)l ) pr = l-1; else if ( pr ) --pr; // when using %e, there is one digit before the decimal
          goto doexpfromg;
        }
        // this is the insane action to get the pr to match %g sematics for %f
        if(dp>0) { pr=(dp<(stbsp__int32)l)?l-dp:0; } else { pr = -dp+((pr>(stbsp__int32)l)?l:pr); }
        goto dofloatfromg;

      case 'E': // float
        h=hexu;  
        goto doexp;

      case 'e': // float
        h=hex;
       doexp:   
        fv = va_arg(va,double);
        if (pr==-1) pr=6; // default is 6
        // read the double into a string
        if ( stbsp__real_to_str( &sn, &l, num, &dp, fv, pr|0x80000000 ) )
          fl |= STBSP__NEGATIVE;
       doexpfromg: 
        tail[0]=0; 
        stbsp__lead_sign(fl, lead);
        if ( dp == STBSP__SPECIAL ) { s=(char*)sn; cs=0; pr=0; goto scopy; }
        s=num+64; 
        // handle leading chars
        *s++=sn[0];

        if (pr) *s++=stbsp__period;

        // handle after decimal
        if ((l-1)>(stbsp__uint32)pr) l=pr+1;
        for(n=1;n<l;n++) *s++=sn[n];
        // trailing zeros
        tz = pr-(l-1); pr=0;
        // dump expo
        tail[1]=h[0xe];
        dp -= 1;
        if (dp<0) { tail[2]='-'; dp=-dp;} else tail[2]='+';
        #ifdef STB_SPRINTF_MSVC_MODE
        n = 5;
        #else
        n = (dp>=100)?5:4;
        #endif
        tail[0]=(char)n;
        for(;;) { tail[n]='0'+dp%10; if (n<=3) break; --n; dp/=10; }
        cs = 1 + (3<<24); // how many tens
        goto flt_lead;   

      case 'f': // float
        fv = va_arg(va,double);
       doafloat: 
        // do kilos
        if (fl&STBSP__METRIC_SUFFIX) 
        {
            double divisor;
            divisor=1000.0f;
            if (fl&STBSP__METRIC_1024) divisor = 1024.0;
            while(fl<0x4000000) { if ((fv<divisor) && (fv>-divisor)) break; fv/=divisor; fl+=0x1000000; }
        }
        if (pr==-1) pr=6; // default is 6
        // read the double into a string
        if ( stbsp__real_to_str( &sn, &l, num, &dp, fv, pr ) )
          fl |= STBSP__NEGATIVE;
        dofloatfromg:
        tail[0]=0;
        stbsp__lead_sign(fl, lead);
        if ( dp == STBSP__SPECIAL ) { s=(char*)sn; cs=0; pr=0; goto scopy; }
        s=num+64; 

        // handle the three decimal varieties
        if (dp<=0) 
        { 
          stbsp__int32 i;
          // handle 0.000*000xxxx
          *s++='0'; if (pr) *s++=stbsp__period; 
          n=-dp; if((stbsp__int32)n>pr) n=pr; i=n; while(i) { if ((((stbsp__uintptr)s)&3)==0) break; *s++='0'; --i; } while(i>=4) { *(stbsp__uint32*)s=0x30303030; s+=4; i-=4; } while(i) { *s++='0'; --i; }
          if ((stbsp__int32)(l+n)>pr) l=pr-n; i=l; while(i) { *s++=*sn++; --i; }
          tz = pr-(n+l);
          cs = 1 + (3<<24); // how many tens did we write (for commas below)
        }
        else
        {
          cs = (fl&STBSP__TRIPLET_COMMA)?((600-(stbsp__uint32)dp)%3):0;
          if ((stbsp__uint32)dp>=l)
          {
            // handle xxxx000*000.0
            n=0; for(;;) { if ((fl&STBSP__TRIPLET_COMMA) && (++cs==4)) { cs = 0; *s++=stbsp__comma; } else { *s++=sn[n]; ++n; if (n>=l) break; } }
            if (n<(stbsp__uint32)dp)
            {
              n = dp - n;
              if ((fl&STBSP__TRIPLET_COMMA)==0) { while(n) { if ((((stbsp__uintptr)s)&3)==0) break; *s++='0'; --n; }  while(n>=4) { *(stbsp__uint32*)s=0x30303030; s+=4; n-=4; } }
              while(n) { if ((fl&STBSP__TRIPLET_COMMA) && (++cs==4)) { cs = 0; *s++=stbsp__comma; } else { *s++='0'; --n; } }
            }
            cs = (int)(s-(num+64)) + (3<<24); // cs is how many tens
            if (pr) { *s++=stbsp__period; tz=pr;}
          }
          else
          {
            // handle xxxxx.xxxx000*000
            n=0; for(;;) { if ((fl&STBSP__TRIPLET_COMMA) && (++cs==4)) { cs = 0; *s++=stbsp__comma; } else { *s++=sn[n]; ++n; if (n>=(stbsp__uint32)dp) break; } }
            cs = (int)(s-(num+64)) + (3<<24); // cs is how many tens
            if (pr) *s++=stbsp__period;
            if ((l-dp)>(stbsp__uint32)pr) l=pr+dp;
            while(n<l) { *s++=sn[n]; ++n; }
            tz = pr-(l-dp);
          }
        }
        pr = 0;
        
        // handle k,m,g,t
        if (fl&STBSP__METRIC_SUFFIX) 
        { 
            char idx;
            idx=1;
            if (fl&STBSP__METRIC_NOSPACE)
                idx=0;
            tail[0]=idx; 
            tail[1]=' '; 
            { 
                if (fl>>24) 
                {   // SI kilo is 'k', JEDEC and SI kibits are 'K'.
                    if (fl&STBSP__METRIC_1024)
                        tail[idx+1]="_KMGT"[fl>>24]; 
                    else
                        tail[idx+1]="_kMGT"[fl>>24]; 
                    idx++;
                    // If printing kibits and not in jedec, add the 'i'.
                    if (fl&STBSP__METRIC_1024&&!(fl&STBSP__METRIC_JEDEC))
                    {
                        tail[idx+1]='i';
                        idx++;
                    }
                    tail[0]=idx;
                } 
            } 
        };

        flt_lead:
        // get the length that we copied
        l = (stbsp__uint32) ( s-(num+64) );
        s=num+64; 
        goto scopy;
#endif

      case 'B': // upper binary
        h = hexu;
        goto binary;

      case 'b': // lower binary
        h = hex;
        binary:
        lead[0]=0;
        if (fl&STBSP__LEADING_0X) { lead[0]=2;lead[1]='0';lead[2]=h[0xb]; }
        l=(8<<4)|(1<<8);
        goto radixnum;

      case 'o': // octal
        h = hexu;
        lead[0]=0;
        if (fl&STBSP__LEADING_0X) { lead[0]=1;lead[1]='0'; }
        l=(3<<4)|(3<<8);
        goto radixnum;

      case 'p': // pointer
        fl |= (sizeof(void*)==8)?STBSP__INTMAX:0;
        pr = sizeof(void*)*2;
        fl &= ~STBSP__LEADINGZERO; // 'p' only prints the pointer with zeros
        // drop through to X
      
      case 'X': // upper binary
        h = hexu;
        goto dohexb;

      case 'x': // lower binary
        h = hex; dohexb:
        l=(4<<4)|(4<<8);
        lead[0]=0;
        if (fl&STBSP__LEADING_0X) { lead[0]=2;lead[1]='0';lead[2]=h[16]; }
       radixnum: 
        // get the number
        if ( fl&STBSP__INTMAX )
          n64 = va_arg(va,stbsp__uint64);
        else
          n64 = va_arg(va,stbsp__uint32);

        s = num + STBSP__NUMSZ; dp = 0;
        // clear tail, and clear leading if value is zero
        tail[0]=0; if (n64==0) { lead[0]=0; if (pr==0) { l=0; cs = ( ((l>>4)&15)) << 24; goto scopy; } }
        // convert to string
        for(;;) { *--s = h[n64&((1<<(l>>8))-1)]; n64>>=(l>>8); if ( ! ( (n64) || ((stbsp__int32) ( (num+STBSP__NUMSZ) - s ) < pr ) ) ) break; if ( fl&STBSP__TRIPLET_COMMA) { ++l; if ((l&15)==((l>>4)&15)) { l&=~15; *--s=stbsp__comma; } } };
        // get the tens and the comma pos
        cs = (stbsp__uint32) ( (num+STBSP__NUMSZ) - s ) + ( ( ((l>>4)&15)) << 24 );
        // get the length that we copied
        l = (stbsp__uint32) ( (num+STBSP__NUMSZ) - s );
        // copy it
        goto scopy;

      case 'u': // unsigned
      case 'i':
      case 'd': // integer
        // get the integer and abs it
        if ( fl&STBSP__INTMAX )
        {
          stbsp__int64 i64 = va_arg(va,stbsp__int64); n64 = (stbsp__uint64)i64; if ((f[0]!='u') && (i64<0)) { n64=(stbsp__uint64)-i64; fl|=STBSP__NEGATIVE; }
        }
        else
        {
          stbsp__int32 i = va_arg(va,stbsp__int32); n64 = (stbsp__uint32)i; if ((f[0]!='u') && (i<0)) { n64=(stbsp__uint32)-i; fl|=STBSP__NEGATIVE; }
        }

        #ifndef STB_SPRINTF_NOFLOAT
        if (fl&STBSP__METRIC_SUFFIX) { if (n64<1024) pr=0; else if (pr==-1) pr=1; fv=(double)(stbsp__int64)n64; goto doafloat; } 
        #endif

        // convert to string
        s = num+STBSP__NUMSZ; l=0; 
        
        for(;;)
        {
          // do in 32-bit chunks (avoid lots of 64-bit divides even with constant denominators)
          char * o=s-8;
          if (n64>=100000000) { n = (stbsp__uint32)( n64 % 100000000);  n64 /= 100000000; } else {n = (stbsp__uint32)n64; n64 = 0; }
          if((fl&STBSP__TRIPLET_COMMA)==0) { while(n) { s-=2; *(stbsp__uint16*)s=*(stbsp__uint16*)&stbsp__digitpair[(n%100)*2]; n/=100; } }
          while (n) { if ( ( fl&STBSP__TRIPLET_COMMA) && (l++==3) ) { l=0; *--s=stbsp__comma; --o; } else { *--s=(char)(n%10)+'0'; n/=10; } }
          if (n64==0) { if ((s[0]=='0') && (s!=(num+STBSP__NUMSZ))) ++s; break; }
          while (s!=o) if ( ( fl&STBSP__TRIPLET_COMMA) && (l++==3) ) { l=0; *--s=stbsp__comma; --o; } else { *--s='0'; }
        }

        tail[0]=0;
        stbsp__lead_sign(fl, lead);

        // get the length that we copied
        l = (stbsp__uint32) ( (num+STBSP__NUMSZ) - s ); if ( l == 0 ) { *--s='0'; l = 1; }
        cs = l + (3<<24);
        if (pr<0) pr = 0;

       scopy: 
        // get fw=leading/trailing space, pr=leading zeros
        if (pr<(stbsp__int32)l) pr = l;
        n = pr + lead[0] + tail[0] + tz;
        if (fw<(stbsp__int32)n) fw = n;
        fw -= n;
        pr -= l;

        // handle right justify and leading zeros
        if ( (fl&STBSP__LEFTJUST)==0 )
        {
          if (fl&STBSP__LEADINGZERO) // if leading zeros, everything is in pr
          { 
            pr = (fw>pr)?fw:pr;
            fw = 0;
          }
          else
          {
            fl &= ~STBSP__TRIPLET_COMMA; // if no leading zeros, then no commas
          }
        }

        // copy the spaces and/or zeros
        if (fw+pr)
        {
          stbsp__int32 i; stbsp__uint32 c; 

          // copy leading spaces (or when doing %8.4d stuff)
          if ( (fl&STBSP__LEFTJUST)==0 ) while(fw>0) { stbsp__cb_buf_clamp(i,fw); fw -= i; while(i) { if ((((stbsp__uintptr)bf)&3)==0) break; *bf++=' '; --i; } while(i>=4) { *(stbsp__uint32*)bf=0x20202020; bf+=4; i-=4; } while (i) {*bf++=' '; --i;} stbsp__chk_cb_buf(1); }
        
          // copy leader
          sn=lead+1; while(lead[0]) { stbsp__cb_buf_clamp(i,lead[0]); lead[0] -= (char)i; while (i) {*bf++=*sn++; --i;} stbsp__chk_cb_buf(1); }
          
          // copy leading zeros
          c = cs >> 24; cs &= 0xffffff;
          cs = (fl&STBSP__TRIPLET_COMMA)?((stbsp__uint32)(c-((pr+cs)%(c+1)))):0;
          while(pr>0) { stbsp__cb_buf_clamp(i,pr); pr -= i; if((fl&STBSP__TRIPLET_COMMA)==0) { while(i) { if ((((stbsp__uintptr)bf)&3)==0) break; *bf++='0'; --i; } while(i>=4) { *(stbsp__uint32*)bf=0x30303030; bf+=4; i-=4; } } while (i) { if((fl&STBSP__TRIPLET_COMMA) && (cs++==c)) { cs = 0; *bf++=stbsp__comma; } else *bf++='0'; --i; } stbsp__chk_cb_buf(1); }
        }

        // copy leader if there is still one
        sn=lead+1; while(lead[0]) { stbsp__int32 i; stbsp__cb_buf_clamp(i,lead[0]); lead[0] -= (char)i; while (i) {*bf++=*sn++; --i;} stbsp__chk_cb_buf(1); }

        // copy the string
        n = l; while (n) { stbsp__int32 i; stbsp__cb_buf_clamp(i,n); n-=i; STBSP__UNALIGNED( while(i>=4) { *(stbsp__uint32*)bf=*(stbsp__uint32*)s; bf+=4; s+=4; i-=4; } ) while (i) {*bf++=*s++; --i;} stbsp__chk_cb_buf(1); }

        // copy trailing zeros
        while(tz) { stbsp__int32 i; stbsp__cb_buf_clamp(i,tz); tz -= i; while(i) { if ((((stbsp__uintptr)bf)&3)==0) break; *bf++='0'; --i; } while(i>=4) { *(stbsp__uint32*)bf=0x30303030; bf+=4; i-=4; } while (i) {*bf++='0'; --i;} stbsp__chk_cb_buf(1); }

        // copy tail if there is one
        sn=tail+1; while(tail[0]) { stbsp__int32 i; stbsp__cb_buf_clamp(i,tail[0]); tail[0] -= (char)i; while (i) {*bf++=*sn++; --i;} stbsp__chk_cb_buf(1); }

        // handle the left justify
        if (fl&STBSP__LEFTJUST) if (fw>0) { while (fw) { stbsp__int32 i; stbsp__cb_buf_clamp(i,fw); fw-=i; while(i) { if ((((stbsp__uintptr)bf)&3)==0) break; *bf++=' '; --i; } while(i>=4) { *(stbsp__uint32*)bf=0x20202020; bf+=4; i-=4; } while (i--) *bf++=' '; stbsp__chk_cb_buf(1); } }
        break;

      default: // unknown, just copy code
        s = num + STBSP__NUMSZ -1; *s = f[0];
        l = 1;
        fw=pr=fl=0;
        lead[0]=0; tail[0]=0; pr = 0; dp = 0; cs = 0;
        goto scopy;
    }
    ++f;
  }
 endfmt:

  if (!callback) 
    *bf = 0;
  else
    stbsp__flush_cb();
 
 done:
  return tlen + (int)(bf-buf);
}

// cleanup
#undef STBSP__LEFTJUST
#undef STBSP__LEADINGPLUS
#undef STBSP__LEADINGSPACE
#undef STBSP__LEADING_0X
#undef STBSP__LEADINGZERO
#undef STBSP__INTMAX
#undef STBSP__TRIPLET_COMMA
#undef STBSP__NEGATIVE
#undef STBSP__METRIC_SUFFIX
#undef STBSP__NUMSZ
#undef stbsp__chk_cb_bufL
#undef stbsp__chk_cb_buf
#undef stbsp__flush_cb
#undef stbsp__cb_buf_clamp

// ============================================================================
//   wrapper functions

STBSP__PUBLICDEF int STB_SPRINTF_DECORATE( sprintf )( char * buf, char const * fmt, ... )
{
  int result;
  va_list va;
  va_start( va, fmt );
  result = STB_SPRINTF_DECORATE( vsprintfcb )( 0, 0, buf, fmt, va );
  va_end(va);
  return result;
}

typedef struct stbsp__context
{
  char * buf;
  int count;
  char tmp[ STB_SPRINTF_MIN ];
} stbsp__context;

static char * stbsp__clamp_callback( char * buf, void * user, int len )
{
  stbsp__context * c = (stbsp__context*)user;

  if ( len > c->count ) len = c->count;

  if (len)
  {
    if ( buf != c->buf )
    {
      char * s, * d, * se;
      d = c->buf; s = buf; se = buf+len;
      do{ *d++ = *s++; } while (s<se);
    }
    c->buf += len;
    c->count -= len;
  }
  
  if ( c->count <= 0 ) return 0;
  return ( c->count >= STB_SPRINTF_MIN ) ? c->buf : c->tmp; // go direct into buffer if you can
}

STBSP__PUBLICDEF int STB_SPRINTF_DECORATE( vsnprintf )( char * buf, int count, char const * fmt, va_list va )
{
  stbsp__context c;
  int l;

  if ( count == 0 )
    return 0;

  c.buf = buf;
  c.count = count;

  STB_SPRINTF_DECORATE( vsprintfcb )( stbsp__clamp_callback, &c, stbsp__clamp_callback(0,&c,0), fmt, va );
  
  // zero-terminate
  l = (int)( c.buf - buf );
  if ( l >= count ) // should never be greater, only equal (or less) than count
    l = count - 1;
  buf[l] = 0;

  return l;
}

STBSP__PUBLICDEF int STB_SPRINTF_DECORATE( snprintf )( char * buf, int count, char const * fmt, ... )
{
  int result;
  va_list va;
  va_start( va, fmt );

  result = STB_SPRINTF_DECORATE( vsnprintf )( buf, count, fmt, va );
  va_end(va);

  return result;
}

STBSP__PUBLICDEF int STB_SPRINTF_DECORATE( vsprintf )( char * buf, char const * fmt, va_list va )
{
  return STB_SPRINTF_DECORATE( vsprintfcb )( 0, 0, buf, fmt, va );
}

// =======================================================================
//   low level float utility functions

#ifndef STB_SPRINTF_NOFLOAT

// copies d to bits w/ strict aliasing (this compiles to nothing on /Ox)
#define STBSP__COPYFP(dest,src) { int cn; for(cn=0;cn<8;cn++) ((char*)&dest)[cn]=((char*)&src)[cn]; }
 
// get float info
static stbsp__int32 stbsp__real_to_parts( stbsp__int64 * bits, stbsp__int32 * expo, double value )
{
  double d;
  stbsp__int64 b = 0;

  // load value and round at the frac_digits
  d = value;

  STBSP__COPYFP( b, d );

  *bits = b & ((((stbsp__uint64)1)<<52)-1);
  *expo = (stbsp__int32) (((b >> 52) & 2047)-1023);
    
  return (stbsp__int32)(b >> 63);
}

static double const stbsp__bot[23]={1e+000,1e+001,1e+002,1e+003,1e+004,1e+005,1e+006,1e+007,1e+008,1e+009,1e+010,1e+011,1e+012,1e+013,1e+014,1e+015,1e+016,1e+017,1e+018,1e+019,1e+020,1e+021,1e+022};
static double const stbsp__negbot[22]={1e-001,1e-002,1e-003,1e-004,1e-005,1e-006,1e-007,1e-008,1e-009,1e-010,1e-011,1e-012,1e-013,1e-014,1e-015,1e-016,1e-017,1e-018,1e-019,1e-020,1e-021,1e-022};
static double const stbsp__negboterr[22]={-5.551115123125783e-018,-2.0816681711721684e-019,-2.0816681711721686e-020,-4.7921736023859299e-021,-8.1803053914031305e-022,4.5251888174113741e-023,4.5251888174113739e-024,-2.0922560830128471e-025,-6.2281591457779853e-026,-3.6432197315497743e-027,6.0503030718060191e-028,2.0113352370744385e-029,-3.0373745563400371e-030,1.1806906454401013e-032,-7.7705399876661076e-032,2.0902213275965398e-033,-7.1542424054621921e-034,-7.1542424054621926e-035,2.4754073164739869e-036,5.4846728545790429e-037,9.2462547772103625e-038,-4.8596774326570872e-039};
static double const stbsp__top[13]={1e+023,1e+046,1e+069,1e+092,1e+115,1e+138,1e+161,1e+184,1e+207,1e+230,1e+253,1e+276,1e+299};
static double const stbsp__negtop[13]={1e-023,1e-046,1e-069,1e-092,1e-115,1e-138,1e-161,1e-184,1e-207,1e-230,1e-253,1e-276,1e-299};
static double const stbsp__toperr[13]={8388608,6.8601809640529717e+028,-7.253143638152921e+052,-4.3377296974619174e+075,-1.5559416129466825e+098,-3.2841562489204913e+121,-3.7745893248228135e+144,-1.7356668416969134e+167,-3.8893577551088374e+190,-9.9566444326005119e+213,6.3641293062232429e+236,-5.2069140800249813e+259,-5.2504760255204387e+282};
static double const stbsp__negtoperr[13]={3.9565301985100693e-040,-2.299904345391321e-063,3.6506201437945798e-086,1.1875228833981544e-109,-5.0644902316928607e-132,-6.7156837247865426e-155,-2.812077463003139e-178,-5.7778912386589953e-201,7.4997100559334532e-224,-4.6439668915134491e-247,-6.3691100762962136e-270,-9.436808465446358e-293,8.0970921678014997e-317};

#if defined(_MSC_VER) && (_MSC_VER<=1200)                                                                                                                                                                                       
static stbsp__uint64 const stbsp__powten[20]={1,10,100,1000, 10000,100000,1000000,10000000, 100000000,1000000000,10000000000,100000000000,  1000000000000,10000000000000,100000000000000,1000000000000000,  10000000000000000,100000000000000000,1000000000000000000,10000000000000000000U };
#define stbsp__tento19th ((stbsp__uint64)1000000000000000000)
#else
static stbsp__uint64 const stbsp__powten[20]={1,10,100,1000, 10000,100000,1000000,10000000, 100000000,1000000000,10000000000ULL,100000000000ULL,  1000000000000ULL,10000000000000ULL,100000000000000ULL,1000000000000000ULL,  10000000000000000ULL,100000000000000000ULL,1000000000000000000ULL,10000000000000000000ULL };
#define stbsp__tento19th (1000000000000000000ULL)
#endif

#define stbsp__ddmulthi(oh,ol,xh,yh) \
{ \
  double ahi=0,alo,bhi=0,blo; \
  stbsp__int64 bt; \
  oh = xh * yh; \
  STBSP__COPYFP(bt,xh); bt&=((~(stbsp__uint64)0)<<27); STBSP__COPYFP(ahi,bt); alo = xh-ahi; \
  STBSP__COPYFP(bt,yh); bt&=((~(stbsp__uint64)0)<<27); STBSP__COPYFP(bhi,bt); blo = yh-bhi; \
  ol = ((ahi*bhi-oh)+ahi*blo+alo*bhi)+alo*blo; \
}

#define stbsp__ddtoS64(ob,xh,xl) \
{ \
  double ahi=0,alo,vh,t;\
  ob = (stbsp__int64)ph;\
  vh=(double)ob;\
  ahi = ( xh - vh );\
  t = ( ahi - xh );\
  alo = (xh-(ahi-t))-(vh+t);\
  ob += (stbsp__int64)(ahi+alo+xl);\
}


#define stbsp__ddrenorm(oh,ol) { double s; s=oh+ol; ol=ol-(s-oh); oh=s; }

#define stbsp__ddmultlo(oh,ol,xh,xl,yh,yl) \
  ol = ol + ( xh*yl + xl*yh ); \

#define stbsp__ddmultlos(oh,ol,xh,yl) \
  ol = ol + ( xh*yl ); \

static void stbsp__raise_to_power10( double *ohi, double *olo, double d, stbsp__int32 power )  // power can be -323 to +350
{
  double ph, pl;
  if ((power>=0) && (power<=22))
  {
    stbsp__ddmulthi(ph,pl,d,stbsp__bot[power]);
  }
  else
  {
    stbsp__int32 e,et,eb;
    double p2h,p2l;

    e=power; if (power<0) e=-e; 
    et = (e*0x2c9)>>14;/* %23 */ if (et>13) et=13; eb = e-(et*23);

    ph = d; pl = 0.0;
    if (power<0)
    {
      if (eb) { --eb; stbsp__ddmulthi(ph,pl,d,stbsp__negbot[eb]); stbsp__ddmultlos(ph,pl,d,stbsp__negboterr[eb]); }
      if (et)
      { 
        stbsp__ddrenorm(ph,pl);
        --et; stbsp__ddmulthi(p2h,p2l,ph,stbsp__negtop[et]); stbsp__ddmultlo(p2h,p2l,ph,pl,stbsp__negtop[et],stbsp__negtoperr[et]); ph=p2h;pl=p2l;
      }
    }
    else
    {
      if (eb) 
      { 
        e = eb; if (eb>22) eb=22; e -= eb;
        stbsp__ddmulthi(ph,pl,d,stbsp__bot[eb]); 
        if ( e ) { stbsp__ddrenorm(ph,pl); stbsp__ddmulthi(p2h,p2l,ph,stbsp__bot[e]); stbsp__ddmultlos(p2h,p2l,stbsp__bot[e],pl); ph=p2h;pl=p2l; }
      }
      if (et)
      {
        stbsp__ddrenorm(ph,pl);
        --et; stbsp__ddmulthi(p2h,p2l,ph,stbsp__top[et]); stbsp__ddmultlo(p2h,p2l,ph,pl,stbsp__top[et],stbsp__toperr[et]); ph=p2h;pl=p2l;
      }
    }
  }
  stbsp__ddrenorm(ph,pl);
  *ohi = ph; *olo = pl;
}

// given a float value, returns the significant bits in bits, and the position of the
//   decimal point in decimal_pos.  +/-INF and NAN are specified by special values
//   returned in the decimal_pos parameter.
// frac_digits is absolute normally, but if you want from first significant digits (got %g and %e), or in 0x80000000
static stbsp__int32 stbsp__real_to_str( char const * * start, stbsp__uint32 * len, char *out, stbsp__int32 * decimal_pos, double value, stbsp__uint32 frac_digits )
{
  double d;
  stbsp__int64 bits = 0;
  stbsp__int32 expo, e, ng, tens;

  d = value;
  STBSP__COPYFP(bits,d);
  expo = (stbsp__int32) ((bits >> 52) & 2047);
  ng = (stbsp__int32)(bits >> 63);
  if (ng) d=-d;

  if ( expo == 2047 ) // is nan or inf?
  {
    *start = (bits&((((stbsp__uint64)1)<<52)-1)) ? "NaN" : "Inf";
    *decimal_pos =  STBSP__SPECIAL;
    *len = 3;
    return ng;
  } 

  if ( expo == 0 ) // is zero or denormal
  {
    if ((bits<<1)==0) // do zero
    {
      *decimal_pos = 1; 
      *start = out;
      out[0] = '0'; *len = 1;
      return ng;
    }
    // find the right expo for denormals
    {
      stbsp__int64 v = ((stbsp__uint64)1)<<51;
      while ((bits&v)==0) { --expo; v >>= 1; }
    }
  }

  // find the decimal exponent as well as the decimal bits of the value
  {
    double ph,pl;

    // log10 estimate - very specifically tweaked to hit or undershoot by no more than 1 of log10 of all expos 1..2046
    tens=expo-1023; tens = (tens<0)?((tens*617)/2048):(((tens*1233)/4096)+1);

    // move the significant bits into position and stick them into an int 
    stbsp__raise_to_power10( &ph, &pl, d, 18-tens );

    // get full as much precision from double-double as possible
    stbsp__ddtoS64( bits, ph,pl );

    // check if we undershot
    if ( ((stbsp__uint64)bits) >= stbsp__tento19th ) ++tens; 
  }

  // now do the rounding in integer land
  frac_digits = ( frac_digits & 0x80000000 ) ? ( (frac_digits&0x7ffffff) + 1 ) : ( tens + frac_digits );
  if ( ( frac_digits < 24 ) )
  {
    stbsp__uint32 dg = 1; if ((stbsp__uint64)bits >= stbsp__powten[9] ) dg=10; while( (stbsp__uint64)bits >= stbsp__powten[dg] ) { ++dg; if (dg==20) goto noround; }
    if ( frac_digits < dg )
    {
      stbsp__uint64 r;
      // add 0.5 at the right position and round
      e = dg - frac_digits;
      if ( (stbsp__uint32)e >= 24 ) goto noround;
      r = stbsp__powten[e];
      bits = bits + (r/2);
      if ( (stbsp__uint64)bits >= stbsp__powten[dg] ) ++tens;
      bits /= r;
    } 
    noround:;
  }

  // kill long trailing runs of zeros
  if ( bits )
  {
    stbsp__uint32 n;
    for(;;) { if ( bits<=0xffffffff ) break; if (bits%1000) goto donez; bits/=1000; }
    n = (stbsp__uint32)bits;
    while ((n%1000)==0) n/=1000;
    bits=n;
    donez:;
  }

  // convert to string
  out += 64;
  e = 0; 
  for(;;)
  {
    stbsp__uint32 n;
    char * o = out-8;
    // do the conversion in chunks of U32s (avoid most 64-bit divides, worth it, constant denomiators be damned)
    if (bits>=100000000) { n = (stbsp__uint32)( bits % 100000000);  bits /= 100000000; } else {n = (stbsp__uint32)bits; bits = 0; }
    while(n) { out-=2; *(stbsp__uint16*)out=*(stbsp__uint16*)&stbsp__digitpair[(n%100)*2]; n/=100; e+=2; }
    if (bits==0) { if ((e) && (out[0]=='0')) { ++out; --e; } break; }
    while( out!=o ) { *--out ='0'; ++e; }
  }
  
  *decimal_pos = tens;
  *start = out;
  *len = e;
  return ng;
}

#undef stbsp__ddmulthi
#undef stbsp__ddrenorm
#undef stbsp__ddmultlo
#undef stbsp__ddmultlos
#undef STBSP__SPECIAL
#undef STBSP__COPYFP

#endif // STB_SPRINTF_NOFLOAT

// clean up
#undef stbsp__uint16
#undef stbsp__uint32
#undef stbsp__int32
#undef stbsp__uint64
#undef stbsp__int64
#undef STBSP__UNALIGNED

#ifdef __GNUC__
	#pragma GCC diagnostic pop
#endif

////////////////////////////////////////////////////////////////////////////////
// #DqnIni Implementation - Simple ini-file reader for C/C++.
////////////////////////////////////////////////////////////////////////////////
#ifdef __GNUC__
	#pragma GCC diagnostic push
	#pragma GCC diagnostic ignored "-Wsign-compare"
#endif

#define INITIAL_CAPACITY (256)

#define _CRT_NONSTDC_NO_DEPRECATE
#define _CRT_SECURE_NO_WARNINGS
#include <stddef.h>

#ifndef DQN_INI_MALLOC
	#define _CRT_NONSTDC_NO_DEPRECATE
	#define _CRT_SECURE_NO_WARNINGS
	#include <stdlib.h>
	#define DQN_INI_MALLOC(ctx, size) (malloc(size))
	#define DQN_INI_FREE(ctx, ptr) (free(ptr))
#endif

#ifndef DQN_INI_MEMCPY
	#define _CRT_NONSTDC_NO_DEPRECATE
	#define _CRT_SECURE_NO_WARNINGS
	#include <string.h>
	#define DQN_INI_MEMCPY(dst, src, cnt) (memcpy(dst, src, cnt))
#endif

#ifndef DQN_INI_STRLEN
	#define _CRT_NONSTDC_NO_DEPRECATE
	#define _CRT_SECURE_NO_WARNINGS
	#include <string.h>
	#define DQN_INI_STRLEN(s) (strlen(s))
#endif

#ifndef DQN_INI_STRICMP
	#ifdef _WIN32
		#define _CRT_NONSTDC_NO_DEPRECATE
		#define _CRT_SECURE_NO_WARNINGS
		#include <string.h>
		#define DQN_INI_STRICMP(s1, s2) ( _stricmp(s1, s2))
	#else
		#include <string.h>
		#define DQN_INI_STRICMP(s1, s2) (strcasecmp(s1, s2))
	#endif
#endif

struct dqn_ini_internal_section_t
{
	char name[32];
	char *name_large;
};

struct dqn_ini_internal_property_t
{
	int section;
	char name[32];
	char *name_large;
	char value[64];
	char *value_large;
};

struct DqnIni
{
	struct dqn_ini_internal_section_t *sections;
	int section_capacity;
	int section_count;

	struct dqn_ini_internal_property_t *properties;
	int property_capacity;
	int property_count;

	void *memctx;
};

static int DqnIni_InternalPropertyIndex(DqnIni const *ini, int section,
                                           int property)
{
	int i;
	int p;

	if (ini && section >= 0 && section < ini->section_count)
	{
		p = 0;
		for (i = 0; i < ini->property_count; ++i)
		{
			if (ini->properties[i].section == section)
			{
				if (p == property) return i;
				++p;
			}
		}
	}

	return DQN_INI_NOT_FOUND;
}

DqnIni *DqnIni_Create(void *memctx)
{
	DqnIni *ini;

	ini           = (DqnIni *)DQN_INI_MALLOC(memctx, sizeof(DqnIni));
	ini->memctx   = memctx;
	ini->sections = (struct dqn_ini_internal_section_t *)DQN_INI_MALLOC(
	    ini->memctx, INITIAL_CAPACITY * sizeof(ini->sections[0]));
	ini->section_capacity       = INITIAL_CAPACITY;
	ini->section_count          = 1; /* global section */
	ini->sections[0].name[0]    = '\0';
	ini->sections[0].name_large = 0;
	ini->properties = (struct dqn_ini_internal_property_t *)DQN_INI_MALLOC(
	    ini->memctx, INITIAL_CAPACITY * sizeof(ini->properties[0]));
	ini->property_capacity = INITIAL_CAPACITY;
	ini->property_count    = 0;
	return ini;
}

DqnIni *DqnIni_Load(char const *data, void *memctx)
{
	DqnIni *ini;
	char const *ptr;
	int s;
	char const *start;
	char const *start2;
	int l;

	ini = DqnIni_Create(memctx);

	ptr = data;
	if (ptr)
	{
		s = 0;
		while (*ptr)
		{
			/* trim leading whitespace */
			while (*ptr && *ptr <= ' ')
				++ptr;

			/* done? */
			if (!*ptr) break;

			/* comment */
			else if (*ptr == ';')
			{
				while (*ptr && *ptr != '\n')
					++ptr;
			}
			/* section */
			else if (*ptr == '[')
			{
				++ptr;
				start = ptr;
				while (*ptr && *ptr != ']' && *ptr != '\n')
					++ptr;

				if (*ptr == ']')
				{
					s = DqnIni_SectionAdd(ini, start, (int)(ptr - start));
					++ptr;
				}
			}
			/* property */
			else
			{
				start = ptr;
				while (*ptr && *ptr != '=' && *ptr != '\n')
					++ptr;

				if (*ptr == '=')
				{
					l = (int)(ptr - start);
					++ptr;
					while (*ptr && *ptr <= ' ' && *ptr != '\n')
						ptr++;
					start2 = ptr;
					while (*ptr && *ptr != '\n')
						++ptr;
					while (*(--ptr) <= ' ')
						(void)ptr;
					ptr++;
					DqnIni_PropertyAdd(ini, s, start, l, start2,
					                     (int)(ptr - start2));
				}
			}
		}
	}

	return ini;
}

int DqnIni_Save(DqnIni const *ini, char *data, int size)
{
	int s;
	int p;
	int i;
	int l;
	char *n;
	int pos;

	if (ini)
	{
		pos = 0;
		for (s = 0; s < ini->section_count; ++s)
		{
			n = ini->sections[s].name_large ? ini->sections[s].name_large
			                                : ini->sections[s].name;
			l = (int)DQN_INI_STRLEN(n);
			if (l > 0)
			{
				if (data && pos < size) data[pos] = '[';
				++pos;
				for (i = 0; i < l; ++i)
				{
					if (data && pos < size) data[pos] = n[i];
					++pos;
				}
				if (data && pos < size) data[pos] = ']';
				++pos;
				if (data && pos < size) data[pos] = '\n';
				++pos;
			}

			for (p = 0; p < ini->property_count; ++p)
			{
				if (ini->properties[p].section == s)
				{
					n = ini->properties[p].name_large
					        ? ini->properties[p].name_large
					        : ini->properties[p].name;
					l = (int)DQN_INI_STRLEN(n);
					for (i = 0; i < l; ++i)
					{
						if (data && pos < size) data[pos] = n[i];
						++pos;
					}
					if (data && pos < size) data[pos] = '=';
					++pos;
					n = ini->properties[p].value_large
					        ? ini->properties[p].value_large
					        : ini->properties[p].value;
					l = (int)DQN_INI_STRLEN(n);
					for (i = 0; i < l; ++i)
					{
						if (data && pos < size) data[pos] = n[i];
						++pos;
					}
					if (data && pos < size) data[pos] = '\n';
					++pos;
				}
			}

			if (pos > 0)
			{
				if (data && pos < size) data[pos] = '\n';
				++pos;
			}
		}

		if (data && pos < size) data[pos] = '\0';
		++pos;

		return pos;
	}

	return 0;
}

void DqnIni_Destroy(DqnIni *ini)
{
	int i;

	if (ini)
	{
		for (i = 0; i < ini->property_count; ++i)
		{
			if (ini->properties[i].value_large)
				DQN_INI_FREE(ini->memctx, ini->properties[i].value_large);
			if (ini->properties[i].name_large)
				DQN_INI_FREE(ini->memctx, ini->properties[i].name_large);
		}
		for (i = 0; i < ini->section_count; ++i)
			if (ini->sections[i].name_large)
				DQN_INI_FREE(ini->memctx, ini->sections[i].name_large);
		DQN_INI_FREE(ini->memctx, ini->properties);
		DQN_INI_FREE(ini->memctx, ini->sections);
		DQN_INI_FREE(ini->memctx, ini);
	}
}

int DqnIni_SectionCount(DqnIni const *ini)
{
	if (ini) return ini->section_count;
	return 0;
}

char const *DqnIni_SectionName(DqnIni const *ini, int section)
{
	if (ini && section >= 0 && section < ini->section_count)
		return ini->sections[section].name_large
		           ? ini->sections[section].name_large
		           : ini->sections[section].name;

	return nullptr;
}

int DqnIni_PropertyCount(DqnIni const *ini, int section)
{
	int i;
	int count;

	if (ini)
	{
		count = 0;
		for (i = 0; i < ini->property_count; ++i)
		{
			if (ini->properties[i].section == section) ++count;
		}
		return count;
	}

	return 0;
}

char const *DqnIni_PropertyName(DqnIni const *ini, int section, int property)
{
	int p;

	if (ini && section >= 0 && section < ini->section_count)
	{
		p = DqnIni_InternalPropertyIndex(ini, section, property);
		if (p != DQN_INI_NOT_FOUND)
			return ini->properties[p].name_large ? ini->properties[p].name_large
			                                     : ini->properties[p].name;
	}

	return nullptr;
}

char const *DqnIni_PropertyValue(DqnIni const *ini, int section, int property)
{
	int p;

	if (ini && section >= 0 && section < ini->section_count)
	{
		p = DqnIni_InternalPropertyIndex(ini, section, property);
		if (p != DQN_INI_NOT_FOUND)
			return ini->properties[p].value_large
			           ? ini->properties[p].value_large
			           : ini->properties[p].value;
	}

	return nullptr;
}

int DqnIni_FindSection(DqnIni const *ini, char const *name, int name_length)
{
	int i;

	if (ini && name)
	{
		if (name_length <= 0) name_length = (int)DQN_INI_STRLEN(name);
		for (i = 0; i < ini->section_count; ++i)
		{
			char const *const other = ini->sections[i].name_large
			                              ? ini->sections[i].name_large
			                              : ini->sections[i].name;
			if ((int)DQN_INI_STRLEN(other) == name_length &&
			    DQN_INI_STRICMP(name, other) == 0)
				return i;
		}
	}

	return DQN_INI_NOT_FOUND;
}

int DqnIni_FindProperty(DqnIni const *ini, int section, char const *name,
                          int name_length)
{
	int i;
	int c;

	if (ini && name && section >= 0 && section < ini->section_count)
	{
		if (name_length <= 0) name_length = (int)DQN_INI_STRLEN(name);
		c                                 = 0;
		for (i = 0; i < ini->property_capacity; ++i)
		{
			if (ini->properties[i].section == section)
			{
				char const *const other = ini->properties[i].name_large
				                              ? ini->properties[i].name_large
				                              : ini->properties[i].name;
				if ((int)DQN_INI_STRLEN(other) == name_length &&
				    DQN_INI_STRICMP(name, other) == 0)
					return c;
				++c;
			}
		}
	}

	return DQN_INI_NOT_FOUND;
}

int DqnIni_SectionAdd(DqnIni *ini, char const *name, int length)
{
	struct dqn_ini_internal_section_t *new_sections;

	if (ini && name)
	{
		if (length <= 0) length = (int)DQN_INI_STRLEN(name);
		if (ini->section_count >= ini->section_capacity)
		{
			ini->section_capacity *= 2;
			new_sections = (struct dqn_ini_internal_section_t *)DQN_INI_MALLOC(
			    ini->memctx, ini->section_capacity * sizeof(ini->sections[0]));
			DQN_INI_MEMCPY(new_sections, ini->sections,
			               ini->section_count * sizeof(ini->sections[0]));
			DQN_INI_FREE(ini->memctx, ini->sections);
			ini->sections = new_sections;
		}

		ini->sections[ini->section_count].name_large = 0;
		if (length + 1 >= sizeof(ini->sections[0].name))
		{
			ini->sections[ini->section_count].name_large =
			    (char *)DQN_INI_MALLOC(ini->memctx, (size_t)length + 1);
			DQN_INI_MEMCPY(ini->sections[ini->section_count].name_large, name,
			               (size_t)length);
			ini->sections[ini->section_count].name_large[length] = '\0';
		}
		else
		{
			DQN_INI_MEMCPY(ini->sections[ini->section_count].name, name,
			               (size_t)length);
			ini->sections[ini->section_count].name[length] = '\0';
		}

		return ini->section_count++;
	}
	return DQN_INI_NOT_FOUND;
}

void DqnIni_PropertyAdd(DqnIni *ini, int section, char const *name,
                          int name_length, char const *value, int value_length)
{
	struct dqn_ini_internal_property_t *new_properties;

	if (ini && name && section >= 0 && section < ini->section_count)
	{
		if (name_length <= 0) name_length   = (int)DQN_INI_STRLEN(name);
		if (value_length <= 0) value_length = (int)DQN_INI_STRLEN(value);

		if (ini->property_count >= ini->property_capacity)
		{

			ini->property_capacity *= 2;
			new_properties =
			    (struct dqn_ini_internal_property_t *)DQN_INI_MALLOC(
			        ini->memctx,
			        ini->property_capacity * sizeof(ini->properties[0]));
			DQN_INI_MEMCPY(new_properties, ini->properties,
			               ini->property_count * sizeof(ini->properties[0]));
			DQN_INI_FREE(ini->memctx, ini->properties);
			ini->properties = new_properties;
		}

		ini->properties[ini->property_count].section     = section;
		ini->properties[ini->property_count].name_large  = 0;
		ini->properties[ini->property_count].value_large = 0;

		if (name_length + 1 >= sizeof(ini->properties[0].name))
		{
			ini->properties[ini->property_count].name_large =
			    (char *)DQN_INI_MALLOC(ini->memctx, (size_t)name_length + 1);
			DQN_INI_MEMCPY(ini->properties[ini->property_count].name_large,
			               name, (size_t)name_length);
			ini->properties[ini->property_count].name_large[name_length] = '\0';
		}
		else
		{
			DQN_INI_MEMCPY(ini->properties[ini->property_count].name, name,
			               (size_t)name_length);
			ini->properties[ini->property_count].name[name_length] = '\0';
		}

		if (value_length + 1 >= sizeof(ini->properties[0].value))
		{
			ini->properties[ini->property_count].value_large =
			    (char *)DQN_INI_MALLOC(ini->memctx, (size_t)value_length + 1);
			DQN_INI_MEMCPY(ini->properties[ini->property_count].value_large,
			               value, (size_t)value_length);
			ini->properties[ini->property_count].value_large[value_length] =
			    '\0';
		}
		else
		{
			DQN_INI_MEMCPY(ini->properties[ini->property_count].value, value,
			               (size_t)value_length);
			ini->properties[ini->property_count].value[value_length] = '\0';
		}

		++ini->property_count;
	}
}

void DqnIni_SectionRemove(DqnIni *ini, int section)
{
	int p;

	if (ini && section >= 0 && section < ini->section_count)
	{
		if (ini->sections[section].name_large)
			DQN_INI_FREE(ini->memctx, ini->sections[section].name_large);
		for (p = ini->property_count - 1; p >= 0; --p)
		{
			if (ini->properties[p].section == section)
			{
				if (ini->properties[p].value_large)
					DQN_INI_FREE(ini->memctx, ini->properties[p].value_large);
				if (ini->properties[p].name_large)
					DQN_INI_FREE(ini->memctx, ini->properties[p].name_large);
				ini->properties[p] = ini->properties[--ini->property_count];
			}
		}

		ini->sections[section] = ini->sections[--ini->section_count];

		for (p = 0; p < ini->property_count; ++p)
		{
			if (ini->properties[p].section == ini->section_count)
				ini->properties[p].section = section;
		}
	}
}

void DqnIni_PropertyRemove(DqnIni *ini, int section, int property)
{
	int p;

	if (ini && section >= 0 && section < ini->section_count)
	{
		p = DqnIni_InternalPropertyIndex(ini, section, property);
		if (p != DQN_INI_NOT_FOUND)
		{
			if (ini->properties[p].value_large)
				DQN_INI_FREE(ini->memctx, ini->properties[p].value_large);
			if (ini->properties[p].name_large)
				DQN_INI_FREE(ini->memctx, ini->properties[p].name_large);
			ini->properties[p] = ini->properties[--ini->property_count];
			return;
		}
	}
}

void DqnIni_SectionNameSet(DqnIni *ini, int section, char const *name,
                              int length)
{
	if (ini && name && section >= 0 && section < ini->section_count)
	{
		if (length <= 0) length = (int)DQN_INI_STRLEN(name);
		if (ini->sections[section].name_large)
			DQN_INI_FREE(ini->memctx, ini->sections[section].name_large);
		ini->sections[section].name_large = 0;

		if (length + 1 >= sizeof(ini->sections[0].name))
		{
			ini->sections[section].name_large =
			    (char *)DQN_INI_MALLOC(ini->memctx, (size_t)length + 1);
			DQN_INI_MEMCPY(ini->sections[section].name_large, name,
			               (size_t)length);
			ini->sections[section].name_large[length] = '\0';
		}
		else
		{
			DQN_INI_MEMCPY(ini->sections[section].name, name, (size_t)length);
			ini->sections[section].name[length] = '\0';
		}
	}
}

void DqnIni_PropertyNameSet(DqnIni *ini, int section, int property,
                               char const *name, int length)
{
	int p;

	if (ini && name && section >= 0 && section < ini->section_count)
	{
		if (length <= 0) length = (int)DQN_INI_STRLEN(name);
		p = DqnIni_InternalPropertyIndex(ini, section, property);
		if (p != DQN_INI_NOT_FOUND)
		{
			if (ini->properties[p].name_large)
				DQN_INI_FREE(ini->memctx, ini->properties[p].name_large);
			ini->properties[ini->property_count].name_large = 0;

			if (length + 1 >= sizeof(ini->properties[0].name))
			{
				ini->properties[p].name_large =
				    (char *)DQN_INI_MALLOC(ini->memctx, (size_t)length + 1);
				DQN_INI_MEMCPY(ini->properties[p].name_large, name,
				               (size_t)length);
				ini->properties[p].name_large[length] = '\0';
			}
			else
			{
				DQN_INI_MEMCPY(ini->properties[p].name, name, (size_t)length);
				ini->properties[p].name[length] = '\0';
			}
		}
	}
}

void DqnIni_PropertyValueSet(DqnIni *ini, int section, int property,
                                char const *value, int length)
{
	int p;

	if (ini && value && section >= 0 && section < ini->section_count)
	{
		if (length <= 0) length = (int)DQN_INI_STRLEN(value);
		p = DqnIni_InternalPropertyIndex(ini, section, property);
		if (p != DQN_INI_NOT_FOUND)
		{
			if (ini->properties[p].value_large)
				DQN_INI_FREE(ini->memctx, ini->properties[p].value_large);
			ini->properties[ini->property_count].value_large = 0;

			if (length + 1 >= sizeof(ini->properties[0].value))
			{
				ini->properties[p].value_large =
				    (char *)DQN_INI_MALLOC(ini->memctx, (size_t)length + 1);
				DQN_INI_MEMCPY(ini->properties[p].name_large, value,
				               (size_t)length);
				ini->properties[p].value_large[length] = '\0';
			}
			else
			{
				DQN_INI_MEMCPY(ini->properties[p].value, value, (size_t)length);
				ini->properties[p].name[length] = '\0';
			}
		}
	}
}

#ifdef __GNUC__
		#pragma GCC diagnostic pop // -Wsign-compare for DQN_INI
#endif
#endif // DQN_IMPLEMENTATION

#if defined(DQN_XPLATFORM_LAYER)
////////////////////////////////////////////////////////////////////////////////
// #XPlatform (Win32 & Unix) Implementation
////////////////////////////////////////////////////////////////////////////////
// Functions in the Cross Platform are guaranteed to be supported in both Unix
// and Win32

#ifdef DQN_UNIX_PLATFORM
	#include <stdio.h>    // Basic File I/O // TODO(doyle): Syscall versions

	#include <dirent.h>   // readdir()/opendir()/closedir()
	#include <sys/stat.h> // file size query
	#include <sys/time.h> // high resolution timer
	#include <time.h>     // timespec
	#include <unistd.h>   // unlink()
#endif

////////////////////////////////////////////////////////////////////////////////
// XPlatform > #DqnFileInternal Implementation
////////////////////////////////////////////////////////////////////////////////
#ifdef DQN_WIN32_PLATFORM
FILE_SCOPE bool DqnFileInternal_Win32OpenW(wchar_t const *const path, DqnFile *const file,
                                           u32 const flags, DqnFile::Action const action)
{
	if (!file || !path) return false;

	DWORD win32Permission = 0;
	if (flags & DqnFile::PermissionFlag::All)
	{
		win32Permission = GENERIC_ALL;
	}
	else
	{
		if (flags & DqnFile::PermissionFlag::FileRead)  win32Permission |= GENERIC_READ;
		if (flags & DqnFile::PermissionFlag::FileWrite) win32Permission |= GENERIC_WRITE;
		if (flags & DqnFile::PermissionFlag::Execute)   win32Permission |= GENERIC_EXECUTE;
	}

	DWORD win32Action = 0;
	switch (action)
	{
		// Allow fall through
		default: DQN_ASSERT(DQN_INVALID_CODE_PATH);
		case DqnFile::Action::OpenOnly:         win32Action = OPEN_EXISTING; break;
		case DqnFile::Action::ClearIfExist:     win32Action = TRUNCATE_EXISTING; break;
		case DqnFile::Action::CreateIfNotExist: win32Action = CREATE_NEW; break;
		case DqnFile::Action::ForceCreate:      win32Action = CREATE_ALWAYS; break;
	}

	HANDLE handle = CreateFileW(path, win32Permission, 0, nullptr, win32Action,
	                            FILE_ATTRIBUTE_NORMAL, nullptr);

	if (handle == INVALID_HANDLE_VALUE)
	{
		return false;
	}

	LARGE_INTEGER size;
	if (GetFileSizeEx(handle, &size) == 0)
	{
		file->Close();
		DqnWin32_DisplayLastError("GetFileSizeEx() failed");
		return false;
	}

	file->handle = handle;
	file->size   = (size_t)size.QuadPart;
	file->flags  = flags;
	return true;
}

DQN_FILE_SCOPE char **DqnFileInternal_PlatformListDir(char const *const dir, i32 &numFiles)
{
	if (!dir) return nullptr;

	i32 currNumFiles = 0;
	wchar_t wideDir[MAX_PATH] = {0};
	DqnWin32_UTF8ToWChar(dir, wideDir, DQN_ARRAY_COUNT(wideDir));

	// Enumerate number of files first
	{
		WIN32_FIND_DATAW findData = {0};
		HANDLE findHandle = FindFirstFileW(wideDir, &findData);
		if (findHandle == INVALID_HANDLE_VALUE)
		{
			DQN_WIN32_ERROR_BOX("FindFirstFile() failed.", nullptr);
			return nullptr;
		}

		bool stayInLoop = true;
		while (stayInLoop)
		{
			BOOL result = FindNextFileW(findHandle, &findData);
			if (result == 0)
			{
				DWORD error = GetLastError();
				if (error != ERROR_NO_MORE_FILES)
				{
					DqnWin32_DisplayErrorCode(error,
					                             "FindNextFileW() failed");
				}

				stayInLoop = false;
			}
			else
			{
				currNumFiles++;
			}
		}
		FindClose(findHandle);
	}

	if (currNumFiles == 0)
	{
		numFiles = 0;
		return nullptr;
	}

	{
		WIN32_FIND_DATAW initFind = {0};
		HANDLE findHandle = FindFirstFileW(wideDir, &initFind);
		if (findHandle == INVALID_HANDLE_VALUE)
		{
			DQN_WIN32_ERROR_BOX("FindFirstFile() failed.", nullptr);
			numFiles = 0;
			return nullptr;
		}

		char **list = (char **)DqnMem_Calloc(
		    sizeof(*list) * (currNumFiles));
		if (!list)
		{
			DQN_WIN32_ERROR_BOX("DqnMem_Calloc() failed.", nullptr);
			numFiles = 0;
			return nullptr;
		}

		for (auto i = 0; i < currNumFiles; i++)
		{
			list[i] = (char *)DqnMem_Calloc(sizeof(**list) * MAX_PATH);
			if (!list[i])
			{
				for (auto j = 0; j < i; j++)
					DqnMem_Free(list[j]);

				DQN_WIN32_ERROR_BOX("DqnMem_Clloc() failed.", nullptr);
				numFiles = 0;
				return nullptr;
			}
		}

		i32 listIndex = 0;
		WIN32_FIND_DATAW findData = {0};
		while (FindNextFileW(findHandle, &findData) != 0)
		{
			DqnWin32_WCharToUTF8(findData.cFileName, list[listIndex++],
			                        MAX_PATH);
		}

		numFiles = currNumFiles;
		FindClose(findHandle);

		return list;
	}
}

#endif // DQN_WIN32_PLATFORM

#ifdef DQN_UNIX_PLATFORM
FILE_SCOPE bool DqnFileInternal_UnixGetFileSizeWithStat(char const *const path, size_t &size)
{
	struct stat fileStat = {0};
	if (stat(path, &fileStat)) return false;
	size = fileStat.st_size;

	return true;
}

FILE_SCOPE size_t DqnFileInternal_UnixGetFileSizeManual(FILE *const handle, bool const rewindHandle)
{
	u64 fileSizeInBytes = 0;

	DQN_ASSERT_HARD(handle);
	char c = fgetc(handle);
	while (c != EOF)
	{
		fileSizeInBytes++;
		c = fgetc(handle);
	}
	if (rewindHandle) rewind(handle);
	return fileSizeInBytes;
}

FILE_SCOPE bool DqnFileInternal_UnixOpen(char const *const path, DqnFile *const file,
                                         u32 const permissionFlags, DqnFile::Action action)
{
	char operation  = 0;
	bool updateFlag = false;

	if (permissionFlags & DqnFile::PermissionFlag::FileWrite)
	{
		updateFlag = true;
		switch (action)
		{
			default: DQN_ASSERT_HARD(DQN_INVALID_CODE_PATH);
			case DqnFile::Action::OpenOnly:
			{
				operation   = 'r';
			}
			break;

			case DqnFile::Action::CreateIfNotExist:
			case DqnFile::Action::ClearIfExist:
			case DqnFile::Action::ForceCreate:
			{
				operation   = 'w';
			}
			break;
		}
	}
	else if ((permissionFlags & DqnFile::PermissionFlag::FileRead) ||
	         (permissionFlags & DqnFile::PermissionFlag::Execute))
	{
		if (permissionFlags & DqnFile::PermissionFlag::Execute)
		{
			// TODO(doyle): Logging, UNIX doesn't have execute param for file
			// handles. Execution goes through system()
		}
		operation = 'r';
	}
	DQN_ASSERT_HARD(operation != 0);

	// TODO(doyle): What about not reading as a binary file and appending to end
	// of file.
	u32 modeIndex     = 0;
	char mode[4]      = {};
	mode[modeIndex++] = operation;

	if (updateFlag) mode[modeIndex++] = '+';

	mode[modeIndex++] = 'b';
	DQN_ASSERT_HARD(modeIndex <= DQN_ARRAY_COUNT(mode) - 1);

	// TODO(doyle): Use open syscall
	// TODO(doyle): Query errno
	FILE *handle = fopen(path, mode);
	if (!handle) return false;

	if (!DqnFileInternal_UnixGetFileSizeWithStat(path, &file->size))
	{
		// TODO(doyle): Logging
		fclose(handle);
		return false;
	}

	file->handle          = (void *)handle;
	file->permissionFlags = permissionFlags;

	// NOTE: Can occur in some instances where files are generated on demand,
	//       i.e. /proc/cpuinfo. But there can also be zero-byte files, we can't
	//       be sure. So manual check by counting bytes
	if (file->size == 0)
		file->size = DqnFileInternal_UnixGetFileSizeManual((FILE *)file->handle, true);

	return true;
}

DQN_FILE_SCOPE char **DqnFileInternal_PlatformListDir(char const *const dir, u32 &numFiles)
{
	if (!dir) return nullptr;

	// Enumerate num files
	u32 currNumFiles = 0;
	{
		DIR *const dirHandle = opendir(dir);
		if (!dirHandle) return nullptr;

		struct dirent *dirFile = readdir(dirHandle);
		while (dirFile)
		{
			currNumFiles++;
			dirFile = readdir(dirHandle);
		}
		closedir(dirHandle);
	}

	if (currNumFiles == 0)
	{
		numFiles = 0;
		return nullptr;
	}

	// Create file list
	{
		DIR *const dirHandle = opendir(dir);
		if (!dirHandle) return nullptr;

		char **list = (char **)DqnMem_Calloc(sizeof(*list) * currNumFiles);
		if (!list)
		{
			// TODO(doyle): Logging
			DQN_ASSERT(DQN_INVALID_CODE_PATH);
			numFiles = 0;
			return nullptr;
		}

		struct dirent *dirFile = readdir(dirHandle);
		for (auto i = 0; i < currNumFiles; i++)
		{
			list[i] = (char *)DqnMem_Calloc(sizeof(**list) * DQN_ARRAY_COUNT(dirFile->d_name));
			if (!list[i])
			{
				for (auto j = 0; j < i; j++) DqnMem_Free(list[j]);

				// TODO(doyle): Logging
				numFiles = 0;
				return nullptr;
			}
		}

		u32 listIndex = 0;
		numFiles      = currNumFiles;
		while (dirFile)
		{
			DqnStr_Copy(list[listIndex++], dirFile->d_name, DQN_ARRAY_COUNT(dirFile->d_name));
			dirFile = readdir(dirHandle);
		}
		closedir(dirHandle);

		return list;
	}
}

#endif // DQN_UNIX_PLATFORM

////////////////////////////////////////////////////////////////////////////////
// XPlatform > #DqnFile Implementation
////////////////////////////////////////////////////////////////////////////////
DqnFile::DqnFile(bool const raiiCleanup)
: flags(0)
, handle(nullptr)
, size(0)
, raiiCleanup(raiiCleanup)
{
}

DqnFile::~DqnFile()
{
	if (raiiCleanup)
	{
		this->Close();
	}
}

bool DqnFile::Open(char const *const path, u32 const flags_, Action const action)
{
	if (!path) return false;

#if defined(DQN_WIN32_PLATFORM)
	// TODO(doyle): MAX PATH is baad
	wchar_t widePath[MAX_PATH] = {0};
	DqnWin32_UTF8ToWChar(path, widePath, DQN_ARRAY_COUNT(widePath));
	return DqnFileInternal_Win32OpenW(widePath, this, flags_, action);

#elif defined(DQN_UNIX_PLATFORM)
	return DqnFileInternal_UnixOpen(path, this, flags_, action);

#else
	DQN_ASSERT_HARD(DQN_INVALID_CODE_PATH);
	return false;

#endif
}

bool DqnFile::OpenW(const wchar_t *const path, u32 const flags_, Action const action)
{
	if (!path) return false;

#if defined(DQN_WIN32_PLATFORM)
	return DqnFileInternal_Win32OpenW(path, this, flags_, action);

#else
	DQN_ASSERT(DQN_INVALID_CODE_PATH);
	return false;

#endif
}

size_t DqnFile::Write(u8 const *const buf, size_t const numBytesToWrite, size_t const fileOffset)
{
	// TODO(doyle): Implement when it's needed
	if (!DQN_ASSERT_MSG(fileOffset == 0, "'fileOffset' not implemented yet")) return 0;

#if defined(DQN_WIN32_PLATFORM)
	DWORD bytesToWrite = (DWORD)numBytesToWrite;
	DWORD bytesWritten;
	BOOL result            = WriteFile(this->handle, (void *)buf, bytesToWrite, &bytesWritten, nullptr);

	size_t numBytesWritten = (size_t)bytesWritten;
	// TODO(doyle): Better logging system
	if (result == 0)
	{
		DQN_WIN32_ERROR_BOX("ReadFile() failed.", nullptr);
	}

#elif defined(DQN_UNIX_PLATFORM)
	const size_t ITEMS_TO_WRITE = 1;
	if (fwrite(buf, numBytesToWrite, ITEMS_TO_WRITE, (FILE *)this->handle) ==
	    ITEMS_TO_WRITE)
	{
		rewind((FILE *)this->handle);
		numBytesWritten = ITEMS_TO_WRITE * numBytesToWrite;
	}
#endif

	return numBytesWritten;
}

size_t DqnFile::Read(u8 *const buf, size_t const numBytesToRead)
{
	size_t numBytesRead = 0;
	if (this->handle)
	{
#if defined(DQN_WIN32_PLATFORM)
		DWORD bytesToRead = (DWORD)numBytesToRead;
		DWORD bytesRead    = 0;
		HANDLE win32Handle = this->handle;

		BOOL result = ReadFile(win32Handle, (void *)buf, bytesToRead, &bytesRead, nullptr);

		numBytesRead = (size_t)bytesRead;
		// TODO(doyle): 0 also means it is completing async, but still valid
		if (result == 0)
		{
			DQN_WIN32_ERROR_BOX("ReadFile() failed.", nullptr);
		}

#elif defined(DQN_UNIX_PLATFORM)
		// TODO(doyle): Syscall version
		const size_t ITEMS_TO_READ = 1;
		if (fread(buf, numBytesToRead, ITEMS_TO_READ, (FILE *)this->handle) == ITEMS_TO_READ)
		{
			rewind((FILE *)this->handle);
			numBytesRead = ITEMS_TO_READ * numBytesToRead;
		}
		else
		{
			// TODO(doyle): Logging, failed read
		}
#else
	DQN_ASSERT_MSG(DQN_INVALID_CODE_PATH, "Non Win32/Unix path not implemented");
#endif
	}
	return numBytesRead;
}

u8 *DqnFile::ReadEntireFileSimpleW(wchar_t const *const path, size_t &bufSize, DqnMemAPI const memAPI)
{
	// TODO(doyle): Logging

	size_t requiredSize = 0;
	if (!DqnFile::GetFileSizeW(path, requiredSize)) return nullptr;

	DqnMemAPI::Request info = DqnMemAPI::RequestAlloc(memAPI, requiredSize, false);
	u8 *buf                 = memAPI.callback(info);
	if (!buf) return nullptr;

	size_t bytesRead = 0;
	if (DqnFile::ReadEntireFileW(path, buf, requiredSize, bytesRead))
	{
		bufSize = requiredSize;
		DQN_ASSERT(bytesRead == requiredSize);
		return buf;
	}

	free(buf);
	return nullptr;
}

u8 *DqnFile::ReadEntireFileSimple(char const *const path, size_t &bufSize, DqnMemAPI const memAPI)
{
	// TODO(doyle): Logging

	size_t requiredSize = 0;
	if (!DqnFile::GetFileSize(path, requiredSize)) return nullptr;

	DqnMemAPI::Request info = DqnMemAPI::RequestAlloc(memAPI, requiredSize, false);
	u8 *buf              = (u8 *)memAPI.callback(info);
	if (!buf) return nullptr;

	size_t bytesRead = 0;
	if (DqnFile::ReadEntireFile(path, buf, requiredSize, bytesRead))
	{
		bufSize = requiredSize;
		DQN_ASSERT(bytesRead == requiredSize);
		return buf;
	}

	free(buf);
	return nullptr;
}

bool DqnFile::ReadEntireFileW(wchar_t const *const path, u8 *const buf, size_t const bufSize,
                              size_t &bytesRead)
{
	if (!path) return false;

	DqnFile file = {};
	bool result = file.OpenW(path, DqnFile::PermissionFlag::FileRead, DqnFile::Action::OpenOnly);

	// TODO(doyle): Logging
	if (!result) goto cleanup;

	if (file.size > bufSize)
	{
		result = false;
		goto cleanup;
	}

	bytesRead = file.Read(buf, file.size);
	DQN_ASSERT_HARD(bytesRead == file.size);

cleanup:
	file.Close();
	return result;
}

bool DqnFile::ReadEntireFile(const char *const path, u8 *const buf, size_t const bufSize,
                             size_t &bytesRead)
{
	if (!path) return false;

	DqnFile file = {};
	bool result  = file.Open(path, DqnFile::PermissionFlag::FileRead, DqnFile::Action::OpenOnly);

	// TODO(doyle): Logging
	if (!result) goto cleanup;

	if (file.size > bufSize)
	{
		result = false;
		goto cleanup;
	}

	bytesRead = file.Read(buf, file.size);
	DQN_ASSERT_HARD(bytesRead == file.size);

cleanup:
	file.Close();
	return result;
}

void DqnFile::Close()
{
	if (this->handle)
	{
#if defined(DQN_WIN32_PLATFORM)
		CloseHandle(this->handle);
#elif defined(DQN_UNIX_PLATFORM)
		fclose((FILE *)this->handle);
#endif
		this->handle = nullptr;
	}

	this->size  = 0;
	this->flags = 0;
}

#if defined(DQN_WIN32_PLATFORM)
	DQN_COMPILE_ASSERT(sizeof(DWORD)  == sizeof(u32));
#endif

bool DqnFile::GetFileSizeW(wchar_t const *const path, size_t &size)
{
#if defined(DQN_WIN32_PLATFORM)
	WIN32_FILE_ATTRIBUTE_DATA attribData = {};
	if (GetFileAttributesExW(path, GetFileExInfoStandard, &attribData))
	{
		// TODO(doyle): What if size_t is < Quad.part?
		LARGE_INTEGER largeInt = {};
		largeInt.HighPart      = attribData.nFileSizeHigh;
		largeInt.LowPart       = attribData.nFileSizeLow;

		size = (size_t)largeInt.QuadPart;
		return true;
	}

#elif defined(DQN_UNIX_PLATFORM)
	// NOTE: Not supported on unix
	DQN_ASSERT_HARD(DQN_INVALID_CODE_PATH);

#endif

	return false;
}

bool DqnFile::GetFileSize(char const *const path, size_t &size)
{
	if (!path) return false;

	// TODO(doyle): Logging
#if defined(DQN_WIN32_PLATFORM)
	// TODO(doyle): MAX PATH is baad
	wchar_t widePath[MAX_PATH] = {0};
	DqnWin32_UTF8ToWChar(path, widePath, DQN_ARRAY_COUNT(widePath));
	return DqnFile::GetFileSizeW(widePath, size);

#elif defined(DQN_UNIX_PLATFORM)
	// TODO(doyle): Error logging
	if (!DqnFileInternal_UnixGetFileSizeWithStat(path, size)) return false;

	// NOTE: 0 size can occur in some instances where files are generated on demand,
	//       i.e. /proc/cpuinfo
	if (*size == 0)
	{
		// If stat fails, then do a manual byte count
		FILE *handle = fopen(path, "r");
		size         = DqnFileInternal_UnixGetFileSizeManual(handle, false);
		fclose(handle);
	}

	return true;
#endif
}

bool DqnFile::Delete(char const *const path)
{
	if (!path) return false;

// TODO(doyle): Logging
#if defined(DQN_WIN32_PLATFORM)
	return DeleteFileA(path);

#elif defined(DQN_UNIX_PLATFORM)
	i32 result = unlink(path);

	if (result == 0) return true;
	return false;

#endif
}

bool DqnFile::DeleteW(wchar_t const *const path)
{
	if (!path) return false;

	// TODO(doyle): Logging
#if defined(DQN_WIN32_PLATFORM)
	return DeleteFileW(path);

#elif defined(DQN_UNIX_PLATFORM)
	DQN_ASSERT_HARD(DQN_INVALID_CODE_PATH);
	return false;

#endif
}

char **DqnFile::ListDir(char const *const dir, i32 &numFiles)
{
	char **result = DqnFileInternal_PlatformListDir(dir, numFiles);
	return result;
}

void DqnFile::ListDirFree(char **fileList, i32 const numFiles)
{
	if (fileList)
	{
		for (auto i = 0; i < numFiles; i++)
		{
			if (fileList[i]) DqnMem_Free(fileList[i]);
			fileList[i] = nullptr;
		}

		DqnMem_Free(fileList);
	}
}

////////////////////////////////////////////////////////////////////////////////
// XPlatform > #DqnTimer Implementation
////////////////////////////////////////////////////////////////////////////////
#if defined (DQN_WIN32_PLATFORM)
FILE_SCOPE f64 DqnTimerInternal_Win32QueryPerfCounterTimeInMs()
{
	LOCAL_PERSIST LARGE_INTEGER queryPerformanceFrequency = {0};
	if (queryPerformanceFrequency.QuadPart == 0)
	{
		QueryPerformanceFrequency(&queryPerformanceFrequency);
		DQN_ASSERT_HARD(queryPerformanceFrequency.QuadPart != 0);
	}

	LARGE_INTEGER qpcResult;
	QueryPerformanceCounter(&qpcResult);

	// Convert to microseconds first then divide by ticks per second then to milliseconds
	qpcResult.QuadPart *= 1000000;
	f64 timestamp = qpcResult.QuadPart / (f64)queryPerformanceFrequency.QuadPart;
	timestamp /= 1000.0f;
	return timestamp;
}
#endif

DQN_FILE_SCOPE f64 DqnTimer_NowInMs()
{
	f64 result = 0;
#if defined(DQN_WIN32_PLATFORM)
	result = DQN_MAX(DqnTimerInternal_Win32QueryPerfCounterTimeInMs(), 0);

#elif defined(DQN_UNIX_PLATFORM)
	struct timespec timeSpec = {0};
	if (clock_gettime(CLOCK_MONOTONIC, &timeSpec))
	{
		// TODO(doyle): Failed logging
		DQN_ASSERT_HARD(DQN_INVALID_CODE_PATH);
	}
	else
	{
		result = (f64)((timeSpec.tv_sec * 1000.0f) + (timeSpec.tv_nsec / 1000000.0f));
	}

#else
	DQN_ASSERT_MSG(DQN_INVALID_CODE_PATH, "Non Unix/Win32 path not implemented yet");

#endif
	return result;
};

DQN_FILE_SCOPE f64 DqnTimer_NowInS() { return DqnTimer_NowInMs() / 1000.0f; }

////////////////////////////////////////////////////////////////////////////////
// XPlatform > #DqnLock Implementation
////////////////////////////////////////////////////////////////////////////////
bool DqnLock_Init(DqnLock *const lock)
{
	if (!lock) return false;

#if defined(DQN_WIN32_PLATFORM)
	if (InitializeCriticalSectionEx(&lock->win32Handle, lock->win32SpinCount, 0))
		return true;

#elif defined(DQN_UNIX_PLATFORM)
	// NOTE: Static initialise, pre-empt a lock so that it gets initialised as per documentation
	lock->unixHandle = PTHREAD_ERRORCHECK_MUTEX_INITIALIZER_NP;
	DqnLock_Acquire(lock);
	DqnLock_Release(lock);
	return true;

#else
	#error Unsupported platform

#endif

	return false;
}

void DqnLock_Acquire(DqnLock *const lock)
{
	if (!lock) return;

#if defined(DQN_WIN32_PLATFORM)
	EnterCriticalSection(&lock->win32Handle);

#elif defined(DQN_UNIX_PLATFORM)
	// TODO(doyle): Better error handling
	i32 error = pthread_mutex_lock(&lock->unixHandle);
	DQN_ASSERT_HARD(error == 0);

#else
	#error Unsupported platform

#endif
}

void DqnLock_Release(DqnLock *const lock)
{
	if (!lock) return;

#if defined(DQN_WIN32_PLATFORM)
	LeaveCriticalSection(&lock->win32Handle);

#elif defined (DQN_UNIX_PLATFORM)
	// TODO(doyle): better error handling
	i32 error = pthread_mutex_unlock(&lock->unixHandle);
	DQN_ASSERT_HARD(error == 0);

#else
	#error Unsupported platform

#endif
}

void DqnLock_Delete(DqnLock *const lock)
{
	if (!lock) return;

#if defined(DQN_WIN32_PLATFORM)
	DeleteCriticalSection(&lock->win32Handle);

#elif defined(DQN_UNIX_PLATFORM)
	i32 error = pthread_mutex_destroy(&lock->unixHandle);
	DQN_ASSERT_HARD(error == 0);

#else
	#error Unsupported platform

#endif
}

////////////////////////////////////////////////////////////////////////////////
// XPlatform > #DqnLock CPP Implementation
////////////////////////////////////////////////////////////////////////////////
bool DqnLock::Init()    { return DqnLock_Init   (this); }
void DqnLock::Acquire() {        DqnLock_Acquire(this); }
void DqnLock::Release() {        DqnLock_Release(this); }
void DqnLock::Delete()  {        DqnLock_Delete (this); }

DqnLockGuard DqnLock::LockGuard()
{
	return DqnLockGuard(this, nullptr);
}

////////////////////////////////////////////////////////////////////////////////
// XPlatform > #DqnLockGuard CPP Implementation
////////////////////////////////////////////////////////////////////////////////
DqnLockGuard::DqnLockGuard(DqnLock *const lock_, bool *const succeeded)
{
	if (lock_)
	{
		this->lock = lock_;
		this->lock->Acquire();
		if (succeeded) *succeeded = true;
	}
	else
	{
		if (succeeded) *succeeded = false;
	}
}

DqnLockGuard::~DqnLockGuard()
{
	if (this->lock) this->lock->Release();
}

////////////////////////////////////////////////////////////////////////////////
// XPlatform > #DqnJobQueueInternal Implementation
////////////////////////////////////////////////////////////////////////////////

typedef void *DqnThreadCallbackInternal(void *threadParam);
size_t DQN_JOB_QUEUE_INTERNAL_THREAD_DEFAULT_STACK_SIZE = 0;

FILE_SCOPE u32 DqnJobQueueInternal_ThreadCreate(const size_t stackSize,
                                                DqnThreadCallbackInternal *const threadCallback,
                                                void *const threadParam, const u32 numThreads)
{
	u32 numThreadsCreated = 0;

#if defined(DQN_WIN32_PLATFORM)
	DQN_ASSERT_HARD(stackSize == 0 || !threadCallback);
	for (u32 i = 0; i < numThreads; i++)
	{
		HANDLE handle = CreateThread(nullptr, stackSize, (LPTHREAD_START_ROUTINE)threadCallback,
		                             threadParam, 0, nullptr);
		CloseHandle(handle);
		numThreadsCreated++;
	}

#elif defined(DQN_UNIX_PLATFORM)
	// TODO(doyle): Better error handling
	pthread_attr_t attribute = {};
	DQN_ASSERT(pthread_attr_init(&attribute) == 0);

	// Allows us to use pthread_join() which lets us wait till a thread finishes execution
	DQN_ASSERT(pthread_attr_setdetachstate(&attribute, PTHREAD_CREATE_JOINABLE) == 0);

	// TODO(doyle): Persist thread handles
	for (u32 i = 0; i < numThreads; i++)
	{
		pthread_t thread = {};
		pthread_create(&thread, &attribute, threadCallback, threadParam);
		numThreadsCreated++;
	}

	DQN_ASSERT(pthread_attr_destroy(&attribute) == 0);

#else
	#error Unsupported platform

#endif

	DQN_ASSERT(numThreadsCreated == numThreads);
	return numThreadsCreated;
}


FILE_SCOPE void *DqnJobQueueInternal_ThreadCallback(void *threadParam)
{
	DqnJobQueue *queue = (DqnJobQueue *)threadParam;
	for (;;)
	{
		if (!DqnJobQueue_TryExecuteNextJob(queue))
		{
#if defined(DQN_WIN32_PLATFORM)
			WaitForSingleObjectEx(queue->semaphore, INFINITE, false);

#elif defined(DQN_UNIX_PLATFORM)
			sem_wait(&queue->semaphore);

#else
	#error Unsupported platform

#endif
		}
	}
}

FILE_SCOPE bool DqnJobQueueInternal_CreateSemaphore(DqnJobQueue *const queue, const u32 initSignalCount, const u32 maxSignalCount)
{
	if (!queue) return false;

#if defined(DQN_WIN32_PLATFORM)
	queue->semaphore = (void *)CreateSemaphore(nullptr, initSignalCount, maxSignalCount, nullptr);
	DQN_ASSERT_HARD(queue->semaphore);

#elif defined(DQN_UNIX_PLATFORM)
	// TODO(doyle): Use max count for unix
	// TODO(doyle): Error handling
	const u32 UNIX_DONT_SHARE_BETWEEN_PROCESSES = 0;
	i32 error = sem_init(&queue->semaphore, UNIX_DONT_SHARE_BETWEEN_PROCESSES, 0);
	DQN_ASSERT_HARD(error == 0);

	for (u32 i = 0; i < initSignalCount; i++)
		DQN_ASSERT_HARD(sem_post(&queue->semaphore) == 0);

#else
	#error Unknown platform

#endif

	return true;
}

FILE_SCOPE bool DqnJobQueueInternal_ReleaseSemaphore(DqnJobQueue *const queue)
{
	DQN_ASSERT(queue);

#if defined(DQN_WIN32_PLATFORM)
	DQN_ASSERT(queue->semaphore);
	ReleaseSemaphore(queue->semaphore, 1, nullptr);

#elif defined(DQN_UNIX_PLATFORM)
	// TODO(doyle): Error handling
	DQN_ASSERT_HARD(sem_post(&queue->semaphore) == 0);

#else
	#error Unknown platform

#endif
	
	return true;
}

////////////////////////////////////////////////////////////////////////////////
// XPlatform > #DqnJobQueue Implementation
////////////////////////////////////////////////////////////////////////////////
DQN_FILE_SCOPE bool DqnJobQueue_Init(DqnJobQueue *const queue, DqnJob *const jobList,
                                     const u32 jobListSize, const u32 numThreads)
{
	if (!queue || !jobList || jobListSize == 0 || numThreads == 0) return false;
	queue->jobList = jobList;
	queue->size    = jobListSize;

	DQN_ASSERT(DqnJobQueueInternal_CreateSemaphore(queue, 0, numThreads));

	// Create threads
	u32 numThreadsCreated = DqnJobQueueInternal_ThreadCreate(
	    DQN_JOB_QUEUE_INTERNAL_THREAD_DEFAULT_STACK_SIZE, DqnJobQueueInternal_ThreadCallback,
	    (void *)queue, numThreads);
	DQN_ASSERT_HARD(numThreads == numThreadsCreated);

	return true;
}

DQN_FILE_SCOPE bool DqnJobQueue_AddJob(DqnJobQueue *const queue, const DqnJob job)
{
	i32 newJobInsertIndex = (queue->jobInsertIndex + 1) % queue->size;
	if (newJobInsertIndex == queue->jobToExecuteIndex) return false;

	queue->jobList[queue->jobInsertIndex] = job;

	DqnAtomic_Add32(&queue->numJobsToComplete, 1);
	DQN_ASSERT(DqnJobQueueInternal_ReleaseSemaphore(queue));

	queue->jobInsertIndex = newJobInsertIndex;
	return true;
}

DQN_FILE_SCOPE void DqnJobQueue_BlockAndCompleteAllJobs(DqnJobQueue *const queue)
{
	while (DqnJobQueue_TryExecuteNextJob(queue) || !DqnJobQueue_AllJobsComplete(queue))
		;
}

DQN_FILE_SCOPE bool DqnJobQueue_TryExecuteNextJob(DqnJobQueue *const queue)
{
	if (!queue) return false;

	i32 originalJobToExecute = queue->jobToExecuteIndex;
	if (originalJobToExecute != queue->jobInsertIndex)
	{
		i32 newJobIndexForNextThread = (originalJobToExecute + 1) % queue->size;
		i32 index = DqnAtomic_CompareSwap32(&queue->jobToExecuteIndex, newJobIndexForNextThread,
		                                    originalJobToExecute);

		// NOTE: If we weren't successful at the interlock, another thread has
		// taken the work and we can't know if there's more work or not. So
		// irrespective of that result, return true to let the thread check
		// again for more work.
		if (index == originalJobToExecute)
		{
			DqnJob job = queue->jobList[index];
			job.callback(queue, job.userData);
			DqnAtomic_Add32(&queue->numJobsToComplete, -1);
		}

		return true;
	}

	return false;
}

DQN_FILE_SCOPE bool DqnJobQueue_AllJobsComplete(DqnJobQueue *const queue)
{
	if (!queue) return false;

	bool result = (queue->numJobsToComplete == 0);
	return result;
}

////////////////////////////////////////////////////////////////////////////////
// XPlatform > #DqnJobQueue CPP Implementation
////////////////////////////////////////////////////////////////////////////////
bool DqnJobQueue::Init(DqnJob *const jobList_, const u32 jobListSize, const u32 numThreads)
{
	bool result = DqnJobQueue_Init(this, jobList_, jobListSize, numThreads);
	return result;
}

bool DqnJobQueue::AddJob           (const DqnJob job) { return DqnJobQueue_AddJob(this, job);             }
void DqnJobQueue::BlockAndCompleteAllJobs()           {        DqnJobQueue_BlockAndCompleteAllJobs(this); }
bool DqnJobQueue::TryExecuteNextJob()                 { return DqnJobQueue_TryExecuteNextJob(this);       }
bool DqnJobQueue::AllJobsComplete  ()                 { return DqnJobQueue_AllJobsComplete(this);         }

////////////////////////////////////////////////////////////////////////////////
// XPlatform > #DqnAtomic Implementation
////////////////////////////////////////////////////////////////////////////////

#if defined(DQN_WIN32_PLATFORM)
	DQN_COMPILE_ASSERT(sizeof(LONG) == sizeof(i32));
#endif

DQN_FILE_SCOPE i32 DqnAtomic_CompareSwap32(i32 volatile *const dest, const i32 swapVal,
                                           const i32 compareVal)
{
	i32 result = 0;
#if defined(DQN_WIN32_PLATFORM)
	result = (i32)InterlockedCompareExchange((LONG volatile *)dest, (LONG)swapVal, (LONG)compareVal);

#elif defined(DQN_UNIX_PLATFORM)
	result = __sync_val_compare_and_swap(dest, compareVal, swapVal);

#else
	#error Unsupported platform

#endif
	return result;
}

DQN_FILE_SCOPE i32 DqnAtomic_Add32(i32 volatile *const src, const i32 value)
{
	i32 result = 0;
#if defined(DQN_WIN32_PLATFORM)
	result = (i32)InterlockedAdd((LONG volatile *)src, value);

#elif defined(DQN_UNIX_PLATFORM)
	result = __sync_add_and_fetch(src, value);

#else
	#error Unsupported platform

#endif

	return result;
}

////////////////////////////////////////////////////////////////////////////////
// XPlatform > #DqnPlatformInternal Implementation
////////////////////////////////////////////////////////////////////////////////
#if defined(DQN_UNIX_PLATFORM)
FILE_SCOPE void DqnPlatformInternal_UnixGetNumCoresAndThreads(u32 *const numCores,
                                                              u32 *const numThreadsPerCore)
{
	if (!numThreadsPerCore && !numCores) return;

	// TODO(doyle): Not exactly standard
	DqnFile file = {};
	DQN_ASSERT_HARD(
	    DqnFile_Open("/proc/cpuinfo", &file, DqnFile::PermissionFlag::FileRead, DqnFile::Action::OpenOnly));
	DQN_ASSERT_HARD(file.size > 0);

	u8 *readBuffer = (u8 *)DqnMem_Calloc(file.size);
	if (readBuffer)
	{
		size_t bytesRead = DqnFile_Read(&file, readBuffer, file.size);
		DQN_ASSERT_HARD(bytesRead == file.size);

		const char *srcPtr = (char *)readBuffer;
		u32 srcLen   = file.size;

#define DQN_ADVANCE_CHAR_PTR_AND_LEN_INTERNAL(ptr, len, offset)                                     \
	ptr += offset;                                                                                 \
	len -= offset

		if (numThreadsPerCore)
		{
			*numThreadsPerCore = 0;
			// Find the offset to the processor field and move to it
			const char processorStr[] = "processor";
			i32 processorOffset       = DqnStr_FindFirstOccurence(srcPtr, srcLen, processorStr,
			                                                          DQN_ARRAY_COUNT(processorStr));
			DQN_ASSERT_HARD(processorOffset != -1);
			DQN_ADVANCE_CHAR_PTR_AND_LEN_INTERNAL(srcPtr, srcLen, processorOffset);

			// Find the offset to the colon delimiter and advance to 1 after it
			i32 colonOffset = DqnStr_FindFirstOccurence(srcPtr, srcLen, ":", 1) + 1;
			DQN_ASSERT_HARD(colonOffset != -1);
			DQN_ADVANCE_CHAR_PTR_AND_LEN_INTERNAL(srcPtr, srcLen, colonOffset);

			// Read num processors, i.e. logical cores/hyper threads
			*numThreadsPerCore = Dqn_StrToI64(srcPtr, srcLen);
			if (*numThreadsPerCore == 0) *numThreadsPerCore = 1;
		}

		if (numCores)
		{
			*numCores   = 0;
			// Find the offset to the cpu cores field and move to it
			const char cpuCoresStr[] = "cpu cores";
			i32 cpuCoresOffset       = DqnStr_FindFirstOccurence(srcPtr, srcLen, cpuCoresStr,
			                                               DQN_ARRAY_COUNT(cpuCoresStr));
			DQN_ASSERT_HARD(cpuCoresOffset != -1);
			DQN_ADVANCE_CHAR_PTR_AND_LEN_INTERNAL(srcPtr, srcLen, cpuCoresOffset);

			// Find the offset to the colon delimiter and advance to 1 after it
			i32 colonOffset = DqnStr_FindFirstOccurence(srcPtr, srcLen, ":", 1) + 1;
			DQN_ASSERT_HARD(colonOffset != -1);
			DQN_ADVANCE_CHAR_PTR_AND_LEN_INTERNAL(srcPtr, srcLen, colonOffset);

			// Read num cores value, i.e. physical cores
			*numCores = Dqn_StrToI64(srcPtr, srcLen);
		}
		DqnFile_Close(&file);
		DqnMem_Free(readBuffer);
	}
	else
	{
		// TODO(doyle): Out of mem
		DQN_ASSERT_HARD(DQN_INVALID_CODE_PATH);
	}
}
#endif // DQN_UNIX_PLATFORM

#if defined(DQN_WIN32_PLATFORM)
FILE_SCOPE void DqnPlatformInternal_Win32GetNumCoresAndThreads(u32 *const numCores,
                                                               u32 *const numThreadsPerCore)
{
	if (numThreadsPerCore)
	{
		SYSTEM_INFO systemInfo;
		GetNativeSystemInfo(&systemInfo);
		*numThreadsPerCore = systemInfo.dwNumberOfProcessors;
	}

	if (numCores)
	{
		*numCores = 0;
		DWORD requiredSize    = 0;
		u8 insufficientBuffer = {0};
		GetLogicalProcessorInformationEx(
		    RelationProcessorCore, (SYSTEM_LOGICAL_PROCESSOR_INFORMATION_EX *)insufficientBuffer,
		    &requiredSize);

		u8 *rawProcInfoArray = (u8 *)DqnMem_Calloc(requiredSize);
		if (!DQN_ASSERT_MSG(rawProcInfoArray, "Calloc failed, could not allocate memory"))
		{
			return;
		}

		if (GetLogicalProcessorInformationEx(
		        RelationProcessorCore, (SYSTEM_LOGICAL_PROCESSOR_INFORMATION_EX *)rawProcInfoArray,
		        &requiredSize))
		{
			SYSTEM_LOGICAL_PROCESSOR_INFORMATION_EX *logicalProcInfo =
			    (SYSTEM_LOGICAL_PROCESSOR_INFORMATION_EX *)rawProcInfoArray;
			DWORD bytesRead = 0;

			do
			{
				// NOTE: High efficiency value has greater performance and less efficiency.
				PROCESSOR_RELATIONSHIP *procInfo = &logicalProcInfo->Processor;
				// u32 efficiency                   = procInfo->EfficiencyClass;
				(*numCores)++;
				DQN_ASSERT_HARD(logicalProcInfo->Relationship == RelationProcessorCore);
				DQN_ASSERT_HARD(procInfo->GroupCount == 1);

				bytesRead += logicalProcInfo->Size;
				logicalProcInfo =
				    (SYSTEM_LOGICAL_PROCESSOR_INFORMATION_EX *)((u8 *)logicalProcInfo +
				                                                logicalProcInfo->Size);
			} while (bytesRead < requiredSize);
		}
		else
		{
			DqnWin32_DisplayLastError("GetLogicalProcessorInformationEx() failed");
		}

		DqnMem_Free(rawProcInfoArray);
	}
}
#endif // DQN_WIN32_PLATFORM

////////////////////////////////////////////////////////////////////////////////
// XPlatform > #DqnPlatform Implementation
////////////////////////////////////////////////////////////////////////////////
DQN_FILE_SCOPE void DqnPlatform_GetNumThreadsAndCores(u32 *const numCores, u32 *const numThreadsPerCore)
{
#if defined(DQN_WIN32_PLATFORM)
	DqnPlatformInternal_Win32GetNumCoresAndThreads(numCores, numThreadsPerCore);

#elif defined(DQN_UNIX_PLATFORM)
	DqnPlatformInternal_UnixGetNumCoresAndThreads(numCores, numThreadsPerCore);

#else
	#error Unsupported platform

#endif
}
#endif // DQN_XPLATFORM_LAYER

////////////////////////////////////////////////////////////////////////////////
// #Platform Implementation
////////////////////////////////////////////////////////////////////////////////

#ifdef DQN_WIN32_PLATFORM
////////////////////////////////////////////////////////////////////////////////
// #Win32Platform Implementation
////////////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////
// Win32Platform > #DqnWin32 Implementation
////////////////////////////////////////////////////////////////////////////////
DQN_FILE_SCOPE i32 DqnWin32_UTF8ToWChar(const char *const in,
                                         wchar_t *const out, const i32 outLen)
{
	i32 result = MultiByteToWideChar(CP_UTF8, 0, in, -1, out, outLen);

	if (result == 0xFFFD || 0)
	{
		DQN_WIN32_ERROR_BOX("WideCharToMultiByte() failed.", nullptr);
		return -1;
	}

	return result;
}

DQN_FILE_SCOPE i32 DqnWin32_WCharToUTF8(const wchar_t *const in,
                                        char *const out, const i32 outLen)
{
	i32 result =
	    WideCharToMultiByte(CP_UTF8, 0, in, -1, out, outLen, nullptr, nullptr);

	if (result == 0xFFFD || 0)
	{
		DQN_WIN32_ERROR_BOX("WideCharToMultiByte() failed.", nullptr);
		return -1;
	}

	return result;
}

DQN_FILE_SCOPE void DqnWin32_GetClientDim(const HWND window, LONG *const width, LONG *const height)
{
	RECT rect;
	GetClientRect(window, &rect);
	if (width)  *width  = rect.right - rect.left;
	if (height) *height = rect.bottom - rect.top;
}

DQN_FILE_SCOPE void DqnWin32_GetRectDim(const RECT rect, LONG *const width, LONG *const height)
{
	if (width)  *width  = rect.right - rect.left;
	if (height) *height = rect.bottom - rect.top;
}

DQN_FILE_SCOPE void DqnWin32_DisplayLastError(const char *const errorPrefix)
{
	DWORD error         = GetLastError();
	char errorMsg[1024] = {0};
	FormatMessageA(FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
	               nullptr, error, 0, errorMsg, DQN_ARRAY_COUNT(errorMsg), nullptr);

	if (errorPrefix)
	{
		char formattedError[2048] = {0};
		Dqn_sprintf(formattedError, "%s: %s", errorPrefix, errorMsg);
		DQN_WIN32_ERROR_BOX(formattedError, nullptr);
	}
	else
	{
		DQN_WIN32_ERROR_BOX(errorMsg, nullptr);
	}
}

const i32 DQN_WIN32_INTERNAL_ERROR_MSG_SIZE = 2048;
DQN_FILE_SCOPE void DqnWin32_DisplayErrorCode(const DWORD error, const char *const errorPrefix)
{
	char errorMsg[DQN_WIN32_INTERNAL_ERROR_MSG_SIZE] = {0};
	FormatMessageA(FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
	               nullptr, error, 0, errorMsg, DQN_ARRAY_COUNT(errorMsg), nullptr);

	char formattedError[2048] = {0};
	Dqn_sprintf(formattedError, "%s: %s", errorPrefix, errorMsg);
	DQN_WIN32_ERROR_BOX(formattedError, nullptr);
}

DQN_FILE_SCOPE void DqnWin32_OutputDebugString(const char *const formatStr, ...)
{
	char str[DQN_WIN32_INTERNAL_ERROR_MSG_SIZE] = {0};

	va_list argList;
	va_start(argList, formatStr);
	{
		i32 numCopied = Dqn_vsprintf(str, formatStr, argList);
		DQN_ASSERT_HARD(numCopied < DQN_ARRAY_COUNT(str));
	}
	va_end(argList);

	OutputDebugStringA(str);
}

DQN_FILE_SCOPE i32 DqnWin32_GetEXEDirectory(char *const buf, const u32 bufLen)
{
	if (!buf || bufLen == 0) return -1;
	u32 copiedLen = GetModuleFileNameA(nullptr, buf, bufLen);
	if (copiedLen == bufLen) return -1;

	// NOTE: Should always work if GetModuleFileName works and we're running an
	// executable.
	i32 lastSlashIndex = 0;
	for (i32 i = copiedLen; i > 0; i--)
	{
		if (buf[i] == '\\')
		{
			lastSlashIndex = i;
			break;
		}
	}

	return lastSlashIndex;
}

#endif // DQN_WIN32_PLATFORM