Add line rendering

Win32DRenderer.sln

@@ -0,0 +1,29 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio 15
+VisualStudioVersion = 15.0.26403.3
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{911E67C6-3D85-4FCE-B560-20A9C3E3FF48}") = "Win32DRenderer", "bin\Win32DRenderer.exe", "{6A9F3AE0-4D5E-4F89-8572-B868AC43C38A}"
+	ProjectSection(DebuggerProjectSystem) = preProject
+		PortSupplier = 00000000-0000-0000-0000-000000000000
+		Executable = C:\git\drenderer\bin\Win32DRenderer.exe
+		RemoteMachine = THAI-PC
+		StartingDirectory = C:\git\drenderer\bin
+		Environment = Default
+		LaunchingEngine = 00000000-0000-0000-0000-000000000000
+		UseLegacyDebugEngines = No
+		LaunchSQLEngine = No
+		AttachLaunchAction = No
+	EndProjectSection
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Release|x64 = Release|x64
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{6A9F3AE0-4D5E-4F89-8572-B868AC43C38A}.Release|x64.ActiveCfg = Release|x64
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+EndGlobal

src/DRenderer.cpp

@@ -1,22 +1,132 @@
 #include "DRenderer.h"
-
 #include "DRendererPlatform.h"
 
+#define DQN_IMPLEMENTATION
+#include "dqn.h"
+
+#include <math.h>
+FILE_SCOPE void DR_DrawLine(PlatformRenderBuffer *const renderBuffer, DqnV2i a,
+                            DqnV2i b, DqnV3 color)
+{
+	if (!renderBuffer) return;
+
+	bool yTallerThanX = false;
+	if (DQN_ABS(a.x - b.x) < DQN_ABS(a.y - b.y))
+	{
+		// NOTE(doyle): Enforce that the X component is always longer than the
+		// Y component. When drawing this we just reverse the order back.
+		// This is to ensure that the gradient is always < 1, such that we can
+		// use the gradient to calculate the distance from the pixel origin, and
+		// at which point we want to increment the y.
+		yTallerThanX = true;
+		DQN_SWAP(i32, a.x, a.y);
+		DQN_SWAP(i32, b.x, b.y);
+	}
+
+	if (b.x < a.x) DQN_SWAP(DqnV2i, a, b);
+
+	i32 rise = b.y - a.y;
+	i32 run  = b.x - a.x;
+
+	i32 delta         = (b.y > a.y) ? 1 : -1;
+	i32 numIterations = b.x - a.x;
+
+	i32 distFromPixelOrigin = DQN_ABS(rise) * 2;
+	i32 distAccumulator     = 0;
+
+	i32 newX = a.x;
+	i32 newY = a.y;
+
+	// Unflip the points if we did for plotting the pixels
+	i32 *plotX, *plotY;
+	if (yTallerThanX)
+	{
+		plotX = &newY;
+		plotY = &newX;
+	}
+	else
+	{
+		plotX = &newX;
+		plotY = &newY;
+	}
+
+	const u32 pitchInU32 =
+	    (renderBuffer->width * renderBuffer->bytesPerPixel) / 4;
+	u32 *const bitmapPtr = (u32 *)renderBuffer->memory;
+	u32 pixel = ((i32)color.r << 16) | ((i32)color.g << 8) | ((i32)color.b << 0);
+	for (i32 iterateX = 0; iterateX < numIterations; iterateX++)
+	{
+		newX = a.x + iterateX;
+		bitmapPtr[*plotX + (*plotY * pitchInU32)] = pixel;
+
+		distAccumulator += distFromPixelOrigin;
+		if (distAccumulator > run)
+		{
+			newY += delta;
+			distAccumulator -= (run * 2);
+		}
+	}
+}
+
+FILE_SCOPE void DR_DrawTriangle(PlatformRenderBuffer *const renderBuffer,
+                                DqnV2 p1, DqnV2 p2, DqnV2 p3, DqnV3 color)
+{
+	DR_DrawLine(renderBuffer, p1, p2, color);
+	DR_DrawLine(renderBuffer, p2, p3, color);
+	DR_DrawLine(renderBuffer, p3, p1, color);
+
+	// NOTE(doyle): This is just an desc sort using bubble sort on 3 elements
+	if (p1.y < p2.y) DQN_SWAP(DqnV2i, p1, p2);
+	if (p2.y < p3.y) DQN_SWAP(DqnV2i, p1, p3);
+	if (p1.y < p2.y) DQN_SWAP(DqnV2i, p2, p3);
+
+	i32 y1i = (i32)(p1.y + 0.5f);
+	i32 y2i = (i32)(p2.y + 0.5f);
+	i32 y3i = (i32)(p3.y + 0.5f);
+
+	if (y1i == y3i) return; // Zero height triangle
+}
+
+FILE_SCOPE void DR_ClearRenderBuffer(PlatformRenderBuffer *const renderBuffer, DqnV3 color)
+{
+	if (!renderBuffer) return;
+
+	DQN_ASSERT(color.r >= 0.0f && color.r <= 255.0f);
+	DQN_ASSERT(color.g >= 0.0f && color.g <= 255.0f);
+	DQN_ASSERT(color.b >= 0.0f && color.b <= 255.0f);
+
+	u32 *const bitmapPtr = (u32 *)renderBuffer->memory;
+	for (i32 y = 0; y < renderBuffer->height; y++)
+	{
+		for (i32 x = 0; x < renderBuffer->width; x++)
+		{
+			u32 pixel = ((i32)color.r << 16) | ((i32)color.g << 8) |
+			            ((i32)color.b << 0);
+			bitmapPtr[x + (y * renderBuffer->width)] = pixel;
+		}
+	}
+}
+
 extern "C" void DR_Update(PlatformRenderBuffer *const renderBuffer,
                           PlatformInput *const input,
                           PlatformMemory *const memory)
 {
-	u32 *bitmapPtr = (u32 *)renderBuffer->memory;
+	DR_ClearRenderBuffer(renderBuffer, DqnV3_3f(0, 0, 0));
-	for (i32 y = 0; y < renderBuffer->height; y++)
-	{
-		for (i32 x = 0; x < renderBuffer->width; x++)
-		{
-			u8 red   = 255;
-			u8 green = 0;
-			u8 blue  = 0;
 
-			u32 color = (red << 16) | (green << 8) | (blue << 0);
+	DqnV3 colorRed    = DqnV3_3i(255, 0, 0);
-			bitmapPtr[x + (y * renderBuffer->width)] = color;
+	DqnV2i bufferMidP = DqnV2i_2f(renderBuffer->width * 0.5f, renderBuffer->height * 0.5f);
-		}
+	i32 boundsOffset  = 50;
-	}
+
+	DqnV2 t0[3] = {DqnV2_2i(10, 70), DqnV2_2i(50, 160), DqnV2_2i(70, 80)};
+	DqnV2 t1[3] = {DqnV2_2i(180, 50),  DqnV2_2i(150, 1),   DqnV2_2i(70, 180)};
+	DqnV2 t2[3] = {DqnV2_2i(180, 150), DqnV2_2i(120, 160), DqnV2_2i(130, 180)};
+	DqnV2 t3[3] = {
+	    DqnV2_2i(boundsOffset, boundsOffset),
+	    DqnV2_2i(bufferMidP.w, renderBuffer->height - boundsOffset),
+	    DqnV2_2i(renderBuffer->width - boundsOffset, boundsOffset)};
+
+	DR_DrawTriangle(renderBuffer, t0[0], t0[1], t0[2], colorRed);
+	// DR_DrawTriangle(renderBuffer, t1[0], t1[1], t1[2], colorRed);
+	// DR_DrawTriangle(renderBuffer, t2[0], t2[1], t2[2], colorRed);
+	// DR_DrawTriangle(renderBuffer, t3[0], t3[1], t3[2], colorRed);
 }

src/Win32DRenderer.cpp

@@ -375,6 +375,7 @@ int WINAPI wWinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,
 		DqnWin32_DisplayLastError("CreateDIBSection() failed");
 		return -1;
 	}
+
 	////////////////////////////////////////////////////////////////////////////
 	// Make DLL Path
 	////////////////////////////////////////////////////////////////////////////
@@ -393,7 +394,7 @@ int WINAPI wWinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,
 
 		numCopied =
 		    Dqn_sprintf(dllTmpPath, "%s%s", exeDir, "drenderer_temp.dll");
-		DQN_ASSERT(numCopied < DQN_ARRAY_COUNT(dllPath));
+		DQN_ASSERT(numCopied < DQN_ARRAY_COUNT(dllTmpPath));
 	}
 
 	////////////////////////////////////////////////////////////////////////////

src/build.bat

@@ -39,7 +39,12 @@ REM wd4505 unreferenced local function not used will be removed
 set CompileFlags=-EHa- -GR- -Oi -MT -Z7 -W4 -wd4100 -wd4201 -wd4189 -wd4505 -Od -FAsc
 set DLLFlags=/Fm%ProjectName% /Fo%ProjectName% /Fa%ProjectName% /Fe%ProjectName%
 set Win32Flags=/FmWin32DRenderer /FeWin32DRenderer
-set TimeStamp=%date:~10,4%%date:~7,2%%date:~4,2%_%time:~0,2%%time:~3,2%%time:~6,2%
+
+REM Clean time necessary for hours <10, which produces  H:MM:SS.SS where the
+REM first character of time is an empty space. CleanTime will pad a 0 if
+REM necessary.
+set CleanTime=%time: =0%
+set TimeStamp=%date:~10,4%%date:~7,2%%date:~4,2%_%CleanTime:~0,2%%CleanTime:~3,2%%CleanTime:~6,2%
 
 REM Link libraries
 set LinkLibraries=user32.lib kernel32.lib gdi32.lib

src/dqn.h

@@ -48,14 +48,14 @@ typedef float  f32;
 #define DQN_ASSERT(expr) if (!(expr)) { (*((i32 *)0)) = 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_SQUARED(x) ((x) * (x))
+#define DQN_SWAP(type, a, b) do { type tmp = a; a = b; b = tmp; } while(0)
-
 ////////////////////////////////////////////////////////////////////////////////
 // DqnMem - Memory
 ////////////////////////////////////////////////////////////////////////////////