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Fix timer running rate, add controller mapping

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This commit is contained in:
Doyle Thai 2017-04-07 16:21:40 +10:00
parent f96394dde0
commit 77346c3674
3 changed files with 132 additions and 78 deletions
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110
src/dchip8.cpp
View File

@ -15,6 +15,11 @@ enum Chip8State
chip8state_off, chip8state_off,
}; };
typedef struct Chip8Controller
{
bool key[0x10];
} Chip8Controller;
typedef struct Chip8CPU typedef struct Chip8CPU
{ {
const u16 INIT_ADDRESS = 0x200; const u16 INIT_ADDRESS = 0x200;
@ -66,7 +71,9 @@ typedef struct Chip8CPU
u8 stackPointer; u8 stackPointer;
u16 stack[16]; u16 stack[16];
u8 keyToStoreToRegisterIndex; // Metadata
u8 storeKeyToRegisterIndex;
f32 elapsedTime;
enum Chip8State state; enum Chip8State state;
} Chip8CPU; } Chip8CPU;
@ -267,6 +274,45 @@ FILE_SCOPE void dchip8_init_display(PlatformRenderBuffer renderBuffer)
} }
} }
FILE_SCOPE Chip8Controller dchip8_controller_map_input(PlatformInput input)
{
// NOTE: Chip8 Hex Controller to Keyboard Mapping
// Keypad Keyboard
// +-+-+-+-+ +-+-+-+-+
// |1|2|3|C| |1|2|3|4|
// +-+-+-+-+ +-+-+-+-+
// |4|5|6|D| |Q|W|E|R|
// +-+-+-+-+ => +-+-+-+-+
// |7|8|9|E| |A|S|D|F|
// +-+-+-+-+ +-+-+-+-+
// |A|0|B|F| |Z|X|C|V|
// +-+-+-+-+ +-+-+-+-+
Chip8Controller result = {};
result.key[0x01] = input.key_1.isDown;
result.key[0x02] = input.key_2.isDown;
result.key[0x03] = input.key_3.isDown;
result.key[0x0C] = input.key_4.isDown;
result.key[0x04] = input.key_q.isDown;
result.key[0x05] = input.key_w.isDown;
result.key[0x06] = input.key_e.isDown;
result.key[0x0D] = input.key_r.isDown;
result.key[0x07] = input.key_a.isDown;
result.key[0x08] = input.key_s.isDown;
result.key[0x09] = input.key_d.isDown;
result.key[0x0E] = input.key_f.isDown;
result.key[0x0A] = input.key_z.isDown;
result.key[0x00] = input.key_x.isDown;
result.key[0x0B] = input.key_c.isDown;
result.key[0x0F] = input.key_v.isDown;
return result;
}
void dchip8_update(PlatformRenderBuffer renderBuffer, PlatformInput input, void dchip8_update(PlatformRenderBuffer renderBuffer, PlatformInput input,
PlatformMemory memory) PlatformMemory memory)
{ {
@ -275,7 +321,8 @@ void dchip8_update(PlatformRenderBuffer renderBuffer, PlatformInput input,
DQNT_ASSERT(renderBuffer.bytesPerPixel == 4); DQNT_ASSERT(renderBuffer.bytesPerPixel == 4);
DQNT_ASSERT(memory.permanentMemSize == 4096); DQNT_ASSERT(memory.permanentMemSize == 4096);
u8 *mainMem = (u8 *)memory.permanentMem; u8 *mainMem = (u8 *)memory.permanentMem;
Chip8Controller controller = dchip8_controller_map_input(input);
if (cpu.state == chip8state_init) if (cpu.state == chip8state_init)
{ {
dchip8_init_cpu(&cpu); dchip8_init_cpu(&cpu);
@ -283,7 +330,6 @@ void dchip8_update(PlatformRenderBuffer renderBuffer, PlatformInput input,
dchip8_init_display(renderBuffer); dchip8_init_display(renderBuffer);
} }
#if 1
if (cpu.state == chip8state_load_file) if (cpu.state == chip8state_load_file)
{ {
PlatformFile file = {}; PlatformFile file = {};
@ -305,31 +351,27 @@ void dchip8_update(PlatformRenderBuffer renderBuffer, PlatformInput input,
platform_close_file(&file); platform_close_file(&file);
} }
} }
#endif
if (cpu.state == chip8state_await_input) if (cpu.state == chip8state_await_input)
{ {
const u32 OFFSET_TO_CHIP_CONTROLS = key_7; for (i32 keyVal = 0; keyVal < DQNT_ARRAY_COUNT(controller.key); keyVal++)
for (i32 i = OFFSET_TO_CHIP_CONTROLS; i < DQNT_ARRAY_COUNT(input.key);
i++)
{ {
KeyState checkKey = input.key[i]; if (controller.key[keyVal])
if (checkKey.isDown)
{ {
u8 regIndex = cpu.keyToStoreToRegisterIndex; u8 regIndex = cpu.storeKeyToRegisterIndex;
u8 keyVal = (u8)i - OFFSET_TO_CHIP_CONTROLS; DQNT_ASSERT(keyVal >= 0 && keyVal < 0x0F);
DQNT_ASSERT(keyVal >= 0 && keyVal <= 0x0F);
cpu.registerArray[regIndex] = keyVal; cpu.registerArray[regIndex] = (u8)keyVal;
cpu.state = chip8state_running; cpu.state = chip8state_running;
break;
} }
} }
} }
if (cpu.state == chip8state_running) if (cpu.state == chip8state_running)
{ {
u8 opHighByte = mainMem[cpu.programCounter++]; u8 opHighByte = mainMem[cpu.programCounter++];
u8 opLowByte = mainMem[cpu.programCounter++]; u8 opLowByte = mainMem[cpu.programCounter++];
u8 opFirstNibble = (opHighByte & 0xF0); u8 opFirstNibble = (opHighByte & 0xF0);
switch (opFirstNibble) switch (opFirstNibble)
@ -655,26 +697,21 @@ void dchip8_update(PlatformRenderBuffer renderBuffer, PlatformInput input,
DQNT_ASSERT(regNum < DQNT_ARRAY_COUNT(cpu.registerArray)); DQNT_ASSERT(regNum < DQNT_ARRAY_COUNT(cpu.registerArray));
u8 vx = cpu.registerArray[regNum]; u8 vx = cpu.registerArray[regNum];
DQNT_ASSERT(vx >= 0 && vx <= 0x0F); DQNT_ASSERT(vx >= 0 && vx <= 0x0F);
DQNT_ASSERT(vx < DQNT_ARRAY_COUNT(controller.key));
const u32 KEY_OFFSET_TO_START_CONTROLS = key_7;
DQNT_ASSERT((KEY_OFFSET_TO_START_CONTROLS + vx) <
DQNT_ARRAY_COUNT(input.key));
KeyState checkKey =
input.key[KEY_OFFSET_TO_START_CONTROLS + vx];
bool skipNextInstruction = false; bool skipNextInstruction = false;
// SKP Vx - Ex9E - Skip next instruction if key with the value // SKP Vx - Ex9E - Skip next instruction if key with the value
// of Vx is pressed // of Vx is pressed
if (opLowByte == 0x9E) if (opLowByte == 0x9E)
{ {
skipNextInstruction = checkKey.isDown; skipNextInstruction = controller.key[vx];
} }
// SKNP Vx - ExA1 - Skip next instruction if key with the value // SKNP Vx - ExA1 - Skip next instruction if key with the value
// of Vx is not pressed // of Vx is not pressed
else else
{ {
DQNT_ASSERT(opLowByte == 0xA1); DQNT_ASSERT(opLowByte == 0xA1);
skipNextInstruction = !checkKey.isDown; skipNextInstruction = !controller.key[vx];
} }
if (skipNextInstruction) cpu.programCounter += 2; if (skipNextInstruction) cpu.programCounter += 2;
@ -696,8 +733,8 @@ void dchip8_update(PlatformRenderBuffer renderBuffer, PlatformInput input,
// the key in Vx // the key in Vx
else if (opLowByte == 0x0A) else if (opLowByte == 0x0A)
{ {
cpu.state = chip8state_await_input; cpu.state = chip8state_await_input;
cpu.keyToStoreToRegisterIndex = regNum; cpu.storeKeyToRegisterIndex = regNum;
} }
// LD DT, Vx - Fx15 - Set delay timer = Vx // LD DT, Vx - Fx15 - Set delay timer = Vx
else if (opLowByte == 0x15) else if (opLowByte == 0x15)
@ -770,10 +807,27 @@ void dchip8_update(PlatformRenderBuffer renderBuffer, PlatformInput input,
break; break;
}; };
if (cpu.delayTimer > 0) cpu.delayTimer--; // IMPORTANT: Timers need to be decremented at a rate of 60hz. Since we
// can run the interpreter faster than that, make sure we decrement
// timers at the fixed rate.
if (cpu.delayTimer > 0 || cpu.soundTimer > 0)
{
cpu.elapsedTime += input.deltaForFrame;
f32 TIMER_DECREMENT_INTERVAL = 1 / 60.0f;
// TODO(doyle): This needs to play a buzzing sound whilst timer > 0 if (cpu.elapsedTime >= TIMER_DECREMENT_INTERVAL)
if (cpu.soundTimer > 0) cpu.soundTimer--; {
cpu.elapsedTime = 0;
if (cpu.delayTimer > 0) cpu.delayTimer--;
// TODO(doyle): This needs to play a buzzing sound whilst timer
// > 0
if (cpu.soundTimer > 0) cpu.soundTimer--;
}
}
else
{
cpu.elapsedTime = 0;
}
} }
} }

64
src/dchip8_platform.h
View File

@ -21,25 +21,25 @@ enum Key
key_right, key_right,
key_escape, key_escape,
key_7, key_1,
key_8, key_2,
key_9, key_3,
key_0, key_4,
key_U, key_q,
key_I, key_w,
key_O, key_e,
key_P, key_r,
key_J, key_a,
key_K, key_s,
key_L, key_d,
key_colon, key_f,
key_M, key_z,
key_comma, key_x,
key_dot, key_c,
key_forward_slash, key_v,
key_count, key_count,
}; };
@ -64,25 +64,25 @@ typedef struct PlatformInput
KeyState right; KeyState right;
KeyState escape; KeyState escape;
KeyState key_7; KeyState key_1;
KeyState key_8; KeyState key_2;
KeyState key_9; KeyState key_3;
KeyState key_0; KeyState key_4;
KeyState key_U; KeyState key_q;
KeyState key_I; KeyState key_w;
KeyState key_O; KeyState key_e;
KeyState key_P; KeyState key_r;
KeyState key_J; KeyState key_a;
KeyState key_K; KeyState key_s;
KeyState key_L; KeyState key_d;
KeyState key_colon; KeyState key_f;
KeyState key_M; KeyState key_z;
KeyState key_comma; KeyState key_x;
KeyState key_dot; KeyState key_c;
KeyState key_forward_slash; KeyState key_v;
}; };
}; };
} PlatformInput; } PlatformInput;

36
src/win32_dchip8.cpp
View File

@ -117,7 +117,7 @@ inline FILE_SCOPE LARGE_INTEGER win32_query_perf_counter_time()
FILE_SCOPE inline void win32_parse_key_msg(KeyState *key, MSG msg) FILE_SCOPE inline void win32_parse_key_msg(KeyState *key, MSG msg)
{ {
WPARAM lParam = msg.lParam; LPARAM lParam = msg.lParam;
bool keyIsDown = ((lParam >> 30) & 1); bool keyIsDown = ((lParam >> 30) & 1);
bool keyTransitioned = ((lParam >> 31) & 1); bool keyTransitioned = ((lParam >> 31) & 1);
@ -144,25 +144,25 @@ FILE_SCOPE void win32_process_messages(HWND window, PlatformInput *input)
case VK_LEFT: win32_parse_key_msg(&input->left, msg); break; case VK_LEFT: win32_parse_key_msg(&input->left, msg); break;
case VK_RIGHT: win32_parse_key_msg(&input->right, msg); break; case VK_RIGHT: win32_parse_key_msg(&input->right, msg); break;
case '7': win32_parse_key_msg(&input->key_7, msg); break; case '1': win32_parse_key_msg(&input->key_1, msg); break;
case '8': win32_parse_key_msg(&input->key_8, msg); break; case '2': win32_parse_key_msg(&input->key_2, msg); break;
case '9': win32_parse_key_msg(&input->key_9, msg); break; case '3': win32_parse_key_msg(&input->key_3, msg); break;
case '0': win32_parse_key_msg(&input->key_0, msg); break; case '4': win32_parse_key_msg(&input->key_4, msg); break;
case 'U': win32_parse_key_msg(&input->key_U, msg); break; case 'Q': win32_parse_key_msg(&input->key_q, msg); break;
case 'I': win32_parse_key_msg(&input->key_I, msg); break; case 'W': win32_parse_key_msg(&input->key_w, msg); break;
case 'O': win32_parse_key_msg(&input->key_O, msg); break; case 'E': win32_parse_key_msg(&input->key_e, msg); break;
case 'P': win32_parse_key_msg(&input->key_P, msg); break; case 'R': win32_parse_key_msg(&input->key_r, msg); break;
case 'J': win32_parse_key_msg(&input->key_J, msg); break; case 'A': win32_parse_key_msg(&input->key_a, msg); break;
case 'K': win32_parse_key_msg(&input->key_K, msg); break; case 'S': win32_parse_key_msg(&input->key_s, msg); break;
case 'L': win32_parse_key_msg(&input->key_L, msg); break; case 'D': win32_parse_key_msg(&input->key_d, msg); break;
case ';': win32_parse_key_msg(&input->key_colon, msg); break; case 'F': win32_parse_key_msg(&input->key_f, msg); break;
case 'M': win32_parse_key_msg(&input->key_M, msg); break; case 'Z': win32_parse_key_msg(&input->key_z, msg); break;
case ',': win32_parse_key_msg(&input->key_comma, msg); break; case 'X': win32_parse_key_msg(&input->key_x, msg); break;
case '.': win32_parse_key_msg(&input->key_dot, msg); break; case 'C': win32_parse_key_msg(&input->key_c, msg); break;
case '/': win32_parse_key_msg(&input->key_forward_slash, msg); break; case 'V': win32_parse_key_msg(&input->key_v, msg); break;
case VK_ESCAPE: case VK_ESCAPE:
{ {
@ -279,7 +279,7 @@ int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,
platformMemory.permanentMemSize = DQNT_ARRAY_COUNT(stackMemory); platformMemory.permanentMemSize = DQNT_ARRAY_COUNT(stackMemory);
QueryPerformanceFrequency(&globalQueryPerformanceFrequency); QueryPerformanceFrequency(&globalQueryPerformanceFrequency);
const f32 TARGET_FRAMES_PER_S = 180.0f; const f32 TARGET_FRAMES_PER_S = 540.0f;
f32 targetSecondsPerFrame = 1 / TARGET_FRAMES_PER_S; f32 targetSecondsPerFrame = 1 / TARGET_FRAMES_PER_S;
f32 frameTimeInS = 0.0f; f32 frameTimeInS = 0.0f;
globalRunning = true; globalRunning = true;