update

misc/bdebug.bat

@@ -1,2 +0,0 @@
-call build || exit /b %errorlevel%
-devenv .\build\handmade_win32.exe

misc/brun.bat

@@ -1,2 +0,0 @@
-call build || exit /b %errorlevel%
-.\build\handmade_win32.exe

misc/cmds/build.bat

@@ -9,7 +9,7 @@ set commonCompilerFlags=^
     -Oi                                                             %= Always use intrinsics  =%^
     -EHa-                                                           %= Disable exception handling =%^
     -GR-                                                            %= Never use runtime type info from C++ =%^
-    -WX -W4 -wd4201 -wd4100 -wd4189                                 %= Compiler warnings, -WX warnings as errors, -W4 warning level 4, -wdXXXX disable warning XXXX =%^
+    -WX -W4 -wd4201 -wd4100 -wd4189 -wd4505                         %= Compiler warnings, -WX warnings as errors, -W4 warning level 4, -wdXXXX disable warning XXXX =%^
     -DHANDMADE_INTERNAL=1 -DHANDMADE_SLOW=1 -DHANDMADE_WIN32=1      %= Custom #defines =%^
     -FC                                                             %= Full path of source code file in diagnostics =%^
     -Zi                                                             %= Generate debugger info =%

misc/cmds/run.bat

@@ -0,0 +1 @@
+.\build\handmade_win32.exe

misc/hh.bat

@@ -0,0 +1,2 @@
+call .\misc\cmds\%1.bat || exit /b %errorlevel%
+.\build\handmade_win32.exe

src/handmade.cpp

@@ -1,112 +1,246 @@
 #include "handmade.h"
+#include "handmade_tile.cpp"
 
-#define PI32 3.141592653589f
+internal void drawRectangle(GameOffscreenBuffer *buffer, real32 realMinX, real32 realMinY, real32 realMaxX, real32 realMaxY, real32 R, real32 G, real32 B) {
+    int32 minX = roundReal32ToInt32(realMinX);
+    int32 minY = roundReal32ToInt32(realMinY);
+    int32 maxX = roundReal32ToInt32(realMaxX);
+    int32 maxY = roundReal32ToInt32(realMaxY);
+
+    uint32 color = (roundReal32ToUInt32(R*255.0f) << 16) |
+                   (roundReal32ToUInt32(G*255.0f) <<  8) |
+                   (roundReal32ToUInt32(B*255.0f) <<  0);
+
+    if (minX < 0) {
+        minX = 0;
+    }
+
+    if (minY < 0) {
+        minY = 0;
+    }
+
+    if (maxX > buffer->width) {
+        maxX = buffer->width;
+    }
+
+    if (maxY > buffer->height) {
+        maxY = buffer->height;
+    }
 
-internal void renderPlayer(GameOffscreenBuffer *buffer, int playerX, int playerY) {
     uint8 *endOfBuffer = (uint8 *)buffer->memory + buffer->pitch*buffer->height;
-    uint32 color = 0xFFFFFFFF;
-    int top = playerY;
-    int bottom = playerY + 10;
-    for (int x = playerX; x < playerX + 10; x++) {
-        uint8 *pixel = ((uint8 *)buffer->memory + x * buffer->bytesPerPixel + top*buffer->pitch);
-        for (int y = top; y < bottom; y++) {
-            if ((pixel >= buffer->memory) && (pixel + 4 < endOfBuffer)) {
-                *(uint32 *)pixel = color;
-            }
-            pixel += buffer->pitch;
-        }
-    }
-
-}
-
-internal void outputSineSound(GameSoundOutputBuffer *soundBuffer, GameState *state) {
-    int16 toneVolume = 3000;
-    int wavePeriod = soundBuffer->samplesPerSecond/state->toneHz;
-
-    int16 *sampleOut = soundBuffer->samples;
-    for (int sampleIndex = 0; sampleIndex < soundBuffer->sampleCount; sampleIndex++) {
-        state->tSine += 2.0f * PI32 / (real32)wavePeriod;
-#if 0
-        int16 sampleValue = (int16)(sin(state->tSine) * (real32)toneVolume);
-#else
-        int16 sampleValue = 0;
-#endif
-        *sampleOut++ = sampleValue;
-        *sampleOut++ = sampleValue;
-    }
-}
-
-internal void renderWeirdGradient(GameOffscreenBuffer *buffer, int xOffset, int yOffset) {
-    uint8 *row = (uint8 *)buffer->memory;
-    for (int y = 0; y < buffer->height; y++) {
+    uint8 *row = ((uint8 *)buffer->memory + minX*buffer->bytesPerPixel + minY*buffer->pitch);
+    for (int y = minY; y < maxY; y++) {
         uint32 *pixel = (uint32 *)row;
-        for (int x = 0; x < buffer->width; x++) {
-            uint8 blue = (uint8)(x + xOffset);
-            uint8 green = (uint8)(y + yOffset);
-            *pixel++ = (green << 8) | blue;
+        for (int x = minX; x < maxX; x++) {
+            *pixel++ = color;
         }
         row += buffer->pitch;
     }
 }
 
+internal void outputSound(GameSoundOutputBuffer *soundBuffer, GameState *state) {
+    int16 toneVolume = 3000;
+    int16 *sampleOut = soundBuffer->samples;
+    for (int sampleIndex = 0; sampleIndex < soundBuffer->sampleCount; sampleIndex++) {
+        int16 sampleValue = 0;
+        *sampleOut++ = sampleValue;
+        *sampleOut++ = sampleValue;
+    }
+}
+
+internal void initialiseArena(MemoryArena *arena, memory_index size, uint8 *base) {
+    arena->size = size;
+    arena->base = base;
+    arena->used = 0;
+}
+
+internal void *_pushSize(MemoryArena *arena, memory_index size) {
+    Assert((arena->used + size) <= arena->size);
+    void *result = (void *)(arena->base + arena->used);
+    arena->used += size;
+    return result;
+}
+#define pushStruct(arena, type) (type *)_pushSize(arena, sizeof(type))
+#define pushArray(arena, count, type) (type *)_pushSize(arena, (count)*sizeof(type))
+
 extern "C" GAME_UPDATE_AND_RENDER(gameUpdateAndRender) {
     Assert(sizeof(GameState) <= memory->permanentStorageSize);
 
     GameState *state = (GameState*)memory->permanentStorage;
 
+    const int WORLD_WIDTH = 2;
+    const int WORLD_HEIGHT = 2;
+
     if (!memory->isInitialised) {
-        DebugReadFileResult bmpMem = memory->debugReadEntireFile(__FILE__);
-        if (bmpMem.contents) {
-            if (false) {
-                memory->debugWriteEntireFile("c:/source/repos/handmade/src/test.cpp", bmpMem.contentsSize, bmpMem.contents);
+        state->playerPos.absTileX = 3;
+        state->playerPos.absTileY = 3;
+        state->playerPos.x = 5.0f;
+        state->playerPos.y = 5.0f;
+
+        initialiseArena(
+            &state->worldArena, 
+            memory->permanentStorageSize - sizeof(GameState), 
+            (uint8*)memory->permanentStorage + sizeof(GameState)
+        );
+
+        state->world = pushStruct(&state->worldArena, World);
+        World *world = state->world;
+
+        world->tileMap = pushStruct(&state->worldArena, TileMap);
+        TileMap *tileMap = state->world->tileMap;
+
+        tileMap->chunkShift = 8;
+        tileMap->chunkMask = 0xFF;
+        tileMap->chunkDim = 256;
+        tileMap->tileChunkCountX = 4;
+        tileMap->tileChunkCountY = 4;
+        tileMap->tileSideInMeters = 1.4f;
+        tileMap->tileSideInPixels = 60;
+        tileMap->metersToPixels = tileMap->tileSideInPixels / tileMap->tileSideInMeters;
+
+        tileMap->tileChunks = pushArray(&state->worldArena, tileMap->tileChunkCountX*tileMap->tileChunkCountY, TileChunk);
+
+        for (uint32 y = 0; y < tileMap->tileChunkCountY; y++) {
+            for (uint32 x = 0; x < tileMap->tileChunkCountX; x++) {
+                tileMap->tileChunks[y*tileMap->tileChunkCountX + x].tiles = pushArray(&state->worldArena, tileMap->chunkDim*tileMap->chunkDim, uint32);
+            }
+        }
+
+
+        uint32 tilesPerWidth = 17;
+        uint32 tilesPerHeight = 9;
+
+        for (uint32 screenY = 0; screenY < 32; screenY++) {
+            for (uint32 screenX = 0; screenX < 32; screenX++) {
+                for (uint32 tileY = 0; tileY < tilesPerHeight; tileY++) {
+                    for (uint32 tileX = 0; tileX < tilesPerWidth; tileX++) {
+                        uint32 absTileX = screenX*tilesPerWidth + tileX;
+                        uint32 absTileY = screenY*tilesPerHeight + tileY;
+                        setTileMapValue(&state->worldArena, tileMap, absTileX, absTileY, (tileX == tileY && (tileX % 5 == 0)));
+                    }
+                }
             }
-            memory->debugFreeFileMemory(bmpMem.contents);
         }
 
-        state->toneHz = 440;
-        state->tSine = 0;
-        state->playerY = 100;
-        state->playerX = 100;
-        state->blueOffset = 0;
-        state->greenOffset = 0;
         memory->isInitialised = true;
     }
 
+    real32 screenCenterX = 0.5f*(real32)videoBuf->width;
+    real32 screenCenterY = 0.5f*(real32)videoBuf->height;
+
+//    uint32 tiles[TILEMAP_WIDTH][TILEMAP_HEIGHT] = {
+//        {1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1, 1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1},
+//        {1, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 1, 1, 0, 0, 0,  0, 1, 0, 0,  0, 0, 0, 0,  0, 1, 0, 1},
+//        {1, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 1, 1, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 1, 1},
+//        {1, 0, 0, 0,  0, 1, 1, 0,  0, 0, 0, 0,  0, 0, 0, 1, 1, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 1},
+//        {1, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0, 0, 0, 0, 0,  0, 1, 0, 0,  0, 0, 0, 0,  0, 0, 1, 1},
+//        {1, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 1, 1, 0, 0, 0,  0, 1, 0, 0,  0, 0, 0, 0,  0, 1, 0, 1},
+//        {1, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 1, 1, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  1, 0, 0, 1},
+//        {1, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 1, 1, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  0, 1, 0, 1},
+//        {1, 1, 1, 1,  1, 1, 1, 0,  0, 1, 1, 1,  1, 1, 1, 1, 1, 1, 1, 1,  1, 1, 1, 0,  0, 1, 1, 1,  1, 1, 1, 1},
+//        {1, 1, 1, 1,  1, 1, 1, 0,  0, 1, 1, 1,  1, 1, 1, 1, 1, 1, 1, 1,  1, 1, 1, 0,  0, 1, 1, 1,  1, 1, 1, 1},
+//        {1, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 1, 1, 0, 0, 0,  0, 1, 0, 0,  0, 0, 0, 0,  0, 1, 0, 1},
+//        {1, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 1, 1, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 1, 1},
+//        {1, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 1, 1, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 1},
+//        {1, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0, 0, 0, 0, 0,  0, 1, 0, 0,  0, 0, 0, 0,  0, 0, 1, 1},
+//        {1, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 1, 1, 0, 0, 0,  0, 1, 0, 0,  0, 0, 0, 0,  0, 1, 0, 1},
+//        {1, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 1, 1, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  1, 0, 0, 1},
+//        {1, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 1, 1, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  0, 1, 0, 1},
+//        {1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1, 1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1},
+//    };
+
+    TileMap *tilemap = state->world->tileMap;
+
+    // player
+    real32 playerR = 1.0f;
+    real32 playerG = 1.0f;
+    real32 playerB = 0.5f;
+    real32 playerWidth = 0.7f;
+    real32 playerHeight = 1.4f;
+
     for (int controllerIndex = 0; controllerIndex < ArrayCount(input->controllers); controllerIndex++) {
-        GameControllerInput *controllerInput = &input->controllers[controllerIndex];
-        /*
-        if (controllerInput->isAnalog) {
-            state->toneHz = 440 + (int)(128.0f*controllerInput->stickAvgX);
-            state->greenOffset -= (int)(20.0f*controllerInput->stickAvgX);
-            state->blueOffset += (int)(20.0f*controllerInput->stickAvgY);
-        } else {
-            if (controllerInput->stickRight.endedDown) {
-                state->toneHz = 440 + 128;
-                state->greenOffset -= 10;
-            } else if (controllerInput->stickLeft.endedDown) {
-                state->toneHz = 440 - 128;
-                state->greenOffset += 10;
-            }
-            if (controllerInput->stickUp.endedDown) {
-                state->blueOffset += 10;
-            } else if (controllerInput->stickDown.endedDown) {
-                state->blueOffset -= 10;
-            }
-        }
-        */
+        GameControllerInput *controller = &input->controllers[controllerIndex];
 
-        if (controllerInput->btnDown.endedDown) {
-            state->playerY -= 30;
+        real32 dPlayerX = 0.0f;
+        real32 dPlayerY = 0.0f;
+
+        if (controller->stickUp.endedDown) {
+            dPlayerY = 1.0f;
+        }
+        if (controller->stickDown.endedDown) {
+            dPlayerY = -1.0f;
+        }
+        if (controller->stickLeft.endedDown) {
+            dPlayerX = -1.0f;
+        }
+        if (controller->stickRight.endedDown) {
+            dPlayerX = 1.0f;
         }
 
-        state->playerX += (int)(4.0f*controllerInput->stickAvgX);
-        state->playerY -= (int)(4.0f*controllerInput->stickAvgY);
+        dPlayerX *= 6.0f;
+        dPlayerY *= 6.0f;
+
+        TileMapPosition newPlayerPos = state->playerPos;
+        newPlayerPos.x += dPlayerX * input->dtForFrame;
+        newPlayerPos.y += dPlayerY * input->dtForFrame;
+        newPlayerPos = recanonicalisePosition(tilemap, newPlayerPos);
+
+        TileMapPosition playerBottomLeft = newPlayerPos;
+        playerBottomLeft.x -= 0.5f * playerWidth;
+        playerBottomLeft = recanonicalisePosition(tilemap, playerBottomLeft);
+
+        TileMapPosition playerTopLeft = newPlayerPos;
+        playerTopLeft.x -= 0.5f * playerWidth;
+        playerTopLeft.y += playerWidth;
+        playerTopLeft = recanonicalisePosition(tilemap, playerTopLeft);
+
+        TileMapPosition playerBottomRight = newPlayerPos;
+        playerBottomRight.x += 0.5f * playerWidth;
+        playerBottomRight = recanonicalisePosition(tilemap, playerBottomRight);
+
+        TileMapPosition playerTopRight = newPlayerPos;
+        playerTopRight.x += 0.5f * playerWidth;
+        playerTopRight.y += playerWidth;
+        playerTopRight = recanonicalisePosition(tilemap, playerTopRight);
+
+        if (
+          isTileMapPointEmpty(tilemap, playerTopLeft) &&
+          isTileMapPointEmpty(tilemap, playerTopRight) &&
+          isTileMapPointEmpty(tilemap, playerBottomLeft) &&
+          isTileMapPointEmpty(tilemap, playerBottomRight)
+        ) {
+            state->playerPos = newPlayerPos;
+        }
     }
 
-    renderWeirdGradient(videoBuf, state->greenOffset, state->blueOffset);
-    renderPlayer(videoBuf, state->playerX, state->playerY);
+    // clearscreen
+    drawRectangle(videoBuf, 0.0f, 0.0f, (real32)videoBuf->width, (real32)videoBuf->height, 1.0f, 0.0f, 1.0f);
+
+    for (int32 relRow = -10; relRow < 10; relRow++) {
+        for (int32 relCol = -20; relCol < 20; relCol++) {
+            uint32 col = state->playerPos.absTileX + relCol;
+            uint32 row = state->playerPos.absTileY + relRow;
+            int32 tileId = getTileValue(tilemap, col, row);
+            real32 fill = 0.5f;
+            if (tileId == 1) {
+                fill = 1.0f;
+            } 
+            if ((row == state->playerPos.absTileY) && (col == state->playerPos.absTileX)) {
+                fill = 0.0f;
+            }
+            real32 minX = screenCenterX - tilemap->metersToPixels*state->playerPos.x + ((real32)relCol)*tilemap->tileSideInPixels;
+            real32 minY = screenCenterY + tilemap->metersToPixels*state->playerPos.y - ((real32)relRow)*tilemap->tileSideInPixels;
+            real32 maxX = minX + tilemap->tileSideInPixels;
+            real32 maxY = minY - tilemap->tileSideInPixels;
+            drawRectangle(videoBuf, minX, maxY, maxX, minY, fill, fill, fill);
+        }
+    }
+
+    real32 playerLeft = screenCenterX - 0.5f*tilemap->metersToPixels*playerWidth;
+    real32 playerTop = screenCenterY - tilemap->metersToPixels*playerHeight;
+    drawRectangle(videoBuf, playerLeft, playerTop, playerLeft + tilemap->metersToPixels*playerWidth, playerTop + tilemap->metersToPixels*playerHeight, playerR, playerG, playerB);
 }
 
 extern "C" GAME_GET_SOUND_SAMPLES(gameGetSoundSamples) {
-    outputSineSound(soundBuf, (GameState*)memory->permanentStorage);
+    outputSound(soundBuf, (GameState*)memory->permanentStorage);
 }

src/handmade.h

@@ -1,10 +1,8 @@
+#pragma once
+
 #include <stdarg.h>
 #include <stdint.h>
 #include <stdio.h>
-#include <math.h>
-#include <windows.h>
-
-#pragma once
 
 /* 
  * ---------------
@@ -47,11 +45,15 @@ typedef uint16_t uint16;
 typedef uint32_t uint32;
 typedef uint64_t uint64;
 
+typedef size_t MemoryIndex;
+
 typedef int8_t int8;
 typedef int16_t int16;
 typedef int32_t int32;
 typedef int64_t int64;
 
+typedef size_t memory_index;
+
 typedef float real32;
 typedef double real64;
 
@@ -64,6 +66,10 @@ inline uint32 safeTruncateUInt64(uint64 val) {
     return (uint32)val;
 }
 
+struct ThreadContext {
+    int placeholder;
+};
+
 // === Platform to game services ===
 #if HANDMADE_INTERNAL
 
@@ -72,13 +78,13 @@ struct DebugReadFileResult {
     void *contents;
 };
 
-#define DEBUG_PLATFORM_READ_ENTIRE_FILE(name) DebugReadFileResult name(char *filename)
+#define DEBUG_PLATFORM_READ_ENTIRE_FILE(name) DebugReadFileResult name(ThreadContext *ctx, char *filename)
 typedef DEBUG_PLATFORM_READ_ENTIRE_FILE(DebugPlatformReadEntireFileFn);
 
-#define DEBUG_PLATFORM_FREE_FILE_MEMORY(name) void name(void *fileMemory)
+#define DEBUG_PLATFORM_FREE_FILE_MEMORY(name) void name(ThreadContext *ctx, void *fileMemory)
 typedef DEBUG_PLATFORM_FREE_FILE_MEMORY(DebugPlatformFreeFileMemoryFn);
 
-#define DEBUG_PLATFORM_WRITE_ENTIRE_FILE(name) bool32 name(char *filename, uint32 memorySize, void *memory)
+#define DEBUG_PLATFORM_WRITE_ENTIRE_FILE(name) bool32 name(ThreadContext *ctx, char *filename, uint32 memorySize, void *memory)
 typedef DEBUG_PLATFORM_WRITE_ENTIRE_FILE(DebugPlatformWriteEntireFileFn);
 
 #define DEBUG_PLATFORM_PRINTF(name) void name(wchar_t* format, ...)
@@ -130,39 +136,51 @@ struct GameControllerInput {
 }; 
 
 struct GameInput {
+    GameButtonState mouseButtons[5];
+    int32 mouseX;
+    int32 mouseY;
+    int32 mouseZ;
+    real32 dtForFrame;
     GameControllerInput controllers[5];
 };
 
 struct GameMemory {
     bool32 isInitialised;
-
     uint64 permanentStorageSize;
     void *permanentStorage; // required to be initialised to zero at startup 
-
     uint64 transientStorageSize;
     void *transientStorage; // required to be initialised to zero at startup 
-
     DebugPlatformReadEntireFileFn *debugReadEntireFile;
     DebugPlatformFreeFileMemoryFn *debugFreeFileMemory;
     DebugPlatformWriteEntireFileFn *debugWriteEntireFile;
     DebugPrintfFn *debug_printf;
 };
 
+#include "handmade_tile.h"
+#include "handmade_intrinsics.h"
+
+struct World {
+    TileMap *tileMap;
+};
+
+struct MemoryArena {
+    memory_index size;
+    uint8 *base;
+    memory_index used;
+};
+
 struct GameState {
-    int toneHz;
-    int greenOffset;
-    int blueOffset;
-    real32 tSine;
-    int playerY;
-    int playerX;
+    TileMapPosition playerPos;
+    World *world;
+    MemoryArena worldArena;
 };
 
 // === Game to platform services ===
 
-#define GAME_UPDATE_AND_RENDER(name) void name(GameMemory *memory, GameOffscreenBuffer *videoBuf, GameInput *input)
+#define GAME_UPDATE_AND_RENDER(name) void name(ThreadContext *ctx, GameMemory *memory, GameOffscreenBuffer *videoBuf, GameInput *input)
 typedef GAME_UPDATE_AND_RENDER(GameUpdateAndRenderFn);
 GAME_UPDATE_AND_RENDER(gameUpdateAndRenderStub) {}
 
-#define GAME_GET_SOUND_SAMPLES(name) void name(GameMemory *memory, GameSoundOutputBuffer *soundBuf)
+#define GAME_GET_SOUND_SAMPLES(name) void name(ThreadContext *ctx, GameMemory *memory, GameSoundOutputBuffer *soundBuf)
 typedef GAME_GET_SOUND_SAMPLES(GameGetSoundSamplesFn);
 GAME_GET_SOUND_SAMPLES(gameGetSoundSamplesStub) {}

src/handmade_intrinsics.h

@@ -0,0 +1,37 @@
+#pragma once
+#include "handmade.h"
+#include "math.h"
+
+#define PI32 3.141592653589f
+
+inline int32 roundReal32ToUInt32(real32 realNum) {
+    return (uint32)(realNum + 0.5f);
+}
+
+inline int32 roundReal32ToInt32(real32 realNum) {
+    return (int32)(realNum + 0.5f);
+}
+
+inline int32 floorReal32ToInt32(real32 realNum) {
+    return (int32)floorf(realNum);
+}
+
+inline int32 truncateReal32ToInt32(real32 realNum) {
+    return (int32)realNum;
+}
+
+inline real32 sin(real32 angle) {
+    return sinf(angle);
+}
+
+inline real32 cos(real32 angle) {
+    return cosf(angle);
+}
+
+inline real32 atan2(real32 y, real32 x) {
+    return atan2f(y, x);
+}
+
+inline uint32 absoluteInt32ToUInt32(int32 signedInt32) {
+    return signedInt32 > 0 ? (uint32)signedInt32 : (uint32)(-1*signedInt32);
+}

src/handmade_tile.cpp

@@ -0,0 +1,95 @@
+#pragma once
+#include "handmade.h"
+
+inline TileChunk *getTileChunk(TileMap *tileMap, uint32 tileChunkX, uint32 tileChunkY) {
+    TileChunk *tileChunk = NULL;
+
+    if ((tileChunkX >= 0) && (tileChunkX < tileMap->tileChunkCountX) &&
+        (tileChunkY >= 0) && (tileChunkY < tileMap->tileChunkCountY)
+    ) {
+        tileChunk = &tileMap->tileChunks[tileChunkY * tileMap->tileChunkCountX + tileChunkX];
+    }
+
+    return tileChunk;
+}
+
+inline void recanonicaliseOrd(TileMap *tileMap, uint32 *tileOrd, real32* ord) {
+    int32 offset = floorReal32ToInt32(*ord / tileMap->tileSideInMeters);
+
+    *tileOrd += offset;
+    *ord -= offset*tileMap->tileSideInMeters;
+
+    Assert(*ord >= 0.0f);
+    Assert(*ord < tileMap->tileSideInMeters);
+}
+
+inline TileChunkPosition getChunkPosition(TileMap* tileMap, uint32 absTileX, uint32 absTileY) {
+    TileChunkPosition result = {};
+    result.tileChunkX = absTileX >> tileMap->chunkShift;
+    result.tileChunkY = absTileY >> tileMap->chunkShift;
+    result.relTileX = absTileX & tileMap->chunkMask; 
+    result.relTileY = absTileY & tileMap->chunkMask; 
+    return result;
+}
+
+inline uint32 getTileValueUnchecked(TileMap *tileMap, TileChunk *tileChunk, uint32 testTileX, uint32 testTileY) {
+    Assert(tileChunk);
+    Assert(testTileX < tileMap->chunkDim);
+    Assert(testTileY < tileMap->chunkDim);
+    return tileChunk->tiles[testTileY * tileMap->chunkDim + testTileX];
+}
+
+inline void setTileValueUnchecked(TileMap *tileMap, TileChunk *tileChunk, uint32 testTileX, uint32 testTileY, uint32 tileValue) {
+    Assert(tileChunk);
+    Assert(testTileX < tileMap->chunkDim);
+    Assert(testTileY < tileMap->chunkDim);
+    tileChunk->tiles[testTileY * tileMap->chunkDim + testTileX] = tileValue;
+}
+
+inline uint32 getTileValue(TileMap *tileMap, TileChunk* tileChunk, uint32 testTileX, uint32 testTileY) {
+    uint32 tileValue = 0;
+    if (tileChunk) {
+        tileValue = getTileValueUnchecked(tileMap, tileChunk, testTileX, testTileY);
+    }
+    return tileValue;
+}
+
+inline void setTileValue(TileMap *tileMap, TileChunk* tileChunk, uint32 testTileX, uint32 testTileY, uint32 tileValue) {
+    if (tileChunk) {
+        setTileValueUnchecked(tileMap, tileChunk, testTileX, testTileY, tileValue);
+    }
+}
+
+inline uint32 getTileValue(TileMap *tileMap, uint32 testTileX, uint32 testTileY) {
+    uint32 tileValue = 0;
+    TileChunkPosition chunkPos = getChunkPosition(tileMap, testTileX, testTileY);
+    TileChunk *tileChunk = getTileChunk(tileMap, chunkPos.tileChunkX, chunkPos.tileChunkY);
+    tileValue = getTileValue(tileMap, tileChunk, testTileX, testTileY);
+    return tileValue;
+}
+
+inline TileMapPosition recanonicalisePosition(TileMap *tileMap, TileMapPosition pos) {
+    TileMapPosition result = pos;
+
+    recanonicaliseOrd(tileMap, &result.absTileX, &result.x);
+    recanonicaliseOrd(tileMap, &result.absTileY, &result.y);
+
+    return result;
+}
+
+internal bool32 isTileMapPointEmpty(TileMap *tileMap, TileMapPosition testPos) {
+    bool32 isEmpty = false;
+
+    TileChunkPosition chunkPos = getChunkPosition(tileMap, testPos.absTileX, testPos.absTileY);
+    TileChunk *tileChunk = getTileChunk(tileMap, chunkPos.tileChunkX, chunkPos.tileChunkY);
+    isEmpty = (getTileValue(tileMap, tileChunk, chunkPos.relTileX, chunkPos.relTileY) == 0);
+
+    return isEmpty;
+}
+
+internal void setTileMapValue(MemoryArena *arena, TileMap *tileMap, uint32 absTileX, uint32 absTileY, uint32 tileValue) {
+    TileChunkPosition chunkPos = getChunkPosition(tileMap, absTileX, absTileY);
+    TileChunk *tileChunk = getTileChunk(tileMap, chunkPos.tileChunkX, chunkPos.tileChunkY);
+    Assert(tileChunk);
+    setTileValue(tileMap, tileChunk, chunkPos.relTileX, chunkPos.relTileY, tileValue);
+}

src/handmade_tile.h

@@ -0,0 +1,41 @@
+#pragma once
+#include "handmade.h"
+
+struct TileChunk {
+    uint32 *tiles;
+};
+
+struct TileChunkPosition {
+    uint32 tileChunkX;
+    uint32 tileChunkY;
+
+    uint32 relTileX;
+    uint32 relTileY;
+};
+
+struct TileMapPosition {
+    // tile map x and y and tile x and y packed, lower 8 bits are tile X,Y and upper 24 bits map X,Y
+    // ---- ---- ---- ---- ---- ---- : ---- ----
+    // TILE MAP ORD                  : TILE ORD
+    uint32 absTileX;
+    uint32 absTileY;
+
+    // Sub-tile position
+    real32 x;
+    real32 y;
+};
+
+struct TileMap {
+    uint32 chunkShift;
+    uint32 chunkMask;
+    uint32 chunkDim;
+
+    real32 tileSideInMeters;
+    int32 tileSideInPixels;
+    real32 metersToPixels;
+
+    uint32 tileChunkCountX;
+    uint32 tileChunkCountY;
+
+    TileChunk *tileChunks;
+};

src/win32_handmade.cpp

@@ -60,7 +60,7 @@ DEBUG_PLATFORM_READ_ENTIRE_FILE(debugReadEntireFile) {
                 if (ReadFile(fileHandle, result.contents, (DWORD)fileSize.QuadPart, &bytesRead, NULL) && (fileSize32 == (uint32)bytesRead)) {
                     result.contentsSize = fileSize32;
                 } else {
-                    debugFreeFileMemory(result.contents);
+                    debugFreeFileMemory(ctx, result.contents);
                     result.contents = NULL;
                     // logging
                 }
@@ -128,9 +128,18 @@ internal Win32WindowDimensions win32GetWindowDimensions(HWND window) {
 
 internal void win32DrawBufferInWindow(Win32OffscreenBuffer *buffer, HWND window) {
     Win32WindowDimensions winDims = win32GetWindowDimensions(window);
-    StretchDIBits(
-        GetDC(window),
-        0, 0, winDims.width, winDims.height,
+    HDC dc = GetDC(window);
+
+    int offsetX = 10;
+    int offsetY = 10;
+
+    PatBlt(dc, 0, 0, winDims.width, offsetY, BLACKNESS);
+    PatBlt(dc, 0, offsetY + buffer->height, winDims.width, winDims.height, BLACKNESS);
+    PatBlt(dc, 0, 0, offsetX, winDims.height, BLACKNESS);
+    PatBlt(dc, offsetX + buffer->width, 0, winDims.width, winDims.height, BLACKNESS);
+
+    StretchDIBits(dc,
+        offsetX, offsetY, buffer->width, buffer->height,
         0, 0, buffer->width, buffer->height,
         buffer->memory,
         &buffer->info, 
@@ -139,14 +148,6 @@ internal void win32DrawBufferInWindow(Win32OffscreenBuffer *buffer, HWND window)
     );
 }
 
-struct Win32GameCode {
-    HMODULE gameCodeLib;
-    GameUpdateAndRenderFn *updateAndRender;
-    GameGetSoundSamplesFn *getSoundSamples;
-    bool isValid;
-    FILETIME lastWriteTime;
-};
-
 inline FILETIME win32GetLastWriteTime(char *filename) {
     FILETIME lastWriteTime = {};
     WIN32_FIND_DATA findData;
@@ -202,9 +203,11 @@ internal void win32LoadXInput() {
 }
 
 internal void win32ProcessKeyboardKeypress(GameButtonState *newState, bool32 isDown) {
+    if (newState->endedDown != isDown) {
         newState->endedDown = isDown;
         newState->halfTransitionCount++;
     }
+}
 
 internal void win32ProcessXInputDigitalButton(DWORD xInputButtonState, GameButtonState *oldState, GameButtonState *newState, DWORD buttonBit) {
     newState->endedDown = (xInputButtonState & buttonBit) == buttonBit;
@@ -258,12 +261,7 @@ internal void win32InitSound(HWND window, int32 samplesPerSec, int bufferSize) {
     }
 }
 
-LRESULT mainWindowCallback(
-  HWND window,
-  UINT message,
-  WPARAM wParam,
-  LPARAM lParam
-) {
+LRESULT mainWindowCallback(HWND window, UINT message, WPARAM wParam, LPARAM lParam) {
     LRESULT result = 0;
     switch (message) {
         case WM_SIZE: {
@@ -360,18 +358,24 @@ internal void win32FillSoundBuffer(Win32SoundOutput *soundOutput, DWORD byteToLo
     }
 }
 
-internal void win32BeginRecordingInput(Win32State *win32State, int inputRecordingIndex) {
-    win32State->inputRecordingIndex = inputRecordingIndex;
-    char *filename = "replay.ipt";
-    win32State->recordingHandle = CreateFileA(filename, GENERIC_WRITE, FILE_SHARE_READ, NULL, CREATE_ALWAYS, NULL, NULL);
-    DWORD bytesToWrite = (DWORD)win32State->gameMemoryTotalSize;
-    Assert(bytesToWrite < 0xFFFFFFFF);
-    DWORD bytesWritten;
-    WriteFile(win32State->recordingHandle, win32State->gameMemoryBlock, bytesToWrite, &bytesWritten, NULL);
+internal Win32ReplayBuffer* win32GetReplayBuffer(Win32State *state, int unsigned index) {
+    Win32ReplayBuffer *result = &state->replayBuffers[index - 1];
+    return result;
+}
+
+internal void win32BeginRecordingInput(Win32State *state, int inputRecordingIndex) {
+    Win32ReplayBuffer *replayBuffer = win32GetReplayBuffer(state, inputRecordingIndex);
+    if (replayBuffer->memoryBlock) {
+        state->inputRecordingIndex = inputRecordingIndex;
+        state->recordingHandle = replayBuffer->fileHandle;
+        LARGE_INTEGER filePosition;
+        filePosition.QuadPart = state->gameMemoryTotalSize;
+        SetFilePointerEx(state->recordingHandle, filePosition, NULL, FILE_BEGIN);
+        CopyMemory(replayBuffer->memoryBlock, state->gameMemoryBlock, state->gameMemoryTotalSize);
+    }
 }
 
 internal void win32EndRecordingInput(Win32State *win32State) {
-    CloseHandle(win32State->recordingHandle);
     win32State->inputRecordingIndex = 0;
 }
 
@@ -380,18 +384,19 @@ internal void win32RecordInput(Win32State *win32State, GameInput *newInput) {
     WriteFile(win32State->recordingHandle, newInput, sizeof(*newInput), &bytesWritten, NULL);
 }
 
-internal void win32BeginInputPlayback(Win32State *win32State, int inputPlayingIndex) {
-    win32State->inputPlayingIndex = inputPlayingIndex;
-    char *filename = "replay.ipt";
-    win32State->playbackHandle = CreateFileA(filename, GENERIC_READ, FILE_SHARE_READ, NULL, OPEN_EXISTING, NULL, NULL);
-    DWORD bytesToRead = (DWORD)win32State->gameMemoryTotalSize;
-    Assert(bytesToRead < 0xFFFFFFFF);
-    DWORD bytesRead;
-    ReadFile(win32State->playbackHandle, win32State->gameMemoryBlock, bytesToRead, &bytesRead, NULL);
+internal void win32BeginInputPlayback(Win32State *state, int inputPlayingIndex) {
+    Win32ReplayBuffer *replayBuffer = win32GetReplayBuffer(state, inputPlayingIndex); 
+    if (replayBuffer->memoryBlock) {
+        state->inputPlayingIndex = inputPlayingIndex;
+        state->playbackHandle = replayBuffer->fileHandle;
+        LARGE_INTEGER filePosition;
+        filePosition.QuadPart = state->gameMemoryTotalSize;
+        SetFilePointerEx(state->playbackHandle, filePosition, NULL, FILE_BEGIN);
+        CopyMemory(state->gameMemoryBlock, replayBuffer->memoryBlock, state->gameMemoryTotalSize);
+    }
 }
 
 internal void win32EndInputPlayback(Win32State *win32State) {
-    CloseHandle(win32State->playbackHandle);
     win32State->inputPlayingIndex = 0;
 }
 
@@ -449,11 +454,13 @@ internal void win32ProcessPendingMessages(Win32State *win32State, GameController
                     } else if (VKCode == VK_SPACE) {
                     } else if (VKCode == 'L') {
                         if (isDown) {
-                            if (win32State->inputRecordingIndex == 0) {
+                            if (win32State->inputRecordingIndex == 0 && win32State->inputPlayingIndex == 0) {
                                 win32BeginRecordingInput(win32State, 1);
-                            } else {
+                            } else if (win32State->inputRecordingIndex != 0 && win32State->inputPlayingIndex == 0) {
                                 win32EndRecordingInput(win32State);
                                 win32BeginInputPlayback(win32State, 1);
+                            } else if (win32State->inputRecordingIndex == 0 && win32State->inputPlayingIndex != 0) {
+                                win32EndInputPlayback(win32State);
                             }
                         }
                     }
@@ -483,12 +490,6 @@ inline real32 win32GetSecondsElapsed(LARGE_INTEGER start, LARGE_INTEGER end) {
     return (real32)(end.QuadPart - start.QuadPart) / (real32)globalPerfCountFrequency;
 }
 
-//    int monitorRefreshHz = 60;
-//    int gameUpdateHz = monitorRefreshHz / 2;
-
-#define monitorRefreshHz 60
-#define gameUpdateHz (monitorRefreshHz / 2)
-
 internal void win32DebugDrawVertical(Win32OffscreenBuffer *buffer, int x, int top, int bottom, int32 color) {
     uint8 *pixel = (uint8 *)buffer->memory + top * buffer->pitch + x*buffer->bytesPerPixel;
     for (int y = top; y < bottom; y++) {
@@ -503,29 +504,6 @@ inline void win32DrawSoundBufferMarker(Win32OffscreenBuffer *buffer, Win32SoundO
     win32DebugDrawVertical(buffer, x, top, bottom, color);
 }
 
-internal void win32DebugSyncDisplay(Win32OffscreenBuffer *buffer, int markerCount, Win32DebugTimeMarker *markers, Win32SoundOutput *soundOutput, real32 targetSecondsPerFrame) {
-    int padX = 16;
-    int padY = 16;
-
-    int top = padY;
-    int bottom = buffer->height - padY;
-    int renderWidth = buffer->width - 2 *padX;
-
-    real32 pxPerSoundBufferEntry = (real32)renderWidth / (real32)soundOutput->secondaryBufferSize;
-
-#if 0
-    for (int markerIndex = 0; markerIndex < markerCount; markerIndex++) {
-        Win32DebugTimeMarker *thisMarker = &markers[markerIndex];
-        real32 alpha = ((real32)(markerIndex + 1) / (real32)markerCount);
-        int x = padX + (int)(pxPerSoundBufferEntry * (real32)thisMarker->writeCursor);
-        uint8 *pixel = (uint8 *)buffer->memory + top * buffer->pitch + x*buffer->bytesPerPixel;
-        uint32 newPixel = (uint32)((real32)alpha * 0xFFFFFFFF + (1.0f - alpha) * (*(uint32 *)pixel));
-        win32DrawSoundBufferMarker(buffer, soundOutput, pxPerSoundBufferEntry, padX, top, bottom, thisMarker->playCursor, newPixel);
-        win32DrawSoundBufferMarker(buffer, soundOutput, pxPerSoundBufferEntry, padX, top, bottom, thisMarker->writeCursor, 0x00FF0000);
-    }
-#endif
-}
-
 void catStrings(size_t sourceACount, char *sourceA, size_t sourceBCount, char *sourceB, size_t destCount, char *dest) {
     for (int i = 0; i < sourceACount; i++) { 
         *dest++ = *sourceA++;
@@ -536,27 +514,34 @@ void catStrings(size_t sourceACount, char *sourceA, size_t sourceBCount, char *s
     *dest++ = 0;
 }
 
-int APIENTRY WinMain(HINSTANCE instance, HINSTANCE prevInstance, PSTR commandLine, int commandShow) {
-    char exeFileName[MAX_PATH];
-    DWORD sizeOfFilename = GetModuleFileNameA(NULL, exeFileName, sizeof(exeFileName));
-    char *onePastLastSlash = exeFileName;
-    for (char *scan = exeFileName; *scan; scan++) {
+void win32GetExeFilename(Win32State *win32State) {
+    DWORD sizeOfFilename = GetModuleFileNameA(NULL, win32State->exeFilename, sizeof(win32State->exeFilename));
+    win32State->onePastLastExeFilenameSlash = win32State->exeFilename;
+    for (char *scan = win32State->exeFilename; *scan; scan++) {
         if (*scan == '\\') {
-            onePastLastSlash = scan + 1;
+            win32State->onePastLastExeFilenameSlash = scan + 1;
+        }
     }
 }
 
-    char sourceGameCodeDLLFilename[] = "handmade.dll";
+void win32GetFullPathToLocalFile(Win32State *state, char *filename, int filenameSize, char *maxPathBuffer) {
+    catStrings(state->onePastLastExeFilenameSlash - state->exeFilename, state->exeFilename, filenameSize, filename, (size_t)MAX_PATH, maxPathBuffer);
+}
+
+#define WINDOW_WIDTH 960
+#define WINDOW_HEIGHT 540
+
+int APIENTRY WinMain(HINSTANCE instance, HINSTANCE prevInstance, PSTR commandLine, int commandShow) {
+    Win32State win32State = {};
+    win32GetExeFilename(&win32State);
+
+    char *sourceGameCodeDLLFilename = "handmade.dll";
     char sourceGameCodeDLLFullPath[MAX_PATH];
-    catStrings(onePastLastSlash - exeFileName, exeFileName, 
-            sizeof(sourceGameCodeDLLFilename) - 1, sourceGameCodeDLLFilename,
-            sizeof(sourceGameCodeDLLFullPath) - 1, sourceGameCodeDLLFullPath);
+    win32GetFullPathToLocalFile(&win32State, sourceGameCodeDLLFilename, sizeof(sourceGameCodeDLLFullPath) - 1, sourceGameCodeDLLFullPath);
 
     char tempGameCodeDLLFilename[] = "handmade_temp.dll";
     char tempGameCodeDLLFullPath[MAX_PATH];
-    catStrings(onePastLastSlash - exeFileName, exeFileName, 
-            sizeof(tempGameCodeDLLFilename) - 1, tempGameCodeDLLFilename,
-            sizeof(tempGameCodeDLLFullPath) - 1, tempGameCodeDLLFullPath);
+    win32GetFullPathToLocalFile(&win32State, tempGameCodeDLLFilename, sizeof(tempGameCodeDLLFullPath) - 1, tempGameCodeDLLFullPath);
 
     LARGE_INTEGER performanceFrequencyResult;
     QueryPerformanceFrequency(&performanceFrequencyResult);
@@ -570,40 +555,45 @@ int APIENTRY WinMain(HINSTANCE instance, HINSTANCE prevInstance, PSTR commandLin
     windowClass.lpfnWndProc = &mainWindowCallback;
     windowClass.hInstance = instance;
     windowClass.lpszClassName = "HandmadeHeroWindowClass";
-
-    resizeDIBSection(&globalBackBuffer, 1280, 720);
-
-    real32 targetSecondsPerFrame = 1.0f / (real32)gameUpdateHz;
+    resizeDIBSection(&globalBackBuffer, WINDOW_WIDTH, WINDOW_HEIGHT);
 
     if (RegisterClass(&windowClass)) {
+        DWORD windowFlags = WS_OVERLAPPEDWINDOW | WS_VISIBLE;
+        RECT rect = { 0, 0, WINDOW_WIDTH, WINDOW_HEIGHT };
+        AdjustWindowRectEx(&rect, windowFlags, false, NULL);
         HWND window = CreateWindowExA(
             NULL,
             windowClass.lpszClassName,
             "Handmade Hero",
-            WS_OVERLAPPEDWINDOW | WS_VISIBLE,
-            CW_USEDEFAULT,
-            CW_USEDEFAULT,
+            windowFlags,
             CW_USEDEFAULT,
             CW_USEDEFAULT,
+            rect.right - rect.left,
+            rect.bottom - rect.top,
             NULL,
             NULL,
             instance,
             NULL
         );
+
         if (window) {
+            int monitorRefreshHz = 60;
+            int win32RefreshRate = GetDeviceCaps(GetDC(window), VREFRESH);
+            if (win32RefreshRate > 1) {
+                monitorRefreshHz = win32RefreshRate;
+            }
+            real32 gameUpdateHz = monitorRefreshHz / 2.0f;
+            real32 targetSecondsPerFrame = 1.0f / (real32)gameUpdateHz;
+
             HH_CTRLW = GlobalAddAtomA("HH_CTRLW");
             RegisterHotKey(window, HH_CTRLW, MOD_CONTROL, 'W');
 
             globalRunning = true;
-            Win32State win32State = {};
 
             GameInput input[2] = {};
             GameInput *oldInput = &input[0];
             GameInput *newInput = &input[1];
 
-            int debugTimeMarkerIndex = 0; 
-            Win32DebugTimeMarker debugMarkers[gameUpdateHz / 2] = {};
-
             win32LoadXInput();
 
             // sound test
@@ -612,7 +602,7 @@ int APIENTRY WinMain(HINSTANCE instance, HINSTANCE prevInstance, PSTR commandLin
             soundOutput.runningSampleIndex = 0;
             soundOutput.bytesPerSample = sizeof(int16)*2;
             soundOutput.secondaryBufferSize = soundOutput.samplesPerSecond*soundOutput.bytesPerSample;
-            soundOutput.safetyBytes = (soundOutput.samplesPerSecond * soundOutput.bytesPerSample / gameUpdateHz) / 2;
+            soundOutput.safetyBytes = (int)((soundOutput.samplesPerSecond * soundOutput.bytesPerSample / gameUpdateHz) / 2.0f);
 
             int16 *samples = (int16*)VirtualAlloc(NULL, soundOutput.secondaryBufferSize, MEM_COMMIT, PAGE_READWRITE);
 
@@ -623,7 +613,7 @@ int APIENTRY WinMain(HINSTANCE instance, HINSTANCE prevInstance, PSTR commandLin
 #endif
             GameMemory gameMemory = {};
             gameMemory.permanentStorageSize = Megabytes(64);
-            gameMemory.transientStorageSize = Gigabytes((uint64)4);
+            gameMemory.transientStorageSize = Gigabytes((uint64)1);
             gameMemory.debugFreeFileMemory = debugFreeFileMemory;
             gameMemory.debugWriteEntireFile = debugWriteEntireFile;
             gameMemory.debugReadEntireFile = debugReadEntireFile;
@@ -634,6 +624,25 @@ int APIENTRY WinMain(HINSTANCE instance, HINSTANCE prevInstance, PSTR commandLin
             gameMemory.permanentStorage = win32State.gameMemoryBlock;
             gameMemory.transientStorage = ((uint8 *)gameMemory.permanentStorage + gameMemory.permanentStorageSize);
 
+            for (int i = 0; i < ArrayCount(win32State.replayBuffers); i++) {
+                // Filename
+                char prefix[] = "replay-";
+                char suffix[] = ".hmr";
+                const int totalLen = ArrayCount(prefix) + 1 + ArrayCount(suffix);
+                char replayFilename[totalLen] = {};
+                char digit[] = {(char)(48 + i)};
+                catStrings(ArrayCount(prefix) - 1, prefix, 1, digit, ArrayCount(replayFilename) - 1, replayFilename);
+                catStrings(ArrayCount(prefix), replayFilename, ArrayCount(suffix) - 1, suffix, ArrayCount(replayFilename) - 1, replayFilename);
+                win32GetFullPathToLocalFile(&win32State, replayFilename, sizeof(replayFilename) - 1, win32State.replayBuffers[i].replayFilename);
+                Win32ReplayBuffer *replayBuffer = &win32State.replayBuffers[i];
+
+                replayBuffer->fileHandle = CreateFileA(replayBuffer->replayFilename, GENERIC_WRITE | GENERIC_READ, NULL, NULL, CREATE_ALWAYS, NULL, NULL);
+                DWORD maxSizeLow = (win32State.gameMemoryTotalSize & 0xFFFFFFFF);
+                DWORD maxSizeHigh = (win32State.gameMemoryTotalSize >> 32);
+                replayBuffer->memoryMap = CreateFileMappingA(replayBuffer->fileHandle, NULL, PAGE_READWRITE, maxSizeHigh, maxSizeLow, NULL);
+                replayBuffer->memoryBlock = MapViewOfFile(replayBuffer->memoryMap, FILE_MAP_ALL_ACCESS, NULL, NULL, win32State.gameMemoryTotalSize);
+            }
+
             win32InitSound(window, soundOutput.samplesPerSecond, soundOutput.secondaryBufferSize);
             win32ClearBuffer(&soundOutput);
             globalSecondaryBuffer->Play(0, 0, DSBPLAY_LOOPING);
@@ -641,7 +650,6 @@ int APIENTRY WinMain(HINSTANCE instance, HINSTANCE prevInstance, PSTR commandLin
             LARGE_INTEGER lastWorkCounter = win32GetWallClock();
             LARGE_INTEGER flipWallClock = win32GetWallClock();
 
-
             DWORD audioLatencyBytes = 0;
             real32 audioLatencySeconds = 0;
             bool soundIsValid = false;
@@ -650,6 +658,8 @@ int APIENTRY WinMain(HINSTANCE instance, HINSTANCE prevInstance, PSTR commandLin
 
             int64 lastCycleCount = __rdtsc();
             while (globalRunning) {
+                newInput->dtForFrame = targetSecondsPerFrame;
+
                 FILETIME newWriteTime = win32GetLastWriteTime(sourceGameCodeDLLFullPath);
                 if (CompareFileTime(&newWriteTime, &game.lastWriteTime) != 0) {
                     win32UnloadGameCode(&game);
@@ -666,6 +676,18 @@ int APIENTRY WinMain(HINSTANCE instance, HINSTANCE prevInstance, PSTR commandLin
 
                 win32ProcessPendingMessages(&win32State, newKeyboardController);
 
+                POINT mousePos;
+                GetCursorPos(&mousePos);
+                ScreenToClient(window, &mousePos);
+                newInput->mouseX = mousePos.x;
+                newInput->mouseY = mousePos.y;
+                newInput->mouseZ = 0; // mouse wheel
+                win32ProcessKeyboardKeypress(&newInput->mouseButtons[0], GetKeyState(VK_LBUTTON) & (1 << 15));
+                win32ProcessKeyboardKeypress(&newInput->mouseButtons[1], GetKeyState(VK_MBUTTON) & (1 << 15));
+                win32ProcessKeyboardKeypress(&newInput->mouseButtons[2], GetKeyState(VK_RBUTTON) & (1 << 15));
+                win32ProcessKeyboardKeypress(&newInput->mouseButtons[3], GetKeyState(VK_XBUTTON1) & (1 << 15));
+                win32ProcessKeyboardKeypress(&newInput->mouseButtons[4], GetKeyState(VK_XBUTTON2) & (1 << 15));
+
                 XINPUT_STATE controllerState;
                 int maxControllerCount = XUSER_MAX_COUNT;
                 if (maxControllerCount > ArrayCount(newInput->controllers) - 1) {
@@ -728,6 +750,8 @@ int APIENTRY WinMain(HINSTANCE instance, HINSTANCE prevInstance, PSTR commandLin
                     }
                 }
 
+                ThreadContext threadCtx = {};
+
                 GameOffscreenBuffer videoBuffer = {};
                 videoBuffer.memory = globalBackBuffer.memory;
                 videoBuffer.width = globalBackBuffer.width;
@@ -742,20 +766,25 @@ int APIENTRY WinMain(HINSTANCE instance, HINSTANCE prevInstance, PSTR commandLin
                     win32PlaybackInput(&win32State, newInput);
                 }
 
-                game.updateAndRender(&gameMemory, &videoBuffer, newInput);
+                if (game.updateAndRender) {
+                    game.updateAndRender(&threadCtx, &gameMemory, &videoBuffer, newInput);
+                }
+
+                LARGE_INTEGER audioWallClock = win32GetWallClock();
+                real32 fromBeginToAudioSeconds = win32GetSecondsElapsed(flipWallClock, audioWallClock);
 
                 DWORD playCursor = 0;
                 DWORD writeCursor = 0;
-
                 if (SUCCEEDED(globalSecondaryBuffer->GetCurrentPosition(&playCursor, &writeCursor))) {
                     if (!soundIsValid) {
                         soundOutput.runningSampleIndex = writeCursor / soundOutput.bytesPerSample;
                         soundIsValid = true;
                     }
                     DWORD byteToLock = (soundOutput.runningSampleIndex*soundOutput.bytesPerSample) % soundOutput.secondaryBufferSize;
-
-                    DWORD expectedSoundBytesPerFrame = (soundOutput.samplesPerSecond * soundOutput.bytesPerSample) / gameUpdateHz;
-                    DWORD expectedFrameBoundaryByte = playCursor + expectedSoundBytesPerFrame;
+                    DWORD expectedSoundBytesPerFrame = (DWORD)((soundOutput.samplesPerSecond * soundOutput.bytesPerSample) / gameUpdateHz);
+                    real32 secondsLeftUntilFlip = targetSecondsPerFrame - fromBeginToAudioSeconds;
+                    DWORD expectedBytesUntilFlip = (DWORD)((secondsLeftUntilFlip/targetSecondsPerFrame) * (real32)expectedSoundBytesPerFrame);
+                    DWORD expectedFrameBoundaryByte = playCursor + expectedBytesUntilFlip;
 
                     DWORD safeWriteCursor = writeCursor;
                     if (safeWriteCursor < playCursor) {
@@ -785,25 +814,7 @@ int APIENTRY WinMain(HINSTANCE instance, HINSTANCE prevInstance, PSTR commandLin
                     soundBuffer.samplesPerSecond = soundOutput.samplesPerSecond;
                     soundBuffer.sampleCount = bytesToWrite / soundOutput.bytesPerSample;
                     soundBuffer.samples = samples;
-                    game.getSoundSamples(&gameMemory, &soundBuffer);
-#if HANDMADE_INTERNAL
-                    Assert(debugTimeMarkerIndex < ArrayCount(debugMarkers));
-
-                    Win32DebugTimeMarker *marker = &debugMarkers[debugTimeMarkerIndex++];
-
-                    DWORD unwrappedWriteCursor = writeCursor;
-                    if (unwrappedWriteCursor < targetCursor) {
-                        unwrappedWriteCursor += soundOutput.secondaryBufferSize;
-                    }
-                    audioLatencyBytes = unwrappedWriteCursor - playCursor;
-                    audioLatencySeconds = (((real32)audioLatencyBytes / (real32)soundOutput.bytesPerSample) / (real32)soundOutput.samplesPerSecond);
-
-                    if (debugTimeMarkerIndex >= ArrayCount(debugMarkers)) {
-                        debugTimeMarkerIndex = 0;
-                    }
-                    
-                    globalSecondaryBuffer->GetCurrentPosition(&marker->playCursor, &marker->writeCursor);
-#endif
+                    game.getSoundSamples(&threadCtx, &gameMemory, &soundBuffer);
                     win32FillSoundBuffer(&soundOutput, byteToLock, bytesToWrite, &soundBuffer);
                 } else {
                     soundIsValid = false;
@@ -827,10 +838,6 @@ int APIENTRY WinMain(HINSTANCE instance, HINSTANCE prevInstance, PSTR commandLin
 
                 lastWorkCounter = win32GetWallClock();
 
-#if HANDMADE_INTERNAL
-                win32DebugSyncDisplay(&globalBackBuffer, ArrayCount(debugMarkers), debugMarkers, &soundOutput, targetSecondsPerFrame);
-#endif
-
                 win32DrawBufferInWindow(&globalBackBuffer, window);
                 flipWallClock = win32GetWallClock();
 

src/win32_handmade.h

@@ -1,4 +1,5 @@
 #include "handmade.h"
+#include <windows.h>
 
 struct Win32OffscreenBuffer {
     BITMAPINFO info;
@@ -24,21 +25,39 @@ struct Win32SoundOutput {
     int safetyBytes;
 };
 
-struct Win32DebugTimeMarker {
-    DWORD playCursor;
-    DWORD writeCursor;
-};
-
 struct Win32RecordedInput {
     int inputCount;
     GameInput *inputStream;
 };
 
+#define WIN32_STATE_FILE_NAME_LENGTH MAX_PATH
+struct Win32ReplayBuffer {
+    HANDLE memoryMap;
+    HANDLE fileHandle;
+    void *memoryBlock;
+    char replayFilename[WIN32_STATE_FILE_NAME_LENGTH];
+};
+
 struct Win32State {
     HANDLE recordingHandle;
     uint32 inputRecordingIndex;
+
     HANDLE playbackHandle;
     uint32 inputPlayingIndex;
+
     uint64 gameMemoryTotalSize;
     void *gameMemoryBlock;
+    Win32ReplayBuffer replayBuffers[4];
+
+    char exeFilename[WIN32_STATE_FILE_NAME_LENGTH];
+    char *onePastLastExeFilenameSlash;
 };
+
+struct Win32GameCode {
+    HMODULE gameCodeLib;
+    GameUpdateAndRenderFn *updateAndRender;
+    GameGetSoundSamplesFn *getSoundSamples;
+    bool isValid;
+    FILETIME lastWriteTime;
+};
+