optimise chunk loading and redrawing

4 files changed, 52 insertions, 90 deletions

diff --git a/src/tiled.c b/src/tiled.c
index b90aea7..436029b 100644
--- a/src/tiled.c
+++ b/src/tiled.c
@@ -14,15 +14,19 @@ void updateCamera(Tiled * tiled) {
     if (IsKeyDown(KEY_W)) tiled->zoom += tiled->zoom * 0.01f;
     if (IsKeyDown(KEY_S)) tiled->zoom -= tiled->zoom * 0.01f;
 
+    tiled->chunkOffset[2] = tiled->chunkOffset[0];
+    tiled->chunkOffset[3] = tiled->chunkOffset[1];
+
     tiled->chunkOffset[0] = tiled->offset.x / tiled->tiledMap.chunkWidth;
     tiled->chunkOffset[1] = tiled->offset.y / tiled->tiledMap.chunkHeight;
 
     tiled->renderOffset.x = tiled->offset.x - tiled->chunkOffset[0]*tiled->tiledMap.chunkWidth;
     tiled->renderOffset.y = tiled->offset.y - tiled->chunkOffset[1]*tiled->tiledMap.chunkHeight;
 
-    // TODO only do this when chunk offset has changed
     // TODO unload chunks when they are no longer visible
-    redrawTiledMap(*tiled);
+    if (tiled->chunkOffset[0] != tiled->chunkOffset[2]
+        || tiled->chunkOffset[1] != tiled->chunkOffset[3])
+        redrawTiledMap(*tiled);
 }
 
 void updateTiledCamera(Tiled *tiled) {
@@ -52,29 +56,35 @@ Vector2 translateTiledPosition(Tiled tiled, Vector2 screenPos) {
 
 Vector2 translateTiledScreenPosition(Tiled tiled, Vector2 tiledPos) {
     return (Vector2) {
-        (tiledPos.x + tiled.renderOffset.x + tiled.chunkOffset[0]*tiled.tiledMap.chunkWidth) * tiled.zoom,
-        (tiledPos.y + tiled.renderOffset.y + tiled.chunkOffset[1]*tiled.tiledMap.chunkHeight) * tiled.zoom
+        (tiledPos.x + tiled.offset.x) * tiled.zoom,
+        (tiledPos.y + tiled.offset.y) * tiled.zoom
     };
 }
 
-Tile getOffsetTile(TiledMap * tiledMap, int chunkOffset[2], int x, int y) {
-    return getChunkedTile(tiledMap, 
-            x - chunkOffset[0]*tiledMap->chunkWidth,
-            y - chunkOffset[1]*tiledMap->chunkHeight);
-}
-
 void redrawTile(Tiled tiled, int x, int y) {
+    int areaX = x + tiled.chunkOffset[0]*tiled.tiledMap.chunkWidth;
+    int areaY = tiled.renderArea[1] - y - tiled.chunkOffset[1]*tiled.tiledMap.chunkHeight - 1;
+
+    Tile v = getChunkedTile(&tiled.tiledMap, x, y);
+
     BeginTextureMode(tiled.tilemapTexture);
-    Tile v = getOffsetTile(&tiled.tiledMap, tiled.chunkOffset, x, y);
-    DrawPixel(x, tiled.renderArea[1] - y - 1, (Color){ v, 0, 0, 255 });
+    DrawPixel(areaX, areaY, (Color){ v, 0, 0, 255 });
     EndTextureMode();
 }
 
 void redrawTiledMap(Tiled tiled) {
+    // TODO since we have to do this every time a chunk is loaded, maybe there is a better way
+    int realX, realY;
+    Tile v;
+
     BeginTextureMode(tiled.tilemapTexture);
     for (int y = 0; y < tiled.renderArea[1]; y++) {
         for (int x = 0; x < tiled.renderArea[0]; x++) {
-            Tile v = getOffsetTile(&tiled.tiledMap, tiled.chunkOffset, x, y);
+            realX = x - tiled.chunkOffset[0]*tiled.tiledMap.chunkWidth;
+            realY = y - tiled.chunkOffset[1]*tiled.tiledMap.chunkHeight;
+
+            v = getChunkedTile(&tiled.tiledMap, realX, realY);
+
             DrawPixel(x, tiled.renderArea[1] - y - 1, (Color){ v, 0, 0, 255 });
         }
     }
@@ -88,9 +98,11 @@ Tiled initTiled(TiledMap tiledMap) {
     tiled.offset = (Vector2) {0, 0};
     tiled.zoom = 64;
 
-    // TODO renderArea is obsolete, should be visible map size
     tiled.renderArea[0] = tiledMap.chunkWidth * RENDER_DISTANCE;
     tiled.renderArea[1] = tiledMap.chunkHeight * RENDER_DISTANCE;
+
+    printf("Render area %dx%d\n", tiled.renderArea[0], tiled.renderArea[1]);
+
     tiled.targetTexture = LoadRenderTexture(1, 1);
     tiled.tilemapTexture = LoadRenderTexture(tiled.renderArea[0], tiled.renderArea[1]);
 
diff --git a/src/tiled.h b/src/tiled.h
index de469be..ae8fcc5 100644
--- a/src/tiled.h
+++ b/src/tiled.h
@@ -5,19 +5,19 @@
 #define SCREEN_W 1280
 #define SCREEN_H 720
 
-#define RENDER_DISTANCE 16
+#define RENDER_DISTANCE 4
 
-typedef struct Tiled {
+typedef struct {
     TiledMap tiledMap;
     float zoom;
-    
+
     // main viewport offset
     Vector2 offset;
 
     // offset passed to shader for rendering
     Vector2 renderOffset;
     // offset used to calculate which chunks to render
-    int chunkOffset[2];
+    int chunkOffset[4];
 
     int atlasSize[2];
     int renderArea[2];
diff --git a/src/tiledmap.c b/src/tiledmap.c
index ea587cc..bb5a1fd 100644
--- a/src/tiledmap.c
+++ b/src/tiledmap.c
@@ -4,56 +4,7 @@
 #include <unistd.h>
 
 #include "tiledmap.h"
-
-const int endian = 1;
-#define is_bigendian() ( (*(char*)&endian) == 0 )
-
-void textureFromPixels(Texture2D *texOut, Color *pixels, int width, int height) {
-    Image checkedIm = {
-        .data = pixels,
-        .width = width,
-        .height = height,
-        .format = PIXELFORMAT_UNCOMPRESSED_R8G8B8A8,
-        .mipmaps = 1
-    };
-
-    *texOut = LoadTextureFromImage(checkedIm);
-}
-
-
-//! read a big endian bytes from file
-int readb(char * out, size_t noBytes, FILE * file) {
-    if (!fread(out, (size_t)1, (size_t) noBytes, file))
-        return 1;
-
-    if (is_bigendian()) 
-        return 0;
-
-    int tmp;
-    // reverse byte order
-    for(int i = 0; i < noBytes/2; i++) {
-        tmp = out[i];
-        out[i] = out[noBytes-i-1];
-        out[noBytes-i-1] = tmp;
-    }
-
-    return 0;
-}
-
-int writeb(char * in, size_t noBytes, FILE * file) {
-    if (!is_bigendian()) {
-        int tmp;
-        // reverse byte order
-        for(int i = 0; i < noBytes/2; i++) {
-            tmp = in[i];
-            in[i] = in[noBytes-i-1];
-            in[noBytes-i-1] = tmp;
-        }
-        
-    }
-
-    return fwrite(in, (size_t)1, (size_t) noBytes, file);
-}
+#include "tiledio.h"
 
 void buildChunkTree(TiledMap *tiledMap) {
     // initialise chunk tree
@@ -143,7 +94,6 @@ void unloadChunk(TiledMap * tiledMap, CachedChunk * cached) {
 
 //! load a chunk into the cache and return it 
 CachedChunk * loadChunk(TiledMap * tiledMap, int x, int y) {
-    // TODO add caching for this
     size_t chunkSizeBytes = tiledMap->chunkWidth * tiledMap->chunkHeight;
 
 
@@ -157,7 +107,6 @@ CachedChunk * loadChunk(TiledMap * tiledMap, int x, int y) {
         cached->chunk = malloc(chunkSizeBytes);
         fseek(tiledMap->file, cached->filePos, SEEK_SET);
         fread(cached->chunk, 1, chunkSizeBytes, tiledMap->file);
-        printf("loading chunk %d,%d, from %ld\n", x, y, cached->filePos);
     }
 
     return cached;
@@ -184,46 +133,49 @@ CachedChunk * createChunk(TiledMap *tiledMap, int x, int y, Chunk chunk) {
     return cached;
 }
 
-CachedChunk * createEmptyChunk(TiledMap * tiledMap, int x, int y) {
+CachedChunk * createEmptyChunkAt(TiledMap * tiledMap, int x, int y) {
     Chunk chunk = calloc(tiledMap->chunkWidth*tiledMap->chunkHeight, 1);
-    return createChunk(tiledMap, x, y, chunk);
+    return createChunk(tiledMap, x / tiledMap->chunkWidth, y / tiledMap->chunkHeight, chunk);
 }
 
-Tile getChunkedTile(TiledMap *tiledMap, int x, int y) {
-    // TODO put this calculation in function
+CachedChunk * loadChunkPosition(TiledMap *tiledMap, int x, int y, int * index) {
     int inChunkX = x % tiledMap->chunkWidth;
     int inChunkY = y % tiledMap->chunkHeight;
     int chunkX = (x - inChunkX) / tiledMap->chunkWidth;
     int chunkY = (y - inChunkY) / tiledMap->chunkHeight;
+    *index = inChunkY * tiledMap->chunkWidth + inChunkX;
 
+    return loadChunk(tiledMap, chunkX, chunkY);
+}
+
+Tile getChunkedTile(TiledMap *tiledMap, int x, int y) {
     if (x < 0 || y < 0)
         return 0;
 
-    CachedChunk * cached = loadChunk(tiledMap, chunkX, chunkY);
+    int index;
+    CachedChunk * cached = loadChunkPosition(tiledMap, x, y, &index);
+
     if (cached == NULL)
         return 0;
 
     if (cached->chunk == NULL)
         return 0;
 
-    Tile v = cached->chunk[inChunkY * tiledMap->chunkWidth + inChunkX];
-    return v;
+    return cached->chunk[index];
 }
 
 Tile setChunkedTile(TiledMap * tiledMap, int x, int y, Tile value) {
-    int inChunkX = x % tiledMap->chunkWidth;
-    int inChunkY = y % tiledMap->chunkHeight;
-    int chunkX = (x - inChunkX) / tiledMap->chunkWidth;
-    int chunkY = (y - inChunkY) / tiledMap->chunkHeight;
+    if (x < 0 || y < 0)
+        return 0;
+
+    int index;
+    CachedChunk * cached = loadChunkPosition(tiledMap, x, y, &index);
 
-    CachedChunk * cached = loadChunk(tiledMap, chunkX, chunkY);
     if (cached == NULL)
-        cached = createEmptyChunk(tiledMap, chunkX, chunkY);
+        cached = createEmptyChunkAt(tiledMap, x, y);
 
-    cached->chunk[inChunkY * tiledMap->chunkWidth + inChunkX] = value;
+    cached->chunk[index] = value;
 
-    // TODO do this when unloading
-    //commitChunk(tiledMap, cached);
     return value;
 }
 
@@ -244,8 +196,6 @@ void writeTiledMapHeader(TiledMap tiledMap) {
     writeb((char *) &tiledMap.atlasSize[1], 4, file);
 
     fwrite(tiledMap.atlasData, 1, atlasSizeBytes, file);
-    // since chunks are already directly written here, do not write anything else
-    // TODO when caching, commit everything left in cache here
 }
 
 TiledMap openNewTiledMap(char * filename, Image atlas, int tileSize, int chunkWidth, int chunkHeight, int width, int height) {
diff --git a/src/tiledmap.h b/src/tiledmap.h
index 972a74d..7b819a2 100644
--- a/src/tiledmap.h
+++ b/src/tiledmap.h
@@ -6,12 +6,12 @@
 typedef unsigned char Tile;
 typedef Tile * Chunk;
 
-typedef struct CachedChunk {
+typedef struct {
     long filePos;
     Chunk chunk;
 } CachedChunk;
 
-typedef struct ChunkedTiledMap {
+typedef struct {
     FILE * file;
     int chunkWidth;
     int chunkHeight;