3 files changed, 161 insertions, 59 deletions

diff --git a/include/isogfx/asset.h b/include/isogfx/asset.h
index 298c469..9aeb55d 100644
--- a/include/isogfx/asset.h
+++ b/include/isogfx/asset.h
@@ -7,6 +7,8 @@
  */
 #pragma once
 
+#include <isogfx/types.h>
+
 #include <assert.h>
 #include <stdint.h>
 
@@ -18,16 +20,16 @@
 // -----------------------------------------------------------------------------
 
 typedef struct Ts_Tile {
-  uint16_t width;     // Tile width in pixels.
-  uint16_t height;    // Tile height in pixels.
-  Pixel    pixels[1]; // Count: width * height.
+  uint16_t width;  // Tile width in pixels.
+  uint16_t height; // Tile height in pixels.
+  uint32_t pixels; // Byte offset into the Ts_TileSet's 'pixels'.
 } Ts_Tile;
 
 typedef struct Ts_TileSet {
   uint16_t num_tiles;
-  uint16_t max_tile_width;  // Maximum tile width in pixels.
-  uint16_t max_tile_height; // Maximum tile height in pixels.
-  Ts_Tile  tiles[1];        // Count: num_tiles.
+  uint16_t _pad;
+  Ts_Tile  tiles[1]; // Count: num_tiles.
+  Pixel    pixels[]; // Count: sum_i(tile[i].width * tile[i].height).
 } Ts_TileSet;
 
 // -----------------------------------------------------------------------------
@@ -35,19 +37,17 @@ typedef struct Ts_TileSet {
 // -----------------------------------------------------------------------------
 
 typedef struct Tm_Layer {
-  union {
-    char tileset_path[ISOGFX_MAX_PATH_LENGTH]; // Relative to the Tm_Map file.
-  };
   Tile tiles[1]; // Count: world_width * world_height.
 } Tm_Layer;
 
 typedef struct Tm_Map {
+  char     tileset_path[ISOGFX_MAX_PATH_LENGTH]; // Relative to the Tm_Map file.
   uint16_t world_width;  // World width in number of tiles.
   uint16_t world_height; // World height in number of tiles.
   uint16_t base_tile_width;
   uint16_t base_tile_height;
   uint16_t num_layers;
-  Tm_Layer layers[1]; // Count: num_layers.
+  Tm_Layer layers[]; // Count: num_layers.
 } Tm_Map;
 
 // -----------------------------------------------------------------------------
@@ -88,28 +88,117 @@ typedef struct Ss_SpriteSheet {
 // Data accessors.
 // -----------------------------------------------------------------------------
 
-/// Return the next tile in the tile set.
-static inline const Ts_Tile* ts_tileset_get_next_tile(
-    const Ts_TileSet* tileset, const Ts_Tile* tile) {
+/// Return the tile set's pixels.
+static inline const Pixel* ts_tileset_get_pixels(const Ts_TileSet* tileset) {
+  assert(tileset);
+  return (const Pixel*)((const uint8_t*)&tileset->tiles[0] +
+                        (tileset->num_tiles * sizeof(Ts_Tile)));
+}
+
+/// Return the ith tile in the tile set.
+static inline const Ts_Tile* ts_tileset_get_tile(
+    const Ts_TileSet* tileset, const int tile) {
+  assert(tileset);
+  assert(tile >= 0);
+  assert(tile < tileset->num_tiles);
+  return &tileset->tiles[tile];
+}
+
+/// Return the ith tile in the tile set.
+static inline Ts_Tile* ts_tileset_get_tile_mut(
+    Ts_TileSet* tileset, const int tile) {
+  return (Ts_Tile*)ts_tileset_get_tile(tileset, tile);
+}
+
+/// Return the ith tile's pixels.
+static inline const Pixel* ts_tileset_get_tile_pixels(
+    const Ts_TileSet* tileset, const int tile) {
   assert(tileset);
+  assert(tile >= 0);
+  assert(tile < tileset->num_tiles);
+  const Pixel*   pixels = ts_tileset_get_pixels(tileset);
+  const Ts_Tile* pTile  = ts_tileset_get_tile(tileset, tile);
+  return (const Pixel*)((const uint8_t*)pixels + pTile->pixels);
+}
+
+/// Return the ith tile's pixels.
+static inline Pixel* ts_tileset_get_tile_pixels_mut(
+    Ts_TileSet* tileset, const int tile) {
+  return (Pixel*)ts_tileset_get_tile_pixels(tileset, tile);
+}
+
+/// Return the ith tile's pixels.
+static inline const Pixel* ts_tile_get_pixels(
+    const Pixel* pixels, const Ts_Tile* tile) {
+  assert(pixels);
   assert(tile);
-  return (const Ts_Tile*)((const uint8_t*)tile + sizeof(Ts_Tile) +
-                          ((tile->width * tile->height - 1) * sizeof(Pixel)));
+  return (const Pixel*)((const uint8_t*)pixels + tile->pixels);
+}
+
+/// Return the tile's pixel at (x,y).
+static const Pixel* ts_tile_xy(
+    const Pixel* tile_pixels, const Ts_Tile* tile, int x, int y) {
+  assert(tile_pixels);
+  assert(tile);
+  assert(x >= 0);
+  assert(y >= 0);
+  assert(x < tile->width);
+  assert(y < tile->height);
+  return &tile_pixels[y * tile->width + x];
+}
+
+/// Return the tile's pixel at (x,y).
+static Pixel* ts_tile_xy_mut(
+    const Pixel* pixels, const Ts_Tile* tile, int x, int y) {
+  return (Pixel*)ts_tile_xy(pixels, tile, x, y);
 }
 
-/// Return the next layer in the tile map.
-static inline const Tm_Layer* tm_map_get_next_layer(
-    const Tm_Map* map, const Tm_Layer* layer) {
+/// Return the ith layer in the tile map.
+static inline const Tm_Layer* tm_map_get_layer(
+    const Tm_Map* map, const int layer) {
   assert(map);
-  assert(layer);
-  return (const Tm_Layer*)((const uint8_t*)layer + sizeof(Tm_Layer) +
-                           ((map->world_width * map->world_height - 1) *
+  assert(layer >= 0);
+  assert(layer < map->num_layers);
+  return (const Tm_Layer*)((const uint8_t*)map->layers +
+                           (layer * map->world_width * map->world_height *
                             sizeof(Tile)));
 }
 
+/// Return the ith layer in the tile map.
+static inline Tm_Layer* tm_map_get_layer_mut(Tm_Map* map, const int layer) {
+  assert(map);
+  assert(layer >= 0);
+  assert(layer < map->num_layers);
+  return (Tm_Layer*)tm_map_get_layer(map, layer);
+}
+
+/// Return the tile in the layer.
+static inline const Tile* tm_layer_get_tile_const_ref(
+    const Tm_Map* map, const Tm_Layer* layer, const int x, const int y) {
+  assert(map);
+  assert(layer);
+  assert(x >= 0);
+  assert(y >= 0);
+  assert(x < map->world_width);
+  assert(y < map->world_height);
+  return &layer->tiles[y * map->world_width + x];
+}
+
+/// Return the tile in the layer.
+static inline Tile tm_layer_get_tile(
+    const Tm_Map* map, const Tm_Layer* layer, const int x, const int y) {
+  return *tm_layer_get_tile_const_ref(map, layer, x, y);
+}
+
+/// Return the tile in the layer.
+static inline Tile* tm_layer_get_tile_mut(
+    Tm_Map* map, Tm_Layer* layer, const int x, const int y) {
+  return (Tile*)tm_layer_get_tile_const_ref(map, layer, x, y);
+}
+
 /// Return the ith row in the sprite sheet.
-static inline const Ss_Row* get_sprite_sheet_row(
-    const Ss_SpriteSheet* sheet, int row) {
+static inline const Ss_Row* ss_get_sprite_sheet_row(
+    const Ss_SpriteSheet* sheet, const int row) {
   assert(sheet);
   assert(row >= 0);
   assert(row < sheet->num_rows);
@@ -120,8 +209,8 @@ static inline const Ss_Row* get_sprite_sheet_row(
 }
 
 /// Return the ith sprite in the row.
-static inline const uint8_t* get_sprite_sheet_sprite(
-    const Ss_SpriteSheet* sheet, const Ss_Row* row, int col) {
+static inline const uint8_t* ss_get_sprite_sheet_sprite(
+    const Ss_SpriteSheet* sheet, const Ss_Row* row, const int col) {
   assert(sheet);
   assert(row);
   assert(col >= 0);
@@ -130,3 +219,13 @@ static inline const uint8_t* get_sprite_sheet_sprite(
   const uint8_t* sprite   = &row->pixels[sprite_offset];
   return sprite;
 }
+
+// -----------------------------------------------------------------------------
+// Validation.
+// -----------------------------------------------------------------------------
+
+/// Validate the tile set.
+bool ts_validate_tileset(const Ts_TileSet* tileset);
+
+/// Validate the map.
+bool tm_validate_map(const Tm_Map* map, const Ts_TileSet* tileset);
diff --git a/include/isogfx/isogfx.h b/include/isogfx/isogfx.h
index 3421a7b..93c6d4e 100644
--- a/include/isogfx/isogfx.h
+++ b/include/isogfx/isogfx.h
@@ -3,26 +3,18 @@
  */
 #pragma once
 
-#include <stdbool.h>
+#include <isogfx/types.h>
+
+#include <stddef.h>
 #include <stdint.h>
 
 typedef struct IsoGfx IsoGfx;
 
 /// Sprite sheet handle.
-typedef uint16_t SpriteSheet;
+typedef uintptr_t SpriteSheet;
 
 /// Sprite handle.
-typedef uint16_t Sprite;
-
-/// Tile handle.
-typedef uint16_t Tile;
-
-/// Colour channel.
-typedef uint8_t Channel;
-
-typedef struct Pixel {
-  Channel r, g, b, a;
-} Pixel;
+typedef uintptr_t Sprite;
 
 typedef enum TileDescType {
   TileFromColour,
@@ -32,32 +24,32 @@ typedef enum TileDescType {
 
 typedef struct TileDesc {
   TileDescType type;
-  int          width;  /// Tile width in pixels.
-  int          height; /// Tile height in pixels.
+  int          width;  // Tile width in pixels.
+  int          height; // Tile height in pixels.
   union {
-    Pixel colour; /// Constant colour tile.
+    Pixel colour; // Constant colour tile.
     struct {
       const char* path;
     } file;
     struct {
-      const uint8_t* data; /// sizeof(Pixel) * width * height
+      const uint8_t* data; // sizeof(Pixel) * width * height
     } mem;
   };
 } TileDesc;
 
 typedef struct WorldDesc {
-  int tile_width;    /// Base tile width in pixels.
-  int tile_height;   /// Base tile height in pixels.
-  int world_width;   /// World width in tiles.
-  int world_height;  /// World height in tiles.
-  int max_num_tiles; /// 0 for an implementation-defined default.
+  int tile_width;   // Base tile width in pixels.
+  int tile_height;  // Base tile height in pixels.
+  int world_width;  // World width in tiles.
+  int world_height; // World height in tiles.
+  int num_tiles;    // Number of tiles to allocate memory for.
 } WorldDesc;
 
 typedef struct IsoGfxDesc {
-  int screen_width;                 /// Screen width in pixels.
-  int screen_height;                /// Screen height in pixels.
-  int max_num_sprites;              /// 0 for an implementation-defined default.
-  int sprite_sheet_pool_size_bytes; /// 0 for an implementation-defined default.
+  void*  memory;        // Block of memory for the engine to use.
+  size_t memory_size;   // Size of memory block in bytes.
+  int    screen_width;  // Screen width in pixels.
+  int    screen_height; // Screen height in pixels.
 } IsoGfxDesc;
 
 /// Create a new isometric graphics engine.
@@ -66,8 +58,11 @@ IsoGfx* isogfx_new(const IsoGfxDesc*);
 /// Destroy the isometric graphics engine.
 void isogfx_del(IsoGfx**);
 
+/// Clear all loaded worlds and sprites.
+void isogfx_clear(IsoGfx*);
+
 /// Create an empty world.
-bool isogfx_make_world(IsoGfx*, const WorldDesc*);
+void isogfx_make_world(IsoGfx*, const WorldDesc*);
 
 /// Load a world from a tile map (.TM) file.
 bool isogfx_load_world(IsoGfx*, const char* filepath);
@@ -88,14 +83,11 @@ void isogfx_set_tile(IsoGfx*, int x, int y, Tile);
 void isogfx_set_tiles(IsoGfx*, int x0, int y0, int x1, int y1, Tile);
 
 /// Load a sprite sheet (.SS) file.
-bool isogfx_load_sprite_sheet(IsoGfx*, const char* filepath, SpriteSheet*);
+SpriteSheet isogfx_load_sprite_sheet(IsoGfx*, const char* filepath);
 
 /// Create an animated sprite.
 Sprite isogfx_make_sprite(IsoGfx*, SpriteSheet);
 
-/// Destroy the sprite.
-void isogfx_del_sprite(IsoGfx*, Sprite);
-
 /// Destroy all the sprites.
 void isogfx_del_sprites(IsoGfx*);
 
@@ -120,9 +112,6 @@ void isogfx_render(IsoGfx*);
 /// position (x,y) instead, use isogfx_set_tile().
 void isogfx_draw_tile(IsoGfx*, int x, int y, Tile);
 
-/// Resize the virtual screen's dimensions.
-bool isogfx_resize(IsoGfx*, int screen_width, int screen_height);
-
 /// Get the virtual screen's dimensions.
 void isogfx_get_screen_size(const IsoGfx*, int* width, int* height);
 
diff --git a/include/isogfx/types.h b/include/isogfx/types.h
new file mode 100644
index 0000000..ce275dc
--- /dev/null
+++ b/include/isogfx/types.h
@@ -0,0 +1,14 @@
+#pragma once
+
+#include <stdint.h>
+
+/// Colour channel.
+typedef uint8_t Channel;
+
+/// Pixel.
+typedef struct Pixel {
+  Channel r, g, b, a;
+} Pixel;
+
+/// Tile handle/index.
+typedef uint16_t Tile;