2 files changed, 257 insertions, 382 deletions

diff --git a/src/asset.c b/src/asset.c
new file mode 100644
index 0000000..98ca083
--- /dev/null
+++ b/src/asset.c
@@ -0,0 +1,34 @@
+#include <isogfx/asset.h>
+
+bool ts_validate_tileset(const Ts_TileSet* tileset) {
+  assert(tileset);
+
+  for (uint16_t i = 0; i < tileset->num_tiles; ++i) {
+    const Ts_Tile* tile = ts_tileset_get_tile(tileset, i);
+    // Tile should be non-empty.
+    if (tile->width == 0) {
+      return false;
+    }
+    if (tile->height == 0) {
+      return false;
+    }
+  }
+  return true;
+}
+
+bool tm_validate_map(const Tm_Map* map, const Ts_TileSet* tileset) {
+  assert(map);
+  assert(tileset);
+
+  for (uint16_t t = 0; t < tileset->num_tiles; ++t) {
+    const Ts_Tile* tile = ts_tileset_get_tile(tileset, t);
+    // Tile dimensions should be a multiple of the base tile size.
+    if ((tile->width % map->base_tile_width) != 0) {
+      return false;
+    }
+    if ((tile->height % map->base_tile_height) != 0) {
+      return false;
+    }
+  }
+  return true;
+}
diff --git a/src/isogfx.c b/src/isogfx.c
index 4dff67b..16760ac 100644
--- a/src/isogfx.c
+++ b/src/isogfx.c
@@ -3,27 +3,16 @@
 #include <isogfx/asset.h>
 
 #include <filesystem.h>
-#include <mem.h>
-#include <mempool.h>
+#include <memstack.h>
 #include <path.h>
 
-#include <linux/limits.h>
-
 #include <assert.h>
-#include <stdbool.h>
 #include <stdint.h>
 #include <stdio.h>
-#include <stdlib.h>
 #include <string.h>
 
-/// Maximum number of tiles unless the user specifies a value.
-#define DEFAULT_MAX_NUM_TILES 1024
-
-/// Maximum number of sprites unless the user specifies a value.
-#define DEFAULT_MAX_NUM_SPRITES 128
-
-/// Size of sprite sheet pool in bytes unless the user specifies a value.
-#define DEFAULT_SPRITE_SHEET_POOL_SIZE_BYTES (8 * 1024 * 1024)
+/// Maximum path length.
+#define MAX_PATH 256
 
 /// Default animation speed.
 #define ANIMATION_FPS 10
@@ -43,41 +32,27 @@ typedef struct vec2 {
 // Renderer state.
 // -----------------------------------------------------------------------------
 
-typedef struct TileData {
-  uint16_t width;
-  uint16_t height;
-  uint16_t pixels_handle; // Handle to the tile's pixels in the pixel pool.
-} TileData;
-
-typedef struct SpriteData {
-  SpriteSheet sheet; // Handle to the sprite's sheet.
-  ivec2       position;
-  int         animation; // Current animation.
-  int         frame;     // Current frame of animation.
-} SpriteData;
+// TODO: Define a struct Screen with width, height and pixels.
 
-DEF_MEMPOOL_DYN(TilePool, TileData)
-DEF_MEM_DYN(PixelPool, Pixel)
-
-DEF_MEMPOOL_DYN(SpritePool, SpriteData)
-DEF_MEM_DYN(SpriteSheetPool, Ss_SpriteSheet)
+typedef struct SpriteInstance {
+  struct SpriteInstance* next;
+  const Ss_SpriteSheet*  sheet;
+  ivec2                  position;
+  int                    animation; // Current animation.
+  int                    frame;     // Current frame of animation.
+} SpriteInstance;
 
 typedef struct IsoGfx {
   int             screen_width;
   int             screen_height;
-  int             tile_width;
-  int             tile_height;
-  int             world_width;
-  int             world_height;
-  int             max_num_sprites;
-  int             sprite_sheet_pool_size_bytes;
   double          last_animation_time;
-  Tile*           world;
+  Tile            next_tile; // For procedurally-generated tiles.
   Pixel*          screen;
-  TilePool        tiles;
-  PixelPool       pixels;
-  SpritePool      sprites;
-  SpriteSheetPool sheets;
+  Tm_Map*         map;
+  Ts_TileSet*     tileset;
+  SpriteInstance* head_sprite; // Head of sprites list.
+  memstack        stack;
+  size_t          watermark;
 } IsoGfx;
 
 // -----------------------------------------------------------------------------
@@ -114,42 +89,6 @@ static inline vec2 cart2iso(vec2 cart, int s, int t, int w) {
                 .y = (-one_over_s * x + one_over_t * cart.y)};
 }
 
-static const Pixel* tile_xy_const_ref(
-    const IsoGfx* iso, const TileData* tile, int x, int y) {
-  assert(iso);
-  assert(tile);
-  assert(x >= 0);
-  assert(y >= 0);
-  assert(x < tile->width);
-  assert(y < tile->height);
-  return &mem_get_chunk(&iso->pixels, tile->pixels_handle)[y * tile->width + x];
-}
-
-// static Pixel tile_xy(const IsoGfx* iso, const TileData* tile, int x, int y) {
-//   return *tile_xy_const_ref(iso, tile, x, y);
-// }
-
-static Pixel* tile_xy_mut(const IsoGfx* iso, TileData* tile, int x, int y) {
-  return (Pixel*)tile_xy_const_ref(iso, tile, x, y);
-}
-
-static inline const Tile* world_xy_const_ref(const IsoGfx* iso, int x, int y) {
-  assert(iso);
-  assert(x >= 0);
-  assert(y >= 0);
-  assert(x < iso->world_width);
-  assert(y < iso->world_height);
-  return &iso->world[y * iso->world_width + x];
-}
-
-static inline Tile world_xy(const IsoGfx* iso, int x, int y) {
-  return *world_xy_const_ref(iso, x, y);
-}
-
-static inline Tile* world_xy_mut(IsoGfx* iso, int x, int y) {
-  return (Tile*)world_xy_const_ref(iso, x, y);
-}
-
 static inline const Pixel* screen_xy_const_ref(
     const IsoGfx* iso, int x, int y) {
   assert(iso);
@@ -168,15 +107,6 @@ static inline Pixel* screen_xy_mut(IsoGfx* iso, int x, int y) {
   return (Pixel*)screen_xy_const_ref(iso, x, y);
 }
 
-static int calc_num_tile_blocks(
-    int base_tile_width, int base_tile_height, int tile_width,
-    int tile_height) {
-  const int base_tile_size = base_tile_width * base_tile_height;
-  const int tile_size      = tile_width * tile_height;
-  const int num_blocks     = tile_size / base_tile_size;
-  return num_blocks;
-}
-
 // -----------------------------------------------------------------------------
 // Renderer, world and tile management.
 // -----------------------------------------------------------------------------
@@ -188,68 +118,54 @@ IsoGfx* isogfx_new(const IsoGfxDesc* desc) {
   assert((desc->screen_width & 1) == 0);
   assert((desc->screen_height & 1) == 0);
 
-  IsoGfx* iso = calloc(1, sizeof(IsoGfx));
-  if (!iso) {
-    return 0;
+  IsoGfx tmp = {0};
+  if (!memstack_make(&tmp.stack, desc->memory_size, desc->memory)) {
+    goto cleanup;
   }
+  IsoGfx* iso =
+      memstack_alloc_aligned(&tmp.stack, sizeof(IsoGfx), alignof(IsoGfx));
+  *iso = tmp;
 
-  iso->screen_width  = desc->screen_width;
-  iso->screen_height = desc->screen_height;
-
+  iso->screen_width        = desc->screen_width;
+  iso->screen_height       = desc->screen_height;
   iso->last_animation_time = 0.0;
 
-  iso->max_num_sprites = desc->max_num_sprites == 0 ? DEFAULT_MAX_NUM_SPRITES
-                                                    : desc->max_num_sprites;
-  iso->sprite_sheet_pool_size_bytes = desc->sprite_sheet_pool_size_bytes == 0
-                                          ? DEFAULT_SPRITE_SHEET_POOL_SIZE_BYTES
-                                          : desc->sprite_sheet_pool_size_bytes;
+  const size_t screen_size_bytes =
+      desc->screen_width * desc->screen_height * sizeof(Pixel);
+  iso->screen =
+      memstack_alloc_aligned(&iso->stack, screen_size_bytes, alignof(Pixel));
 
-  const int screen_size = desc->screen_width * desc->screen_height;
-  if (!(iso->screen = calloc(screen_size, sizeof(Pixel)))) {
-    goto cleanup;
-  }
+  iso->watermark = memstack_get_watermark(&iso->stack);
 
   return iso;
 
 cleanup:
   isogfx_del(&iso);
-  return 0;
+  return nullptr;
 }
 
-/// Destroy the world, its tile set, and the underlying pools.
-static void destroy_world(IsoGfx* iso) {
+void isogfx_clear(IsoGfx* iso) {
   assert(iso);
-  if (iso->world) {
-    free(iso->world);
-    iso->world = 0;
-  }
-  mempool_del(&iso->tiles);
-  mem_del(&iso->pixels);
-}
-
-/// Destroy all loaded sprites and the underlying pools.
-static void destroy_sprites(IsoGfx* iso) {
-  assert(iso);
-  mempool_del(&iso->sprites);
-  mem_del(&iso->sheets);
-}
-
-void isogfx_del(IsoGfx** pIso) {
-  assert(pIso);
-  IsoGfx* iso = *pIso;
+  iso->last_animation_time = 0.0;
+  iso->next_tile           = 0;
+  iso->map                 = nullptr;
+  iso->tileset             = nullptr;
+  iso->head_sprite         = nullptr;
+  // The base of the stack contains the IsoGfx and the screen buffer. Make sure
+  // we don't clear them.
+  memstack_set_watermark(&iso->stack, iso->watermark);
+}
+
+void isogfx_del(IsoGfx** ppIso) {
+  assert(ppIso);
+  IsoGfx* iso = *ppIso;
   if (iso) {
-    destroy_world(iso);
-    destroy_sprites(iso);
-    if (iso->screen) {
-      free(iso->screen);
-      iso->screen = 0;
-    }
-    free(iso);
-    *pIso = 0;
+    memstack_del(&iso->stack);
+    *ppIso = nullptr;
   }
 }
 
-bool isogfx_make_world(IsoGfx* iso, const WorldDesc* desc) {
+void isogfx_make_world(IsoGfx* iso, const WorldDesc* desc) {
   assert(iso);
   assert(desc);
   assert(desc->tile_width > 0);
@@ -258,36 +174,41 @@ bool isogfx_make_world(IsoGfx* iso, const WorldDesc* desc) {
   // precision.
   assert((desc->tile_width & 1) == 0);
   assert((desc->tile_height & 1) == 0);
-
-  // Handle recreation by destroying the previous world.
-  destroy_world(iso);
-
-  iso->tile_width   = desc->tile_width;
-  iso->tile_height  = desc->tile_height;
-  iso->world_width  = desc->world_width;
-  iso->world_height = desc->world_height;
-
-  const int world_size      = desc->world_width * desc->world_height;
-  const int tile_size       = desc->tile_width * desc->tile_height;
-  const int tile_size_bytes = tile_size * (int)sizeof(Pixel);
-  const int tile_pool_size =
-      desc->max_num_tiles > 0 ? desc->max_num_tiles : DEFAULT_MAX_NUM_TILES;
-
-  if (!(iso->world = calloc(world_size, sizeof(Tile)))) {
-    goto cleanup;
-  }
-  if (!mempool_make_dyn(&iso->tiles, world_size, sizeof(TileData))) {
-    goto cleanup;
-  }
-  if (!mem_make_dyn(&iso->pixels, tile_pool_size, tile_size_bytes)) {
-    goto cleanup;
-  }
-
-  return true;
-
-cleanup:
-  destroy_world(iso);
-  return false;
+  // World must be non-empty.
+  assert(desc->world_width > 0);
+  assert(desc->world_height > 0);
+  // Must have >0 tiles.
+  assert(desc->num_tiles > 0);
+
+  // Handle recreation by destroying the previous world and sprites.
+  isogfx_clear(iso);
+
+  const int    world_size     = desc->world_width * desc->world_height;
+  const size_t map_size_bytes = sizeof(Tm_Map) + (world_size * sizeof(Tile));
+
+  // This implies that all tiles are of the base tile dimensions.
+  // We could enhance the API to allow for supertiles as well. Take in max tile
+  // width and height and allocate enough space using those values.
+  const size_t tile_size            = desc->tile_width * desc->tile_height;
+  const size_t tile_size_bytes      = tile_size * sizeof(Pixel);
+  const size_t tile_data_size_bytes = desc->num_tiles * tile_size_bytes;
+  const size_t tileset_size_bytes   = sizeof(Ts_TileSet) +
+                                    (desc->num_tiles * sizeof(Ts_Tile)) +
+                                    tile_data_size_bytes;
+
+  iso->map  = memstack_alloc_aligned(&iso->stack, map_size_bytes, 4);
+  *iso->map = (Tm_Map){
+      .world_width      = desc->world_width,
+      .world_height     = desc->world_height,
+      .base_tile_width  = desc->tile_width,
+      .base_tile_height = desc->tile_height,
+      .num_layers       = 1,
+  };
+
+  iso->tileset  = memstack_alloc_aligned(&iso->stack, tileset_size_bytes, 4);
+  *iso->tileset = (Ts_TileSet){
+      .num_tiles = desc->num_tiles,
+  };
 }
 
 bool isogfx_load_world(IsoGfx* iso, const char* filepath) {
@@ -296,135 +217,74 @@ bool isogfx_load_world(IsoGfx* iso, const char* filepath) {
 
   bool success = false;
 
-  // Handle recreation by destroying the previous world.
-  destroy_world(iso);
+  // Handle recreation by destroying the previous world and sprites.
+  isogfx_clear(iso);
 
   // Load the map.
   printf("Load tile map: %s\n", filepath);
-  Tm_Map* map = read_file(filepath);
-  if (!map) {
+  WITH_FILE(filepath, {
+    const size_t map_size = get_file_size_f(file);
+    iso->map              = memstack_alloc_aligned(&iso->stack, map_size, 4);
+    success               = read_file_f(file, iso->map);
+  });
+  if (!success) {
     goto cleanup;
   }
+  Tm_Map* const map = iso->map;
 
-  // Allocate memory for the map and tile sets.
-  const int world_size           = map->world_width * map->world_height;
-  const int base_tile_size       = map->base_tile_width * map->base_tile_height;
-  const int base_tile_size_bytes = base_tile_size * (int)sizeof(Pixel);
-  // TODO: Need to get the total number of tiles from the map.
-  const int tile_pool_size = DEFAULT_MAX_NUM_TILES;
-
-  if (!(iso->world = calloc(world_size, sizeof(Tile)))) {
-    goto cleanup;
-  }
-  if (!mempool_make_dyn(&iso->tiles, tile_pool_size, sizeof(TileData))) {
+  // Load the tile set.
+  //
+  // Tile set path is relative to the tile map file. Make it relative to the
+  // current working directory before loading.
+  const char* ts_path               = map->tileset_path;
+  char        ts_path_cwd[MAX_PATH] = {0};
+  if (!path_make_relative(filepath, ts_path, ts_path_cwd, MAX_PATH)) {
     goto cleanup;
   }
-  if (!mem_make_dyn(&iso->pixels, tile_pool_size, base_tile_size_bytes)) {
+  printf("Load tile set: %s\n", ts_path_cwd);
+  WITH_FILE(ts_path_cwd, {
+    const size_t file_size = get_file_size_f(file);
+    iso->tileset           = memstack_alloc_aligned(&iso->stack, file_size, 4);
+    success                = read_file_f(file, iso->tileset);
+  });
+  if (!success) {
+    // TODO: Log errors using the log library.
     goto cleanup;
   }
+  const Ts_TileSet* const tileset = iso->tileset;
+  printf("Loaded tile set (%u tiles): %s\n", tileset->num_tiles, ts_path_cwd);
 
-  // Load the tile sets.
-  const Tm_Layer* layer = &map->layers[0];
-  // TODO: Handle num_layers layers.
-  for (int i = 0; i < 1; ++i) {
-    const char* ts_path = layer->tileset_path;
-
-    // Tile set path is relative to the tile map file. Make it relative to the
-    // current working directory before loading.
-    char ts_path_cwd[PATH_MAX] = {0};
-    if (!path_make_relative(filepath, ts_path, ts_path_cwd, PATH_MAX)) {
-      goto cleanup;
-    }
-
-    Ts_TileSet* tileset = read_file(ts_path_cwd);
-    if (!tileset) {
-      // TODO: Log errors using the log library.
-      goto cleanup;
-    };
-
-    // Load tile data.
-    const Ts_Tile* tile = &tileset->tiles[0];
-    for (uint16_t j = 0; j < tileset->num_tiles; ++j) {
-      // TODO: These checks should be library runtime errors.
-      // Tile dimensions should be a multiple of the base tile size.
-      assert((tile->width % map->base_tile_width) == 0);
-      assert((tile->height % map->base_tile_height) == 0);
-
-      // Allocate N base tile size blocks for the tile.
-      const uint16_t tile_size  = tile->width * tile->height;
-      const int      num_blocks = tile_size / base_tile_size;
-      Pixel*         pixels     = mem_alloc(&iso->pixels, num_blocks);
-      assert(pixels);
-      memcpy(pixels, tile->pixels, tile_size * sizeof(Pixel));
-
-      // Allocate the tile data.
-      TileData* tile_data = mempool_alloc(&iso->tiles);
-      assert(tile_data);
-      tile_data->width  = tile->width;
-      tile_data->height = tile->height;
-      tile_data->pixels_handle =
-          (uint16_t)mem_get_chunk_handle(&iso->pixels, pixels);
-
-      tile = ts_tileset_get_next_tile(tileset, tile);
-    }
-
-    printf("Loaded tile set (%u tiles): %s\n", tileset->num_tiles, ts_path_cwd);
-
-    free(tileset);
-    layer = tm_map_get_next_layer(map, layer);
-  }
-
-  // Load the map into the world.
-  layer = &map->layers[0];
-  // TODO: Handle num_layers layers.
-  for (int i = 0; i < 1; ++i) {
-    memcpy(iso->world, layer->tiles, world_size * sizeof(Tile));
-
-    // TODO: We need to handle 'firsgid' in TMX files.
-    for (int j = 0; j < world_size; ++j) {
-      iso->world[j] -= 1;
-    }
-
-    layer = tm_map_get_next_layer(map, layer);
-  }
-
-  iso->world_width  = map->world_width;
-  iso->world_height = map->world_height;
-  iso->tile_width   = map->base_tile_width;
-  iso->tile_height  = map->base_tile_height;
+  // TODO: These assertions on input data should be library runtime errors.
+  assert(ts_validate_tileset(tileset));
+  assert(tm_validate_map(map, tileset));
 
   success = true;
 
 cleanup:
-  if (map) {
-    free(map);
-  }
   if (!success) {
-    destroy_world(iso);
+    isogfx_clear(iso);
   }
   return success;
 }
 
 int isogfx_world_width(const IsoGfx* iso) {
   assert(iso);
-  return iso->world_width;
+  return iso->map->world_width;
 }
 
 int isogfx_world_height(const IsoGfx* iso) {
   assert(iso);
-  return iso->world_height;
+  return iso->map->world_height;
 }
 
-/// Create a tile mask procedurally.
 static void make_tile_from_colour(
-    const IsoGfx* iso, Pixel colour, TileData* tile) {
-  assert(iso);
+    Pixel colour, const Ts_Tile* tile, Pixel* tile_pixels) {
   assert(tile);
+  assert(tile_pixels);
 
   const int width  = tile->width;
   const int height = tile->height;
   const int r      = width / height;
-
   for (int y = 0; y < height / 2; ++y) {
     const int mask_start = width / 2 - r * y - 1;
     const int mask_end   = width / 2 + r * y + 1;
@@ -433,11 +293,11 @@ static void make_tile_from_colour(
       const Pixel val = mask ? colour : (Pixel){.r = 0, .g = 0, .b = 0, .a = 0};
 
       // Top half.
-      *tile_xy_mut(iso, tile, x, y) = val;
+      *ts_tile_xy_mut(tile_pixels, tile, x, y) = val;
 
       // Bottom half reflects the top half.
-      const int y_reflected                   = height - y - 1;
-      *tile_xy_mut(iso, tile, x, y_reflected) = val;
+      const int y_reflected                              = height - y - 1;
+      *ts_tile_xy_mut(tile_pixels, tile, x, y_reflected) = val;
     }
   }
 }
@@ -445,41 +305,58 @@ static void make_tile_from_colour(
 Tile isogfx_make_tile(IsoGfx* iso, const TileDesc* desc) {
   assert(iso);
   assert(desc);
-  // Client must create world before creating tiles.
-  assert(iso->tile_width > 0);
-  assert(iso->tile_height > 0);
+  // Client must create a world first.
+  assert(iso->map);
+  assert(iso->tileset);
+  // Currently, procedural tiles must match the base tile size.
+  assert(desc->width == iso->map->base_tile_width);
+  assert(desc->height == iso->map->base_tile_height);
+  // Cannot exceed max tiles.
+  assert(iso->next_tile < iso->tileset->num_tiles);
 
-  TileData* tile = mempool_alloc(&iso->tiles);
-  assert(tile); // TODO: Make this a hard assert.
+  const Tile tile = iso->next_tile++;
 
-  const int num_blocks = calc_num_tile_blocks(
-      iso->tile_width, iso->tile_height, desc->width, desc->height);
+  const size_t tile_size_bytes = desc->width * desc->height * sizeof(Pixel);
 
-  Pixel* pixels = mem_alloc(&iso->pixels, num_blocks);
-  assert(pixels); // TODO: Make this a hard assert.
+  switch (desc->type) {
+  case TileFromColour: {
+    assert(desc->width > 0);
+    assert(desc->height > 0);
 
-  tile->width         = desc->width;
-  tile->height        = desc->height;
-  tile->pixels_handle = mem_get_chunk_handle(&iso->pixels, pixels);
+    Ts_Tile* const ts_tile = ts_tileset_get_tile_mut(iso->tileset, tile);
 
-  switch (desc->type) {
-  case TileFromColour:
-    make_tile_from_colour(iso, desc->colour, tile);
+    *ts_tile = (Ts_Tile){
+        .width  = iso->map->base_tile_width,
+        .height = iso->map->base_tile_height,
+        .pixels = tile * tile_size_bytes,
+    };
+
+    Pixel* const tile_pixels =
+        ts_tileset_get_tile_pixels_mut(iso->tileset, tile);
+    make_tile_from_colour(desc->colour, ts_tile, tile_pixels);
     break;
+  }
   case TileFromFile:
     assert(false); // TODO
     break;
-  case TileFromMemory:
+  case TileFromMemory: {
+    assert(desc->width > 0);
+    assert(desc->height > 0);
     assert(false); // TODO
     break;
   }
+  }
 
-  return (Tile)mempool_get_block_index(&iso->tiles, tile);
+  return tile;
 }
 
 void isogfx_set_tile(IsoGfx* iso, int x, int y, Tile tile) {
   assert(iso);
-  *world_xy_mut(iso, x, y) = tile;
+
+  Tm_Layer* const layer    = tm_map_get_layer_mut(iso->map, 0);
+  Tile*           map_tile = tm_layer_get_tile_mut(iso->map, layer, x, y);
+
+  *map_tile = tile;
 }
 
 void isogfx_set_tiles(IsoGfx* iso, int x0, int y0, int x1, int y1, Tile tile) {
@@ -491,88 +368,67 @@ void isogfx_set_tiles(IsoGfx* iso, int x0, int y0, int x1, int y1, Tile tile) {
   }
 }
 
-bool isogfx_load_sprite_sheet(
-    IsoGfx* iso, const char* filepath, SpriteSheet* p_sheet) {
+SpriteSheet isogfx_load_sprite_sheet(IsoGfx* iso, const char* filepath) {
   assert(iso);
   assert(filepath);
-  assert(p_sheet);
 
-  bool success = false;
-
-  // Lazy initialization of sprite pools.
-  if (mempool_capacity(&iso->sprites) == 0) {
-    if (!mempool_make_dyn(
-            &iso->sprites, iso->max_num_sprites, sizeof(SpriteData))) {
-      return false;
-    }
-  }
-  if (mem_capacity(&iso->sheets) == 0) {
-    // Using a block size of 1 byte for sprite sheet data.
-    if (!mem_make_dyn(&iso->sheets, iso->sprite_sheet_pool_size_bytes, 1)) {
-      return false;
-    }
-  }
+  bool         success     = false;
+  SpriteSheet  spriteSheet = 0;
+  const size_t watermark   = memstack_get_watermark(&iso->stack);
 
   // Load sprite sheet file.
   printf("Load sprite sheet: %s\n", filepath);
-  FILE* file = fopen(filepath, "rb");
-  if (file == NULL) {
-    goto cleanup;
-  }
-  const size_t    sheet_size = get_file_size(file);
-  Ss_SpriteSheet* ss_sheet   = mem_alloc(&iso->sheets, sheet_size);
-  if (!ss_sheet) {
-    goto cleanup;
-  }
-  if (fread(ss_sheet, sheet_size, 1, file) != 1) {
+  Ss_SpriteSheet* ss_sheet = nullptr;
+  WITH_FILE(filepath, {
+    const size_t file_size = get_file_size_f(file);
+    ss_sheet =
+        memstack_alloc_aligned(&iso->stack, file_size, alignof(Ss_SpriteSheet));
+    success = read_file_f(file, ss_sheet);
+  });
+  if (!success) {
     goto cleanup;
   }
+  assert(ss_sheet);
 
-  *p_sheet = mem_get_chunk_handle(&iso->sheets, ss_sheet);
-  success  = true;
+  spriteSheet = (SpriteSheet)ss_sheet;
 
 cleanup:
-  // Pools remain initialized since client may attempt to load other sprites.
-  if (file != NULL) {
-    fclose(file);
-  }
   if (!success) {
     if (ss_sheet) {
-      mem_free(&iso->sheets, &ss_sheet);
+      memstack_set_watermark(&iso->stack, watermark);
     }
   }
-  return success;
+  return spriteSheet;
 }
 
 Sprite isogfx_make_sprite(IsoGfx* iso, SpriteSheet sheet) {
   assert(iso);
+  assert(sheet);
 
-  SpriteData* sprite = mempool_alloc(&iso->sprites);
-  assert(sprite);
+  // TODO: Remove memstack_alloc() and replace it with a same-name macro that
+  //  calls memstack_alloc_aligned() with sizeof/alignof. No real point in
+  //  having unaligned allocations.
+  SpriteInstance* sprite = memstack_alloc_aligned(
+      &iso->stack, sizeof(SpriteInstance), alignof(SpriteInstance));
 
-  sprite->sheet = sheet;
+  sprite->sheet    = (const Ss_SpriteSheet*)sheet;
+  sprite->next     = iso->head_sprite;
+  iso->head_sprite = sprite;
 
-  return mempool_get_block_index(&iso->sprites, sprite);
+  return (Sprite)sprite;
 }
 
-#define with_sprite(SPRITE, BODY)                                \
-  {                                                              \
-    SpriteData* data = mempool_get_block(&iso->sprites, sprite); \
-    assert(data);                                                \
-    BODY;                                                        \
-  }
-
-void isogfx_set_sprite_position(IsoGfx* iso, Sprite sprite, int x, int y) {
+void isogfx_set_sprite_position(IsoGfx* iso, Sprite hSprite, int x, int y) {
   assert(iso);
-  with_sprite(sprite, {
-    data->position.x = x;
-    data->position.y = y;
-  });
+  SpriteInstance* sprite = (SpriteInstance*)hSprite;
+  sprite->position.x     = x;
+  sprite->position.y     = y;
 }
 
-void isogfx_set_sprite_animation(IsoGfx* iso, Sprite sprite, int animation) {
+void isogfx_set_sprite_animation(IsoGfx* iso, Sprite hSprite, int animation) {
   assert(iso);
-  with_sprite(sprite, { data->animation = animation; });
+  SpriteInstance* sprite = (SpriteInstance*)hSprite;
+  sprite->animation      = animation;
 }
 
 void isogfx_update(IsoGfx* iso, double t) {
@@ -586,14 +442,14 @@ void isogfx_update(IsoGfx* iso, double t) {
   }
 
   if ((t - iso->last_animation_time) >= ANIMATION_UPDATE_DELTA) {
-    // TODO: Consider linking animated sprites in a list so that we only walk
-    // over those here and not also the static sprites.
-    mempool_foreach(&iso->sprites, sprite, {
-      const Ss_SpriteSheet* sheet = mem_get_chunk(&iso->sheets, sprite->sheet);
-      assert(sheet); // TODO: Make this a hard assert inside the mem/pool.
-      const Ss_Row* row = get_sprite_sheet_row(sheet, sprite->animation);
+    // TODO: Consider linking animated sprites in a separate list so that we
+    //  only walk over those here and not also the static sprites.
+    for (SpriteInstance* sprite = iso->head_sprite; sprite;
+         sprite                 = sprite->next) {
+      const Ss_SpriteSheet* sheet = sprite->sheet;
+      const Ss_Row* row = ss_get_sprite_sheet_row(sheet, sprite->animation);
       sprite->frame     = (sprite->frame + 1) % row->num_cols;
-    });
+    }
 
     iso->last_animation_time = t;
   }
@@ -614,8 +470,10 @@ typedef struct CoordSystem {
 static CoordSystem make_iso_coord_system(const IsoGfx* iso) {
   assert(iso);
   const ivec2 o = {iso->screen_width / 2, 0};
-  const ivec2 x = {.x = iso->tile_width / 2, .y = iso->tile_height / 2};
-  const ivec2 y = {.x = -iso->tile_width / 2, .y = iso->tile_height / 2};
+  const ivec2 x = {
+      .x = iso->map->base_tile_width / 2, .y = iso->map->base_tile_height / 2};
+  const ivec2 y = {
+      .x = -iso->map->base_tile_width / 2, .y = iso->map->base_tile_height / 2};
   return (CoordSystem){o, x, y};
 }
 
@@ -696,19 +554,20 @@ static void draw_rect(
 ///     World (0, 0) -> (screen_width / 2, 0).
 static void draw_tile(IsoGfx* iso, ivec2 screen_origin, Tile tile) {
   assert(iso);
+  assert(iso->tileset);
 
-  const TileData* tile_data = mempool_get_block(&iso->tiles, tile);
-  assert(tile_data);
-  const Pixel* pixels = tile_xy_const_ref(iso, tile_data, 0, 0);
+  const Ts_Tile* pTile  = ts_tileset_get_tile(iso->tileset, tile);
+  const Pixel*   pixels = ts_tileset_get_tile_pixels(iso->tileset, tile);
 
   // Move from the top diamond-corner to the top-left corner of the tile image.
   // For regular tiles, tile height == base tile height, so the y offset is 0.
   // For super tiles, move as high up as the height of the tile.
   const ivec2 offset = {
-      -(iso->tile_width / 2), tile_data->height - iso->tile_height};
+      -(iso->map->base_tile_width / 2),
+      pTile->height - iso->map->base_tile_height};
   const ivec2 top_left = ivec2_add(screen_origin, offset);
 
-  draw_rect(iso, top_left, tile_data->width, tile_data->height, pixels, 0);
+  draw_rect(iso, top_left, pTile->width, pTile->height, pixels, 0);
 }
 
 static void draw_world(IsoGfx* iso) {
@@ -721,14 +580,16 @@ static void draw_world(IsoGfx* iso) {
 
   const CoordSystem iso_space = make_iso_coord_system(iso);
 
+  const Tm_Layer* layer = tm_map_get_layer(iso->map, 0);
+
   // TODO: Culling.
   // Ex: map the screen corners to tile space to cull.
   // Ex: walk in screen space and fetch the tile.
   // The tile-centric approach might be more cache-friendly since the
   // screen-centric approach would juggle multiple tiles throughout the scan.
-  for (int wy = 0; wy < iso->world_height; ++wy) {
-    for (int wx = 0; wx < iso->world_width; ++wx) {
-      const Tile  tile          = world_xy(iso, wx, wy);
+  for (int wy = 0; wy < iso->map->world_height; ++wy) {
+    for (int wx = 0; wx < iso->map->world_width; ++wx) {
+      const Tile  tile          = tm_layer_get_tile(iso->map, layer, wx, wy);
       const ivec2 screen_origin = GetTileScreenOrigin(iso_space, wx, wy);
       draw_tile(iso, screen_origin, tile);
     }
@@ -736,7 +597,7 @@ static void draw_world(IsoGfx* iso) {
 }
 
 static void draw_sprite(
-    IsoGfx* iso, ivec2 origin, const SpriteData* sprite,
+    IsoGfx* iso, ivec2 origin, const SpriteInstance* sprite,
     const Ss_SpriteSheet* sheet) {
   assert(iso);
   assert(sprite);
@@ -745,8 +606,8 @@ static void draw_sprite(
   assert(sprite->animation < sheet->num_rows);
   assert(sprite->frame >= 0);
 
-  const Ss_Row*  row   = get_sprite_sheet_row(sheet, sprite->animation);
-  const uint8_t* frame = get_sprite_sheet_sprite(sheet, row, sprite->frame);
+  const Ss_Row*  row   = ss_get_sprite_sheet_row(sheet, sprite->animation);
+  const uint8_t* frame = ss_get_sprite_sheet_sprite(sheet, row, sprite->frame);
   draw_rect(
       iso, origin, sheet->sprite_width, sheet->sprite_height,
       sheet->palette.colours, frame);
@@ -757,14 +618,15 @@ static void draw_sprites(IsoGfx* iso) {
 
   const CoordSystem iso_space = make_iso_coord_system(iso);
 
-  mempool_foreach(&iso->sprites, sprite, {
-    const Ss_SpriteSheet* sheet = mem_get_chunk(&iso->sheets, sprite->sheet);
+  for (const SpriteInstance* sprite = iso->head_sprite; sprite;
+       sprite                       = sprite->next) {
+    const Ss_SpriteSheet* sheet = sprite->sheet;
     assert(sheet);
 
     const ivec2 screen_origin =
         GetTileScreenOrigin(iso_space, sprite->position.x, sprite->position.y);
     draw_sprite(iso, screen_origin, sprite, sheet);
-  });
+  }
 }
 
 void isogfx_render(IsoGfx* iso) {
@@ -777,35 +639,14 @@ void isogfx_draw_tile(IsoGfx* iso, int x, int y, Tile tile) {
   assert(iso);
   assert(x >= 0);
   assert(y >= 0);
-  assert(x < iso->world_width);
-  assert(y < iso->world_height);
+  assert(x < iso->map->world_width);
+  assert(y < iso->map->world_height);
 
   const CoordSystem iso_space     = make_iso_coord_system(iso);
   const ivec2       screen_origin = GetTileScreenOrigin(iso_space, x, y);
   draw_tile(iso, screen_origin, tile);
 }
 
-bool isogfx_resize(IsoGfx* iso, int screen_width, int screen_height) {
-  assert(iso);
-  assert(iso->screen);
-
-  const int current_size = iso->screen_width * iso->screen_height;
-  const int new_size     = screen_width * screen_height;
-
-  if (new_size > current_size) {
-    Pixel* new_screen = calloc(new_size, sizeof(Pixel));
-    if (new_screen) {
-      free(iso->screen);
-      iso->screen = new_screen;
-    } else {
-      return false;
-    }
-  }
-  iso->screen_width  = screen_width;
-  iso->screen_height = screen_height;
-  return true;
-}
-
 void isogfx_get_screen_size(const IsoGfx* iso, int* width, int* height) {
   assert(iso);
   assert(width);
@@ -826,11 +667,11 @@ void isogfx_pick_tile(
   assert(yiso);
 
   const vec2 xy_iso = cart2iso(
-      (vec2){.x = xcart, .y = ycart}, iso->tile_width, iso->tile_height,
-      iso->screen_width);
+      (vec2){.x = xcart, .y = ycart}, iso->map->base_tile_width,
+      iso->map->base_tile_height, iso->screen_width);
 
-  if ((0 <= xy_iso.x) && (xy_iso.x < iso->world_width) && (0 <= xy_iso.y) &&
-      (xy_iso.y < iso->world_height)) {
+  if ((0 <= xy_iso.x) && (xy_iso.x < iso->map->world_width) &&
+      (0 <= xy_iso.y) && (xy_iso.y < iso->map->world_height)) {
     *xiso = (int)xy_iso.x;
     *yiso = (int)xy_iso.y;
   } else {