make textures_dump_atlases work again and expose it as a utility function

apps/platformer/game.c

@@ -23,6 +23,9 @@ void game_tick(void) {
         input_add_action(&ctx.input, "debug_toggle");
         input_bind_action_scancode(&ctx.input, "debug_toggle", SDL_SCANCODE_BACKSPACE);
 
+        input_add_action(&ctx.input, "debug_dump_atlases");
+        input_bind_action_scancode(&ctx.input, "debug_dump_atlases", SDL_SCANCODE_HOME);
+
         input_add_action(&ctx.input, "player_left");
         input_bind_action_scancode(&ctx.input, "player_left", SDL_SCANCODE_A);
 
@@ -54,6 +57,10 @@ void game_tick(void) {
         ctx.debug = !ctx.debug;
     }
 
+    if (input_is_action_just_pressed(&ctx.input, "debug_dump_atlases")) {
+        textures_dump_atlases();
+    }
+
     state->scene->tick(state);
 
     /* there's a scene switch pending, we can do it now that the tick is done */

apps/scenery/game.c

@@ -23,6 +23,9 @@ void game_tick(void) {
         input_add_action(&ctx.input, "debug_toggle");
         input_bind_action_scancode(&ctx.input, "debug_toggle", SDL_SCANCODE_BACKSPACE);
 
+        input_add_action(&ctx.input, "debug_dump_atlases");
+        input_bind_action_scancode(&ctx.input, "debug_dump_atlases", SDL_SCANCODE_HOME);
+
         input_add_action(&ctx.input, "player_left");
         input_bind_action_scancode(&ctx.input, "player_left", SDL_SCANCODE_A);
 
@@ -54,6 +57,10 @@ void game_tick(void) {
         ctx.debug = !ctx.debug;
     }
 
+    if (input_is_action_just_pressed(&ctx.input, "debug_dump_atlases")) {
+        textures_dump_atlases();
+    }
+
     state->scene->tick(state);
 
     /* there's a scene switch pending, we can do it now that the tick is done */

include/twn_util.h

@@ -68,6 +68,10 @@ TWN_API int64_t file_to_bytes(const char *path, unsigned char **buf_out);
 TWN_API char *file_to_str(const char *path);
 
 
+/* saves all texture atlases as BMP files in the write directory */
+TWN_API void textures_dump_atlases(void);
+
+
 /* returns true if str ends with suffix */
 TWN_API TWN_API bool strends(const char *str, const char *suffix);
 

src/twn_textures.c

@@ -300,31 +300,6 @@ void textures_cache_deinit(TextureCache *cache) {
 }
 
 
-void textures_dump_atlases(TextureCache *cache) {
-    PHYSFS_mkdir("/dump");
-
-    const char string_template[] = "/dump/atlas%zd.png";
-    char buf[2048]; /* larger than will ever be necessary */
-
-    size_t i = 0;
-    for (; i < arrlenu(cache->atlas_surfaces); ++i) {
-        SDL_snprintf(buf, sizeof buf, string_template, i);
-
-        SDL_RWops *handle = PHYSFSRWOPS_openWrite(buf);
-
-        if (handle == NULL) {
-            CRY("Texture atlas dump failed.", "File could not be opened");
-            return;
-        }
-
-        /* TODO: */
-        // IMG_SavePNG_RW(cache->atlas_surfaces[i], handle, true);
-        CRY("Unimplemented", "textures_dump_atlases dumping is not there, sorry");
-        log_info("Dumped atlas %s", buf);
-    }
-}
-
-
 static enum TextureMode infer_texture_mode(SDL_Surface *surface) {
     const uint32_t amask = surface->format->Amask;
     if (amask == 0)

src/twn_textures_c.h

@@ -50,9 +50,6 @@ typedef struct TextureKey { uint16_t id; } TextureKey;
 void textures_cache_init(struct TextureCache *cache, SDL_Window *window);
 void textures_cache_deinit(struct TextureCache *cache);
 
-/* for debugging */
-void textures_dump_atlases(struct TextureCache *cache);
-
 /* loads an image if it isn't in the cache, otherwise a no-op. */
 /* can be called from anywhere at any time after init, useful if you want to */
 /* preload textures you know will definitely be used */

src/twn_util.c

@@ -165,6 +165,30 @@ char *file_to_str(const char *path) {
 }
 
 
+void textures_dump_atlases(void) {
+    PHYSFS_mkdir("/dump");
+
+    /* TODO: png instead of bmp */
+    const char string_template[] = "/dump/atlas%zd.bmp";
+
+    size_t i = 0;
+    for (; i < arrlenu(ctx.texture_cache.atlas_surfaces); ++i) {
+        char *buf = NULL;
+        SDL_asprintf(&buf, string_template, i);
+
+        SDL_RWops *handle = PHYSFSRWOPS_openWrite(buf);
+
+        if (handle == NULL) {
+            CRY("Texture atlas dump failed.", "File could not be opened");
+            return;
+        }
+
+        SDL_SaveBMP_RW(ctx.texture_cache.atlas_surfaces[i], handle, true);
+        log_info("Dumped atlas %zu to %s", i, buf);
+    }
+}
+
+
 bool strends(const char *str, const char *suffix) {
     size_t str_length = SDL_strlen(str);
     size_t suffix_length = SDL_strlen(suffix);