Added support for loading animated GIFs

libsdl-org · Oct 4, 2019 · b1300c4 · b1300c4
1 parent f5eef6b
commit b1300c4
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Showing 7 changed files with 574 additions and 89 deletions.
diff --git a/CHANGES.txt b/CHANGES.txt
@@ -1,3 +1,7 @@
+2.0.6:
+Sam Lantinga - Thu Oct  3 18:09:17 PDT 2019
+ * Added support for loading animated GIFs
+
 2.0.5:
 Sam Lantinga - Wed Jun 19 07:30:51 PDT 2019
  * Updated external libraries libpng-1.6.32, libwebp-1.0.2

diff --git a/IMG.c b/IMG.c
@@ -27,7 +27,6 @@
 #include <emscripten/emscripten.h>
 #endif
 
-#define ARRAYSIZE(a) (sizeof(a) / sizeof((a)[0]))
 
 /* Table of image detection and loading functions */
 static struct {
@@ -54,6 +53,16 @@ static struct {
     { "WEBP", IMG_isWEBP, IMG_LoadWEBP_RW },
 };
 
+/* Table of animation detection and loading functions */
+static struct {
+    const char *type;
+    int (SDLCALL *is)(SDL_RWops *src);
+    IMG_Animation *(SDLCALL *load)(SDL_RWops *src);
+} supported_anims[] = {
+    /* keep magicless formats first */
+    { "GIF", IMG_isGIF, IMG_LoadGIFAnimation_RW },
+};
+
 const SDL_version *IMG_Linked_Version(void)
 {
     static SDL_version linked_version;
@@ -146,10 +155,10 @@ SDL_Surface *IMG_Load(const char *file)
 
     SDL_RWops *src = SDL_RWFromFile(file, "rb");
     const char *ext = SDL_strrchr(file, '.');
-    if(ext) {
+    if (ext) {
         ext++;
     }
-    if(!src) {
+    if (!src) {
         /* The error message has been set in SDL_RWFromFile */
         return NULL;
     }
@@ -191,7 +200,7 @@ SDL_Surface *IMG_LoadTyped_RW(SDL_RWops *src, int freesrc, const char *type)
     /* See whether or not this data source can handle seeking */
     if ( SDL_RWseek(src, 0, RW_SEEK_CUR) < 0 ) {
         IMG_SetError("Can't seek in this data source");
-        if(freesrc)
+        if (freesrc)
             SDL_RWclose(src);
         return(NULL);
     }
@@ -206,15 +215,15 @@ SDL_Surface *IMG_LoadTyped_RW(SDL_RWops *src, int freesrc, const char *type)
 
         data = emscripten_get_preloaded_image_data_from_FILE(src->hidden.stdio.fp, &w, &h);
 
-        if(data)
+        if (data)
         {
             surf = SDL_CreateRGBSurface(0, w, h, 32, 0xFF, 0xFF00, 0xFF0000, 0xFF000000);
             if (surf != NULL) {
                 memcpy(surf->pixels, data, w * h * 4);
             }
             free(data);
 
-            if(freesrc)
+            if (freesrc)
                 SDL_RWclose(src);
 
             /* If SDL_CreateRGBSurface returns NULL, it has set the error message for us */
@@ -224,23 +233,21 @@ SDL_Surface *IMG_LoadTyped_RW(SDL_RWops *src, int freesrc, const char *type)
 #endif
 
     /* Detect the type of image being loaded */
-    image = NULL;
-    for ( i=0; i < ARRAYSIZE(supported); ++i ) {
-        if(supported[i].is) {
-            if(!supported[i].is(src))
+    for ( i=0; i < SDL_arraysize(supported); ++i ) {
+        if (supported[i].is) {
+            if (!supported[i].is(src))
                 continue;
         } else {
             /* magicless format */
-            if(!type
-               || !IMG_string_equals(type, supported[i].type))
+            if (!type || !IMG_string_equals(type, supported[i].type))
                 continue;
         }
 #ifdef DEBUG_IMGLIB
         fprintf(stderr, "IMGLIB: Loading image as %s\n",
             supported[i].type);
 #endif
         image = supported[i].load(src);
-        if(freesrc)
+        if (freesrc)
             SDL_RWclose(src);
         return image;
     }
@@ -286,3 +293,109 @@ SDL_Texture *IMG_LoadTextureTyped_RW(SDL_Renderer *renderer, SDL_RWops *src, int
     return texture;
 }
 #endif /* SDL 2.0 */
+
+/* Load an animation from a file */
+IMG_Animation *IMG_LoadAnimation(const char *file)
+{
+    SDL_RWops *src = SDL_RWFromFile(file, "rb");
+    const char *ext = SDL_strrchr(file, '.');
+    if (ext) {
+        ext++;
+    }
+    if (!src) {
+        /* The error message has been set in SDL_RWFromFile */
+        return NULL;
+    }
+    return IMG_LoadAnimationTyped_RW(src, 1, ext);
+}
+
+/* Load an animation from an SDL datasource (for compatibility) */
+IMG_Animation *IMG_LoadAnimation_RW(SDL_RWops *src, int freesrc)
+{
+    return IMG_LoadAnimationTyped_RW(src, freesrc, NULL);
+}
+
+/* Load an animation from an SDL datasource, optionally specifying the type */
+IMG_Animation *IMG_LoadAnimationTyped_RW(SDL_RWops *src, int freesrc, const char *type)
+{
+    int i;
+    IMG_Animation *anim;
+    SDL_Surface *image;
+
+    /* Make sure there is something to do.. */
+    if ( src == NULL ) {
+        IMG_SetError("Passed a NULL data source");
+        return(NULL);
+    }
+
+    /* See whether or not this data source can handle seeking */
+    if ( SDL_RWseek(src, 0, RW_SEEK_CUR) < 0 ) {
+        IMG_SetError("Can't seek in this data source");
+        if (freesrc)
+            SDL_RWclose(src);
+        return(NULL);
+    }
+
+    /* Detect the type of image being loaded */
+    for ( i=0; i < SDL_arraysize(supported_anims); ++i ) {
+        if (supported_anims[i].is) {
+            if (!supported_anims[i].is(src))
+                continue;
+        } else {
+            /* magicless format */
+            if (!type || !IMG_string_equals(type, supported_anims[i].type))
+                continue;
+        }
+#ifdef DEBUG_IMGLIB
+        fprintf(stderr, "IMGLIB: Loading image as %s\n",
+            supported_anims[i].type);
+#endif
+        anim = supported_anims[i].load(src);
+        if (freesrc)
+            SDL_RWclose(src);
+        return anim;
+    }
+
+    /* Create a single frame animation from an image */
+    image = IMG_LoadTyped_RW(src, freesrc, type);
+    if (image) {
+        anim = (IMG_Animation *)SDL_malloc(sizeof(*anim));
+        if (anim) {
+            anim->w = image->w;
+            anim->h = image->h;
+            anim->count = 1;
+
+            anim->frames = (SDL_Surface **)SDL_calloc(anim->count, sizeof(*anim->frames));
+            anim->delays = (int *)SDL_calloc(anim->count, sizeof(*anim->delays));
+
+            if (anim->frames && anim->delays) {
+                anim->frames[0] = image;
+                return anim;
+            }
+            IMG_FreeAnimation(anim);
+        }
+        SDL_FreeSurface(image);
+        SDL_OutOfMemory();
+    }
+    return NULL;
+}
+
+void IMG_FreeAnimation(IMG_Animation *anim)
+{
+    if (anim) {
+        if (anim->frames) {
+            int i;
+            for (i = 0; i < anim->count; ++i) {
+                if (anim->frames[i]) {
+                    SDL_FreeSurface(anim->frames[i]);
+                }
+            }
+            SDL_free(anim->frames);
+        }
+        if (anim->delays) {
+            SDL_free(anim->delays);
+        }
+        SDL_free(anim);
+    }
+}
+