Fixed bug 3324 - SDL_RenderReadPixels: Wrong rect coordinates with software renderer

Daniel

SDL_RenderReadPixels with SDL_RENDERER_SOFTWARE reads pixels from wrong coordinates.

SW_RenderReadPixels adjusts the rect coordinates according to the viewport. But since this is already done by SDL_RenderReadPixels, the final rect has x2 bigger X and Y.

src/render/software/SDL_render_sw.c

@@ -833,19 +833,14 @@ SW_RenderReadPixels(SDL_Renderer * renderer, const SDL_Rect * rect,
     SDL_Surface *surface = SW_ActivateRenderer(renderer);
     Uint32 src_format;
     void *src_pixels;
-    SDL_Rect final_rect;
 
     if (!surface) {
         return -1;
     }
 
-    if (renderer->viewport.x || renderer->viewport.y) {
-        final_rect.x = renderer->viewport.x + rect->x;
-        final_rect.y = renderer->viewport.y + rect->y;
-        final_rect.w = rect->w;
-        final_rect.h = rect->h;
-        rect = &final_rect;
-    }
+    /* NOTE: The rect is already adjusted according to the viewport by
+     * SDL_RenderReadPixels.
+     */
 
     if (rect->x < 0 || rect->x+rect->w > surface->w ||
         rect->y < 0 || rect->y+rect->h > surface->h) {