Fixed bug 3349 - GLES2_RenderReadPixels doesn't use target texture format

Simon Hug

The OpenGL ES 2 renderer does not check the target texture format when using SDL_RenderReadPixels and just always uses ABGR8888. This can result in swapped or wrong colors.

The attached patch adds a check and selects the target texture format, if a texture is set as the target.

src/render/opengl/SDL_render_gl.c

@@ -1414,7 +1414,7 @@ GL_RenderReadPixels(SDL_Renderer * renderer, const SDL_Rect * rect,
                     Uint32 pixel_format, void * pixels, int pitch)
 {
     GL_RenderData *data = (GL_RenderData *) renderer->driverdata;
-    Uint32 temp_format = SDL_PIXELFORMAT_ARGB8888;
+    Uint32 temp_format = renderer->target ? renderer->target->format : SDL_PIXELFORMAT_ABGR8888;
     void *temp_pixels;
     int temp_pitch;
     GLint internalFormat;

src/render/opengles/SDL_render_gles.c

@@ -1069,7 +1069,7 @@ GLES_RenderReadPixels(SDL_Renderer * renderer, const SDL_Rect * rect,
                     Uint32 pixel_format, void * pixels, int pitch)
 {
     GLES_RenderData *data = (GLES_RenderData *) renderer->driverdata;
-    Uint32 temp_format = SDL_PIXELFORMAT_ABGR8888;
+    Uint32 temp_format = renderer->target ? renderer->target->format : SDL_PIXELFORMAT_ABGR8888;
     void *temp_pixels;
     int temp_pitch;
     Uint8 *src, *dst, *tmp;

src/render/opengles2/SDL_render_gles2.c

@@ -1817,7 +1817,7 @@ GLES2_RenderReadPixels(SDL_Renderer * renderer, const SDL_Rect * rect,
                     Uint32 pixel_format, void * pixels, int pitch)
 {
     GLES2_DriverContext *data = (GLES2_DriverContext *)renderer->driverdata;
-    Uint32 temp_format = SDL_PIXELFORMAT_ABGR8888;
+    Uint32 temp_format = renderer->target ? renderer->target->format : SDL_PIXELFORMAT_ABGR8888;
     void *temp_pixels;
     int temp_pitch;
     Uint8 *src, *dst, *tmp;