sdl/render: fix broken build on older SDL2
@@ -191,6 +191,9 @@ static int SDLCALL SDL_GetTextureScaleMode(SDL_Texture * texture, SDL_ScaleMode
}
static int SDL_LockTextureToSurface(SDL_Texture *texture, const SDL_Rect *rect, SDL_Surface **surface)
+{
+ return -1;
+}
#endif
