Started making SDL2 migration via https://wiki.libsdl.org/MigrationGuide

src/platform/mac/platform_mac.c

@@ -26,7 +26,7 @@
 
 #include <CoreServices/CoreServices.h>
 
-#include <SDL2/SDL.h>
+#include <SDL/SDL.h>
 
 
 #include "wrogue.h"

src/platform/sdl/platform_sdl.c

@@ -619,7 +619,7 @@ static void background_init(void)
         background_image = SDL_LoadBMP(data_path());
         if (background_image == NULL) load_bmp_error();
 
-        Background = SDL_DisplayFormat(background_image);
+        Background = SDL_ConvertSurfaceFormat(background_image);
         
         SDL_FreeSurface(background_image);
 }