Fix SDL gfx import

spawn.h

@@ -3,7 +3,7 @@
 
 #include <SDL/SDL.h>
 #include "Input.h"
-#include "SDL_gfxPrimitives.h"
+#include <SDL/SDL_gfxPrimitives.h>
 #include <vector>
 #include <cstdlib>
 #include <ctime>