public void rotozoomSurface()
{
this.InitSdl();
Sdl.SDL_Rect rect1 = new Sdl.SDL_Rect(0, 0, 400, 400);
Sdl.SDL_Rect rect2 = new Sdl.SDL_Rect(0, 0, 400, 400);
IntPtr bmpImagePtr = Sdl.SDL_LoadBMP("test.bmp");
IntPtr rotoSurfacePtr = SdlGfx.rotozoomSurface(bmpImagePtr, 90, 2, SdlGfx.SMOOTHING_OFF);
Sdl.SDL_BlitSurface(rotoSurfacePtr, ref rect1, surfacePtr, ref rect2);
Assert.IsNotNull(rotoSurfacePtr);
Assert.IsFalse(rotoSurfacePtr == IntPtr.Zero);
Sdl.SDL_UpdateRect(surfacePtr, 0, 0, 400, 400);
//int results = Sdl.SDL_Flip(surfacePtr);
Thread.Sleep(sleepTime);
}