/// <summary>
/// Blits the surface onto the specified destination surface.
/// </summary>
/// <param name="src">The source surface.</param>
/// <param name="srcRect">The area of this surface that will be copied to the destination surface.</param>
/// <param name="dst">The destination surface.</param>
/// <param name="dstRect">The area on the destination surface to which this surface will be copied.</param>
private static void BlitInternal(OpenGLSurface2D src, Rectangle srcRect, OpenGLSurface2D dst, Rectangle dstRect)
{
var sdlSrcRect = new SDL_Rect()
{
x = srcRect.X, y = srcRect.Y, w = srcRect.Width, h = srcRect.Height
};
var sdlDstRect = new SDL_Rect()
{
x = dstRect.X, y = dstRect.Y, w = dstRect.Width, h = dstRect.Height
};
if (SDL.SetSurfaceBlendMode(src.nativesurf.Native, SDL_BlendMode.NONE) < 0)
{
throw new SDL2Exception();
}
if (srcRect.Width != dstRect.Width || srcRect.Height != dstRect.Height)
{
if (SDL.BlitScaled(src.nativesurf.Native, &sdlSrcRect, dst.nativesurf.Native, &sdlDstRect) < 0)
{
throw new SDL2Exception();
}
}
else
{
if (SDL.BlitSurface(src.nativesurf.Native, &sdlSrcRect, dst.nativesurf.Native, &sdlDstRect) < 0)
{
throw new SDL2Exception();
}
}
}
/// <summary>
/// Creates a copy of a region of this surface.
/// </summary>
/// <param name="region">The region of this surface to copy.</param>
/// <returns>A new surface which is a copy of the specified region of this surface.</returns>
public override Surface2D CreateSurface(Rectangle region)
{
Contract.EnsureNotDisposed(this, Disposed);
if (region.Left < 0 || region.Top < 0 || region.Right > Width || region.Bottom > Height || region.Width <= 0 || region.Height <= 0)
{
throw new ArgumentOutOfRangeException("region");
}
var copysurf = new SDL_Surface(region.Width, region.Height);
var srcrect = new SDL_Rect()
{
x = region.X, y = region.Y, w = region.Width, h = region.Height
};
var dstrect = new SDL_Rect()
{
x = 0, y = 0, w = region.Width, h = region.Height
};
if (SDL.BlitSurface(nativesurf.Native, &srcrect, copysurf.Native, &dstrect) < 0)
{
throw new SDL2Exception();
}
return(new OpenGLSurface2D(Ultraviolet, copysurf));
}
/// <summary>
/// Creates a texture from the surface.
/// </summary>
/// <param name="premultiplyAlpha">A value indicating whether to premultiply the surface's alpha when creating the texture.</param>
/// <returns>The texture that was created from the surface.</returns>
public override Texture2D CreateTexture(Boolean premultiplyAlpha)
{
Contract.EnsureNotDisposed(this, Disposed);
using (var copysurf = new SDL_Surface(Width, Height))
{
if (SDL.SetSurfaceBlendMode(nativesurf.Native, SDL_BlendMode.NONE) < 0)
{
throw new SDL2Exception();
}
if (SDL.BlitSurface(nativesurf.Native, null, copysurf.Native, null) < 0)
{
throw new SDL2Exception();
}
copysurf.PrepareForTextureExport(premultiplyAlpha);
return(new OpenGLTexture2D(Ultraviolet, copysurf));
}
}
private unsafe void Create(IntPtr sdlsurface)
{
Sdl.Surface *surface = (Sdl.Surface *)sdlsurface;
uint width = NextPowerOfTwo((uint)surface->w);
uint height = NextPowerOfTwo((uint)surface->h);
IntPtr pixelbufferp;
if (BitConverter.IsLittleEndian)
{
pixelbufferp = SDL.CreateRGBSurface(SDL.SWSURFACE,
(int)width, (int)height, 32,
0x000000ff, 0x0000ff00, 0x00ff0000, 0xff000000);
}
else
{
pixelbufferp = SDL.CreateRGBSurface(SDL.SWSURFACE,
(int)width, (int)height, 32,
0xff000000, 0x00ff0000, 0x0000ff00, 0x000000ff);
}
if (pixelbufferp == IntPtr.Zero)
{
throw new Exception("Couldn't create surface texture (out of memory?)");
}
try {
SDL.SetAlpha(sdlsurface, 0, 0);
SDL.BlitSurface(sdlsurface, IntPtr.Zero, pixelbufferp, IntPtr.Zero);
CreateFromSurface(pixelbufferp, gl.RGBA);
} finally {
SDL.FreeSurface(pixelbufferp);
}
ImageWidth = (float)surface->w;
ImageHeight = (float)surface->h;
}