protected unsafe void CreateFromSurface(IntPtr surfacep, uint glformat)
{
Sdl.Surface *surface = (Sdl.Surface *)surfacep;
this.width = (uint)surface->w;
this.height = (uint)surface->h;
if (!IsPowerOf2(width) || !IsPowerOf2(height))
{
throw new Exception("Texture size must be power of 2");
}
GlUtil.Assert("before creating texture");
CreateTexture();
try {
gl.BindTexture(gl.TEXTURE_2D, handle);
uint surface_format = SetupPixelFormat(surfacep);
gl.TexImage2D(gl.TEXTURE_2D, 0, (int)glformat,
(int)width, (int)height, 0, surface_format,
gl.UNSIGNED_BYTE, surface->pixels);
GlUtil.Assert("creating texture (too big?)");
SetTextureParams();
} catch (Exception) {
uint[] handles = { handle };
gl.DeleteTextures(1, handles);
throw;
}
}
public unsafe void copy_to(IntPtr surfacep, uint surface_x, uint surface_y,
uint texture_x, uint texture_y,
uint width, uint height)
{
Sdl.Surface *surface = (Sdl.Surface *)surfacep;
PixelFormat *format = (PixelFormat *)surface->format;
GlUtil.Assert("Before update texture");
uint surface_format = SetupPixelFormat(surfacep);
/* We're extracting sub rectangles from the SDL_Surface pixeldata, by
* setting the pitch to the real width, but telling OpenGL just our
* desired image dimensions.
*/
IntPtr pixeldata = (IntPtr)
(((byte *)surface->pixels) + surface_y * surface->pitch
+ format->BytesPerPixel * surface_x);
gl.TexSubImage2D(gl.TEXTURE_2D, 0, (int)texture_x, (int)texture_y,
(int)width, (int)height, surface_format,
gl.UNSIGNED_BYTE, pixeldata);
GlUtil.Assert("Updating Texture Part");
}
private static unsafe uint SetupPixelFormat(IntPtr surfacep)
{
Sdl.Surface *surface = (Sdl.Surface *)surfacep;
PixelFormat *format = (PixelFormat *)surface->format;
uint glformat;
if (format->BytesPerPixel == 3)
{
glformat = gl.RGB;
}
else if (format->BytesPerPixel == 4)
{
glformat = gl.RGBA;
}
else
{
throw new Exception("Surface format not supported (only 24 and 32BPP modes supported at the moment)");
}
gl.PixelStorei(gl.UNPACK_ALIGNMENT, 1);
gl.PixelStorei(gl.UNPACK_ROW_LENGTH,
surface->pitch / format->BytesPerPixel);
return(glformat);
}
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;
}
