SDL_CreateRGBSurface(3) SDL API Reference SDL_CreateRGBSurface(3)NAME
SDL_CreateRGBSurface- Create an empty SDL_Surface
SYNOPSIS
#include "SDL.h"
SDL_Surface *SDL_CreateRGBSurface(Uint32 flags, int width,
int height, int depth, Uint32 Rmask, Uint32 Gmask, Uint32
Bmask, Uint32 Amask);
DESCRIPTION
Allocate an empty surface (must be called after
SDL_SetVideoMode)
If depth is 8 bits an empty palette is allocated for the
surface, otherwise a 'packed-pixel' SDL_PixelFormat is
created using the [RGBA]mask's provided (see SDL_PixelFor-
mat). The flags specifies the type of surface that should
be created, it is an OR'd combination of the following
possible values.
SDL_SWSURFACE SDL will create the surface in system
memory. This improves the performance
of pixel level access, however you may
not be able to take advantage of some
types of hardware blitting.
SDL_HWSURFACE SDL will attempt to create the surface
in video memory. This will allow SDL
to take advantage of Video->Video
blits (which are often accelerated).
SDL_SRCCOLORKEY This flag turns on colourkeying for
blits from this surface. If SDL_HWSUR-
FACE is also specified and colourkeyed
blits are hardware-accelerated, then
SDL will attempt to place the surface
in video memory. Use SDL_SetColorKey
to set or clear this flag after sur-
face creation.
SDL_SRCALPHA This flag turns on alpha-blending for
blits from this surface. If SDL_HWSUR-
FACE is also specified and alpha-
blending blits are hardware-acceler-
ated, then the surface will be placed
in video memory if possible. Use
SDL_SetAlpha to set or clear this flag
after surface creation.
Note:
If an alpha-channel is specified (that is, if Amask
is nonzero), then the SDL_SRCALPHA flag is automat-
ically set. You may remove this flag by calling
SDL_SetAlpha after surface creation.
RETURN VALUE
Returns the created surface, or NULL upon error.
EXAMPLE
/* Create a 32-bit surface with the bytes of each pixel in R,G,B,A order,
as expected by OpenGL for textures */
SDL_Surface *surface;
Uint32 rmask, gmask, bmask, amask;
/* SDL interprets each pixel as a 32-bit number, so our masks must depend
on the endianness (byte order) of the machine */
#if SDL_BYTEORDER == SDL_BIG_ENDIAN
rmask = 0xff000000;
gmask = 0x00ff0000;
bmask = 0x0000ff00;
amask = 0x000000ff;
#else
rmask = 0x000000ff;
gmask = 0x0000ff00;
bmask = 0x00ff0000;
amask = 0xff000000;
#endif
surface = SDL_CreateRGBSurface(SDL_SWSURFACE, width, height, 32,
rmask, gmask, bmask, amask);
if(surface == NULL) {
fprintf(stderr, "CreateRGBSurface failed: %s
", SDL_GetError());
exit(1);
}
SEE ALSO
SDL_CreateRGBSurfaceFrom, SDL_FreeSurface, SDL_SetVideo-
Mode, SDL_LockSurface, SDL_PixelFormat, SDL_Surface
SDL_SetAlpha SDL_SetColorKey
SDL Tue 11 Sep 2001, 23:SDL_CreateRGBSurface(3)
