SDL_CreateRGBSurface

Section: SDL API Reference (3)
Updated: Tue 11 Sep 2001, 23:01
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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_PixelFormat). 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_HWSURFACE 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 surface creation.
SDL_SRCALPHA: This flag turns on alpha-blending for blits from this surface. If SDL_HWSURFACE is also specified and alpha-blending blits are hardware-accelerated, 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 automatically 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);
    }