1 .TH "SDL_CreateRGBSurface" "3" "Tue 11 Sep 2001, 23:01" "SDL" "SDL API Reference" 

     2 .SH "NAME"

     3 SDL_CreateRGBSurface \- Create an empty SDL_Surface

     4 .SH "SYNOPSIS"

     5 .PP

     6 \fB#include "SDL\&.h"

     7 .sp

     8 \fBSDL_Surface *\fBSDL_CreateRGBSurface\fP\fR(\fBUint32 flags, int width, int height, int depth, Uint32 Rmask, Uint32 Gmask, Uint32 Bmask, Uint32 Amask\fR);

     9 .SH "DESCRIPTION"

    10 .PP

    11 Allocate an empty surface (must be called after \fISDL_SetVideoMode\fR)

    12 .PP

    13 If \fBdepth\fR is 8 bits an empty palette is allocated for the surface, otherwise a \&'packed-pixel\&' \fI\fBSDL_PixelFormat\fR\fR is created using the \fB[RGBA]mask\fR\&'s provided (see \fI\fBSDL_PixelFormat\fR\fR)\&. The \fBflags\fR specifies the type of surface that should be created, it is an OR\&'d combination of the following possible values\&.

    14 .TP 20

    15 \fBSDL_SWSURFACE\fP

    16 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\&.

    17 .TP 20

    18 \fBSDL_HWSURFACE\fP

    19 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)\&.

    20 .TP 20

    21 \fBSDL_SRCCOLORKEY\fP

    22 This flag turns on colourkeying for blits from this surface\&. If \fBSDL_HWSURFACE\fP is also specified and colourkeyed blits are hardware-accelerated, then SDL will attempt to place the surface in video memory\&. Use \fI\fBSDL_SetColorKey\fP\fR to set or clear this flag after surface creation\&.

    23 .TP 20

    24 \fBSDL_SRCALPHA\fP

    25 This flag turns on alpha-blending for blits from this surface\&. If \fBSDL_HWSURFACE\fP is also specified and alpha-blending blits are hardware-accelerated, then the surface will be placed in video memory if possible\&. Use \fI\fBSDL_SetAlpha\fP\fR to set or clear this flag after surface creation\&.

    26 .PP

    27 .RS

    28 \fBNote:  

    29 .PP

    30 If an alpha-channel is specified (that is, if \fBAmask\fR is nonzero), then the \fBSDL_SRCALPHA\fP flag is automatically set\&. You may remove this flag by calling \fI\fBSDL_SetAlpha\fP\fR after surface creation\&.

    31 .RE

    32 .SH "RETURN VALUE"

    33 .PP

    34 Returns the created surface, or \fBNULL\fR upon error\&.

    35 .SH "EXAMPLE"

    36 .PP

    37 .nf

    38 \f(CW    /* Create a 32-bit surface with the bytes of each pixel in R,G,B,A order,

    39        as expected by OpenGL for textures */

    40     SDL_Surface *surface;

    41     Uint32 rmask, gmask, bmask, amask;

    42 

    43     /* SDL interprets each pixel as a 32-bit number, so our masks must depend

    44        on the endianness (byte order) of the machine */

    45 #if SDL_BYTEORDER == SDL_BIG_ENDIAN

    46     rmask = 0xff000000;

    47     gmask = 0x00ff0000;

    48     bmask = 0x0000ff00;

    49     amask = 0x000000ff;

    50 #else

    51     rmask = 0x000000ff;

    52     gmask = 0x0000ff00;

    53     bmask = 0x00ff0000;

    54     amask = 0xff000000;

    55 #endif

    56 

    57     surface = SDL_CreateRGBSurface(SDL_SWSURFACE, width, height, 32,

    58                                    rmask, gmask, bmask, amask);

    59     if(surface == NULL) {

    60         fprintf(stderr, "CreateRGBSurface failed: %s

    61 ", SDL_GetError());

    62         exit(1);

    63     }\fR

    64 .fi

    65 .PP

    66 .SH "SEE ALSO"

    67 .PP

    68 \fI\fBSDL_CreateRGBSurfaceFrom\fP\fR, \fI\fBSDL_FreeSurface\fP\fR, \fI\fBSDL_SetVideoMode\fP\fR, \fI\fBSDL_LockSurface\fP\fR, \fI\fBSDL_PixelFormat\fR\fR, \fI\fBSDL_Surface\fR\fR \fI\fBSDL_SetAlpha\fP\fR \fI\fBSDL_SetColorKey\fP\fR

    69 ...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:01