view docs/man3/SDL_CreateRGBSurface.3 @ 939:c7c04f811994

Date: Tue, 01 Jun 2004 15:27:44 +0300 From: Martin_Storsj Subject: Update for dynamic loading of ALSA I sent you a patch a few months ago which enables SDL to load ALSA dynamically. Now I've finally got time to tweak this yet some more. I've added code from alsa.m4 (from alsa's dev package) to acinclude.m4, and made the detection of the alsa library name a bit better. I've also fixed up the loading versioned symbols with dlvsym, so that it falls back to dlsym. I wouldn't say the configure script is complete yet, but this is how far I've come this time, and I'm no expert at those things.
author Sam Lantinga <slouken@libsdl.org>
date Sat, 21 Aug 2004 04:20:00 +0000
parents e5bc29de3f0a
children 546f7c1eb755
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.TH "SDL_CreateRGBSurface" "3" "Tue 11 Sep 2001, 23:01" "SDL" "SDL API Reference" 
.SH "NAME"
SDL_CreateRGBSurface\- Create an empty SDL_Surface
.SH "SYNOPSIS"
.PP
\fB#include "SDL\&.h"
.sp
\fBSDL_Surface *\fBSDL_CreateRGBSurface\fP\fR(\fBUint32 flags, int width, int height, int depth, Uint32 Rmask, Uint32 Gmask, Uint32 Bmask, Uint32 Amask\fR);
.SH "DESCRIPTION"
.PP
Allocate an empty surface (must be called after \fISDL_SetVideoMode\fR)
.PP
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\&.
.TP 20
\fBSDL_SWSURFACE\fP
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\&.
.TP 20
\fBSDL_HWSURFACE\fP
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)\&.
.TP 20
\fBSDL_SRCCOLORKEY\fP
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\&.
.TP 20
\fBSDL_SRCALPHA\fP
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\&.
.PP
.RS
\fBNote:  
.PP
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\&.
.RE
.SH "RETURN VALUE"
.PP
Returns the created surface, or \fBNULL\fR upon error\&.
.SH "EXAMPLE"
.PP
.nf
\f(CW    /* 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);
    }\fR
.fi
.PP
.SH "SEE ALSO"
.PP
\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
...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:01