Mercurial > sdl-ios-xcode
view docs/man3/SDL_CreateRGBSurface.3 @ 883:50f5a29c6a17
Date: Sat, 10 Apr 2004 02:25:33 -0400
From: Glenn Maynard
To: sdl@libsdl.org
Subject: [SDL] SDL_SetVideoMode() failing and not setting an error (patch)
Running an OpenGL SDL application off 1.2.7, at SDL_InitSubSystem(SDL_INIT_VIDEO) time:
Warning: Unable to initialize AAlib mouseUsing AAlib driver: Slang driver 1.0 (slang)
SDL_SetVideoMode then fails; SDL_GetError() returns "".
The installation problem is straightforward: X (the higher priority
driver) isn't running, so SDL is falling back on aalib. However,
no error is being set when aalib fails to initialize. This also
happens with the svgalib driver.
SDL_video.c line ~653 sets mode to NULL, since aalib didn't return an
OpenGL surface. Line ~711 ("failed setting a video mode") returns NULL.
The attached patch sets an error. It's a horrible, useless error
message--it should really say eg. "aalib does not support OpenGL"; this
should probably be done earlier in the individual drivers, too.
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Sun, 11 Apr 2004 19:54:40 +0000 |
parents | e5bc29de3f0a |
children | 546f7c1eb755 |
line wrap: on
line source
.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