view docs/man3/SDL_SetPalette.3 @ 1120:8e1fde455471

Patch by me to fix crash described below. --ryan. To: sdl@libsdl.org From: Rainer Deyke <rainerd@eldwood.com> Date: Tue, 16 Aug 2005 01:08:18 -0600 Subject: [SDL] Bug report: SDL_CreateRGBSurface with SDL_HWSURFACE crashes If SDL is in full-screen mode with a hardware video surface on OS X, SDL_CreateRGBSurface with SDL_HWSURFACE crashes. The crash occurs on line 109 of SDL_Surface.c. This was tested on OS X 10.3.9 with both SDL 1.2.8 and the latest CVS. Here is a small C++ program that demonstrates the problem: #include "SDL.h" #include <stdio.h> namespace { void wait_for_key() { SDL_Event e; printf("%d\n", SDL_GetAppState()); while (SDL_WaitEvent(&e)) { if (e.type == SDL_KEYDOWN || e.type == SDL_QUIT) return; } } } int main(int, char *[]) { SDL_Init(SDL_INIT_VIDEO); SDL_Surface *screen = SDL_SetVideoMode(640, 480, 32, SDL_FULLSCREEN | SDL_HWSURFACE); SDL_Surface *s = SDL_CreateRGBSurface(SDL_HWSURFACE, 640, 480, 32, screen->format->Rmask, screen->format->Gmask, screen->format->Bmask, screen->format->Amask); wait_for_key(); if (s) SDL_FreeSurface(s); SDL_Quit(); printf("Success!\n"); return 0; }
author Ryan C. Gordon <icculus@icculus.org>
date Thu, 18 Aug 2005 06:46:32 +0000
parents e5bc29de3f0a
children 546f7c1eb755
line wrap: on
line source

.TH "SDL_SetPalette" "3" "Tue 11 Sep 2001, 23:01" "SDL" "SDL API Reference" 
.SH "NAME"
SDL_SetPalette\- Sets the colors in the palette of an 8-bit surface\&.
.SH "SYNOPSIS"
.PP
\fB#include "SDL\&.h"
.sp
\fBint \fBSDL_SetPalette\fP\fR(\fBSDL_Surface *surface, int flags, SDL_Color *colors, int firstcolor, int ncolors\fR);
.SH "DESCRIPTION"
.PP
Sets a portion of the palette for the given 8-bit surface\&.
.PP
Palettized (8-bit) screen surfaces with the \fBSDL_HWPALETTE\fP flag have two palettes, a logical palette that is used for mapping blits to/from the surface and a physical palette (that determines how the hardware will map the colors to the display)\&. \fISDL_BlitSurface\fR always uses the logical palette when blitting surfaces (if it has to convert between surface pixel formats)\&. Because of this, it is often useful to modify only one or the other palette to achieve various special color effects (e\&.g\&., screen fading, color flashes, screen dimming)\&.
.PP
This function can modify either the logical or physical palette by specifing \fBSDL_LOGPAL\fP or \fBSDL_PHYSPAL\fPthe in the \fBflags\fR parameter\&.
.PP
When \fBsurface\fR is the surface associated with the current display, the display colormap will be updated with the requested colors\&. If \fBSDL_HWPALETTE\fP was set in \fISDL_SetVideoMode\fR flags, \fBSDL_SetPalette\fP will always return \fB1\fR, and the palette is guaranteed to be set the way you desire, even if the window colormap has to be warped or run under emulation\&.
.PP
The color components of a \fI\fBSDL_Color\fR\fR structure are 8-bits in size, giving you a total of 256^3=16777216 colors\&.
.SH "RETURN VALUE"
.PP
If \fBsurface\fR is not a palettized surface, this function does nothing, returning \fB0\fR\&. If all of the colors were set as passed to \fBSDL_SetPalette\fP, it will return \fB1\fR\&. If not all the color entries were set exactly as given, it will return \fB0\fR, and you should look at the surface palette to determine the actual color palette\&.
.SH "EXAMPLE"
.PP
.nf
\f(CW        /* Create a display surface with a grayscale palette */
        SDL_Surface *screen;
        SDL_Color colors[256];
        int i;
        \&.
        \&.
        \&.
        /* Fill colors with color information */
        for(i=0;i<256;i++){
          colors[i]\&.r=i;
          colors[i]\&.g=i;
          colors[i]\&.b=i;
        }

        /* Create display */
        screen=SDL_SetVideoMode(640, 480, 8, SDL_HWPALETTE);
        if(!screen){
          printf("Couldn\&'t set video mode: %s
", SDL_GetError());
          exit(-1);
        }

        /* Set palette */
        SDL_SetPalette(screen, SDL_LOGPAL|SDL_PHYSPAL, colors, 0, 256);
        \&.
        \&.
        \&.
        \&.\fR
.fi
.PP
.SH "SEE ALSO"
.PP
\fISDL_SetColors\fR, \fISDL_SetVideoMode\fR, \fISDL_Surface\fR, \fISDL_Color\fR
...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:01