view docs/man3/SDL_SetColors.3 @ 1856:21f13c787b46

Date: Mon, 22 May 2006 01:16:47 -0400 From: Mike Frysinger Subject: [SDL] [patch] fix sed expression in sdl-config just noticed that sdl-config uses '[a-z]' with sed in sdl-config without forcing the locale to C ... this could cause problems with locales where the letter 'z' is not the last letter in the alphabet
author Sam Lantinga <slouken@libsdl.org>
date Tue, 23 May 2006 15:07:56 +0000
parents e5bc29de3f0a
children 546f7c1eb755
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.TH "SDL_SetColors" "3" "Tue 11 Sep 2001, 23:01" "SDL" "SDL API Reference" 
.SH "NAME"
SDL_SetColors\- Sets a portion of the colormap for the given 8-bit surface\&.
.SH "SYNOPSIS"
.PP
\fB#include "SDL\&.h"
.sp
\fBint \fBSDL_SetColors\fP\fR(\fBSDL_Surface *surface, SDL_Color *colors, int firstcolor, int ncolors\fR);
.SH "DESCRIPTION"
.PP
Sets a portion of the colormap for the given 8-bit surface\&.
.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_SetColors\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\&.
.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)\&. \fBSDL_SetColors\fP modifies both palettes (if present), and is equivalent to calling \fISDL_SetPalette\fR with the \fBflags\fR set to \fB(SDL_LOGPAL | SDL_PHYSPAL)\fP\&.
.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_SetColors\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_SetColors(screen, colors, 0, 256);
\&.
\&.
\&.
\&.\fR
.fi
.PP
.SH "SEE ALSO"
.PP
\fI\fBSDL_Color\fR\fR \fI\fBSDL_Surface\fR\fR, \fI\fBSDL_SetPalette\fP\fR, \fI\fBSDL_SetVideoMode\fP\fR
...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:01