SDL_SetColors(3) SDL API Reference SDL_SetColors(3)NAME
SDL_SetColors- Sets a portion of the colormap for the
given 8-bit surface.
SYNOPSIS
#include "SDL.h"
int SDL_SetColors(SDL_Surface *surface, SDL_Color *colors,
int firstcolor, int ncolors);
DESCRIPTION
Sets a portion of the colormap for the given 8-bit sur-
face.
When surface is the surface associated with the current
display, the display colormap will be updated with the
requested colors. If SDL_HWPALETTE was set in
SDL_SetVideoMode flags, SDL_SetColors will always return
1, 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.
The color components of a SDL_Color structure are 8-bits
in size, giving you a total of 256^3 =16777216 colors.
Palettized (8-bit) screen surfaces with the SDL_HWPALETTE
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). SDL_SetColors modifies both palettes (if
present), and is equivalent to calling SDL_SetPalette with
the flags set to (SDL_LOGPAL | SDL_PHYSPAL).
RETURN VALUE
If surface is not a palettized surface, this function does
nothing, returning 0. If all of the colors were set as
passed to SDL_SetColors, it will return 1. If not all the
color entries were set exactly as given, it will return 0,
and you should look at the surface palette to determine
the actual color palette.
EXAMPLE
/* 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);
.
.
.
.
SEE ALSO
SDL_Color SDL_Surface, SDL_SetPalette, SDL_SetVideoMode
SDL Tue 11 Sep 2001, 23:01 SDL_SetColors(3)
