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 surface.

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)