SDL_SetColors
From SDL Library
SDL_SetColors
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 2563
=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\n", SDL_GetError());
exit(-1);
}
/* Set palette */
SDL_SetColors(screen, colors, 0, 256);
.
.
.
.