SDL_SetPalette(3) SDL API Reference SDL_SetPalette(3)NAME
SDL_SetPalette- Sets the colors in the palette of an 8-bit
surface.
SYNOPSIS
#include "SDL.h"
int SDL_SetPalette(SDL_Surface *surface, int flags,
SDL_Color *colors, int firstcolor, int ncolors);
DESCRIPTION
Sets a portion of the palette for the given 8-bit surface.
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_BlitSurface 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 fad-
ing, color flashes, screen dimming).
This function can modify either the logical or physical
palette by specifing SDL_LOGPAL or SDL_PHYSPALthe in the
flags parameter.
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_SetPalette 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.
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_SetPalette, 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_SetPalette(screen, SDL_LOGPAL|SDL_PHYSPAL, colors, 0, 256);
.
.
.
.
SEE ALSO
SDL_SetColors, SDL_SetVideoMode, SDL_Surface, SDL_Color
SDL Tue 11 Sep 2001, 23:01 SDL_SetPalette(3)
