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 thedisplay). 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 tomodify only one or the other palette to achieve various spe-
cial color effects (e.g., screen fading, color flashes, screen dimming). This function can modify either the logical or physicalpalette 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 therequested 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 aspassed 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; SDL Last change: Tue 11 Sep 2001, 23:01 1SDL API Reference SDL_SetPalette(3)
. . . /* 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 Last change: Tue 11 Sep 2001, 23:01 2