SDL_SetColors — Sets a portion of the colormap for the given 8-bit surface.
#include "SDL.h"
int
SDL_SetColors( |
SDL_Surface * | surface, |
| SDL_Color * | colors, | |
| int | firstcolor, | |
| int | ncolors); |
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).
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.
/* 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);
.
.
.
.
SDL_Color(3) SDL_Surface(3), SDL_SetPalette(3), SDL_SetVideoMode(3)
| COPYRIGHT |
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This manual page is taken from the SDL library, licensed under GNU LGPL. |