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 fading, 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