1 .TH "SDL_SetPalette" "3" "Tue 11 Sep 2001, 23:01" "SDL" "SDL API Reference" 

     2 .SH "NAME"

     3 SDL_SetPalette \- Sets the colors in the palette of an 8-bit surface\&.

     4 .SH "SYNOPSIS"

     5 .PP

     6 \fB#include "SDL\&.h"

     7 .sp

     8 \fBint \fBSDL_SetPalette\fP\fR(\fBSDL_Surface *surface, int flags, SDL_Color *colors, int firstcolor, int ncolors\fR);

     9 .SH "DESCRIPTION"

    10 .PP

    11 Sets a portion of the palette for the given 8-bit surface\&.

    12 .PP

    13 Palettized (8-bit) screen surfaces with the \fBSDL_HWPALETTE\fP 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)\&. \fISDL_BlitSurface\fR 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)\&.

    14 .PP

    15 This function can modify either the logical or physical palette by specifing \fBSDL_LOGPAL\fP or \fBSDL_PHYSPAL\fPthe in the \fBflags\fR parameter\&.

    16 .PP

    17 When \fBsurface\fR is the surface associated with the current display, the display colormap will be updated with the requested colors\&. If \fBSDL_HWPALETTE\fP was set in \fISDL_SetVideoMode\fR flags, \fBSDL_SetPalette\fP will always return \fB1\fR, 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\&.

    18 .PP

    19 The color components of a \fI\fBSDL_Color\fR\fR structure are 8-bits in size, giving you a total of 256^3=16777216 colors\&.

    20 .SH "RETURN VALUE"

    21 .PP

    22 If \fBsurface\fR is not a palettized surface, this function does nothing, returning \fB0\fR\&. If all of the colors were set as passed to \fBSDL_SetPalette\fP, it will return \fB1\fR\&. If not all the color entries were set exactly as given, it will return \fB0\fR, and you should look at the surface palette to determine the actual color palette\&.

    23 .SH "EXAMPLE"

    24 .PP

    25 .nf

    26 \f(CW        /* Create a display surface with a grayscale palette */

    27         SDL_Surface *screen;

    28         SDL_Color colors[256];

    29         int i;

    30         \&.

    31         \&.

    32         \&.

    33         /* Fill colors with color information */

    34         for(i=0;i<256;i++){

    35           colors[i]\&.r=i;

    36           colors[i]\&.g=i;

    37           colors[i]\&.b=i;

    38         }

    39 

    40         /* Create display */

    41         screen=SDL_SetVideoMode(640, 480, 8, SDL_HWPALETTE);

    42         if(!screen){

    43           printf("Couldn\&'t set video mode: %s

    44 ", SDL_GetError());

    45           exit(-1);

    46         }

    47 

    48         /* Set palette */

    49         SDL_SetPalette(screen, SDL_LOGPAL|SDL_PHYSPAL, colors, 0, 256);

    50         \&.

    51         \&.

    52         \&.

    53         \&.\fR

    54 .fi

    55 .PP

    56 .SH "SEE ALSO"

    57 .PP

    58 \fISDL_SetColors\fR, \fISDL_SetVideoMode\fR, \fISDL_Surface\fR, \fISDL_Color\fR

    59 ...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:01