| 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 |