Mercurial > sdl-ios-xcode
view docs/html/sdlsetpalette.html @ 1552:b2462b772cce
Fixed bug #79
Implemented snd_pcm_sw_params_set_start_threshold() and snd_pcm_sw_params_set_avail_min() in the ALSA 0.9 driver.
This doesn't actually change any latency for me, but it's the right thing to do...
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Sun, 19 Mar 2006 10:41:49 +0000 (2006-03-19) |
parents | 355632dca928 |
children |
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<HTML ><HEAD ><TITLE >SDL_SetPalette</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.76b+ "><LINK REL="HOME" TITLE="SDL Library Documentation" HREF="index.html"><LINK REL="UP" TITLE="Video" HREF="video.html"><LINK REL="PREVIOUS" TITLE="SDL_SetColors" HREF="sdlsetcolors.html"><LINK REL="NEXT" TITLE="SDL_SetGamma" HREF="sdlsetgamma.html"></HEAD ><BODY CLASS="REFENTRY" BGCOLOR="#FFF8DC" TEXT="#000000" LINK="#0000ee" VLINK="#551a8b" ALINK="#ff0000" ><DIV CLASS="NAVHEADER" ><TABLE SUMMARY="Header navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TH COLSPAN="3" ALIGN="center" >SDL Library Documentation</TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="bottom" ><A HREF="sdlsetcolors.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="sdlsetgamma.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><H1 ><A NAME="SDLSETPALETTE" ></A >SDL_SetPalette</H1 ><DIV CLASS="REFNAMEDIV" ><A NAME="AEN1517" ></A ><H2 >Name</H2 >SDL_SetPalette -- Sets the colors in the palette of an 8-bit surface.</DIV ><DIV CLASS="REFSYNOPSISDIV" ><A NAME="AEN1520" ></A ><H2 >Synopsis</H2 ><DIV CLASS="FUNCSYNOPSIS" ><A NAME="AEN1521" ></A ><P ></P ><PRE CLASS="FUNCSYNOPSISINFO" >#include "SDL.h"</PRE ><P ><CODE ><CODE CLASS="FUNCDEF" >int <B CLASS="FSFUNC" >SDL_SetPalette</B ></CODE >(SDL_Surface *surface, int flags, SDL_Color *colors, int firstcolor, int ncolors);</CODE ></P ><P ></P ></DIV ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN1527" ></A ><H2 >Description</H2 ><P >Sets a portion of the palette for the given 8-bit surface.</P ><P >Palettized (8-bit) screen surfaces with the <TT CLASS="LITERAL" >SDL_HWPALETTE</TT > 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). <A HREF="sdlblitsurface.html" >SDL_BlitSurface</A > 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).</P ><P >This function can modify either the logical or physical palette by specifing <TT CLASS="LITERAL" >SDL_LOGPAL</TT > or <TT CLASS="LITERAL" >SDL_PHYSPAL</TT >the in the <TT CLASS="PARAMETER" ><I >flags</I ></TT > parameter.</P ><P >When <TT CLASS="PARAMETER" ><I >surface</I ></TT > is the surface associated with the current display, the display colormap will be updated with the requested colors. If <TT CLASS="LITERAL" >SDL_HWPALETTE</TT > was set in <A HREF="sdlsetvideomode.html" >SDL_SetVideoMode</A > flags, <TT CLASS="FUNCTION" >SDL_SetPalette</TT > will always return <SPAN CLASS="RETURNVALUE" >1</SPAN >, 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.</P ><P >The color components of a <A HREF="sdlcolor.html" ><SPAN CLASS="STRUCTNAME" >SDL_Color</SPAN ></A > structure are 8-bits in size, giving you a total of 256<SUP >3</SUP >=16777216 colors.</P ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN1547" ></A ><H2 >Return Value</H2 ><P >If <TT CLASS="PARAMETER" ><I >surface</I ></TT > is not a palettized surface, this function does nothing, returning <SPAN CLASS="RETURNVALUE" >0</SPAN >. If all of the colors were set as passed to <TT CLASS="FUNCTION" >SDL_SetPalette</TT >, it will return <SPAN CLASS="RETURNVALUE" >1</SPAN >. If not all the color entries were set exactly as given, it will return <SPAN CLASS="RETURNVALUE" >0</SPAN >, and you should look at the surface palette to determine the actual color palette.</P ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN1555" ></A ><H2 >Example</H2 ><PRE CLASS="PROGRAMLISTING" > /* 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\n", SDL_GetError()); exit(-1); } /* Set palette */ SDL_SetPalette(screen, SDL_LOGPAL|SDL_PHYSPAL, colors, 0, 256); . . . .</PRE ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN1558" ></A ><H2 >See Also</H2 ><P ><A HREF="sdlsetcolors.html" >SDL_SetColors</A >, <A HREF="sdlsetvideomode.html" >SDL_SetVideoMode</A >, <A HREF="sdlsurface.html" >SDL_Surface</A >, <A HREF="sdlcolor.html" >SDL_Color</A ></P ></DIV ><DIV CLASS="NAVFOOTER" ><HR ALIGN="LEFT" WIDTH="100%"><TABLE SUMMARY="Footer navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><A HREF="sdlsetcolors.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" ACCESSKEY="H" >Home</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="sdlsetgamma.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >SDL_SetColors</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="video.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >SDL_SetGamma</TD ></TR ></TABLE ></DIV ></BODY ></HTML >