1 <HTML 2 ><HEAD 3 ><TITLE 4 >SDL_SetGamma</TITLE 5 ><META 6 NAME="GENERATOR" 7 CONTENT="Modular DocBook HTML Stylesheet Version 1.76b+ 8 "><LINK 9 REL="HOME" 10 TITLE="SDL Library Documentation" 11 HREF="index.html"><LINK 12 REL="UP" 13 TITLE="Video" 14 HREF="video.html"><LINK 15 REL="PREVIOUS" 16 TITLE="SDL_SetPalette" 17 HREF="sdlsetpalette.html"><LINK 18 REL="NEXT" 19 TITLE="SDL_GetGammaRamp" 20 HREF="sdlgetgammaramp.html"></HEAD 21 ><BODY 22 CLASS="REFENTRY" 23 BGCOLOR="#FFF8DC" 24 TEXT="#000000" 25 LINK="#0000ee" 26 VLINK="#551a8b" 27 ALINK="#ff0000" 28 ><DIV 29 CLASS="NAVHEADER" 30 ><TABLE 31 SUMMARY="Header navigation table" 32 WIDTH="100%" 33 BORDER="0" 34 CELLPADDING="0" 35 CELLSPACING="0" 36 ><TR 37 ><TH 38 COLSPAN="3" 39 ALIGN="center" 40 >SDL Library Documentation</TH 41 ></TR 42 ><TR 43 ><TD 44 WIDTH="10%" 45 ALIGN="left" 46 VALIGN="bottom" 47 ><A 48 HREF="sdlsetpalette.html" 49 ACCESSKEY="P" 50 >Prev</A 51 ></TD 52 ><TD 53 WIDTH="80%" 54 ALIGN="center" 55 VALIGN="bottom" 56 ></TD 57 ><TD 58 WIDTH="10%" 59 ALIGN="right" 60 VALIGN="bottom" 61 ><A 62 HREF="sdlgetgammaramp.html" 63 ACCESSKEY="N" 64 >Next</A 65 ></TD 66 ></TR 67 ></TABLE 68 ><HR 69 ALIGN="LEFT" 70 WIDTH="100%"></DIV 71 ><H1 72 ><A 73 NAME="SDLSETGAMMA" 74 ></A 75 >SDL_SetGamma</H1 76 ><DIV 77 CLASS="REFNAMEDIV" 78 ><A 79 NAME="AEN1569" 80 ></A 81 ><H2 82 >Name</H2 83 >SDL_SetGamma -- Sets the color gamma function for the display</DIV 84 ><DIV 85 CLASS="REFSYNOPSISDIV" 86 ><A 87 NAME="AEN1572" 88 ></A 89 ><H2 90 >Synopsis</H2 91 ><DIV 92 CLASS="FUNCSYNOPSIS" 93 ><A 94 NAME="AEN1573" 95 ></A 96 ><P 97 ></P 98 ><PRE 99 CLASS="FUNCSYNOPSISINFO" 100 >#include "SDL.h"</PRE 101 ><P 102 ><CODE 103 ><CODE 104 CLASS="FUNCDEF" 105 >int <B 106 CLASS="FSFUNC" 107 >SDL_SetGamma</B 108 ></CODE 109 >(float redgamma, float greengamma, float bluegamma);</CODE 110 ></P 111 ><P 112 ></P 113 ></DIV 114 ></DIV 115 ><DIV 116 CLASS="REFSECT1" 117 ><A 118 NAME="AEN1579" 119 ></A 120 ><H2 121 >Description</H2 122 ><P 123 >Sets the "gamma function" for the display of each color component. Gamma 124 controls the brightness/contrast of colors displayed on the screen. 125 A gamma value of <TT 126 CLASS="CONSTANT" 127 >1.0</TT 128 > is identity (i.e., no adjustment 129 is made).</P 130 ><P 131 >This function adjusts the gamma based on the "gamma function" parameter, 132 you can directly specify lookup tables for gamma adjustment with 133 <A 134 HREF="sdlsetgammaramp.html" 135 >SDL_SetGammaRamp</A 136 >.</P 137 ><P 138 >Not all display hardware is able to change gamma.</P 139 ></DIV 140 ><DIV 141 CLASS="REFSECT1" 142 ><A 143 NAME="AEN1586" 144 ></A 145 ><H2 146 >Return Value</H2 147 ><P 148 >Returns -1 on error (or if gamma adjustment is not supported).</P 149 ></DIV 150 ><DIV 151 CLASS="REFSECT1" 152 ><A 153 NAME="AEN1589" 154 ></A 155 ><H2 156 >See Also</H2 157 ><P 158 ><A 159 HREF="sdlgetgammaramp.html" 160 >SDL_GetGammaRamp</A 161 > 162 <A 163 HREF="sdlsetgammaramp.html" 164 >SDL_SetGammaRamp</A 165 ></P 166 ></DIV 167 ><DIV 168 CLASS="NAVFOOTER" 169 ><HR 170 ALIGN="LEFT" 171 WIDTH="100%"><TABLE 172 SUMMARY="Footer navigation table" 173 WIDTH="100%" 174 BORDER="0" 175 CELLPADDING="0" 176 CELLSPACING="0" 177 ><TR 178 ><TD 179 WIDTH="33%" 180 ALIGN="left" 181 VALIGN="top" 182 ><A 183 HREF="sdlsetpalette.html" 184 ACCESSKEY="P" 185 >Prev</A 186 ></TD 187 ><TD 188 WIDTH="34%" 189 ALIGN="center" 190 VALIGN="top" 191 ><A 192 HREF="index.html" 193 ACCESSKEY="H" 194 >Home</A 195 ></TD 196 ><TD 197 WIDTH="33%" 198 ALIGN="right" 199 VALIGN="top" 200 ><A 201 HREF="sdlgetgammaramp.html" 202 ACCESSKEY="N" 203 >Next</A 204 ></TD 205 ></TR 206 ><TR 207 ><TD 208 WIDTH="33%" 209 ALIGN="left" 210 VALIGN="top" 211 >SDL_SetPalette</TD 212 ><TD 213 WIDTH="34%" 214 ALIGN="center" 215 VALIGN="top" 216 ><A 217 HREF="video.html" 218 ACCESSKEY="U" 219 >Up</A 220 ></TD 221 ><TD 222 WIDTH="33%" 223 ALIGN="right" 224 VALIGN="top" 225 >SDL_GetGammaRamp</TD 226 ></TR 227 ></TABLE 228 ></DIV 229 ></BODY 230 ></HTML 231 >
