1<HTML 2><HEAD 3><TITLE 4>SDL_GL_SetAttribute</TITLE 5><META 6NAME="GENERATOR" 7CONTENT="Modular DocBook HTML Stylesheet Version 1.76b+ 8"><LINK 9REL="HOME" 10TITLE="SDL Library Documentation" 11HREF="index.html"><LINK 12REL="UP" 13TITLE="Video" 14HREF="video.html"><LINK 15REL="PREVIOUS" 16TITLE="SDL_GL_GetAttribute" 17HREF="sdlglgetattribute.html"><LINK 18REL="NEXT" 19TITLE="SDL_GL_SwapBuffers" 20HREF="sdlglswapbuffers.html"></HEAD 21><BODY 22CLASS="REFENTRY" 23BGCOLOR="#FFF8DC" 24TEXT="#000000" 25LINK="#0000ee" 26VLINK="#551a8b" 27ALINK="#ff0000" 28><DIV 29CLASS="NAVHEADER" 30><TABLE 31SUMMARY="Header navigation table" 32WIDTH="100%" 33BORDER="0" 34CELLPADDING="0" 35CELLSPACING="0" 36><TR 37><TH 38COLSPAN="3" 39ALIGN="center" 40>SDL Library Documentation</TH 41></TR 42><TR 43><TD 44WIDTH="10%" 45ALIGN="left" 46VALIGN="bottom" 47><A 48HREF="sdlglgetattribute.html" 49ACCESSKEY="P" 50>Prev</A 51></TD 52><TD 53WIDTH="80%" 54ALIGN="center" 55VALIGN="bottom" 56></TD 57><TD 58WIDTH="10%" 59ALIGN="right" 60VALIGN="bottom" 61><A 62HREF="sdlglswapbuffers.html" 63ACCESSKEY="N" 64>Next</A 65></TD 66></TR 67></TABLE 68><HR 69ALIGN="LEFT" 70WIDTH="100%"></DIV 71><H1 72><A 73NAME="SDLGLSETATTRIBUTE" 74></A 75>SDL_GL_SetAttribute</H1 76><DIV 77CLASS="REFNAMEDIV" 78><A 79NAME="AEN2742" 80></A 81><H2 82>Name</H2 83>SDL_GL_SetAttribute -- Set a special SDL/OpenGL attribute</DIV 84><DIV 85CLASS="REFSYNOPSISDIV" 86><A 87NAME="AEN2745" 88></A 89><H2 90>Synopsis</H2 91><DIV 92CLASS="FUNCSYNOPSIS" 93><A 94NAME="AEN2746" 95></A 96><P 97></P 98><PRE 99CLASS="FUNCSYNOPSISINFO" 100>#include "SDL.h"</PRE 101><P 102><CODE 103><CODE 104CLASS="FUNCDEF" 105>int <B 106CLASS="FSFUNC" 107>SDL_GL_SetAttribute</B 108></CODE 109>(SDL_GLattr attr, int value);</CODE 110></P 111><P 112></P 113></DIV 114></DIV 115><DIV 116CLASS="REFSECT1" 117><A 118NAME="AEN2752" 119></A 120><H2 121>Description</H2 122><P 123>Sets the OpenGL <A 124HREF="sdlglattr.html" 125>attribute</A 126> <TT 127CLASS="PARAMETER" 128><I 129>attr</I 130></TT 131> to <TT 132CLASS="PARAMETER" 133><I 134>value</I 135></TT 136>. The attributes you set don't take effect until after a call to <A 137HREF="sdlsetvideomode.html" 138><TT 139CLASS="FUNCTION" 140>SDL_SetVideoMode</TT 141></A 142>. You should use <A 143HREF="sdlglgetattribute.html" 144><TT 145CLASS="FUNCTION" 146>SDL_GL_GetAttribute</TT 147></A 148> to check the values after a <TT 149CLASS="FUNCTION" 150>SDL_SetVideoMode</TT 151> call.</P 152></DIV 153><DIV 154CLASS="REFSECT1" 155><A 156NAME="AEN2763" 157></A 158><H2 159>Return Value</H2 160><P 161>Returns <SPAN 162CLASS="RETURNVALUE" 163>0</SPAN 164> on success, or <SPAN 165CLASS="RETURNVALUE" 166>-1</SPAN 167> on error.</P 168></DIV 169><DIV 170CLASS="REFSECT1" 171><A 172NAME="AEN2768" 173></A 174><H2 175>Example</H2 176><PRE 177CLASS="PROGRAMLISTING" 178>SDL_GL_SetAttribute( SDL_GL_RED_SIZE, 5 ); 179SDL_GL_SetAttribute( SDL_GL_GREEN_SIZE, 5 ); 180SDL_GL_SetAttribute( SDL_GL_BLUE_SIZE, 5 ); 181SDL_GL_SetAttribute( SDL_GL_DEPTH_SIZE, 16 ); 182SDL_GL_SetAttribute( SDL_GL_DOUBLEBUFFER, 1 ); 183if ( (screen=SDL_SetVideoMode( 640, 480, 16, SDL_OPENGL )) == NULL ) { 184 fprintf(stderr, "Couldn't set GL mode: %s\n", SDL_GetError()); 185 SDL_Quit(); 186 return; 187}</PRE 188><DIV 189CLASS="NOTE" 190><BLOCKQUOTE 191CLASS="NOTE" 192><P 193><B 194>Note: </B 195>The <TT 196CLASS="LITERAL" 197>SDL_DOUBLEBUF</TT 198> flag is not required to enable double buffering when setting an OpenGL video mode. Double buffering is enabled or disabled using the SDL_GL_DOUBLEBUFFER attribute.</P 199></BLOCKQUOTE 200></DIV 201></DIV 202><DIV 203CLASS="REFSECT1" 204><A 205NAME="AEN2774" 206></A 207><H2 208>See Also</H2 209><P 210><A 211HREF="sdlglgetattribute.html" 212><TT 213CLASS="FUNCTION" 214>SDL_GL_GetAttribute</TT 215></A 216>, 217<A 218HREF="sdlglattr.html" 219>GL Attributes</A 220></P 221></DIV 222><DIV 223CLASS="NAVFOOTER" 224><HR 225ALIGN="LEFT" 226WIDTH="100%"><TABLE 227SUMMARY="Footer navigation table" 228WIDTH="100%" 229BORDER="0" 230CELLPADDING="0" 231CELLSPACING="0" 232><TR 233><TD 234WIDTH="33%" 235ALIGN="left" 236VALIGN="top" 237><A 238HREF="sdlglgetattribute.html" 239ACCESSKEY="P" 240>Prev</A 241></TD 242><TD 243WIDTH="34%" 244ALIGN="center" 245VALIGN="top" 246><A 247HREF="index.html" 248ACCESSKEY="H" 249>Home</A 250></TD 251><TD 252WIDTH="33%" 253ALIGN="right" 254VALIGN="top" 255><A 256HREF="sdlglswapbuffers.html" 257ACCESSKEY="N" 258>Next</A 259></TD 260></TR 261><TR 262><TD 263WIDTH="33%" 264ALIGN="left" 265VALIGN="top" 266>SDL_GL_GetAttribute</TD 267><TD 268WIDTH="34%" 269ALIGN="center" 270VALIGN="top" 271><A 272HREF="video.html" 273ACCESSKEY="U" 274>Up</A 275></TD 276><TD 277WIDTH="33%" 278ALIGN="right" 279VALIGN="top" 280>SDL_GL_SwapBuffers</TD 281></TR 282></TABLE 283></DIV 284></BODY 285></HTML 286>