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view docs/html/sdlglsetattribute.html @ 4355:9b464226e541 SDL-1.2

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Fixed bug #855 Ludwig Nussel 2009-10-18 06:31:52 PDT an mprotect call was added to fix bug 528. However that results in a buffer that allows writing and code execution. Ie the no-execute security features of modern operating systems are defeated this way. Two mprotect calls are needed. One to make the buffer executable but not writeable when done and another one to make the buffer writeable again if the content needs to be changed.
author Sam Lantinga <slouken@libsdl.org>
date Sun, 18 Oct 2009 17:31:37 +0000
parents 355632dca928
children
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>SDL_GL_SetAttribute</TITLE
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><H1
><A
NAME="SDLGLSETATTRIBUTE"
></A
>SDL_GL_SetAttribute</H1
><DIV
CLASS="REFNAMEDIV"
><A
NAME="AEN2742"
></A
><H2
>Name</H2
>SDL_GL_SetAttribute&nbsp;--&nbsp;Set a special SDL/OpenGL attribute</DIV
><DIV
CLASS="REFSYNOPSISDIV"
><A
NAME="AEN2745"
></A
><H2
>Synopsis</H2
><DIV
CLASS="FUNCSYNOPSIS"
><A
NAME="AEN2746"
></A
><P
></P
><PRE
CLASS="FUNCSYNOPSISINFO"
>#include "SDL.h"</PRE
><P
><CODE
><CODE
CLASS="FUNCDEF"
>int <B
CLASS="FSFUNC"
>SDL_GL_SetAttribute</B
></CODE
>(SDL_GLattr attr, int value);</CODE
></P
><P
></P
></DIV
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN2752"
></A
><H2
>Description</H2
><P
>Sets the OpenGL <A
HREF="sdlglattr.html"
>attribute</A
> <TT
CLASS="PARAMETER"
><I
>attr</I
></TT
> to <TT
CLASS="PARAMETER"
><I
>value</I
></TT
>. The attributes you set don't take effect until after a call to <A
HREF="sdlsetvideomode.html"
><TT
CLASS="FUNCTION"
>SDL_SetVideoMode</TT
></A
>. You should use <A
HREF="sdlglgetattribute.html"
><TT
CLASS="FUNCTION"
>SDL_GL_GetAttribute</TT
></A
> to check the values after a <TT
CLASS="FUNCTION"
>SDL_SetVideoMode</TT
> call.</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN2763"
></A
><H2
>Return Value</H2
><P
>Returns <SPAN
CLASS="RETURNVALUE"
>0</SPAN
> on success, or <SPAN
CLASS="RETURNVALUE"
>-1</SPAN
> on error.</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN2768"
></A
><H2
>Example</H2
><PRE
CLASS="PROGRAMLISTING"
>SDL_GL_SetAttribute( SDL_GL_RED_SIZE, 5 );
SDL_GL_SetAttribute( SDL_GL_GREEN_SIZE, 5 );
SDL_GL_SetAttribute( SDL_GL_BLUE_SIZE, 5 );
SDL_GL_SetAttribute( SDL_GL_DEPTH_SIZE, 16 );
SDL_GL_SetAttribute( SDL_GL_DOUBLEBUFFER, 1 );
if ( (screen=SDL_SetVideoMode( 640, 480, 16, SDL_OPENGL )) == NULL ) {
  fprintf(stderr, "Couldn't set GL mode: %s\n", SDL_GetError());
  SDL_Quit();
  return;
}</PRE
><DIV
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><BLOCKQUOTE
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><P
><B
>Note: </B
>The <TT
CLASS="LITERAL"
>SDL_DOUBLEBUF</TT
> 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
></BLOCKQUOTE
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><H2
>See Also</H2
><P
><A
HREF="sdlglgetattribute.html"
><TT
CLASS="FUNCTION"
>SDL_GL_GetAttribute</TT
></A
>,
<A
HREF="sdlglattr.html"
>GL Attributes</A
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