Mercurial > sdl-ios-xcode
view docs/html/sdlvideomodeok.html @ 4355:9b464226e541 SDL-1.2
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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<HTML ><HEAD ><TITLE >SDL_VideoModeOK</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_ListModes" HREF="sdllistmodes.html"><LINK REL="NEXT" TITLE="SDL_SetVideoMode" HREF="sdlsetvideomode.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="sdllistmodes.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="sdlsetvideomode.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><H1 ><A NAME="SDLVIDEOMODEOK" ></A >SDL_VideoModeOK</H1 ><DIV CLASS="REFNAMEDIV" ><A NAME="AEN1202" ></A ><H2 >Name</H2 >SDL_VideoModeOK -- Check to see if a particular video mode is supported.</DIV ><DIV CLASS="REFSYNOPSISDIV" ><A NAME="AEN1205" ></A ><H2 >Synopsis</H2 ><DIV CLASS="FUNCSYNOPSIS" ><A NAME="AEN1206" ></A ><P ></P ><PRE CLASS="FUNCSYNOPSISINFO" >#include "SDL.h"</PRE ><P ><CODE ><CODE CLASS="FUNCDEF" >int <B CLASS="FSFUNC" >SDL_VideoModeOK</B ></CODE >(int width, int height, int bpp, Uint32 flags);</CODE ></P ><P ></P ></DIV ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN1212" ></A ><H2 >Description</H2 ><P ><TT CLASS="FUNCTION" >SDL_VideoModeOK</TT > returns <SPAN CLASS="RETURNVALUE" >0</SPAN > if the requested mode is not supported under any bit depth, or returns the bits-per-pixel of the closest available mode with the given width, height and requested <A HREF="sdlsurface.html" >surface</A > flags (see <A HREF="sdlsetvideomode.html" ><TT CLASS="FUNCTION" >SDL_SetVideoMode</TT ></A >).</P ><P >The bits-per-pixel value returned is only a suggested mode. You can usually request and bpp you want when <A HREF="sdlsetvideomode.html" >setting</A > the video mode and SDL will emulate that color depth with a shadow video surface.</P ><P >The arguments to <TT CLASS="FUNCTION" >SDL_VideoModeOK</TT > are the same ones you would pass to <A HREF="sdlsetvideomode.html" >SDL_SetVideoMode</A ></P ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN1225" ></A ><H2 >Example</H2 ><PRE CLASS="PROGRAMLISTING" >SDL_Surface *screen; Uint32 bpp; . . . printf("Checking mode 640x480@16bpp.\n"); bpp=SDL_VideoModeOK(640, 480, 16, SDL_HWSURFACE); if(!bpp){ printf("Mode not available.\n"); exit(-1); } printf("SDL Recommends 640x480@%dbpp.\n", bpp); screen=SDL_SetVideoMode(640, 480, bpp, SDL_HWSURFACE); . .</PRE ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN1228" ></A ><H2 >See Also</H2 ><P ><A HREF="sdlsetvideomode.html" ><TT CLASS="FUNCTION" >SDL_SetVideoMode</TT ></A >, <A HREF="sdlgetvideoinfo.html" ><TT CLASS="FUNCTION" >SDL_GetVideoInfo</TT ></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="sdllistmodes.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="sdlsetvideomode.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >SDL_ListModes</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_SetVideoMode</TD ></TR ></TABLE ></DIV ></BODY ></HTML >