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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><H1
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>SDL_VideoModeOK</H1
><DIV
CLASS="REFNAMEDIV"
><A
NAME="AEN1202"
></A
><H2
>Name</H2
>SDL_VideoModeOK&nbsp;--&nbsp;Check to see if a particular video mode is supported.</DIV
><DIV
CLASS="REFSYNOPSISDIV"
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><H2
>Synopsis</H2
><DIV
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><P
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><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
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><A
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></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
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><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
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