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Date: Thu, 4 Dec 2003 07:48:40 +0200 From: "Mike Gorchak" Subject: SDL/QNX6 new patch Here in attachment my patch for the SDL/QNX6 again :) It contain non-crtitical/cosmetic fixes: 1. Fixed window centering at other than the first consoles. 2. Fixed window centering algorithm in case when window height or width are greater than the desktop resolution. 3. Fixed window positioning on other than the first consoles. 4. Fixed occasional input focus lost when switching to fullscreen. 5. Removed the Photon's default chroma color for the overlays, added RGB(12, 6, 12) color instead (very dark pink). 6. Added more checks to the YUV overlay code (fixed crashes during resolution mode switches). 7. Added support for Enter/Backspace keys in unicode mode (used by Maelstrom and by other games). 8. Fixed window restore/maximize function. It works, finally.
author Sam Lantinga <slouken@libsdl.org>
date Wed, 10 Dec 2003 12:35:56 +0000
parents e5bc29de3f0a
children 355632dca928
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<HTML
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><TITLE
>SDL_LockSurface</TITLE
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><H1
><A
NAME="SDLLOCKSURFACE"
>SDL_LockSurface</A
></H1
><DIV
CLASS="REFNAMEDIV"
><A
NAME="AEN1535"
></A
><H2
>Name</H2
>SDL_LockSurface&nbsp;--&nbsp;Lock a surface for directly access.</DIV
><DIV
CLASS="REFSYNOPSISDIV"
><A
NAME="AEN1538"
></A
><H2
>Synopsis</H2
><DIV
CLASS="FUNCSYNOPSIS"
><A
NAME="AEN1539"
></A
><P
></P
><PRE
CLASS="FUNCSYNOPSISINFO"
>#include "SDL.h"</PRE
><P
><CODE
><CODE
CLASS="FUNCDEF"
>int <B
CLASS="FSFUNC"
>SDL_LockSurface</B
></CODE
>(SDL_Surface *surface);</CODE
></P
><P
></P
></DIV
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN1545"
></A
><H2
>Description</H2
><P
><TT
CLASS="FUNCTION"
>SDL_LockSurface</TT
> sets up a surface for directly 
accessing the pixels.  Between calls to <TT
CLASS="FUNCTION"
>SDL_LockSurface</TT
>
and <TT
CLASS="FUNCTION"
>SDL_UnlockSurface</TT
>, you can write to and read from 
<TT
CLASS="PARAMETER"
><I
>surface-&#62;<TT
CLASS="STRUCTFIELD"
><I
>pixels</I
></TT
></I
></TT
>, using the pixel format stored in
<TT
CLASS="PARAMETER"
><I
>surface-&#62;<TT
CLASS="STRUCTFIELD"
><I
>format</I
></TT
></I
></TT
>.  Once you are done accessing the
surface, you should use <TT
CLASS="FUNCTION"
>SDL_UnlockSurface</TT
> to release it.</P
><P
>Not all surfaces require locking.  
If <TT
CLASS="LITERAL"
>SDL_MUSTLOCK</TT
>(<TT
CLASS="PARAMETER"
><I
>surface</I
></TT
>)
evaluates to <SPAN
CLASS="RETURNVALUE"
>0</SPAN
>, then you can read and write to the 
surface at any time, and the pixel format of the surface will not change. </P
><P
>No operating system or library calls should be made between lock/unlock
pairs, as critical system locks may be held during this time.</P
><P
>It should be noted, that since SDL 1.1.8 surface locks are recursive. This means that you can lock a surface multiple times, but each lock must have a match unlock.
<PRE
CLASS="PROGRAMLISTING"
>    .
    .
    SDL_LockSurface( surface );
    .
    /* Surface is locked */
    /* Direct pixel access on surface here */
    .
    SDL_LockSurface( surface );
    .
    /* More direct pixel access on surface */
    .
    SDL_UnlockSurface( surface );
    /* Surface is still locked */
    /* Note: Is versions &#60; 1.1.8, the surface would have been */
    /* no longer locked at this stage                         */
    .
    SDL_UnlockSurface( surface );
    /* Surface is now unlocked */
    .
    .</PRE
></P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN1563"
></A
><H2
>Return Value</H2
><P
><TT
CLASS="FUNCTION"
>SDL_LockSurface</TT
> returns <SPAN
CLASS="RETURNVALUE"
>0</SPAN
>, 
or <SPAN
CLASS="RETURNVALUE"
>-1</SPAN
> if the surface couldn't be locked.</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN1569"
></A
><H2
>See Also</H2
><P
><A
HREF="sdlunlocksurface.html"
><TT
CLASS="FUNCTION"
>SDL_UnlockSurface</TT
></A
></P
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