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Date: Sat, 8 Sep 2001 04:42:23 +0200 From: Max Horn <max@quendi.de> Subject: SDL/OSX: Joystick; Better key handling I just finished implementing improved keyhandling for OS X (in fact the code should be easily ported to the "normal" MacOS part of SDL, I just had no chance yet). Works like this: First init the mapping table statically like before. Them, it queries the OS for the "official" key table, then iterates over all 127 scancode and gets the associates ascii code. It ignores everythng below 32 (has to, as it would lead to many problems if we did not... e.g. both ESC and NUM LOCk produce an ascii code 27 on my keyboard), and all stuff above 127 is mapped to SDLK_WORLD_* simply in the order it is encountered. In addition, caps lock is now working, too. The code work flawless for me, but since I only have one keyboard, I may have not encountered some serious problem... but I am pretty confident that it is better than the old code in most cases. The joystick driver works fine for me, too. I think it can be added to CVS already. It would simply be helpful if more people would test it. Hm, I wonder if Maelstrom or GLTron has Joystick support? That would be a wonderful test application :) I also took the liberty of modifying some text files like BUGS, README.CVS, README.MacOSX (which now contains the OS X docs I long promised)
author Sam Lantinga <slouken@libsdl.org>
date Tue, 11 Sep 2001 19:00:18 +0000
parents 55f1f1b3e27d
children e5bc29de3f0a
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<HTML
><HEAD
><TITLE
>SDL_SemTryWait</TITLE
><META
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><H1
><A
NAME="SDLSEMTRYWAIT"
>SDL_SemTryWait</A
></H1
><DIV
CLASS="REFNAMEDIV"
><A
NAME="AEN7520"
></A
><H2
>Name</H2
>SDL_SemTryWait&nbsp;--&nbsp;Attempt to lock a semaphore but don't suspend the thread.</DIV
><DIV
CLASS="REFSYNOPSISDIV"
><A
NAME="AEN7523"
></A
><H2
>Synopsis</H2
><DIV
CLASS="FUNCSYNOPSIS"
><A
NAME="AEN7524"
></A
><P
></P
><PRE
CLASS="FUNCSYNOPSISINFO"
>#include "SDL.h"
#include "SDL_thread.h"</PRE
><P
><CODE
><CODE
CLASS="FUNCDEF"
>int <B
CLASS="FSFUNC"
>SDL_SemTryWait</B
></CODE
>(SDL_sem *sem);</CODE
></P
><P
></P
></DIV
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN7530"
></A
><H2
>Description</H2
><P
><TT
CLASS="FUNCTION"
>SDL_SemTryWait</TT
> is a non-blocking varient of
<A
HREF="sdlsemwait.html"
><TT
CLASS="FUNCTION"
>SDL_SemWait</TT
></A
>. If the value of the semaphore
pointed to by <TT
CLASS="PARAMETER"
><I
>sem</I
></TT
> is positive it will atomically
decrement the semaphore value and return 0, otherwise it will return
<SPAN
CLASS="RETURNVALUE"
>SDL_MUTEX_TIMEOUT</SPAN
> instead of suspending the thread.</P
><P
>After <TT
CLASS="FUNCTION"
>SDL_SemTryWait</TT
> is successful, the semaphore
can be released and its count atomically incremented by a successful call to
<A
HREF="sdlsempost.html"
>SDL_SemPost</A
>.</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN7541"
></A
><H2
>Return Value</H2
><P
>Returns <SPAN
CLASS="RETURNVALUE"
>0</SPAN
> if the semaphore was successfully locked or
either <SPAN
CLASS="RETURNVALUE"
>SDL_MUTEX_TIMEOUT</SPAN
> or <SPAN
CLASS="RETURNVALUE"
>-1</SPAN
>
if the thread would have suspended or there was an error, respectivly.</P
><P
>If the semaphore was not successfully locked, the semaphore will be unchanged.</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN7548"
></A
><H2
>Examples</H2
><P
><PRE
CLASS="PROGRAMLISTING"
>res = SDL_SemTryWait(my_sem);

if (res == SDL_MUTEX_TIMEOUT) {
        return TRY_AGAIN;
}
if (res == -1) {
        return WAIT_ERROR;
}

...

SDL_SemPost(my_sem);</PRE
></P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN7552"
></A
><H2
>See Also</H2
><P
><A
HREF="sdlcreatesemaphore.html"
><TT
CLASS="FUNCTION"
>SDL_CreateSemaphore</TT
></A
>,
<A
HREF="sdldestroysemaphore.html"
><TT
CLASS="FUNCTION"
>SDL_DestroySemaphore</TT
></A
>,
<A
HREF="sdlsemwait.html"
><TT
CLASS="FUNCTION"
>SDL_SemWait</TT
></A
>,
<A
HREF="sdlsemwaittimeout.html"
><TT
CLASS="FUNCTION"
>SDL_SemWaitTimeout</TT
></A
>,
<A
HREF="sdlsempost.html"
><TT
CLASS="FUNCTION"
>SDL_SemPost</TT
></A
>,
<A
HREF="sdlsemvalue.html"
><TT
CLASS="FUNCTION"
>SDL_SemValue</TT
></A
></P
></DIV
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>Home</A
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