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Date: Mon, 11 Oct 2004 15:17:27 +0300 (EEST) From: Hannu Savolainen Subject: Re: SDL uses obsolete OSS features I did some work on getting OSS to work better with SDL. There have been some problems with select which should be fixed now. I'm having some problems in understanding what is the purpose of the DSP_WaitAudio() routine. I added a return to the very beginning of this routine and commendted out the define for USE_BLOCKING_WRITES. At least lbreakout2 seems to work as well as earlier. The latencies are the same. An ordinary blocking write does exactly the same thing than DSP_WaitAudio does. So I would recommend using the USE_BLOCKING_WRITES approach and removing everything from the DSP_WaitAudio routine. Also enabling USE_BLOCKING_WRITES makes it possible to simplify DSP_PlayAudio() because you don't need to handle the partial writes (the do-while loop). Attached is a patch against SDL-1.2.7. After these changes SDL will use OSS as it's designed to be used (make it as simple as possible). This code should work with all OSS implementations because it uses only the very fundamental features that have been there since the jurassic times.
author Sam Lantinga <slouken@libsdl.org>
date Fri, 12 Nov 2004 21:39:04 +0000
parents 355632dca928
children
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<HTML
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>SDL_PeepEvents</TITLE
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><H1
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>SDL_PeepEvents</H1
><DIV
CLASS="REFNAMEDIV"
><A
NAME="AEN5421"
></A
><H2
>Name</H2
>SDL_PeepEvents&nbsp;--&nbsp;Checks the event queue for messages and optionally returns them.</DIV
><DIV
CLASS="REFSYNOPSISDIV"
><A
NAME="AEN5424"
></A
><H2
>Synopsis</H2
><DIV
CLASS="FUNCSYNOPSIS"
><A
NAME="AEN5425"
></A
><P
></P
><PRE
CLASS="FUNCSYNOPSISINFO"
>#include "SDL.h"</PRE
><P
><CODE
><CODE
CLASS="FUNCDEF"
>int <B
CLASS="FSFUNC"
>SDL_PeepEvents</B
></CODE
>(SDL_Event *events, int numevents, SDL_eventaction action, Uint32 mask);</CODE
></P
><P
></P
></DIV
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN5431"
></A
><H2
>Description</H2
><P
>Checks the event queue for messages and optionally returns them.</P
><P
>If <TT
CLASS="PARAMETER"
><I
>action</I
></TT
> is <TT
CLASS="LITERAL"
>SDL_ADDEVENT</TT
>, up to 
<TT
CLASS="PARAMETER"
><I
>numevents</I
></TT
> events will be added to the back of the event
 queue.</P
><P
>If <TT
CLASS="PARAMETER"
><I
>action</I
></TT
> is <TT
CLASS="LITERAL"
>SDL_PEEKEVENT</TT
>, up to
<TT
CLASS="PARAMETER"
><I
>numevents</I
></TT
> events at the front of the event queue, 
matching <A
HREF="sdlevent.html"
><TT
CLASS="PARAMETER"
><I
>mask</I
></TT
></A
>, 
will be returned and will not be removed from the queue.</P
><P
>If <TT
CLASS="PARAMETER"
><I
>action</I
></TT
> is <TT
CLASS="LITERAL"
>SDL_GETEVENT</TT
>, up to 
<TT
CLASS="PARAMETER"
><I
>numevents</I
></TT
> events at the front of the event queue, 
matching <A
HREF="sdlevent.html"
><TT
CLASS="PARAMETER"
><I
>mask</I
></TT
></A
>, 
will be returned and will be removed from the queue.</P
><P
>The <TT
CLASS="PARAMETER"
><I
>mask</I
></TT
> parameter is an bitwise OR of
<TT
CLASS="LITERAL"
>SDL_EVENTMASK</TT
>(<TT
CLASS="PARAMETER"
><I
>event_type</I
></TT
>), for all
event types you are interested in.</P
><P
>This function is thread-safe.</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN5455"
></A
><H2
>Return Value</H2
><P
>This function returns the number of events actually stored, or 
<SPAN
CLASS="RETURNVALUE"
>-1</SPAN
> if there was an error.  </P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN5459"
></A
><H2
>See Also</H2
><P
><A
HREF="sdlevent.html"
><SPAN
CLASS="STRUCTNAME"
>SDL_Event</SPAN
></A
>,
<A
HREF="sdlpollevent.html"
><TT
CLASS="FUNCTION"
>SDL_PollEvent</TT
></A
>,
<A
HREF="sdlpushevent.html"
><TT
CLASS="FUNCTION"
>SDL_PushEvent</TT
></A
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