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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
><HEAD
><TITLE
>Time</TITLE
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>Chapter 13. Time</H1
><DIV
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><DL
><DT
><B
>Table of Contents</B
></DT
><DT
><A
HREF="sdlgetticks.html"
>SDL_GetTicks</A
>&nbsp;--&nbsp;Get the number of milliseconds since the SDL library initialization.</DT
><DT
><A
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>SDL_Delay</A
>&nbsp;--&nbsp;Wait a specified number of milliseconds before returning.</DT
><DT
><A
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>SDL_AddTimer</A
>&nbsp;--&nbsp;Add a timer which will call a callback after the specified number of milliseconds has
elapsed.</DT
><DT
><A
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>SDL_RemoveTimer</A
>&nbsp;--&nbsp;Remove a timer which was added with
<A
HREF="sdladdtimer.html"
>SDL_AddTimer</A
>.</DT
><DT
><A
HREF="sdlsettimer.html"
>SDL_SetTimer</A
>&nbsp;--&nbsp;Set a callback to run after the specified number of milliseconds has
elapsed.</DT
></DL
></DIV
><P
>SDL provides several cross-platform functions for dealing with time.
It provides a way to get the current time, a way to wait a little while,
and a simple timer mechanism.  These functions give you two ways of moving an
object every x milliseconds:

<P
></P
><UL
><LI
><P
>Use a timer callback function.  This may have the bad effect that it runs in a seperate thread or uses alarm signals, but it's easier to implement.</P
></LI
><LI
><P
>Or you can get the number of milliseconds passed, and move the object if, for example, 30 ms passed.</P
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>&#13;</P
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