view docs/html/sdlpollevent.html @ 765:4c2ba6161939

Editors Note: The original patch was modified to use SDL_Delay() instead of nanosleep because nanosleep may not be portable to all systems using SDL with the ALSA backend. This may be a moot point with the switch to blocking writes anyway... Date: Sat, 27 Dec 2003 21:47:36 +0100 From: Michel Daenzer To: Debian Bug Tracking System Subject: [SDL] Bug#225252: [PATCH] ALSA fixes Package: libsdl1.2debian-all Version: 1.2.6-2 Severity: normal Tags: patch For SDL 1.2.6, the ALSA backend was changed to call snd_pcm_open() with SND_PCM_NONBLOCK. That's a good idea per se, however, it causes high CPU usage, interrupted sound and stuttering in some games here. Taking a nanosleep whenever snd_pcm_writei() returns -EAGAIN fixes this, but I think it's more efficient to use blocking mode for the actual sound playback. Feedback from the SDL and ALSA lists appreciated. The patch also fixes the default ALSA device to be used.
author Sam Lantinga <slouken@libsdl.org>
date Sun, 04 Jan 2004 15:40:50 +0000
parents e5bc29de3f0a
children 355632dca928
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>Name</H2
>SDL_PollEvent&nbsp;--&nbsp;Polls for currently pending events.</DIV
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><PRE
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>#include "SDL.h"</PRE
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><CODE
><CODE
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>int <B
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>SDL_PollEvent</B
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>(SDL_Event *event);</CODE
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>Description</H2
><P
>Polls for currently pending events, and returns <SPAN
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>1</SPAN
> 
if there are any pending events, or <SPAN
CLASS="RETURNVALUE"
>0</SPAN
> if there 
are none available.  </P
><P
>If <TT
CLASS="PARAMETER"
><I
>event</I
></TT
> is not <TT
CLASS="LITERAL"
>NULL</TT
>, the next 
event is removed from the queue and stored in that area.</P
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>SDL_Event event; /* Event structure */

.
.
.
/* Check for events */
while(SDL_PollEvent(&#38;event)){  /* Loop until there are no events left on the queue */
  switch(event.type){  /* Process the appropiate event type */
    case SDL_KEYDOWN:  /* Handle a KEYDOWN event */         
      printf("Oh! Key press\n");
      break;
    case SDL_MOUSEMOTION:
      .
      .
      .
    default: /* Report an unhandled event */
      printf("I don't know what this event is!\n");
  }
}</PRE
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