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view docs/html/sdllistmodes.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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<HTML ><HEAD ><TITLE >SDL_ListModes</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.64 "><LINK REL="HOME" TITLE="SDL Library Documentation" HREF="index.html"><LINK REL="UP" TITLE="Video" HREF="video.html"><LINK REL="PREVIOUS" TITLE="SDL_VideoDriverName" HREF="sdlvideodrivername.html"><LINK REL="NEXT" TITLE="SDL_VideoModeOK" HREF="sdlvideomodeok.html"></HEAD ><BODY CLASS="REFENTRY" BGCOLOR="#FFF8DC" TEXT="#000000" LINK="#0000ee" VLINK="#551a8b" ALINK="#ff0000" ><DIV CLASS="NAVHEADER" ><TABLE WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TH COLSPAN="3" ALIGN="center" >SDL Library Documentation</TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="bottom" ><A HREF="sdlvideodrivername.html" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="sdlvideomodeok.html" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><H1 ><A NAME="SDLLISTMODES" >SDL_ListModes</A ></H1 ><DIV CLASS="REFNAMEDIV" ><A NAME="AEN776" ></A ><H2 >Name</H2 >SDL_ListModes -- Returns a pointer to an array of available screen dimensions for the given format and video flags</DIV ><DIV CLASS="REFSYNOPSISDIV" ><A NAME="AEN779" ></A ><H2 >Synopsis</H2 ><DIV CLASS="FUNCSYNOPSIS" ><A NAME="AEN780" ></A ><P ></P ><PRE CLASS="FUNCSYNOPSISINFO" >#include "SDL.h"</PRE ><P ><CODE ><CODE CLASS="FUNCDEF" >SDL_Rect **<B CLASS="FSFUNC" >SDL_ListModes</B ></CODE >(SDL_PixelFormat *format, Uint32 flags);</CODE ></P ><P ></P ></DIV ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN786" ></A ><H2 >Description</H2 ><P >Return a pointer to an array of available screen dimensions for the given format and video flags, sorted largest to smallest. Returns <TT CLASS="LITERAL" >NULL</TT > if there are no dimensions available for a particular format, or <SPAN CLASS="RETURNVALUE" >-1</SPAN > if any dimension is okay for the given format.</P ><P >If <TT CLASS="PARAMETER" ><I >format</I ></TT > is <TT CLASS="LITERAL" >NULL</TT >, the mode list will be for the format returned by <A HREF="sdlgetvideoinfo.html" >SDL_GetVideoInfo()</A >-><TT CLASS="STRUCTFIELD" ><I >vfmt</I ></TT >. The <TT CLASS="PARAMETER" ><I >flag</I ></TT > parameter is an OR'd combination of <A HREF="sdlsurface.html" >surface</A > flags. The flags are the same as those used <A HREF="sdlsetvideomode.html" ><TT CLASS="FUNCTION" >SDL_SetVideoMode</TT ></A > and they play a strong role in deciding what modes are valid. For instance, if you pass <TT CLASS="LITERAL" >SDL_HWSURFACE</TT > as a flag only modes that support hardware video surfaces will be returned.</P ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN801" ></A ><H2 >Example</H2 ><PRE CLASS="PROGRAMLISTING" >SDL_Rect **modes; int i; . . . /* Get available fullscreen/hardware modes */ modes=SDL_ListModes(NULL, SDL_FULLSCREEN|SDL_HWSURFACE); /* Check is there are any modes available */ if(modes == (SDL_Rect **)0){ printf("No modes available!\n"); exit(-1); } /* Check if or resolution is restricted */ if(modes == (SDL_Rect **)-1){ printf("All resolutions available.\n"); } else{ /* Print valid modes */ printf("Available Modes\n"); for(i=0;modes[i];++i) printf(" %d x %d\n", modes[i]->w, modes[i]->h); } . .</PRE ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN804" ></A ><H2 >See Also</H2 ><P ><A HREF="sdlsetvideomode.html" ><TT CLASS="FUNCTION" >SDL_SetVideoMode</TT ></A >, <A HREF="sdlgetvideoinfo.html" ><TT CLASS="FUNCTION" >SDL_GetVideoInfo</TT ></A >, <A HREF="sdlrect.html" ><SPAN CLASS="STRUCTNAME" >SDL_Rect</SPAN ></A >, <A HREF="sdlpixelformat.html" ><SPAN CLASS="STRUCTNAME" >SDL_PixelFormat</SPAN ></A ></P ></DIV ><DIV CLASS="NAVFOOTER" ><HR ALIGN="LEFT" WIDTH="100%"><TABLE WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><A HREF="sdlvideodrivername.html" >Prev</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" >Home</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="sdlvideomodeok.html" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >SDL_VideoDriverName</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="video.html" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >SDL_VideoModeOK</TD ></TR ></TABLE ></DIV ></BODY ></HTML >