Mercurial > sdl-ios-xcode
view docs/html/sdlcdstatus.html @ 1157:baf35853ad54
Date: Mon, 10 Oct 2005 13:09:32 +0300
From: Tommi Kyntola <tommi.kyntola@ray.fi>
To: sdl@libsdl.org
Subject: [SDL] [RFC] get_ticks broken on linux
It uses gettimeofday to calculate the timedifference.
Gettimeofday returns current time which is seldom monotonous.
This breaks SDL timer subsystem. (time callbacks and all that
get borked when the time difference ms is suddenly ~ 2^32)
I posted a message about this earlier but got no response.
Some thoughts on this matter would be appreciated.
(Or even an explanation for the lack of interest.)
A patch below would use the posix timers that have been around
since posix 93 and do provide a good source of monotonous time
on linux boxes (and on few others too).
The following patch is also availabe at:
http://www.hut.fi/u/tkyntola/SDL-1.2.9-clockfix.patch
It's against 1.2.9, but I can easily rediffit against
the cvs branch is needed.
cheers,
Tommi Kyntola tommi.kyntola@ray.fi
author | Ryan C. Gordon <icculus@icculus.org> |
---|---|
date | Tue, 11 Oct 2005 18:16:12 +0000 |
parents | 355632dca928 |
children |
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<HTML ><HEAD ><TITLE >SDL_CDStatus</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.76b+ "><LINK REL="HOME" TITLE="SDL Library Documentation" HREF="index.html"><LINK REL="UP" TITLE="CD-ROM" HREF="cdrom.html"><LINK REL="PREVIOUS" TITLE="SDL_CDOpen" HREF="sdlcdopen.html"><LINK REL="NEXT" TITLE="SDL_CDPlay" HREF="sdlcdplay.html"></HEAD ><BODY CLASS="REFENTRY" BGCOLOR="#FFF8DC" TEXT="#000000" LINK="#0000ee" VLINK="#551a8b" ALINK="#ff0000" ><DIV CLASS="NAVHEADER" ><TABLE SUMMARY="Header navigation 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="sdlcdopen.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="sdlcdplay.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><H1 ><A NAME="SDLCDSTATUS" ></A >SDL_CDStatus</H1 ><DIV CLASS="REFNAMEDIV" ><A NAME="AEN7308" ></A ><H2 >Name</H2 >SDL_CDStatus -- Returns the current status of the given drive.</DIV ><DIV CLASS="REFSYNOPSISDIV" ><A NAME="AEN7311" ></A ><H2 >Synopsis</H2 ><DIV CLASS="FUNCSYNOPSIS" ><A NAME="AEN7312" ></A ><P ></P ><PRE CLASS="FUNCSYNOPSISINFO" >#include "SDL.h"</PRE ><P ><CODE ><CODE CLASS="FUNCDEF" >CDstatus <B CLASS="FSFUNC" >SDL_CDStatus</B ></CODE >(SDL_CD *cdrom);</CODE ></P ><PRE CLASS="FUNCSYNOPSISINFO" >/* Given a status, returns true if there's a disk in the drive */ #define CD_INDRIVE(status) ((int)status > 0)</PRE ><P ></P ></DIV ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN7319" ></A ><H2 >Description</H2 ><P >This function returns the current status of the given drive. Status is described like so: <PRE CLASS="PROGRAMLISTING" >typedef enum { CD_TRAYEMPTY, CD_STOPPED, CD_PLAYING, CD_PAUSED, CD_ERROR = -1 } CDstatus;</PRE ></P ><P >If the drive has a CD in it, the table of contents of the CD and current play position of the CD will be stored in the SDL_CD structure.</P ><P >The macro <TT CLASS="LITERAL" >CD_INDRIVE</TT > is provided for convenience, and given a status returns true if there's a disk in the drive.</P ><DIV CLASS="NOTE" ><BLOCKQUOTE CLASS="NOTE" ><P ><B >Note: </B ><TT CLASS="FUNCTION" >SDL_CDStatus</TT > also updates the <A HREF="sdlcd.html" ><SPAN CLASS="STRUCTNAME" >SDL_CD</SPAN ></A > structure passed to it.</P ></BLOCKQUOTE ></DIV ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN7331" ></A ><H2 >Example</H2 ><PRE CLASS="PROGRAMLISTING" >int playTrack(int track) { int playing = 0; if ( CD_INDRIVE(SDL_CDStatus(cdrom)) ) { /* clamp to the actual number of tracks on the CD */ if (track >= cdrom->numtracks) { track = cdrom->numtracks-1; } if ( SDL_CDPlayTracks(cdrom, track, 0, 1, 0) == 0 ) { playing = 1; } } return playing; }</PRE ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN7334" ></A ><H2 >See Also</H2 ><P ><A HREF="sdlcd.html" ><TT CLASS="FUNCTION" >SDL_CD</TT ></A ></P ></DIV ><DIV CLASS="NAVFOOTER" ><HR ALIGN="LEFT" WIDTH="100%"><TABLE SUMMARY="Footer navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><A HREF="sdlcdopen.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" ACCESSKEY="H" >Home</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="sdlcdplay.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >SDL_CDOpen</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="cdrom.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >SDL_CDPlay</TD ></TR ></TABLE ></DIV ></BODY ></HTML >