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Date: Sun, 4 Jan 2004 23:48:19 +0100 From: Max Horn Subject: Re: Again Audio CD patch Am 04.01.2004 um 22:38 schrieb Sam Lantinga: > > Okay, I fixed the buffering problems by simply using a 4 second buffer > instead of a 1 second buffer. However, using your code I can't play an > entire CD - the playback stops after the first song. > Found the problem: FSReadFork returns eofErr when the file is finished. However, we check its return value for errors, and if anything but noErr occurs, the reader thread aborts its current iteration. That is bad, because it aborts before it can ever set the flag which tells that the file is over (also, any remaining data which FSRead did return is lost - so you'd not hear about to 4 seconds from the end of the file. Furthermore, the computed data size was 8 bytes to high (I forgot to account for the fact that the size of an (A)IFF chunk always contains the chunk header & size fields, too). This is enough to make it work. However, the end condition is rather fragile, so I tuned some other things to be pessimistic (check for <= 0 instead of == 0, when eofErr is encountered enforce mReadFilePosition == mFileLength). You never know... The attached patch fixes the issue for me.
author Sam Lantinga <slouken@libsdl.org>
date Mon, 05 Jan 2004 00:57:51 +0000
parents 55f1f1b3e27d
children 355632dca928
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<HTML
><HEAD
><TITLE
>Joystick</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="SDL Reference"
HREF="reference.html"><LINK
REL="PREVIOUS"
TITLE="SDL_JoystickEventState"
HREF="sdljoystickeventstate.html"><LINK
REL="NEXT"
TITLE="SDL_NumJoysticks"
HREF="sdlnumjoysticks.html"><META
NAME="KEYWORD"
CONTENT="joystick"><META
NAME="KEYWORD"
CONTENT="function"></HEAD
><BODY
CLASS="CHAPTER"
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="sdljoystickeventstate.html"
>Prev</A
></TD
><TD
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><A
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>Next</A
></TD
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><HR
ALIGN="LEFT"
WIDTH="100%"></DIV
><DIV
CLASS="CHAPTER"
><H1
><A
NAME="JOYSTICK"
>Chapter 9. Joystick</A
></H1
><DIV
CLASS="TOC"
><DL
><DT
><B
>Table of Contents</B
></DT
><DT
><A
HREF="sdlnumjoysticks.html"
>SDL_NumJoysticks</A
> &#8212; Count available joysticks.</DT
><DT
><A
HREF="sdljoystickname.html"
>SDL_JoystickName</A
> &#8212; Get joystick name.</DT
><DT
><A
HREF="sdljoystickopen.html"
>SDL_JoystickOpen</A
> &#8212; Opens a joystick for use.</DT
><DT
><A
HREF="sdljoystickopened.html"
>SDL_JoystickOpened</A
> &#8212; Determine if a joystick has been opened</DT
><DT
><A
HREF="sdljoystickindex.html"
>SDL_JoystickIndex</A
> &#8212; Get the index of an SDL_Joystick.</DT
><DT
><A
HREF="sdljoysticknumaxes.html"
>SDL_JoystickNumAxes</A
> &#8212; Get the number of joystick axes</DT
><DT
><A
HREF="sdljoysticknumballs.html"
>SDL_JoystickNumBalls</A
> &#8212; Get the number of joystick trackballs</DT
><DT
><A
HREF="sdljoysticknumhats.html"
>SDL_JoystickNumHats</A
> &#8212; Get the number of joystick hats</DT
><DT
><A
HREF="sdljoysticknumbuttons.html"
>SDL_JoystickNumButtons</A
> &#8212; Get the number of joysitck buttons</DT
><DT
><A
HREF="sdljoystickupdate.html"
>SDL_JoystickUpdate</A
> &#8212; Updates the state of all joysticks</DT
><DT
><A
HREF="sdljoystickgetaxis.html"
>SDL_JoystickGetAxis</A
> &#8212; Get the current state of an axis</DT
><DT
><A
HREF="sdljoystickgethat.html"
>SDL_JoystickGetHat</A
> &#8212; Get the current state of a joystick hat</DT
><DT
><A
HREF="sdljoystickgetbutton.html"
>SDL_JoystickGetButton</A
> &#8212; Get the current state of a given button on a given joystick</DT
><DT
><A
HREF="sdljoystickgetball.html"
>SDL_JoystickGetBall</A
> &#8212; Get relative trackball motion</DT
><DT
><A
HREF="sdljoystickclose.html"
>SDL_JoystickClose</A
> &#8212; Closes a previously opened joystick</DT
></DL
></DIV
><P
>Joysticks, and other similar input devices, have a very strong role in game playing and SDL provides comprehensive support for them. Axes, Buttons, POV Hats and trackballs are all supported.</P
><P
>Joystick support is initialized by passed the <TT
CLASS="LITERAL"
>SDL_INIT_JOYSTICK</TT
> flag to <A
HREF="sdlinit.html"
><TT
CLASS="FUNCTION"
>SDL_Init</TT
></A
>. Once initilized joysticks must be opened using <A
HREF="sdljoystickopen.html"
><TT
CLASS="FUNCTION"
>SDL_JoystickOpen</TT
></A
>.</P
><P
>While using the functions describe in this secton may seem like the best way to access and read from joysticks, in most cases they aren't. Ideally joysticks should be read using the <A
HREF="event.html"
>event</A
> system. To enable this, you must set the joystick event processing state with <A
HREF="sdljoystickeventstate.html"
><TT
CLASS="FUNCTION"
>SDL_JoystickEventState</TT
></A
>. Joysticks must be <A
HREF="sdljoystickopen.html"
>opened</A
> before they can be used of course.</P
><DIV
CLASS="NOTE"
><BLOCKQUOTE
CLASS="NOTE"
><P
><B
>Note: </B
>If you are <I
CLASS="EMPHASIS"
>not</I
> handling the joystick via the event queue then you must explicitly request a joystick update by calling <A
HREF="sdljoystickupdate.html"
><TT
CLASS="FUNCTION"
>SDL_JoystickUpdate</TT
></A
>.</P
></BLOCKQUOTE
></DIV
><DIV
CLASS="NOTE"
><BLOCKQUOTE
CLASS="NOTE"
><P
><B
>Note: </B
>Force Feedback is not yet support. Sam (slouken@libsdl.org) is soliciting suggestions from people with force-feedback experience on the best wat to desgin the API.</P
></BLOCKQUOTE
></DIV
></DIV
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>Prev</A
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>