Mercurial > sdl-ios-xcode
view docs/html/time.html @ 2866:e532417a6977
Fixed SDL 1.2 compatibility problem.
The API specifies that SDL_OpenAudio() will fill out the 'desired' audio spec
with the correct samples and size set by the driver. This value is important
since it may be used by applications that size audio buffers, etc.
However, we want to allow advanced applications to call SDL_OpenAudioDevice()
which gets passed a const 'desired' parameter, and have the correct data filled
into the 'obtained' parameter, possibly allowing or not allowing format changes.
So... 'obtained' becomes the audio format the user callback is expected to use,
and we add flags to allow the application to specify which format changes are
allowed.
Note: We really need to add a way to query the 'obtained' audio spec.
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Sat, 13 Dec 2008 06:36:47 +0000 |
parents | 355632dca928 |
children |
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<HTML ><HEAD ><TITLE >Time</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="SDL Reference" HREF="reference.html"><LINK REL="PREVIOUS" TITLE="SDL_CondWaitTimeout" HREF="sdlcondwaittimeout.html"><LINK REL="NEXT" TITLE="SDL_GetTicks" HREF="sdlgetticks.html"><META NAME="KEYWORD" CONTENT="time"><META NAME="KEYWORD" CONTENT="function"></HEAD ><BODY CLASS="CHAPTER" 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="sdlcondwaittimeout.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="sdlgetticks.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><DIV CLASS="CHAPTER" ><H1 ><A NAME="TIME" ></A >Chapter 13. Time</H1 ><DIV CLASS="TOC" ><DL ><DT ><B >Table of Contents</B ></DT ><DT ><A HREF="sdlgetticks.html" >SDL_GetTicks</A > -- Get the number of milliseconds since the SDL library initialization.</DT ><DT ><A HREF="sdldelay.html" >SDL_Delay</A > -- Wait a specified number of milliseconds before returning.</DT ><DT ><A HREF="sdladdtimer.html" >SDL_AddTimer</A > -- Add a timer which will call a callback after the specified number of milliseconds has elapsed.</DT ><DT ><A HREF="sdlremovetimer.html" >SDL_RemoveTimer</A > -- Remove a timer which was added with <A HREF="sdladdtimer.html" >SDL_AddTimer</A >.</DT ><DT ><A HREF="sdlsettimer.html" >SDL_SetTimer</A > -- 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 ></LI ></UL > </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="sdlcondwaittimeout.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="sdlgetticks.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >SDL_CondWaitTimeout</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="reference.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >SDL_GetTicks</TD ></TR ></TABLE ></DIV ></BODY ></HTML >