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view docs/html/sdlactiveevent.html @ 968:4675910b0b7b
Date: Mon, 11 Oct 2004 15:17:27 +0300 (EEST)
From: Hannu Savolainen
Subject: Re: SDL uses obsolete OSS features
I did some work on getting OSS to work better with SDL. There have been
some problems with select which should be fixed now.
I'm having some problems in understanding what is the purpose of the
DSP_WaitAudio() routine. I added a return to the very beginning of this
routine and commendted out the define for USE_BLOCKING_WRITES. At least
lbreakout2 seems to work as well as earlier. The latencies are the same.
An ordinary blocking write does exactly the same thing than DSP_WaitAudio
does. So I would recommend using the USE_BLOCKING_WRITES approach and
removing everything from the DSP_WaitAudio routine. Also enabling
USE_BLOCKING_WRITES makes it possible to simplify DSP_PlayAudio() because
you don't need to handle the partial writes (the do-while loop).
Attached is a patch against SDL-1.2.7. After these changes SDL will use
OSS as it's designed to be used (make it as simple as possible). This code
should work with all OSS implementations because it uses only the very
fundamental features that have been there since the jurassic times.
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Fri, 12 Nov 2004 21:39:04 +0000 |
parents | 355632dca928 |
children |
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<HTML ><HEAD ><TITLE >SDL_ActiveEvent</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 Event Structures." HREF="eventstructures.html"><LINK REL="PREVIOUS" TITLE="SDL_Event" HREF="sdlevent.html"><LINK REL="NEXT" TITLE="SDL_KeyboardEvent" HREF="sdlkeyboardevent.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="sdlevent.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="sdlkeyboardevent.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><H1 ><A NAME="SDLACTIVEEVENT" ></A >SDL_ActiveEvent</H1 ><DIV CLASS="REFNAMEDIV" ><A NAME="AEN3955" ></A ><H2 >Name</H2 >SDL_ActiveEvent -- Application visibility event structure</DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN3958" ></A ><H2 >Structure Definition</H2 ><PRE CLASS="PROGRAMLISTING" >typedef struct{ Uint8 type; Uint8 gain; Uint8 state; } SDL_ActiveEvent;</PRE ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN3961" ></A ><H2 >Structure Data</H2 ><DIV CLASS="INFORMALTABLE" ><A NAME="AEN3963" ></A ><P ></P ><TABLE BORDER="0" CLASS="CALSTABLE" ><TBODY ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="STRUCTFIELD" ><I >type</I ></TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="LITERAL" >SDL_ACTIVEEVENT.</TT ></TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="STRUCTFIELD" ><I >gain</I ></TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >0 if the event is a loss or 1 if it is a gain.</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="STRUCTFIELD" ><I >state</I ></TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="LITERAL" >SDL_APPMOUSEFOCUS</TT > if mouse focus was gained or lost, <TT CLASS="LITERAL" >SDL_APPINPUTFOCUS</TT > if input focus was gained or lost, or <TT CLASS="LITERAL" >SDL_APPACTIVE</TT > if the application was iconified (<TT CLASS="STRUCTFIELD" ><I >gain</I ></TT >=0) or restored(<TT CLASS="STRUCTFIELD" ><I >gain</I ></TT >=1).</TD ></TR ></TBODY ></TABLE ><P ></P ></DIV ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN3984" ></A ><H2 >Description</H2 ><P ><SPAN CLASS="STRUCTNAME" >SDL_ActiveEvent</SPAN > is a member of the <A HREF="sdlevent.html" ><SPAN CLASS="STRUCTNAME" >SDL_Event</SPAN ></A > union and is used when an event of type <TT CLASS="LITERAL" >SDL_ACTIVEEVENT</TT > is reported.</P ><P >When the mouse leaves or enters the window area a <TT CLASS="LITERAL" >SDL_APPMOUSEFOCUS</TT > type activation event occurs, if the mouse entered the window then <TT CLASS="STRUCTFIELD" ><I >gain</I ></TT > will be 1, otherwise <TT CLASS="STRUCTFIELD" ><I >gain</I ></TT > will be 0. A <TT CLASS="LITERAL" >SDL_APPINPUTFOCUS</TT > type activation event occurs when the application loses or gains keyboard focus. This usually occurs when another application is made active. Finally, a <TT CLASS="LITERAL" >SDL_APPACTIVE</TT > type event occurs when the application is either minimised/iconified (<TT CLASS="STRUCTFIELD" ><I >gain</I ></TT >=0) or restored.</P ><DIV CLASS="NOTE" ><BLOCKQUOTE CLASS="NOTE" ><P ><B >Note: </B >This event does not occur when an application window is first created.</P ></BLOCKQUOTE ></DIV ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN4000" ></A ><H2 >See Also</H2 ><P ><A HREF="sdlevent.html" ><SPAN CLASS="STRUCTNAME" >SDL_Event</SPAN ></A >, <A HREF="sdlgetappstate.html" ><TT CLASS="FUNCTION" >SDL_GetAppState</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="sdlevent.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="sdlkeyboardevent.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >SDL_Event</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="eventstructures.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >SDL_KeyboardEvent</TD ></TR ></TABLE ></DIV ></BODY ></HTML >