Mercurial > sdl-ios-xcode

view docs/html/sdlactiveevent.html @ 765:4c2ba6161939

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
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
line wrap: on
line source

<HTML
><HEAD
><TITLE
>SDL_ActiveEvent</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 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
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"
>Prev</A
></TD
><TD
WIDTH="80%"
ALIGN="center"
VALIGN="bottom"
></TD
><TD
WIDTH="10%"
ALIGN="right"
VALIGN="bottom"
><A
HREF="sdlkeyboardevent.html"
>Next</A
></TD
></TR
></TABLE
><HR
ALIGN="LEFT"
WIDTH="100%"></DIV
><H1
><A
NAME="SDLACTIVEEVENT"
>SDL_ActiveEvent</A
></H1
><DIV
CLASS="REFNAMEDIV"
><A
NAME="AEN3571"
></A
><H2
>Name</H2
>SDL_ActiveEvent&nbsp;--&nbsp;Application visibility event structure</DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN3574"
></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="AEN3577"
></A
><H2
>Structure Data</H2
><DIV
CLASS="INFORMALTABLE"
><A
NAME="AEN3579"
></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="AEN3600"
></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="AEN3616"
></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
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
><A
HREF="sdlevent.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="sdlkeyboardevent.html"
>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"
>Up</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
>SDL_KeyboardEvent</TD
></TR
></TABLE
></DIV
></BODY
></HTML
>