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view docs/html/event.html @ 3846:66fb40445587 SDL-ryan-multiple-audio-device

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Removed distinction between "available" and "init" in audio backends, since both had to be checked for success as a pair at the higher level and several of the Available methods were just always-succeed placeholders anyhow. Now the availability check is done in the init code, and the higher level tries all possible drivers until one manages to initialize successfully.
author Ryan C. Gordon <icculus@icculus.org>
date Tue, 17 Oct 2006 09:09:21 +0000
parents 355632dca928
children
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<HTML
><HEAD
><TITLE
>Events</TITLE
><META
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CONTENT="events"><META
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><DIV
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><H1
><A
NAME="EVENT"
></A
>Chapter 8. Events</H1
><DIV
CLASS="TOC"
><DL
><DT
><B
>Table of Contents</B
></DT
><DT
><A
HREF="event.html#AEN3691"
>Introduction</A
></DT
><DT
><A
HREF="eventstructures.html"
>SDL Event Structures.</A
></DT
><DT
><A
HREF="eventfunctions.html"
>Event Functions.</A
></DT
></DL
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><DIV
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><H1
CLASS="SECT1"
><A
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></A
>Introduction</H1
><P
>Event handling allows your application to receive input from the user. Event handling is initalised (along with video) with a call to:
<PRE
CLASS="PROGRAMLISTING"
>SDL_Init(SDL_INIT_VIDEO);</PRE
>
Internally, SDL stores all the events waiting to be handled in an event queue. Using functions like <A
HREF="sdlpollevent.html"
><TT
CLASS="FUNCTION"
>SDL_PollEvent</TT
></A
> and <A
HREF="sdlpeepevents.html"
><TT
CLASS="FUNCTION"
>SDL_PeepEvents</TT
></A
> you can observe and handle waiting input events.</P
><P
>The key to event handling in SDL is the <A
HREF="sdlevent.html"
><SPAN
CLASS="STRUCTNAME"
>SDL_Event</SPAN
></A
> union. The event queue itself is composed of a series of <SPAN
CLASS="STRUCTNAME"
>SDL_Event</SPAN
> unions, one for each waiting event. <SPAN
CLASS="STRUCTNAME"
>SDL_Event</SPAN
> unions are read from the queue with the <TT
CLASS="FUNCTION"
>SDL_PollEvent</TT
> function and it is then up to the application to process the information stored with them.</P
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