Mercurial > sdl-ios-xcode
view docs/html/joystick.html @ 1614:6162b8d921ce
Date: Wed, 29 Mar 2006 17:26:55 +0200 CEST
From: "Fran���is Revol"
Subject: [SDL] BeOS port fix: PrintScreen key crashing
It seems the latest SDL crashes when someone hits the PrtScrn key in
ZETA (BeOS R6), somewhere it gets a negative value as key code (or a
big unsigned maybe ?), and uses it as an index in the keysym table...
I'll investigate the cause for the negative value, but it's always
better to check for bounds correctly when indexing a table. The
attached diff fixes it.
Fran���is Revol
--
Software Architect
yellowTAB GmbH
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Fri, 31 Mar 2006 06:16:20 +0000 |
parents | 355632dca928 |
children |
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<HTML ><HEAD ><TITLE >Joystick</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_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 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="sdljoystickeventstate.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="sdlnumjoysticks.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><DIV CLASS="CHAPTER" ><H1 ><A NAME="JOYSTICK" ></A >Chapter 9. Joystick</H1 ><DIV CLASS="TOC" ><DL ><DT ><B >Table of Contents</B ></DT ><DT ><A HREF="sdlnumjoysticks.html" >SDL_NumJoysticks</A > -- Count available joysticks.</DT ><DT ><A HREF="sdljoystickname.html" >SDL_JoystickName</A > -- Get joystick name.</DT ><DT ><A HREF="sdljoystickopen.html" >SDL_JoystickOpen</A > -- Opens a joystick for use.</DT ><DT ><A HREF="sdljoystickopened.html" >SDL_JoystickOpened</A > -- Determine if a joystick has been opened</DT ><DT ><A HREF="sdljoystickindex.html" >SDL_JoystickIndex</A > -- Get the index of an SDL_Joystick.</DT ><DT ><A HREF="sdljoysticknumaxes.html" >SDL_JoystickNumAxes</A > -- Get the number of joystick axes</DT ><DT ><A HREF="sdljoysticknumballs.html" >SDL_JoystickNumBalls</A > -- Get the number of joystick trackballs</DT ><DT ><A HREF="sdljoysticknumhats.html" >SDL_JoystickNumHats</A > -- Get the number of joystick hats</DT ><DT ><A HREF="sdljoysticknumbuttons.html" >SDL_JoystickNumButtons</A > -- Get the number of joysitck buttons</DT ><DT ><A HREF="sdljoystickupdate.html" >SDL_JoystickUpdate</A > -- Updates the state of all joysticks</DT ><DT ><A HREF="sdljoystickgetaxis.html" >SDL_JoystickGetAxis</A > -- Get the current state of an axis</DT ><DT ><A HREF="sdljoystickgethat.html" >SDL_JoystickGetHat</A > -- Get the current state of a joystick hat</DT ><DT ><A HREF="sdljoystickgetbutton.html" >SDL_JoystickGetButton</A > -- Get the current state of a given button on a given joystick</DT ><DT ><A HREF="sdljoystickgetball.html" >SDL_JoystickGetBall</A > -- Get relative trackball motion</DT ><DT ><A HREF="sdljoystickclose.html" >SDL_JoystickClose</A > -- 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 <SPAN CLASS="emphasis" ><I CLASS="EMPHASIS" >not</I ></SPAN > 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 ><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="sdljoystickeventstate.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="sdlnumjoysticks.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >SDL_JoystickEventState</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_NumJoysticks</TD ></TR ></TABLE ></DIV ></BODY ></HTML >