Mercurial > sdl-ios-xcode
view docs/html/sdljoyballevent.html @ 2321:c5feceb0395e
SetupWindowData in SDL_X11window.c was realloc()ing the display window list and incrementing numwindows even though those are being updated in functions that call
this function. The result is that it is possible to get the same window added to the list twice.
author | Bob Pendleton <bob@pendleton.com> |
---|---|
date | Tue, 04 Mar 2008 23:09:28 +0000 |
parents | 355632dca928 |
children |
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<HTML ><HEAD ><TITLE >SDL_JoyBallEvent</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_JoyHatEvent" HREF="sdljoyhatevent.html"><LINK REL="NEXT" TITLE="SDL_ResizeEvent" HREF="sdlresizeevent.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="sdljoyhatevent.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="sdlresizeevent.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><H1 ><A NAME="SDLJOYBALLEVENT" ></A >SDL_JoyBallEvent</H1 ><DIV CLASS="REFNAMEDIV" ><A NAME="AEN4396" ></A ><H2 >Name</H2 >SDL_JoyBallEvent -- Joystick trackball motion event structure</DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN4399" ></A ><H2 >Structure Definition</H2 ><PRE CLASS="PROGRAMLISTING" >typedef struct{ Uint8 type; Uint8 which; Uint8 ball; Sint16 xrel, yrel; } SDL_JoyBallEvent;</PRE ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN4402" ></A ><H2 >Structure Data</H2 ><DIV CLASS="INFORMALTABLE" ><A NAME="AEN4404" ></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_JOYBALLMOTION</TT ></TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="STRUCTFIELD" ><I >which</I ></TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >Joystick device index</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="STRUCTFIELD" ><I >ball</I ></TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >Joystick trackball index</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="STRUCTFIELD" ><I >xrel</I ></TT >, <TT CLASS="STRUCTFIELD" ><I >yrel</I ></TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >The relative motion in the X/Y direction</TD ></TR ></TBODY ></TABLE ><P ></P ></DIV ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN4425" ></A ><H2 >Description</H2 ><P ><SPAN CLASS="STRUCTNAME" >SDL_JoyBallEvent</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_JOYBALLMOTION</TT > is reported.</P ><P >A <TT CLASS="LITERAL" >SDL_JOYBALLMOTION</TT > event occurs when a user moves a trackball on the joystick. The field <TT CLASS="STRUCTFIELD" ><I >which</I ></TT > is the index of the joystick that reported the event and <TT CLASS="STRUCTFIELD" ><I >ball</I ></TT > is the index of the trackball (for a more detailed explaination see the <A HREF="joystick.html" >Joystick section</A >). Trackballs only return relative motion, this is the change in position on the ball since it was last polled (last cycle of the event loop) and it is stored in <TT CLASS="STRUCTFIELD" ><I >xrel</I ></TT > and <TT CLASS="STRUCTFIELD" ><I >yrel</I ></TT >.</P ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN4439" ></A ><H2 >See Also</H2 ><P ><A HREF="sdlevent.html" ><SPAN CLASS="STRUCTNAME" >SDL_Event</SPAN ></A >, <A HREF="joystick.html" >Joystick Functions</A >, <A HREF="sdljoystickeventstate.html" ><TT CLASS="FUNCTION" >SDL_JoystickEventState</TT ></A >, <A HREF="sdljoystickgetball.html" ><TT CLASS="FUNCTION" >SDL_JoystickGetBall</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="sdljoyhatevent.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="sdlresizeevent.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >SDL_JoyHatEvent</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_ResizeEvent</TD ></TR ></TABLE ></DIV ></BODY ></HTML >