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Fixed bug #611 From Tim Angus 2008-08-12 11:18:06 I'm one of the maintainers of ioquake3.org, an updated version of the Quake 3 engine. Relatively recently, we moved ioq3 to use SDL as a replacement for 95% of the platform specific code that was there. On the whole it's doing a great job but unfortunately since the move we've been getting complaints about the quality of the mouse input on the Windows platform to the point where for many the game is unplayable. Put in other terms, the current stable SDL 1.2 is basically not fit for purpose if you need high quality mouse input as you do in a first person shooter. Over the weekend I decided to pull my finger out and actually figure out what's going on. There are basically two major problems. Firstly, when using the "windib" driver, mouse input is gathered via the WM_MOUSEMOVE message. Googling for this indicates that often this is known to result in "spurious" and/or "missing" mouse movement events; this is the primary cause of the poor mouse input. The second problem is that the "directx" driver does not work at all in combination with OpenGL meaning that you can't use DirectInput if your application also uses OpenGL. In other words you're locked into using the "windib" driver and its poor mouse input. In order to address these problems I've done the following: * Remove WM_MOUSEMOVE based motion event generation and replace with calls to GetCursorPos which seems much more reliable. In order to achieve this I've moved mouse motion out into a separate function that is called once per DIB_PumpEvents. * Remove the restriction on the "directx" driver being inoperable in combination with OpenGL. There is a bug for this issues that I've hijacked to a certain extent (http://bugzilla.libsdl.org/show_bug.cgi?id=265). I'm the first to admit I don't really understand why this restriction is there in the first place. The commit message for the bug fix that introduced this restriction (r581) isn't very elaborate and I couldn't see any other bug tracking the issue. If anyone has more information on the bug that was avoided by r581 it would be helpful as I/someone could then look into addressing the problem without disabling the "directx" driver. * I've also removed the restriction on not being allowed to use DirectInput in windowed mode. I couldn't see any reason for this, at least not from our perspective. I have my suspicions that it'll be something like matching up the cursor with the mouse coordinates... * I bumped up the DirectInput API used to version 7 in order to get access to mouse buttons 4-7. I've had to inject a little bit of the DX7 headers into SDL there as the MinGW ones aren't up to date in this respect.
author Sam Lantinga <slouken@libsdl.org>
date Thu, 02 Apr 2009 04:43:36 +0000
parents 355632dca928
children
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<HTML
><HEAD
><TITLE
>Joystick</TITLE
><META
NAME="GENERATOR"
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TITLE="SDL_JoystickEventState"
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><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
>&nbsp;--&nbsp;Count available joysticks.</DT
><DT
><A
HREF="sdljoystickname.html"
>SDL_JoystickName</A
>&nbsp;--&nbsp;Get joystick name.</DT
><DT
><A
HREF="sdljoystickopen.html"
>SDL_JoystickOpen</A
>&nbsp;--&nbsp;Opens a joystick for use.</DT
><DT
><A
HREF="sdljoystickopened.html"
>SDL_JoystickOpened</A
>&nbsp;--&nbsp;Determine if a joystick has been opened</DT
><DT
><A
HREF="sdljoystickindex.html"
>SDL_JoystickIndex</A
>&nbsp;--&nbsp;Get the index of an SDL_Joystick.</DT
><DT
><A
HREF="sdljoysticknumaxes.html"
>SDL_JoystickNumAxes</A
>&nbsp;--&nbsp;Get the number of joystick axes</DT
><DT
><A
HREF="sdljoysticknumballs.html"
>SDL_JoystickNumBalls</A
>&nbsp;--&nbsp;Get the number of joystick trackballs</DT
><DT
><A
HREF="sdljoysticknumhats.html"
>SDL_JoystickNumHats</A
>&nbsp;--&nbsp;Get the number of joystick hats</DT
><DT
><A
HREF="sdljoysticknumbuttons.html"
>SDL_JoystickNumButtons</A
>&nbsp;--&nbsp;Get the number of joysitck buttons</DT
><DT
><A
HREF="sdljoystickupdate.html"
>SDL_JoystickUpdate</A
>&nbsp;--&nbsp;Updates the state of all joysticks</DT
><DT
><A
HREF="sdljoystickgetaxis.html"
>SDL_JoystickGetAxis</A
>&nbsp;--&nbsp;Get the current state of an axis</DT
><DT
><A
HREF="sdljoystickgethat.html"
>SDL_JoystickGetHat</A
>&nbsp;--&nbsp;Get the current state of a joystick hat</DT
><DT
><A
HREF="sdljoystickgetbutton.html"
>SDL_JoystickGetButton</A
>&nbsp;--&nbsp;Get the current state of a given button on a given joystick</DT
><DT
><A
HREF="sdljoystickgetball.html"
>SDL_JoystickGetBall</A
>&nbsp;--&nbsp;Get relative trackball motion</DT
><DT
><A
HREF="sdljoystickclose.html"
>SDL_JoystickClose</A
>&nbsp;--&nbsp;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
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