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.

These are test programs for the SDL library:

	checkkeys	Watch the key events to check the keyboard
	graywin		Display a gray gradient and center mouse on spacebar
	loopwave	Audio test -- loop playing a WAV file
	testalpha	Display an alpha faded icon -- paint with mouse
	testbitmap	Test displaying 1-bit bitmaps
	testblitspeed	Tests performance of SDL's blitters and converters.
	testcdrom	Sample audio CD control program
	testcursor	Tests custom mouse cursor
	testdyngl	Tests dynamically loading OpenGL library
	testerror	Tests multi-threaded error handling
	testfile	Tests RWops layer
	testgamma	Tests video device gamma ramp
	testgl		A very simple example of using OpenGL with SDL
	testhread	Hacked up test of multi-threading
	testiconv	Tests international string conversion
	testjoystick	List joysticks and watch joystick events
	testkeys	List the available keyboard keys
	testloadso	Tests the loadable library layer
	testlock	Hacked up test of multi-threading and locking
	testoverlay	Tests the software/hardware overlay functionality.
	testoverlay2	Tests the overlay flickering/scaling during playback.
	testpalette	Tests palette color cycling
	testplatform	Tests types, endianness and cpu capabilities
	testsem		Tests SDL's semaphore implementation
	testsprite	Example of fast sprite movement on the screen
	testtimer	Test the timer facilities
	testver		Check the version and dynamic loading and endianness
	testvidinfo	Show the pixel format of the display and perfom the benchmark
	testwin		Display a BMP image at various depths
	testwm		Test window manager -- title, icon, events
	threadwin	Test multi-threaded event handling
	torturethread	Simple test for thread creation/destruction