README
author Sam Lantinga <slouken@libsdl.org>
Mon, 02 Jun 2003 14:50:22 +0000
changeset 632 85e104fe14c2
parent 630 550bccdf04bd
child 702 61b7f5eed0e8
permissions -rw-r--r--
Date: Sun, 1 Jun 2003 15:38:45 -0700 (PDT)
From: Jeff Brown <jabrown@caida.org>
Subject: [patch] SDL-1.2.5 + FreeBSD joystick axes, hat fixes

Hello again! When I sent in some SDL fixes last December, I found out
they'd already been fixed in the CVS version. This time, I checked the
repository before bugging you. =)

I'm using SDL-1.2.5 on a FreeBSD 4.6.2-RELEASE system, and in the course
of getting my multi-analog-axis USB controller (with a hat switch!)
working with d2x-sdl -- the SDL port of the Descent 2 engine -- I came
across a few problems:

1) The second analog stick is reported as a slider in one direction, and
"Rz" in the other. SDL was ignoring the Rz axis, so I added Rx/Ry/Rz to
the set of things SDL considers to be axes.

2) After the above change, the set of JOYAXE_* axes for my gamepad was
{0,1,3,7}; however, d2x-sdl expects the axes to be contiguously numbered
from 0, which seems like a pretty reasonable expectation, rather than
having to scan the entire space of axes that SDL may or may not have.
So, I added a table lookup which maps the JOYAXE_* axis numbers to 0,1,...
in the order they're detected by SDL_SYS_JoystickOpen(), when reporting
them to the application. I also added a function "usage_to_joyaxe()"
which maps the USB HUG_* usage values to JOYAXE_values, since the repeated
case statements testing for HUG_* were getting out of hand.

3) The BSD joystick driver had no hat support, so I added it. It looks
like our USB library can only support one hat switch per device, which
makes life easy.

The patch against SDL-1.2.5 which implements these changes is at:

http://www.caida.org/~jabrown/patches/sdl-1.2.5-bsdhat.diff

After applying, SDL's "testjoystick" reports all activity from my gamepad
correctly, and d2x works too (though it needed some other fixes).

Moving on...

There is also a problem with slightly different USBHID library interfaces
on different versions of FreeBSD. I wasn't going to mention this since the
FreeBSD port for SDL-1.2.5 (and not SDL itself) was doing the FreeBSD
version-specific patching, so I e-mailed the port maintainer with this
change. However, I see that you've incorporated the FreeBSD
version-checking stuff into the CVS version of SDL, so now it's relevant
for you too.

The problem is, the FreeBSD #if tests don't work right for FreeBSD
4.6.2-RELEASE. There may be other versions with this problem, but I've
only tested 4.6.2-R. The following patch against your latest CVS version
fixes this:

--- SDL_sysjoystick.c-1.16 Tue Apr 15 09:02:08 2003
+++ SDL_sysjoystick.c Sun Jun 1 15:10:28 2003
@@ -420,6 +420,8 @@
# else
len = hid_report_size(rd, repinfo[repind].kind, r->rid);
# endif
+# elif (__FreeBSD_version == 460002)
+ len = hid_report_size(rd, r->rid, repinfo[repind].kind);
# else
len = hid_report_size(rd, repinfo[repind].kind, &r->rid);
#endif


I hope this is all useful to you. I've been getting myself dizzy playing
Descent 2 with it, all morning!

-Jeff Brown


P.S. My USB controller is a Thrustmaster Firestorm Dual Analog 2. That's
probably irrelevant, but I threw it in for completeness.
     1 
     2                          Simple DirectMedia Layer
     3 
     4                                   (SDL)
     5 
     6                                 Version 1.2
     7 
     8 ---
     9 http://www.libsdl.org/
    10 
    11 This is the Simple DirectMedia Layer, a general API that provides low
    12 level access to audio, keyboard, mouse, joystick, 3D hardware via OpenGL,
    13 and 2D framebuffer across multiple platforms.
    14 
    15 SDL is written in C, but works with C++ natively, and has bindings to
    16 several other languages, including Ada, C#, Eiffel, Java, Lua, ML,
    17 Objective C, Perl, PHP, Pike, Python, and Ruby.
    18 
    19 The current version supports Linux, Windows, BeOS, MacOS, MacOS X,
    20 FreeBSD, OpenBSD, BSD/OS, Solaris, and IRIX.  The code contains support
    21 for Windows CE, AmigaOS, Dreamcast, Atari, QNX, NetBSD, AIX, OSF/Tru64,
    22 RISC OS, and SymbianOS, but these are not officially supported.
    23 
    24 This library is distributed under GNU LGPL version 2, which can be
    25 found in the file  "COPYING".  This license allows you to use SDL
    26 freely in commercial programs as long as you link with the dynamic
    27 library.
    28 
    29 The best way to learn how to use SDL is to check out the header files in
    30 the "include" subdirectory and the programs in the "test" subdirectory.
    31 The header files and test programs are well commented and always up to date.
    32 More documentation is available in HTML format in "./docs/index.html"
    33 
    34 The test programs in the "test" subdirectory are in the public domain.
    35 
    36 Frequently asked questions are answered online:
    37 	http://www.libsdl.org/faq.php
    38 
    39 If you need help with the library, or just want to discuss SDL related
    40 issues, you can join the developers mailing list:
    41 	http://www.libsdl.org/mailing-list.php
    42 
    43 Enjoy!
    44 	Sam Lantinga				(slouken@libsdl.org)
    45