C/C++/mex wrappers for SDL Joystick. C wrappers currently broken

SDL development library

Available through apt-get

apt-get install libsdl1.2-dev

Available through macports (which you can get at http://www.macports.org/install.php)

then

port install libsdl-devel

>> cd cppexample
>> make
>> ./cpp_example 
initializing SDL Joystick subsystem
found 1 joystick(s)
Opening joystick 0... found Logitech Dual Action
Joystick 0, name: Logitech Dual Action, buttons: [0, 0, 0, 0], axes: [0.00390637, -0.0117798, 0.00390637, 0.00390637]
Joystick 0, name: Logitech Dual Action, buttons: [0, 0, 0, 0], axes: [0.00390637, -0.0117798, 0.00390637, 0.00390637]
...

from MATLAB

>> cd mex
>> build

Then you can call "joystick" immediately.

To see all available joysticks:

>> joystick()
Connected joysticks:
0: Logitech Dual Action

To get one of those joysticks, call "joystick(joystick_index)"

>> joystick(0)
ans = 

       name: 'Logitech Dual Action'
       axes: [4x1 double]
    buttons: [12x1 double]

You don't need to call joystick() first, you can call joystick(0) immediately.

SDL and individual joysticks are opened and closed automatically by the wrapper. The SDL and joystick wrapper memory can be cleared with clear all or clear mex.

For some reason (only?) the first struct gotten is bad and random, you should manually discard it or suffer the consequences.

>> clear all
Closing "Logitech Dual Action"
quitting SDL Joystick subsystem
>> js = joystick(0);
initializing SDL Joystick subsystem
Opening joystick 0... found Logitech Dual Action
>> js.buttons

ans =

   1.0e+09 *

         0
    1.0737
    0.3022
    0.5369

>> js = joystick(0);
>> js.buttons

ans =

     0
     0
     0
     0

I've tried to repeatedly grab values internally (in the wrapper) in a loop, but this does not force it to cycle. I suspect the bug is related to SDL events not working properly without having SDLMain.