While toying around with Allegro's joystick routines with JOY_TYPE_AUTODETECT under Windows, I discovered that I couldn't actually utilize all the axes/sliders on my joystick (a Saitek X-36) - to be specific, Allegro didn't report Rotary #2.

After digging around in the sources, I thought I had found the cause of it:

/* From joystick.h */

#define MAX_JOYSTICKS            8
#define MAX_JOYSTICK_AXIS        3
#define MAX_JOYSTICK_STICKS      5
#define MAX_JOYSTICK_BUTTONS     32

Since my joystick was being reported as having 5 sticks, I thought I was running into the hardcoded limit and changed MAX_JOYSTICK_STICKS to a higher value, but to no avail. So I did some more testing, and discovered that the problem is with JOY_TYPE_DIRECTX (the default) and not with JOY_TYPE_WIN32.

With JOY_TYPE_DIRECTX the joystick gets this layout:

Stick 0:
   Axis 0: X Axis
   Axis 1: Y Axis
Stick 1:
   Axis 0: Rudder
Stick 2:
   Axis 0: Throttle
Stick 3:
   Axis 0: Rotary #1
Stick 4:
   Axis 0: Main POV hat X
   Axis 1: Main POV hat Y

+ 26 buttons

Rotary #2 (identical to Rotary #1) is nowhere to be seen.

And with JOY_TYPE_WIN32:

Stick 0:
   Axis 0: X Axis
   Axis 1: Y Axis
   Axis 2: Throttle
Stick 1:
   Axis 0: Rudder
Stick 2:
   Axis 0: Rotary #1
Stick 3:
   Axis 0: Rotary #2
Stick 4:
   Axis 0: Main POV hat X
   Axis 1: Main POV hat Y

+ 26 buttons

Since I figure most people probably haven't tested Allegro's joystick input with more complex joysticks, I feel I may have run into an obscure Allegro bug here...
Any devs or people who can stand looking at DirectX code who can look into this?

In any case: is there a reason for MAX_JOYSTICK_STICKS to be set at 5?

I'd recommend posting to the developers list or asking someone here to do so.

Don't worry, I've seen it, and I'm sure Peter and Elias will see it too if they haven't already.
Personally, I'm not in a position where I can do much about this though - I don't use Windows very often and my gamepad doesn't work in Windows anyway (at least, I haven't tried to get it to work yet, too little incentive to do so).

I think not. This, I think, is completely arbitrary.

Sorry for the delay. I think the problem is in object_enum_callback() in src/win/wjoydx.c. I suspect the missing axis falls under GUID_RxAxis or GUID_RyAxis which is not being tested for there.