("Master files") Warthog-Stick.xml and Warthog-Throttle.xml support
configuration overlay files. These are optional and can be used to
modify the default configuration. Warthog-Stick.xml searches for
overlay files in

  {$FG_HOME,$FG_ROOT}/Input/Joysticks/ThrustMaster/Warthog/Stick/

and Warthog-Throttle.xml in

  {$FG_HOME,$FG_ROOT}/Input/Joysticks/ThrustMaster/Warthog/Throttle/


Available files are loaded in the following order, where <x> is replaced
by the contents of property "x":

  - generic.xml
  - helicopter.xml  (only helicopters)
  - </sim/type>.xml  (some aircraft set this property to "seaplane")
  - </input/joysticks/overlays>.xml  (not used by the system; meant to
               be set on the command line or in wrapper scripts,
               for example: --prop:input/joysticks/overlays=modern_jet;
               accepts a single overlay file name -- withtout extension --
               or a list of names separated by colon ":")
  - </sim/aircraft>.xml  (aircraft name, for example "harrier.xml")


If a file is found under $FG_HOME, then an equally named file under
$FG_ROOT will be ignored.

Overlay files are like stripped down joystick driver files, but shall
not have a <name> entry. They only need to define what should differ
from the already loaded joystick configuration. Make sure that an
axis definition uses the same index as the master file. The n-th
<axis> in an XML config file usually has index n, even if the axis
uses <number><unix> etc. Nasal blocks are properly executed in the
namespace of the master file, so you can access all its functions
and variables.




Standard overlay files:
- stick_rotate: rotates stick X/Y axis by given angle. Apparently desired
  by some users who have the stick between their knees and want to move it
  in a more natural fashion. Usage:

  fgfs --prop:input/joysticks/overlays=stick_rotate --prop:d:input/joysticks/stick-angle=15





Joystick configuration from within FlightGear under Linux:
--------------------------------------------------------------------------------
This allows to set backlight brightness and LEDs from within FlightGear
without requiring any config application, by directly writing to the devices
via raw HID support.



(1) Make sure your kernel has hidraw support compiled in: check if there is at
    least one file listed with

        $ ls /dev/hidraw*

    or if your kernel .config contains:

        CONFIG_HIDRAW=y



(2) To get a reliable, persistent file name for your Warthog devices, create
    a file /etc/udev/rules.d/00-local.rules and add these lines:

        SUBSYSTEM=="input", ENV{ID_INPUT_JOYSTICK}!="?*", IMPORT{program}="input_id %p"
        SUBSYSTEM=="hidraw", ENV{ID_SERIAL}!="?*", IMPORT{program}="usb_id --export %p"
        SUBSYSTEM=="hidraw", SYMLINK+="input/hidraw/%E{ID_SERIAL}"
        SUBSYSTEM=="hidraw", ENV{ID_INPUT_JOYSTICK}!="0", GROUP:="js"

    If you don't have a user group "js" (for joystick hardware access) either
    create one or, in the fourth line, use a group instead where all joystick
    users are member, e.g. GROUP:="users". Then plug your Warthog devices out
    and in again and check if this created two device links:

        $ ls -l /dev/input/hidraw/*
        lrwxrwxrwx 1 root root 10 Oct  2 14:23 Thrustmaster_Throttle_-_HOTAS_Warthog -> ../hidraw1
        lrwxrwxrwx 1 root root 10 Oct  2 14:23 Thustmaster_Joystick_-_HOTAS_Warthog -> ../hidraw0

    Also check if the linked-to hidraw devices have proper permissions (rw for "js"):

        $ ls -l /dev/hidraw*
        crw-rw---- 1 root js 251, 0 Oct  2 09:11 /dev/hidraw0
        crw-rw---- 1 root js 251, 1 Oct  2 14:23 /dev/hidraw1
            ^^            ^^


(3) Allow FlightGear to write to the two devices. The best way to do this is
    to edit a local copy of the global IOrules. Just copy the global file
    to your FG_HOME directory:

        $ mkdir -p ~/.fgfs/Nasal
        $ cp $FG_ROOT/Nasal/IOrules ~/.fgfs/Nasal

    Now add these four lines there:

        READ ALLOW /dev/input/hidraw/Thustmaster_Joystick_-_HOTAS_Warthog
        READ ALLOW /dev/input/hidraw/Thrustmaster_Throttle_-_HOTAS_Warthog
        WRITE ALLOW /dev/input/hidraw/Thustmaster_Joystick_-_HOTAS_Warthog
        WRITE ALLOW /dev/input/hidraw/Thrustmaster_Throttle_-_HOTAS_Warthog

    CAVE: Don't fix the bad spelling of "Thrustmaster", unless your stick
          really uses that!




DISCLAIMER: Of course, you take all responsibility for any possible
damages to your hardware if you make these changes. Neither the
FlightGear project nor any of its developers and contributors are in
any way liable.