Merges a stick and throttle axis, using the throttle axis as the neutral point for the stick axis.

offset_throttle.py

import gremlin
from gremlin.user_plugin import *

# UI variable definitions
mode = ModeVariable("Mode", "Mode in which to use these settings")
input_joystick = PhysicalInputVariable(
        "Joystick axis",
        "Axis corresponding to the joystick axis to use",
        [gremlin.common.InputType.JoystickAxis]
)
invert_joystick = BoolVariable(
        "Invert joystick axis",
        "Whether or not to invert the joystick axis",
        False
)
input_throttle = PhysicalInputVariable(
        "Throttle axis",
        "Axis corresponding to the throttle slider to use",
        [gremlin.common.InputType.JoystickAxis]
)
invert_throttle = BoolVariable(
        "Invert throttle axis",
        "Whether or not to invert the throttle axis",
        False
)
output = VirtualInputVariable(
        "Output axis",
        "Axis to which the combined output is sent",
        [gremlin.common.InputType.JoystickAxis]
)


# Device decorators
dec_joystick = input_joystick.create_decorator(mode.value)
dec_throttle = input_throttle.create_decorator(mode.value)


# Global state variables
g_throttle = 0.0
g_joystick = 0.0


def update_vjoy(vjoy):
    """Computes the merged output value and sets it.

    Args:
        vjoy: vJoy device instance to use
    """
    device = vjoy[output.value["device_id"]]
    device.axis(output.value["input_id"]).value = \
        max(-1.0, min(1.0, g_throttle + g_joystick))


# Callback handlers
@dec_joystick.axis(input_joystick.input_id)
def axis_joystick(event, vjoy):
    global g_joystick
    g_joystick = event.value if not invert_joystick.value else -event.value
    update_vjoy(vjoy)


@dec_throttle.axis(input_throttle.input_id)
def axis_throttle(event, vjoy):
    global g_throttle
    g_throttle = event.value if not invert_throttle.value else -event.value
    g_throttle = (g_throttle + 1.0) / 2.0
    update_vjoy(vjoy)