Python script for navigating FreeCAD view with a gamepad

gamepad-navigation.py

# move FreeCAD camera with a gamepad

import ctypes
import time
from sdl2 import *

from pivy.coin import SbVec3f, SbRotation
from PySide import QtCore
from math import pi

class JoystickNavi:
    def __init__(self):
        SDL_Init(SDL_INIT_JOYSTICK)
        self.axis = {1: 0, 2: 0, 3: 0, 4: 0}
        self.button = {}
        # adjust linear and angular velocity coefficient below
        self.vel_coeff = 0.001
        self.angv_coeff = 0.0000001
        self.camera = Gui.ActiveDocument.ActiveView.getCameraNode()
        self.timer = QtCore.QTimer()
        QtCore.QObject.connect(self.timer, QtCore.SIGNAL("timeout()"), self.update)
        self.timer.start(16)

    def update(self):
        event = SDL_Event()
        while SDL_PollEvent(ctypes.byref(event)) != 0:
            if event.type == SDL_JOYDEVICEADDED:
                self.device = SDL_JoystickOpen(event.jdevice.which)
            elif event.type == SDL_JOYAXISMOTION:
                self.axis[event.jaxis.axis] = event.jaxis.value
            elif event.type == SDL_JOYBUTTONDOWN:
                self.button[event.jbutton.button] = True
            elif event.type == SDL_JOYBUTTONUP:
                self.button[event.jbutton.button] = False
        # print(joystick.axis)
        # print(joystick.button)
        # axes numbers may need adjustments for your gamepad
        dz = -self.axis[1] * self.vel_coeff
        dy = self.axis[2] * self.vel_coeff
        dx = self.axis[4] * self.vel_coeff
        drot = -self.axis[3] * self.angv_coeff
        cam_rot = self.camera.orientation.getValue()
        cam_pos = self.camera.position.getValue()
        cam_rot_mod = SbRotation(SbVec3f(0, 0, 1), drot)
        cam_pos_mod = cam_rot.multVec(SbVec3f(dy, dz, dx))

        self.camera.orientation.setValue(cam_rot * cam_rot_mod)
        self.camera.position.setValue(cam_pos + cam_pos_mod)

    def stop(self):
        self.timer.stop()

if __name__ == "__main__":
    navi = JoystickNavi()

# type navi.stop() to stop script