def main(ctx):
    which = "where" if sys.platform == "win32" else "which"
    if envoy.run(which + " git").status_code != 0:
        click.secho("fatal: git not found in PATH", fg="red")
        sys.exit(1)
    ctx.obj = Hydrogen()
def update(dt=0):
  global projpts, rgb, depth
  depth,_ = freenect.sync_get_depth()
  rgb,_ = freenect.sync_get_video()
  q = depth
  X,Y = np.meshgrid(range(640),range(480))
  # YOU CAN CHANGE THIS AND RERUN THE PROGRAM!
  # Point cloud downsampling
  d = 4
  projpts = calibkinect.depth2xyzuv(q[::d,::d],X[::d,::d],Y[::d,::d])
  refresh()