Purgatory/Vehicle Values
Angle
A vehicle's direction of drive is computed using the positions of the vehicle's front and back:
p1 = vehicle's front position p2 = vehicle's back position if p1!=p2: angle = atan2(p1.x()-p2.x(), p2.y()-p1.y())*180./PI; else: angle = lane's angle at vehicle's front
The check for p1!=p2
is necessary as the lane's used length may differ from the lane's geometrical length. Not regarding this caused vehicles to change the direction of drive to 0°, reported as ticket#430.
The following image shows how the resulting encoding.