def __init__(self, previous, current):
"""
Constructor
"""
self.position = previous
self.vector = TupleMath.unit(TupleMath.subtract(current, previous))
self.angle = 0.0
self.tangent = self.vector
def set_vector(self, vector):
"""
Set the vector of the axis, converting it to unit length
Also calculates axis end points
"""
if vector:
vector = TupleMath.unit(vector)
self.vector = vector
if not self.vector:
return