def tool_move(self, event):
if self._handle < 0:
return
# Nearest point on line A to line B:
# N = (Da x Db) x Db
# t = ((Pb - Pa) . N) / (Da . N)
# A == bone
# B == event
# event axis (Db) is normalized, so t in units of |Da|
pos, axis = self.get_world_bone_axis(self._bones[self._handle])
eventpos = Vector(event.posRaw[0], event.posRaw[1], event.posRaw[2])
eventaxis = Vector(event.axis[0], event.axis[1], event.axis[2])
N = Vector.cross(Vector.cross(axis, eventaxis), eventaxis)
DaN = Vector.dot(axis, N)
Pba = eventpos - pos
self._frac = Vector.dot(Pba, N) / DaN
if self._frac < 0: self._frac = 0
if self._frac > 1: self._frac = 1
self._dirty = True
self._moved = True
