Function orient3dfastVector

orient3dfastVector(a: VectorPoint, b: VectorPoint, c: VectorPoint): number
Find the orientation of a point relative to a vector a-b plane relative to the origin
Parameters
- a: VectorPoint
  first point
- b: VectorPoint
  second point
- c: VectorPoint
  comparison point
Returns number
- a positive value if the point-plane of a-b via c occur in counterclockwise order (c lies to the left of the directed line defined by points a and b).
- Returns a negative value if they occur in clockwise order (c lies to the right of the directed line ab).
- Returns zero if they are collinear.