-float dotproduct(vector a, vector b)
-{
- return a.x * b.x + a.y * b.y + a.z * b.z;
-}
-
-vector cross(vector a, vector b)
-{
- return
- '1 0 0' * (a.y * b.z - a.z * b.y)
- + '0 1 0' * (a.z * b.x - a.x * b.z)
- + '0 0 1' * (a.x * b.y - a.y * b.x);
-}
-