[metapost] Re: new is_clockwise routine

[Werner LEMBERG]

> Finding the direction at which a curve turns at any given
> point is easy: just find the sign of the cross product [...]

In my macros I use the cross product to check for grazing intersection
only.

> In general, to find the clockwiseness of a single Bézier
> cubics it suffices to check [...]

Far too complicated and slow to be implemented as macros IMHO.


    Werner