This class represents a cubic bezier segment between two points

Instance variables:
via1, via2 <Point> The additional control points (OFF the curve)

	converting
	asBezierShape asPointArray bezier2SegmentCount:

	initialization
	from:via:and:to:

	private
	bezier2SegmentCount

	instance creation
	from:to: from:via:and:to:

	utilities
	convertBezier3ToBezier2:

	accessing	top
	bounds Return the bounds containing the receiver
	valueAt: | p1 p2 p3 | p1 _ start interpolateTo: via1 at: t. p2 _ via1 interpolateTo: via2 at: t. p3 _ via2 interpolateTo: end at: t. p1 _ p1 interpolateTo: p2 at: t. p2 _ p2 interpolateTo: p3 at: t. ^ p1 interpolateTo: p2 at: t
	via1:
	via2:

	converting	top
	asBezierShape Demote a cubic bezier to a set of approximating quadratic beziers. Should convert to forward differencing someday
	asPointArray
	bezier2SegmentCount: Compute the number of quadratic bezier segments needed to approximate this cubic with no more than a specified error

	initialization	top
	from:via:and:to:

	private	top
	bezier2SegmentCount Compute the number of quadratic bezier segments needed to approximate this cubic with less than a 1-pixel error

	examples	top
	example1
	example2 draws a cubic bezier on the screen

	instance creation	top
	from:to:
	from:via:and:to:

	utilities	top
	convertBezier3ToBezier2: