CGAL users discussion list

[Ben Supnik <>]

Thanks Fernando,

That's what I was afraid of....

> AFAICT they would both render the same (or maybe not? I never tried
> such a degenerate cubic).

Sadly they do not...the problem is that the weighting of the control 
points is different - more weight on the "one good" control point (and 
not enough on the end point colocated with the degeneracy) than in the 
quadratic case.

Hrm...it looks like I might be able to fudge things, if I can accept 
small error.

In a degenerate bezier, P1, C1, C2, P2 (p1 == c1) the curve starting at 
P1 is tangent to the line P1 C2.

So if I "create" a point C1 along the line P1 C2, the non-degenerate 
curve approaches the degenerate curve as C1 approaches P1.

If I can accept very slow exact processing and small amounts of error, I 
can construct a CGAL-happy bezier. :-)

cheers
Ben

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