[PATCH 4/4] d2d1: Implement cubic bezier-line intersection.

[Paul Gofman]

On 4/1/20 20:03, Giovanni Mascellani wrote:
> Il 01/04/20 18:46, Paul Gofman ha scritto:
>> Given the complex roots are not needed here and the polynomial is always
>> cubic, is this generic method really beneficial? It would probably be
>> simpler and quicker to find one root x1 with simple bisection, then
>> divide the polynomial into (x - x1) and deal with remaining quadratic
>> equation.
> This kind of division is typically numerically unstable. It might be
> that for cubic polynomials the problem is not very apparent,

Yes, factoring out the roots from a high degree polynomial can
accumulate the error, but how's that a problem for just one root?

Also, I think just using double precision in analytical solution will
avoid any practical stability problems in this case.