When calculating the angle of one tangent based on the other, check if the radius of the other is zero to do not update the angle (arctan(0/0)==undefined).
Outline: consider the vertex split in any of the two possible cases.
This allow to create sharp corners when radius is split but one of them is zero.
AdvancedOutline: consider the vertex split if the angle is split or if one of the radius is zero.
This allow to create sharp corners when radius is split but one of them is zero.
CurveGradient: Consider split angle and split radius when rendering a corner.
CurveWarp: Consider split angle and split radius when rendering a corner.