directly compared the variable with zero may cause bugs

[eteced]

fitCurves/fitCurves.py

Line 82 in c59eccf

alpha_l = 0.0 if det_C0_C1 == 0 else det_X_C1 / det_C0_C1

Try to fit this bad case:
points: [[1605.99181736 1433.82668586]
[1608.81290918 1436.66242932]
[1612.4412136 1438.2910418 ]]
leftTangent:[0.65773635 0.75324822] rightTangent:[-0.71222538 -0.70195086]

I think changed to fabs(_) < 1e-3 is better, and would solve the problem.