let c' = PointF(e'.Cx, e'.Cy)
let v = pointFromTwoLines d1 (lineFromTwoPoints c c')
let case1 = sign (v.X - c.X) <> sign (v.X - c'.X) || Utils.squaredDistanceTwoPoints v c > Utils.squaredDistanceTwoPoints v c'
let c' = PointF(e'.Cx, e'.Cy)
let v = pointFromTwoLines d1 (lineFromTwoPoints c c')
let case1 = sign (v.X - c.X) <> sign (v.X - c'.X) || Utils.squaredDistanceTwoPoints v c > Utils.squaredDistanceTwoPoints v c'