Two UIBezierPaths intersection as a UIBezierPath

Question

I have two UIBezierPaths, one that represents the polygon of part of an image and the other is a path to be drawn on top of it.

I need to find the intersection between them so that only the point that are inside this intersection area will be colored.

Is there a method in UIBezierPath that can find intersection points - or a new path - between two paths ?

Answer 1

I wrote a UIBezierPath library that will let you cut a given closed path into sub shapes based on an intersecting path. It'll do essentially exactly what you're looking for: https://github.com/adamwulf/ClippingBezier

NSArray<UIBezierPath*>* componentShapes = [shapePath uniqueShapesCreatedFromSlicingWithUnclosedPath:scissorPath];

Alternatively, you can also just find the intersection points:

NSArray* intersections = [scissorPath findIntersectionsWithClosedPath:shapePath andBeginsInside:nil];