AttributedString to UIBezierPath

UIBezierPath+AttributedString.swift

extension UIBezierPath {

    // Source: https://github.com/aderussell/string-to-CGPathRef/blob/0bd9350dc2100029f3ddb8d9667384841549ecd6/ARCGPathFromString/ARCGPathFromString.m
    convenience init(attributedString: NSAttributedString) {
        let letters = CGMutablePath()

        let line = CTLineCreateWithAttributedString(attributedString as CFAttributedString)

        let runArray = CTLineGetGlyphRuns(line)

        // for each RUN
        for runIndex in 0..<CFArrayGetCount(runArray) {
            // Get FONT for this run
            let run = unsafeBitCast(CFArrayGetValueAtIndex(runArray, runIndex), to: CTRun.self)
            let runFontValue = CFDictionaryGetValue(CTRunGetAttributes(run), unsafeBitCast(kCTFontAttributeName, to: UnsafeRawPointer.self))
            let runFont = unsafeBitCast(runFontValue, to: CTFont.self)

            // for each GLYPH in run
            for runGlyphIndex in 0..<CTRunGetGlyphCount(run) {
                // get Glyph & Glyph-data
                let thisGlyphRange = CFRangeMake(runGlyphIndex, 1)
                var glyph: CGGlyph = CGGlyph()
                var position: CGPoint = .zero
                CTRunGetGlyphs(run, thisGlyphRange, &glyph)
                CTRunGetPositions(run, thisGlyphRange, &position)

                // Get PATH of outline
                do {
                    var glyphTransform = CGAffineTransform(translationX: position.x, y: position.y)
                    if let letter = CTFontCreatePathForGlyph(runFont, glyph, &glyphTransform) {
                        // The glyph will initially be upsidedown because CoreText works in an inverted coordinate system.
                        // After flipping we need to move the glyph back down.
                        let t = CGAffineTransform(scaleX: 1, y: -1).translatedBy(x: 0, y: -letter.boundingBoxOfPath.height)
                        // Because we flipped the text with a transform the drawing direction of the path is unexpectedly reversed
                        // This will reverse it back to make evenOdd binary path operations behave as expected
                        let reverseWindingLetter = UIBezierPath(cgPath: letter).reversing().cgPath
                        letters.addPath(reverseWindingLetter, transform: t)
                    }
                }
            }
        }

        self.init(cgPath: letters.copy()!)
    }
}

Thanks