Drawing shapes (arrow, point) using CGMutablePath. Based on: https://gist.github.com/mwermuth/07825df27ea28f5fc89a

CGMutablePath+Shapes.swift

extension CGMutablePath {

    func addArrow(to point: CGPoint, tailWidth: CGFloat = 4.0, headWidth: CGFloat = 10.0, headLength: CGFloat = 14.0) {
        let length = hypot(point.x - currentPoint.x, point.y - currentPoint.y)
        let tailLength = length - headLength

        let points: [CGPoint] = [
            CGPoint(x: 0.0, y: tailWidth / 2),
            CGPoint(x: tailLength, y: tailWidth / 2),
            CGPoint(x: tailLength, y: headWidth / 2),
            CGPoint(x: length, y: 0.0),
            CGPoint(x: tailLength, y: -headWidth / 2),
            CGPoint(x: tailLength, y: -tailWidth / 2),
            CGPoint(x: 0.0, y: -tailWidth / 2)
        ]
        
        let cosine: CGFloat = (point.x - currentPoint.x) / length
        let sine: CGFloat = (point.y - currentPoint.y) / length
        let transform = CGAffineTransform(a: cosine, b: sine, c: -sine, d: cosine, tx: currentPoint.x, ty: currentPoint.y)
        
        addLines(between: points, transform: transform)
    }

    func markPoint(at point: CGPoint, crossSize: CGFloat = 9.0) {
        move(to: CGPoint(x: point.x - crossSize / 2, y: point.y - crossSize / 2))
        addLine(to: CGPoint(x: point.x + crossSize / 2, y: point.y + crossSize / 2))

        move(to: CGPoint(x: point.x - crossSize / 2, y: point.y + crossSize / 2))
        addLine(to: CGPoint(x: point.x + crossSize / 2, y: point.y - crossSize / 2))
    }

}

Usage:

let path = CGMutablePath()
path.move(to: start)
path.addArrow(to: end)

Point:

let path = CGMutablePath()
path.move(to: location)
path.markPoint(at: location)