Draw Semircle Between Any Two Arbirtary CGPoints

Semicircle.swift

extension CGContext {
  
    // via https://stackoverflow.com/a/50419334/27779
    func drawSemicircle(from: CGPoint, to: CGPoint, clockwise: Bool) {
        let center = CGPoint(x: 0.5 * (from.x + to.x), y: 0.5 * (from.y + to.y))
        let radius = 0.5 * hypot(to.x - from.x, to.y - from.y)
        let startAngle = atan2(to.y - from.y, to.x - from.x)
        let endAngle = startAngle + .pi
        move(to: from)
        addArc(center: center, radius: radius, startAngle: startAngle, endAngle: endAngle, clockwise: clockwise)
    }
  
}