import CoreGraphics
import UIKit

let ctx = UIGraphicsGetCurrentContext()

func
addArc(inCenter : CGPoint, _ inRadius : CGFloat, _ inStartAngle : CGFloat, _ inEndAngle : CGFloat, _ inClockwise : Bool = false)
{
    CGContextAddArc(ctx, inCenter.x, inCenter.y, inRadius, inStartAngle, inEndAngle, inClockwise ? 1 : 0)
}


addArc(CGPoint(x: 0, y: 0), 50.0, 0.0, M_PI)