Returns an array of `CGPoint`s that are evenly distributed around the circumference of a circle for a given radius, center x, center y, and number of decimal points precision.

SwiftCGPointsOnCircle.swift

import UIKit

/**
 Returns an array of `CGPoint`s that are evenly distributed around the circumference of a circle for a number of points, center x, center y, and radius of the circle, and maximum number of decimal points precision for the x and y values.
 - author: Scott Gardner
 - parameter numberOfPoints: the number of points to plot; 1 or more
 - parameter centerX: the center `x` of the circle
 - parameter centerY: the center `y` of the circle
 - parameter radius: the radius of the circle (distance from center)
 - parameter precision: the maximum number of decimal places precision, 0 or higher, **defaults to 3**
 - returns: `[CGPoint]`
 */
public func pointsOnCircleFor(numberOfPoints: UInt, centerX: CGFloat, centerY: CGFloat, radius: CGFloat, precision: UInt = 3) -> [CGPoint] {
  var points = [CGPoint]()
  let angle = CGFloat(M_PI) / CGFloat(numberOfPoints) * 2.0
  let p = CGFloat(pow(10.0, Double(precision)))
  
  for i in 0..<numberOfPoints {
    let x = centerX - radius * cos(angle * CGFloat(i))
    let roundedX = Double(round(p * x)) / Double(p)
    let y = centerY - radius * sin(angle * CGFloat(i))
    let roundedY = Double(round(p * y)) / Double(p)
    points.append(CGPoint(x: roundedX, y: roundedY))
  }
  
  print(points)
  return points
}