How to draw stars using Quartz Core?

Question

I\'m trying to adapt an example provided by Apple in order to programmatically draw stars in line, the code is the following:

CGContextRef context = UIGraphi         


        

Answer 1

I prefer using a CAShaperLayer to implementing drawRect, as it can then be animated. Here's a function that will create a path in the shape of a 5 point star:

func createStarPath(size: CGSize) -> CGPath {
    let numberOfPoints: CGFloat = 5

    let starRatio: CGFloat = 0.5

    let steps: CGFloat = numberOfPoints * 2

    let outerRadius: CGFloat = min(size.height, size.width) / 2
    let innerRadius: CGFloat = outerRadius * starRatio

    let stepAngle = CGFloat(2) * CGFloat(M_PI) / CGFloat(steps)
    let center = CGPoint(x: size.width / 2, y: size.height / 2)

    let path = CGPathCreateMutable()

    for i in 0..

It can then be used with a CAShapeLayer like so:

let layer = CAShapeLayer()
layer.path = createStarPath(CGSize(width: 100, height: 100))
layer.lineWidth = 1
layer.strokeColor = UIColor.blackColor().CGColor
layer.fillColor = UIColor.yellowColor().CGColor
layer.fillRule = kCAFillRuleNonZero