UIMandelbrot — Appropriate for Xcode Playgrounds

gistfile1.swift

import UIKit

let white = UIColor.whiteColor().CGColor
let black = UIColor.blackColor().CGColor

let w :CGFloat = 105
let h :CGFloat = 60
let size = CGSizeMake(w, h)

UIGraphicsBeginImageContextWithOptions(size, true, 0.0)
let context = UIGraphicsGetCurrentContext()

let maxIteration = 15

var pal = [CGColor]()
for var c :CGFloat = 0; c < CGFloat( maxIteration + 1); c = c + 1 {
    pal.append(UIColor(white: c / CGFloat(maxIteration), alpha: 1).CGColor)
}

for var Px :CGFloat = 0; Px < w; Px = Px + 1 {
    for var Py :CGFloat = 0; Py < h; Py = Py + 1 {
        
        let x0 = ((Px / w) * 3.5) - 2.5
        let y0 = ((Py / h) * 2) - 1
        
        var x :CGFloat = 0
        var y :CGFloat = 0
        var iteration = 0
        
        while ( x*x + y*y < 2*2  &&  iteration < maxIteration )
        {
            let xtemp = x*x - y*y + x0
            y = 2*x*y + y0
            x = xtemp
            iteration = iteration + 1
        }
        
        CGContextSetFillColorWithColor(context, pal[iteration])
        
        CGContextFillRect(context, CGRectMake(Px, Py, 1, 1))
    }
}

let image = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()