subunit = CGFloat(20.0) context.setFillColor(red: 0.5, green: 0, blue: 0, alpha: 1) context.fill(CGRect(x: 0, y: 0, width: subunit, height: subunit)) context.setFillColor(red: 1, green: 0.3, blue: 0.3, alpha: 1) context.fill(CGRect(x: subunit, y: subunit, width: subunit, height: subunit)) context.setFillColor(red: 0.7, green: 0.3, blue: 0, alpha: 1) context.fill(CGRect(x: 0, y: subunit, width: subunit, height: subunit)) context.setFillColor(red: 0.7, green: 0.3, blue: 0, alpha: 1) context.fill(CGRect(x: subunit, y: 0, width: subunit, height: subunit)) } var callbacks = CGPatternCallbacks(version: 0, drawPattern: drawPattern, releaseInfo: nil) let pattern = CGPattern(info: nil, bounds: CGRect(x: 0, y: 0, width: 1, height: 1), matrix: CGAffineTransform(a: 1, b: 0, c: 0, d: 1, tx: 0, ty: 0), xStep: 40, yStep: 40, tiling: .constantSpacing, isColored: true, callbacks: &callbacks)! let color = UIColor(cgColor: CGColor(patternSpace: CGColorSpace(patternBaseSpace: nil)!, pattern: pattern, components: [1, 1, 1, 1])!) ࣈదͰ͢ 42