drawLineFrom

gistfile1.swift

func drawLineFrom(fromPoint: CGPoint, toPoint: CGPoint, color: UIColor, brushWidth: CGFloat) {
        UIGraphicsBeginImageContext(view.frame.size)
        let context = UIGraphicsGetCurrentContext()
        paintCanvas.image?.drawInRect(CGRect(x: 0, y: 0, width: view.frame.size.width, height: view.frame.size.height))
        
        let colorConverted = CIColor(color: color)!
        
        let redComp = colorConverted.red()
        let greenComp = colorConverted.green()
        let blueComp = colorConverted.blue()
        let alphaComp = colorConverted.alpha()
        
        CGContextMoveToPoint(context, fromPoint.x, fromPoint.y)
        CGContextAddLineToPoint(context, toPoint.x, toPoint.y)
        
        CGContextSetLineCap(context, kCGLineCapRound)
        CGContextSetLineWidth(context, brushWidth)
        CGContextSetRGBStrokeColor(context, redComp, greenComp, blueComp, 1.0)
        CGContextSetBlendMode(context, kCGBlendModeNormal)
        
        CGContextStrokePath(context)
        
        paintCanvas.image = UIGraphicsGetImageFromCurrentImageContext()
        paintCanvas.alpha = paintCanvasOpacity
        UIGraphicsEndImageContext()
    }