Mask blur with image - ios

Question

So in my swift app I'm allowing the user to paint with there finger on touch. I'm using cgcontext to do this. After the user lifts the finger and the touch ends I am dynamically adding a visualeffect view on top of the shape with the same height and width of the drawn shape.
What i want to do next is use the shape as a mask for visualeffect view. The problem right now is if i try to mask the visualeffect view with the shape. the masked view does not show unless the origin point of the shape is (0,0). Here is a link to how i'm currently attempting to implementing this (https://pastebin.com/JaM9kx4G)
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
swiped = false
if let touch = touches.first as? UITouch {
if (touch.view == sideView){
return
}
tempPath = UIBezierPath()
lastPoint = touch.location(in: view)
tempPath.move(to:lastPoint)
}
}
func drawLineFrom(fromPoint: CGPoint, toPoint: CGPoint) {
tempPath.addLine(to: CGPoint(x: toPoint.x, y: toPoint.y))
UIGraphicsBeginImageContext(view.frame.size)
let context = UIGraphicsGetCurrentContext()
otherImageView.image?.draw(in: CGRect(x: 0, y: 0, width: view.frame.size.width, height: view.frame.size.height))
// 2
context!.move(to: CGPoint(x:fromPoint.x,y:fromPoint.y))
context!.addLine(to: CGPoint(x:toPoint.x, y:toPoint.y))
// 3
context!.setLineCap(CGLineCap.round)
context!.setLineWidth(brushWidth)
context!.setStrokeColor(red: red, green: green, blue: blue, alpha: 1.0)
context!.setBlendMode(CGBlendMode.normal)
// 4
context!.strokePath()
// 5
otherImageView.image = UIGraphicsGetImageFromCurrentImageContext()
otherImageView.alpha = opacity
UIGraphicsEndImageContext()
}
override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
swiped = true
if let touch = touches.first as? UITouch {
let currentPoint = touch.location(in: view)
drawLineFrom(fromPoint: lastPoint, toPoint: currentPoint)
// 7
lastPoint = currentPoint
}
}
override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
tempPath.close()
let tempImage = UIImageView(frame: CGRect(x: 0, y: 0, width: view.frame.size.width, height: view.frame.size.height))
UIGraphicsBeginImageContext(tempImage.frame.size)
tempImage.image?.draw(in: CGRect(x: 0, y: 0, width: view.frame.size.width, height: view.frame.size.height), blendMode: CGBlendMode.normal, alpha: 1.0)
otherImageView.image?.draw(in: CGRect(x: 0, y: 0, width: view.frame.size.width, height: view.frame.size.height), blendMode: CGBlendMode.normal, alpha: opacity)
let context = UIGraphicsGetCurrentContext()
let image = UIGraphicsGetImageFromCurrentImageContext()
tempImage.image = image
otherImageView.image = nil
imageView.addSubview(tempImage)
let blur = VisualEffectView()
blur.frame = CGRect(x:tempPath.bounds.origin.x,y:tempPath.bounds.origin.y, width:tempPath.bounds.width, height:tempPath.bounds.height)
blur.blurRadius = 5
blur.layer.mask = tempImage.layer
}