Error: Use of unresolved identifier 'kCGBlendModeMultiply' - xcode

Question

I recently updated to Xcode 7, beta 3.
And I've run into some issues, I can't seem to find any questions for on SO.
When I run my application, i get 3 errors:
Use of unresolved identifier 'kCGBlendModeMultiply'
Use of unresolved identifier 'kCGLineCapRound'
Use of unresolved identifier 'kCGLineJoinMiter'
However the 2 latter ones, disappear, although I assume they will show up after the first one is fixed (hence why I included it in this question).
I didn't see anything in the release notes about these being removed? So I'm a bit stuck at what to do. I tried rewriting the lines of course, but the 3 things I used don't show up as options anymore. In case that they are just gone in the latest Swift 2.0, what can I use instead?
Here's the code for the first error.
func alpha(value:CGFloat)->UIImage
{
UIGraphicsBeginImageContextWithOptions(self.size, false, 0.0)
let ctx = UIGraphicsGetCurrentContext()
let area = CGRect(x: 0, y: 0, width: self.size.width, height: self.size.height)
CGContextScaleCTM(ctx, 1, -1);
CGContextTranslateCTM(ctx, 0, -area.size.height)
CGContextSetBlendMode(ctx, kCGBlendModeMultiply)
CGContextSetAlpha(ctx, value)
CGContextDrawImage(ctx, area, self.CGImage)
let newImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return newImage;
}
Here's the code for the 2 latter errors:
for layer in [ self.top, self.middle, self.bottom ] {
layer.fillColor = nil
layer.strokeColor = UIColor.whiteColor().CGColor
layer.lineWidth = 4
layer.miterLimit = 4
layer.lineCap = kCALineCapRound
layer.masksToBounds = true
let strokingPath = CGPathCreateCopyByStrokingPath(layer.path, nil, 4, kCGLineCapRound, kCGLineJoinMiter, 4)
layer.bounds = CGPathGetPathBoundingBox(strokingPath)
layer.actions = [
"strokeStart": NSNull(),
"strokeEnd": NSNull(),
"transform": NSNull()
]
self.layer.addSublayer(layer)
}
Any help would be greatly appreciated! :)

Answer 1

This should work:
CGContextSetBlendMode(ctx, CGBlendMode.Multiply)
... or even just this:
CGContextSetBlendMode(ctx, .Multiply)
If you Ctrl-click on CGContextSetBlendMode and then from its declaration jump (in the same way) to declaration of CGBlendMode then you will see:
enum CGBlendMode : Int32 {
/* Available in Mac OS X 10.4 & later. */
case Normal
case Multiply
case Screen
case Overlay
// ...
}
Similarly, the other line that produces the error should be changed to:
let strokingPath = CGPathCreateCopyByStrokingPath(layer.path, nil, 4, .Round, .Miter, 4)