CALayer BlendMode

Question

I am creating a simple iOS application in which I have two CALayers, I want to add the blend effect on the upper CALayer to display the content on the second layer. I dont want to do it alpha. Is there any way to do this without changing the alpha?

Answer 1

iOS (as of 5.1) does not currently support any blend effects on CALayer. In my testing, the compositingFilter property is ignored.

Answer 2

There's a tricky way to achieve this.

compositingFilter works but filter names should be like subtractBlendMode (lower camel case), not CISubtractBlendMode.

Here is a demo:

https://github.com/arthurschiller/CompositingFilters