Additive Mixing with Core Graphics

Question

How can I compose two images in additive blending mode with Core Graphics?

The listing does not have something like kCGBlendModeAdd : http://developer.apple.com/library/ios/documentation/GraphicsImaging/Reference/CGContext/Reference/reference.html#//apple_ref/doc/c_ref/CGBlendMode

Any solution?

Answer 1

What is wrong with kCGBlendModePlusLighter ?

From a linked document:

 R = MIN(1, S + D) 

So this is additive mixing limited to 1.0.