Android Porter-Duff合成性能

Question

I have been unable to find any internet articles or Google documentation on the relative performance of compositing bitmaps using different Porter-Duff modes. What has become very apparent to me whilst programming is that the traditional SRC/DST prefix modes are performing a lot faster (3 - 4 times faster) than the Android Mode.DARKEN, Mode.LIGHTEN, Mode.MULTIPLY modes. Use of the latter modes can bring down my game engine's performance from 40+ to around 13 FPS when rendering a lighting mask on a 720p screen.

My questions are thus:

1. Is there a faster way for compositing images using the darken/lighten property than the supplied Porter-Duff modes? Would it be worth the switch to OpenGL?
2. Are there data available on the relative speeds of different compositing modes?

Answer 1

1. Yes, there are many faster ways, for a game engine switching to opengl (or to something like Unity if you want something more high level) can be a very good idea. Renderscript is also a very good alternative that already has built-in multiply intrinsic.

2. You should probably bench these things yourself, there are few measurements on this kind of topic and hardware moves fast.