Has anyone tried implementing the PorterDuff compositing rules using standard opengl blend modes? I am working on some stuff for a hardware accelerated Vector graphics library for mobile platforms (http://www.khronos.org/openvg/ if you want to know more). Some of the team want to include porter duff compositing, whereas some of us are more sceptical since it will prevent the standards rapid addoption to opengl level hardware. I am just doing some investigation into what functions can be achieved and was curious if anyone had done work on this in the past. Some of the modes are easily implemented, A OVER B and B OVER A. And the A OUT B and B OUT A operations can be achieved in multiple passes, as far as i can tell. I have tried using the frame buffer's alpha and the DST blend modes but I am not getting the results I hoped for. Thanks for any help you can give. EDIT:: Here is a link to the porter duff paper if your interested. http://www.keithp.com/~keithp/porterduff/p253-porter.pdf [Edited by - aleks_1661 on December 8, 2004 7:55:22 AM]