PdGetDevices() returns array of rids, it's ok with this function. Clear and understandable.

a) PdSetTargetDevice() requires DC, and documentation mentions, that I can pass PdOffscreenContext_t to it, so I need to
 create it.

b) PdCreateOffscreenContext() and PdCreateOffscreenContextGF() documentation mentions, that before offscreen context 
creation I must target this function to the specific device, go to step a).

This looks a bit of recursive for me.

What to do if I have two different video cards which are handled by Photon ? As far as I understand, PdGetDevices() 
returns two rids in array. But what to do next ? How to target PdCreateOffscreenContext() or 
PdCreateOffscreenContextGF() to specific video driver, for right memory allocation. I can imaging what would be if 
memory was allocated by one driver and then was passed it to another driver :-/