i know there are a lot of topics in internet about which one is better or in which field which one is better, but i dont know the exact answer. i think these questions are mostly about exprience. and i want to know your exprience.
1) i read an article about valve engineers. it said opengl is faster than directx even on windows. is that true?
2) its said in directx programmer has more controll rather than opengl.
3) which one give better visuals about sahders or technology they use? is it make difference or that is all the same and depend only on programmer that work on them? what about built in effects, particles, lightening,...
4)as I searched in internet, there is no much difference between them, so why Microsoft introduced directx when there was opengl? or why is still developing it? a developer can use opengl for all platforms and forget pain of using a single platform api.
5) I see in engines like unity or unreal that says dx11 version or... it seems using new directx gives more important features. what are those features that can only be used on windows or xbox? are they just for editor or for last output game?
6) what is given in every update of those api,s? for example what is difference of dx10 and dx11? is this about new tools and functions or math or something else? so when in a graphic card is written it supports dx11 what does it mean?
thank you for helping