"using the Direct3D API in Citra would not speed up things as you think and would be lot's of time to work on fixing previous code just to be compatible with it" just this says what you "need" to know why you will not see this API in Citra anytime soon. What you should know: Google about API's and how games/emulators use them, this will give you some basic knowledge and also kills lot's of future questions you may have. Note that I didn't have the intention to be rude (nothing personal), I guess this thread it's just taking the better of me with so much sh*t posted all the time. Sorry if you were offended in any way by my answer