For the next release... I'm still testing it:"CPU <--> GPU synchrony" in OpenGL
Looks like MAME implementation of OpenGL drawing needs this feature, or at least it seems my AMD Radeon HD7400M video card. It's simply an extra OpenGL instruction call in the renderer source code. I decided to make it an option and not an internal default because there are a lot of discussion on the web about its use. It has been verified that it can severely reduce input lags but it seems it's also a performance loss, even if with a modern hardware you shouldn't notice anything relevant. My video card really benefits from this option, expecially with Vertical Sync
enabled in its Control Panel
and with MAMEUIFX "Sync to monitor refresh"
option enabled. I have perfect smooth scrolling, no tearings, no hiccups and no one frame is skipped during emulation. I could post here some interesting links but now I'm in a hurry. Maybe tomorrow. If you want to do some researches by yourself, try to google "glFinish()"