I'm trying to decide which GUI library to use, and so far I am really leaning towards MyGUI. I compiled the source under VC++10 using Ogre and OIS input, and have noticed that when I enable vsync in my ogre.cfg for the demos, there is a noticeable mouse latency that goes away with higher frame rates (vsync disabled). I have not noticed the same issue with CEGUI for example with vsync on, so I was wondering if this is related to how the demos themselves are coded, or if it's an issue of MyGUI or MyGUI+OIS.
MyGUI don't handle mouse, so it depends only on OIS/input setup. May be we did it partially wrong. MyGUI get injectMouse*** events with mouse position in pixels relative to your application, so it never know what is mouse, how it moves, etc.
That makes sense, it must have something to do with either OIS or the way it is being utilized in the demos. At any rate, I think I can safely ignore that in deciding which GUI to use, since both MyGUI's input and CEGUI's input are injected, the latency should not be related to the library. Looks like I'll be using MyGUI after all!