David Megginson writes: > > Norman Vine writes: > > > If we can half the frame rate hit of the Panel using this kind of scheme, > > and I expect even a better boost, then we could render half the instruments > > one frame and the other half the next and still have the ~same instrument > > update rate as we currently have and an overall ~25% boost in framerate > > when the Panel is displayed > > > > (1) This is assuming that the Panel rendering hit is approx half of the overall > > cost of a complete frame > > Actually, you'd slow it down slightly -- you'd have to double the > framerate to get the same instrument update rate, not just add 25%. > If you went from 40 fps to 50 fps, the instruments would still be > updating at only 25 fps.
Close :-) the instruments would be updating a little faster say ~30fps < the math is a little more complicated then a straight addition > but this was *lowballing* what I would expect to see for a speedup ie if we were only redrawing 20% of the instruments each frame I would expect to take approx 25% of the current time to draw the the Panel also note I think we would all be happy with a 15hz instrument update if it meant we went from a 30hz to a 60hz screen refresh rate :-) misc thoughts: We could maintain current_value, last_value and a redraw_value for each instrument and each frame check to see if the instrument needed refreshing. This would be real quick and hardly add any delay in the worse case scenario where all of the instruments needed refresh but could potentially save a *lot* of work ! ie in quasi steady flight conditions most instruments would probably go minutes before needing a refresh esp. if we were smart about the delta value that required an update. Also note that if this were done as a 3D cockpit rather then a monolithic Panel then each instrument would capable of being individually culled by SSG eliminating anywork required for that instrument Norman _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
