Hi :) > >>Blit from front buffer to the back one so the two buffer be > > > identical > >>at this moment. > > > > So, can be done, but adding the third buffer makes the whole setup > > 'transparant' to the system and apps, while without this a lot of > > app_server support is needed, and also BDirectWindow apps get into > > trouble (I think?) > > I have some doubts. > Are you talking about page flipping? Once we've done that, if I'm > not wrong, we loose compatibility > with R5 - BWindowScreen; as it writes to the location which is now > the backbuffer. We have to make sure we look from the same viewpoint to this thing. Let's see: 1. app_server / BDirectWindow /apps/whatever 2. third buffer, previously the one and only 'onscreen' buffer, now always offscreen (but still in graphicsmemory) 3. two buffers, page-flipping during (every) retrace. Say, the accelerant simply does this: -waitfor retrace; -flip to buffer #2 -blit 'third buffer' (back-buffer you called it) to buffer #1, which is now invisible -waitfor retrace; -flip to buffer #1 (making visible _everything_ done in the backbuffer!!) -blit 'third buffer' (back-buffer you called it) to buffer #2, which is now invisible -repeat from first step above. With this setup, the whole system is completely transparant to the current drivers, making no single modification nessesary inside the system or apps (if I can manage the engine correctly that is: but for a test I can simply force R5 to work without acceleration, and use the engine for the sole purpose of doing this double-buffer feature: that I am sure will work 100% OK.) > IMHO, the only solution, is to always draw into the backbuffer and > then blit into front buffer > during retrace. Correct. By adding a third buffer this setup remains! (only the backbuffer is the 'third buffer' and the front buffer is alternating #1 and #2: _but_ we now draw in the one of those two that's _currently_, _temporary_ offscreen giving us loads of time to do it in :-) > I don't see how triple buffering could solve our/(this?) problem. > (??) How about now? Rudolf.