Re: Vector Emulation

>I suspect a proper implementation of this would go a long way toward
>making the B/W vector emulations look better. It doesn't address the
>trails you leave, but I suspect carefull use of alpha buffers could
>help (but 8 bits of alpha won't allow much precision in the decay).
>Hmmm, dump the last N frames into separate buffers and blend according
>to predefined formula... Hmmm tons of video RAM, but it could be an
>option for people with SGIs.

        Maybe. Or just a single frame buffer whose contents "decay" to black
over time with a simple pixel op (e.g. start with the last frame's image in
the frame buffer, reduce it by doing (say) a 30% blend with black, then draw
the current frame - this would cause lines to fade out over the subsequent 3
frames). This would seem to more closely model the behavior of real hardware,
without requiring multiple frame buffers, and I think most 3D cards will do
a single blend operation quite quickly).

        I'd be interested in seeing what the results of that decay + a
3D card's built-in anti-aliasing would produce. You could probably do the
decay in MAME without using a 3D card, just by doing the decay op instead
of clearing the frame buffer between frames.

                        Drew
Received on Mon Oct 4 16:53:43 1999