Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!usc!snorkelwacker!spdcc!denbeste
From: denbeste@spdcc.COM (Steven Den Beste)
Newsgroups: comp.sys.amiga.tech
Subject: Am I even or odd?
Message-ID: <1958@ursa-major.SPDCC.COM>
Date: 5 Mar 90 00:23:45 GMT
Reply-To: denbeste@ursa-major.spdcc.COM (Steven Den Beste)
Organization: S.P. Dyer Computer Consulting, Cambridge MA
Lines: 19

I picked up a set of 3D LC-shutter glasses, and I'm trying to put together
a package allowing 3D animations with them. To that end, I have plugged
a small routine into the vertical retrace which swaps eye lenses.

That works just fine, about half the time. The other half, for reasons which
should be obvious, the eyes are swapped and the image is rather odd looking.
I need one of the following:

	1. A way when I start to force one of the two fields (either even
	   or odd) to be the next one used, and to have them alternate
	   from there.

	or

	2. A way to find out during the vertical retrace which field will be
	   the next to be shown.

I've spent an amazing amount of time looking through my 3-year-old RKM's, with
predictable results. Can anyone help me out? Please mail if possible.