Subject: Sega thing

From: [email-masked]
Date: Fri, 28 Aug 92 21:43:42 EDT

We'll be putting out a new demo Real Soon Now that uses a different Sega
switching method.  It relies on the fact that there are 2 or 3 interrupts per frame to switch the video page in advance of the synchronized Sega switch.

Keep in mind the difference between REND386 and the stereo viewing program
you're comparing it to: REND386 >cannot< sit around and wait for the sync
signal to switch pages-- it must draw all the time, and handle page switching 
and Sega switching via interrupts.  If this new method doesn't work, I'll have to find a system locally that shows the problem.

- Dave STampe

---

From: [email-masked]
Date: Sun, 30 Aug 1992 07:47:21 +0200

Hi!

About  the sega flippery problem....

are you using the beam-synchronized interrupt to do the flip? If not
this would be the ideal place to do it!

Just my 0.0000001 milliSKR worth.

/Z

---

From: [email-masked]
Date: Mon, 31 Aug 1992 22:58:26 +0200

Hi!

Somehing is really really fucked with the PAGE FLIPPING. I am not saying
a thing about the SEGA switching coz I dont own any glasses. But with
demo4 room4.wld -x running I can, on my DELL 486/33 see the following
things:

"Half screens" flipping, e.g. pages swapped in before they are drawn. By
just using up-down arrow in the default view in room4.wld I get every now
and then clearly blue sky/green ground see thru for a nanosecond or two.
Page switches seem to occur at the wrong place completely. Also, the
timing is different, one page is shown longer than the other. You
can see that by looking at some object's appearance against a solid
background, e.g. look at the carpet from some distance, you will see the
carpet flicker back and forth. Now your eye should percieve the 'intensity'
of both carpet's images to be equal, but they are not. At least my old
eyes percieve one carpet image to be brighter and seam 'steadier' than
the other one. I think it is the left image that is on too long.

Note that this flippery-flppery of pages only occurs when rend386 is
actually DOING something, e.g. movin back and forth. When I stand still
and the cones and stuff are just spinning, well, it works really nice
and never fails.

My advice: USE the beam synchronized interrupt. Ok, you dudes claim it
doesn't work on some adapters. Well, ok, keep the old code and add a
command line switch for those poor souls for whom it does no work. 
Since the beam interrupt is part of the EGA specification, and every VGA
on the face of the planet is a superset of the EGA specification, well,
I find it hard-ish to believe it would fall apart on all that many systems.

This is just my 0.02 Swedish Crowns worth.

P.S. I have a long list with ideas about rend386 under writing. I will mail
it to the list when I finish it. It has to do with many things, stereo co-
herence, crossed eye views and more stuff.

UNtil then.....

!! The ANSWER   : 42     ("Hitchhikers Guide to the Galaxy" - Douglas Adams) 
!! The QUESTION : 0x2b | ~0x2b   ("Hamlet" - William Shakespear) | Dont Worry -
!! The EMAIL    : [email-masked]  The PHONE: +46 16 96460    | Mail Zappie!