Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!mnetor!uunet!husc6!mit-eddie!uw-beaver!cornell!batcomputer!itsgw!nysernic!rpicsb8!csv.rpi.edu!guilford
From: guilford@csv.rpi.edu (Jim Guilford)
Newsgroups: comp.sys.amiga
Subject: Re: PopCLI Fade
Message-ID: <106@rpicsb8>
Date: Mon, 12-Oct-87 14:39:42 EDT
Article-I.D.: rpicsb8.106
Posted: Mon Oct 12 14:39:42 1987
Date-Received: Wed, 14-Oct-87 01:18:21 EDT
References: <1852@gryphon.CTS.COM>
Sender: nobody@rpicsb8
Reply-To: guilford@csv.rpi.edu (Jim Guilford)
Organization: RPI CS Dept, Troy, New York
Lines: 29
Keywords: Popcli fade
Summary: Fade is not easy

In article <1852@gryphon.CTS.COM> bilbo@pnet02.CTS.COM (Bill Daggett) writes:
>I've been using PopCLI for some time and am curious to know if it would be
>possible for the screen to fade rather then pop?  Also, I do not know how to
>reach the author - who's name escapes me now (that doen't help much does it?).
>I am not a hacker and I don't call long distance.  Perhaps someone saying "no,
>it is not possible" will suffice...
>
>
>UUCP: {hplabs!hp-sdd!crash, seismo!scgvaxd!cadovax}!gryphon!pnet02!bilbo
>INET: bilbo@pnet02.CTS.COM
>
>*Bilbo*
>(Recombinant Hobbit)

As far as I can remember, the code creates a tall but narrow screen which
overlays all the other screens. It is only one bit deep and is set to black.
Then the program turns off the DMA to free up as much time for the CPU as
possible. In order to do a fade, one would have to create a set of screens
(one for each screen being displayed), copy the currently displayed image
onto the new screen, and then fade it. Then to unfade it, it would have to
copy the new version of the other screens (remember that output continues
while faded) to the top screen, quickly unfade it, and then remove the new
screens. All in all, it would be very messy.
One might try playing with the color registers directly, but then if the
user's programs diddled with them during a fade you would have a mess.
Due to the versatility of the amiga, I don't think it is easily possible.

--JimG
(guilford@csv.rpi.edu)