Path: utzoo!utgpu!water!watmath!clyde!att-cb!osu-cis!tut.cis.ohio-state.edu!mailrus!husc6!bbn!rochester!udel!mmdf
From: smith@nrl-aic.arpa (Russ Smith)
Newsgroups: comp.sys.amiga
Subject: Strangeness with Ellipses
Message-ID: <2106@louie.udel.EDU>
Date: 17 Apr 88 15:43:07 GMT
Sender: mmdf@udel.EDU
Lines: 40

[sent to the generic "amiga-relay" ARPA list]

A local BBSer has a problem with using AreaDraw and AreaEllipse. I've
had similar problems while trying to do a double-buffered/dual-playfield
display. The AreaEllipse function leaves an interesting trail of
garbage that has only very faint relation to the places that it SHOULD
have drawn. His message is

>Message : 24665 [Open] 04/16/88 20:01 
>From    : Richard Krehbiel
>To      : Russ Smith (x)
>Subject : #24614 AreaXxx() problems
>Sig(s)  : 2 (Amiga Util/Term)
>
>   I just left a message on Compu$erve about it (borrowing my brother's
>account). The thing is this: I can perform a series of AreaMove/Draw/End
>calls and it works; I can perform a series of AreaEllipse/End calls and it
>works; when I mix AreaDraw with AreaEllipse I get corrupted ellipses (they
>look like they have diagonal lines drawn through them before being filled)
>and/or Gurus. I'm not mixing AreaDraw and AreaEllipse under the same
>AreaEnd. I can upload the program and a few sample data files too if that
>would help. Thanks for the help.

My symptoms were similar in that I had a "step-like" trail of garbage
(was "translating" a filled circle from about (30,30) to (120,120) by
2's or so) follow the circle. True strangeness was exhibited because
the garbage appeared in a location that could ALMOST have been
an encompassing rectangle, but NOT ALWAYS where the circle would
have been drawn/redrawn).

Anyway, has this been discussed before? Is there a solution/work-around?
Are we both doing something unobviously wrong (*I* have and he probably
has reduced the problem in scope so as not to throw in too many unknown
variables)?

Any response would be appreciated.

Russ <Smith@nrl-aic.arpa>
JAYCOR
Navy Center for Applied Research in Artificial Intelligence (whew!)