lehmann@ss3a.cs.cmu.edu (Eric Lehmann) (03/27/90)
I am interested in learning how Quickdraw region operations work so efficiently. In particular, I would like to find out how Quickdraw determines if two regions overlap. Are there any articles explaining how it works? Thanks. -Eric
segal@husc9.harvard.edu (Jonathan Segal) (03/28/90)
In article <8609@pt.cs.cmu.edu> lehmann@ss3a.cs.cmu.edu (Eric Lehmann) writes:
I am interested in learning how Quickdraw region operations work so
efficiently. In particular, I would like to find out how Quickdraw
determines if two regions overlap. Are there any articles explaining
how it works? Thanks.
-Eric
There is a story (probably apocryphal, but who knows?) that one day,
Bill Atkinson (the inventor of quickdraw regions) was in a car
accident. The first question the apple folks (Jobs, Woz, etc.) asked
him when he first awakened was "Bill, do you still know how regions
work?" because he was the only person in the known universe who
understood them. I would assume that since then they have trained a
few people, deep within the apple hierarchy, as to the inner workings
of regions, but they have had to take vows of silence to protect the
sacred secret.
JAS
(with apologies if I got any of the facts wrong...)jg@max.crl.dec.com (Jim Gettys) (03/28/90)
Dunno how Apple represents regions. If you want to look at another, public implementation of code which does that sort of thing, look at the MIT X11R4 server. It is pretty well tuned at this point... Has to be; it is fundamental to the X server and used all over the place (and X now does very complex shapes due to the shape extension; it had to be fast to make that work well). Of course, I don't guarantee the code is understandable, only that it is portable, fast, and believed to be correct. Jim Gettys Digital Equipment Corporation Cambridge Research Laboratory
kaufman@Neon.Stanford.EDU (Marc T. Kaufman) (03/28/90)
.In article <8609@pt.cs.cmu.edu> lehmann@ss3a.cs.cmu.edu (Eric Lehmann) writes:
. I am interested in learning how Quickdraw region operations work so
. efficiently. In particular, I would like to find out how Quickdraw
. determines if two regions overlap. Are there any articles explaining
. how it works? Thanks.
-Eric
Try the May, 1987, issue of MacTutor for an explanation of Regions.
Marc Kaufman (kaufman@Neon.stanford.edu)paul@taniwha.UUCP (Paul Campbell) (03/29/90)
In article <SEGAL.90Mar27182149@husc9.harvard.edu> segal@husc9.harvard.edu (Jonathan Segal) writes: >In article <8609@pt.cs.cmu.edu> lehmann@ss3a.cs.cmu.edu (Eric Lehmann) writes: > I am interested in learning how Quickdraw region operations work so >understood them. I would assume that since then they have trained a >few people, deep within the apple hierarchy, as to the inner workings >of regions, but they have had to take vows of silence to protect the >sacred secret. There was an article in MacTutor a 18 months or so ago which told all. Actually the information is available from the US government - just pull Apple's patent. Paul -- Paul Campbell UUCP: ..!mtxinu!taniwha!paul AppleLink: CAMPBELL.P "The current plan is to replace the flag with one with alternating vertical black and white stripes of varying widths - this is thought to better represent the country's system of government ..."