Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!iuvax!rutgers!gatech!ncar!husc6!lloyd!kent
From: kent@lloyd.camex.uucp (Kent Borg)
Newsgroups: comp.sys.mac
Subject: Re: Inverse video/text
Message-ID: <364@lloyd.camex.uucp>
Date: 6 Apr 89 18:38:18 GMT
References: <6806@saturn.ucsc.edu> <141200011@cdp> <5894@pdn.paradyne.com> <38395@think.UUCP>
Reply-To: kent@lloyd.UUCP (Kent Borg)
Organization: Camex, Inc., Boston, Mass USA
Lines: 25

In article <38395@think.UUCP> barmar@kulla.think.com.UUCP (Barry Margolin) writes:
[talking about whether x-oring a cursor is patented]

>It may also cover things like blinking block cursors.  I suspect it
>DOESN'T cover the standard Macintosh arrow mouse cursor, since that
>displays a black arrow, rather than an inverted arrow.  However, it
>inverts the border, so that the arrow is still visible on a black
>background; I don't know whether this hybrid scheme is covered by the
>patent.

When I move my cursor it looks like the pixels under the arrow itself
are set black and bits under the the 1-pixel wide border are set
white.  I don't see any x-oring going on.

I have heard that, if as a programmer, you want to animate between
windows (like the Finder does with draging icons between folders or
open/close zooming rectangles) you are supposed to do everything with
paired x-ors as a way to be sure to put all the bits back the way you
found them before letting anybody else have the CPU.  (Before calling
SystemTask, GetNextEvent, etc.)

Kent Borg
kent@lloyd.uucp
or
...!hscfvax!lloyd!kent