Path: utzoo!attcan!uunet!lll-winken!lll-tis!ames!mailrus!uwmcsd1!uxc!tank!nucsrl!bob
From: bob@eecs.nwu.edu (Bob Hablutzel)
Newsgroups: comp.sys.mac
Subject: Re: Desktop icon mask
Message-ID: <10330032@eecs.nwu.edu>
Date: 12 Sep 88 12:58:37 GMT
References: <698@tasis.utas.oz>
Organization: Northwestern U, Evanston IL, USA
Lines: 15

> The way that the finder handles the icon mask in the latest system software
> has changed.  Previously it did an XOR with the mask to show the selected
> icon.  However this is not so anymore.  Does anyone know what the actual
> alogorithm is now.

This has changed as part of the color support for new machines. In a color
environment, XORing with the hardcoded mask leads to results that Apple's
engineers didn't like. The current algorithm involves figuring out an all
solid black mask from the first ICON in the ICN# resource, and XORing with
that.

This was foreshadowed in TN 147, but I couldn't find any reference which
explained this.

Bob Hablutzel		BOB@NUACC.ACNS.NWU.EDU
Disclaimer:	<Deleted on request of my lawyers>