Xref: utzoo comp.sys.mac:35792 comp.sys.mac.programmer:8029
Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!iuvax!ndcheg!ndmath!milo
From: milo@ndmath.UUCP (Greg Corson)
Newsgroups: comp.sys.mac,comp.sys.mac.programmer
Subject: Re: System 7.0 speculations: Hot Scoop?
Message-ID: <1506@ndmath.UUCP>
Date: 3 Aug 89 15:26:44 GMT
References: <2397@pur-phy>
Organization: Math. Dept., Univ. of Notre Dame
Lines: 41

From article <2397@pur-phy>, by sho@pur-phy (Sho Kuwamoto):
> In article <458@lloyd.camex.uucp> kent@lloyd.UUCP (Kent Borg) writes:
>>
>>Want an answer in the form of a wild-ass prediction?  
>>
>>Apple knows that fuzzy fonts are better, but Apple has *no* intention
>>of making the new font manager output fuzzy fonts.
>>
>>Never.  
>>
>>Rather, when they fix QuickDraw (i.e., give it all that PostScript can
>>do, plus some) they will give *it* antialiasing.  That way, not only
>>will fonts be antialiased, but so will diagonal lines, circles, etc.
> 
I think the only real way to impliment GOOD anti-aliasing is in the video board
hardware.  You store 4x as many pixels and hardware average quads of pixels
down to single ones.  This isn't particularly difficult to do, but memory
access has to be fast (althought that isn't much of a problem these days).

The problem with doing it in SOFTWARE (ie quickdraw) is how to handle drawing
overtop of already existing bits in a bitmap...  You can't tell where the
existing bits came from, their color or alignment from the anti-aliased image
already in the video card...so how do you draw (accurately) anti-aliased
images over top of it?

The only way to do it in software AND allow random drawing of additions to 
the picture would be to have a "high" resolution non-antialiased off-screen
bitmap in addition to the antialiased image on the video card RAM.  Then you
draw everything (bigger) on the off-screen bitmap, average groups of pixels
as you go, writing them to the video card.  It works...but is very expensive
in CPU time and RAM.  Doing the anti-aliasing in hardware is much more efficient
and quite a bit faster...it still uses a lot of RAM, but not as much as
doing a software anti-alias!


Greg Corson
19141 Summers Drive
South Bend, IN 46637
(219) 277-5306 
{pur-ee,rutgers,uunet}!iuvax!ndmath!milo