Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!cs.utexas.edu!natinst!sequoia!chinacat!woody
From: woody@chinacat.Unicom.COM (Woody Baker @ Eagle Signal)
Newsgroups: comp.lang.postscript
Subject: Re: PostScript Level II, contextual forms
Summary: doing things twice
Message-ID: <1543@chinacat.Unicom.COM>
Date: 4 Sep 90 02:46:57 GMT
References: <9607@goofy.Apple.COM> <1289.26d27708@waikato.ac.nz> <5805@memqa.uucp>
Organization: a guest of Unicom Systems Development, Austin
Lines: 68

In article <5805@memqa.uucp>, r91400@memqa.uucp (Michael C. Grant) writes:
> In article <1376.26dc15f6@waikato.ac.nz>, ccc_ldo@waikato.ac.nz (Lawrence D'Oliveiro, Waikato University) writes:
> 
> Okay, tell me the flaw in this logic:
> Assume that Postscript handles contextual forms for me.  So, if I send
> it the 'gloop' character, there might be four or five different ways
> that it would print out, depending upon its 'surroundings'.

I think that contextual forms are fairly limited.  If you send it the
gloop character as you call it, about the only thing that really
could happen would be automatic capitalization, and there is a fairly
specific set of rules to do that.  A character is a character.


> 
> Great.  Now, assume that we DON'T have Display Postscript.  How in the
> world are we going to display these forms on the screen before we
> send them to the laser printer?  Easy, just DUPLICATE THE WORK

Why is this even a concern?  Why should you even need to worry about
displaying these forms to the screen?  If they exist in the machines
characterset, they will automatically be displayed.  Take the 
ntilde for example. It is directly accessable from the character set
on the pc.  If you are working on a machine that supports some other
language, it will certainly have it's own set of built in characters.


> Now, let us assume that there is more than one code for the 'gloop'
> character--a unique code for each of its forms (just as there is a separate
> code for capital and lowercase 'a', for example).  Now, either the user
> or the application chooses the proper form, and send that UNIQUE code to
> the PostScript printer.  Voila--the printer does not have to interpret
> the code contextually, it just runs through the lookup table as always.
>

Or the printer, which more than likely has more computational power than
the machine that is driving it, can choose the proper form.  A PC/AT
class machine running DOS (there are more of them than all other
machines put together) does one thing at a time.  I prefer to be able
to let some other CPU do as much work as possible, so my machine does
not stay tied up.  After all, what impacts me the most is the tool
that I use.

> Sure, contextual forms are usually more complex that 'A' vs. 'a', but
> the idea is similar: we press the SHIFT key to get 'A'.  Why not press
> a special key, for example, to get the end-of-the-word representation
> of a Japanese character?  When we write by hand, we must make that
> adjustment, and so it is quite natural for us to think this way.

Certainly, but why should my machine have to worry about placement of
characters, or substitution.  The program running in the printer is
perfectly capable of that.  Now, this does require a shift in the
perspective that one views PostScript in, that is rather than a
page description laser driver, it is a complex programming language
that happens to (by design) do a very fine job of laying graphics
and text down.  If all you want to do is send minimal command
sequences, then why even have Postscript at all?



> 
> than the former scenario, in which it is performed at least TWICE,
Generaly the hardware can and does handle this, and if it doesnot,
well, you don't *have* to have WYSIWYG.


Cheers
Woody