Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!rutgers!rochester!pt.cs.cmu.edu!andrew.cmu.edu!jm36+
From: jm36+@andrew.cmu.edu (John Gardiner Myers)
Newsgroups: comp.lang.postscript
Subject: Re: need help with postscript interpreter
Message-ID: <0YAGS2y00jaS80S3Vk@andrew.cmu.edu>
Date: 29 Mar 89 18:59:14 GMT
Organization: Mathematics, Carnegie Mellon, Pittsburgh, PA
Lines: 49

First, make sure you have my bug fixes to the interpreter.  Run the
interpreter with the switches:

	-c 'version =='

and you should see "1.4 with jgm/bzs mods v3" in the printed string.
If you don't, the standard blurb follows:

There are a number of bug fixes and improvements available via
anonymous ftp to z.andrew.cmu.edu (128.2.30.8) in the subdirectory
psdiffs.  The patches should be applied to an unpacked virgin
distribution.  READ THE INSTRUCTIONS AT THE BEGINNING OF EACH FILE
BEFORE APPLYING THEM WITH PATCH.

opus@athena.mit.edu (David C. Jedlinsky) writes:
>2) The PostScript manual doesn't say one way or another how many
>entries the Encoding Array must have.  So modify CheckFont in font.c
>to not look at lengthArray(enc), like it does now.  Or make it print a
>warning message.  Your choice.  The LaserWriter, and most other
>printers I've tried, allow smaller than 256 entry arrays.  So ignoring
>it may be defacto correct.

The Red Book I have states in section 5.3 that "POSTSCRIPT requires
that the following key-value pairs exist in each font dictionary:",
followed by a table listing "Encoding" as "an array of 256 names ...
this is described in section 5.4".  Section 5.4 states that "The
encoding vector is defined by a 256-element POSTSCRIPT array object."

If you remove the check in CheckFont, you will have to add another
check elsewhere in order to make sure that the program does not access
memory outside the bounds of the encoding array when displaying a string.

>One more thing: I haven't been able to get dvi2ps output to display
>correctly even with this fix.  Some problem with the bitmap fonts,
>which I haven't solved yet.

dvi2ps does not define a correct bounding box and there are bugs in
the font cacheing code.  I'm in the process of fixing these bugs, but
haven't had any time to work on the interpreter in the last few
months.

If anyone else is interested in working on it, send me mail.  I can
give you what I have and tell you exactly what needs to be done.

-- 
_.John G. Myers		Internet: jm36+@andrew.cmu.edu
(412) 268-5655		LoseNet:  ...!seismo!ihnp4!wiscvm.wisc.edu!give!up
"Whenever faced with a problem, some people say `Lets use AWK.'
 Now, they have two problems." -- D. Tilbrook