ruud@tnoibbc.UUCP (Ruud) (10/23/90)
I'm looking for a tool for the Mac which enables me to read
a Postscript file (describing a picture) and interpret it
in such a way that the initial picture results.
In know that this is partially possible in MS Word 4.0: MS Word
has the possibility to assign the style Postscript to a text
containing Postscript instructions. If that particular file
is then sent to a laserprinter, the Postscript text is
interpreted and a picture is the result (on paper).
However, this method has the major disadvantage that I can
only see the result once it is printed on paper.
I heard from a possible other solution with Adobe
Illustrator. Since, we haven't got Adobe Illustrator at our
department I couldn't try this option (could anyone verify
this possibility for me). However, knowing a little of the
functionality of Adobe Illustrator, I assume that importing
a Postscript picture in Adobe Illustrator has the following
disadvantage:
If I use Postscript to describe two circles connected by a
line I'd like to transport my picture in such a way that
the receiving application (e.g. Adobe Illustrator) still
sees my picture as two circles and one connecting line (and
not just one big picture).
Why do I want this so badly ? My eventual goal is to import
my picture(s) in MacDrawII. Within MacDrawII I want to be able
to manipulate the individual objects before I transport the
picture to, for instance, MS Word.
A picture in MacDrawII is always treated as a set of user-
defined objects. Therefore, I think that MacDrawII supports
some kind of macro language to describe the objects of a
picture (just as PostScript does). I also think that the same
macro language is used to store the picture in a file. In
other words, if a MacDraw file is opened, this results
probably in the interpretation of some kind of program
written in some kind of language (I think).
To conclude, I have the following questions for all Mac
experts:
1. Does anyone know of a tool to interpret Postscript
pictures in such a way that I can still manipulate the
picture as a set of objects (circles, lines, etc.) ?
2. Does anyone know the technical specifications of a
MacDraw file ? Is a macro language used to describe the
different objects of a MacDraw picture and, if so, how does
this macro language look like ?
3. Are there any tools available (public or commercial) to
interpret or generate a MacDraw file (except for MacDraw
itself, ofcourse) ? I'm thinking of a programming language
or whatsoever.
If you have any idea, additional questions or remarks
concerning the questions above, please respond by e-mail.
Thanks in advance, Ruud.
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Ruud van Mieghem : TNO - BOUW INTERNET : ruud@tnoibbc
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================================================================================shiva@well.sf.ca.us (Kenneth Porter) (11/06/90)
Your description of MacDraw suggests that it is a descriptive graphic format. PostScript is a procedural language, like C and Forth. Imagine what would be involved in converting a C program to a MacDraw file. Even a C or Forth program that consisted mostly of drawing primitives would be quite difficult to parse and convert. The models are just too different. This is a general problem associated with converting PostScript to other graphics formats. Because PostScript is procedural, the graphics operators are normally embedded within quite a bit of control structure (loops and conditionals). Unless the PostScript source restricts itself to a well-defined set of operators, it is essentially impossible to convert the source to an object description. Illustrator can parse PostScript files and recover objects provided that the PostScript uses a specific set of procedures defined in Illustrator's prolog (see the Illustrator file format document available from ps-file-server@adobe.com). These procedures are designed to represent objects. An Illustrator object is represented by a call to a procedure with appropriate parameters. If your PostScript file was generated mechanically by an application, it's possible that it uses a prolog to encapsulate the application's object descriptions into PostScript procedures (as Illustrator does). If this is the case, your parsing job gets considerably easier because you just have to parse the application's pseudo-object-language (ie. the PostScript script containing calls to the application's object procedures). If what you want is PostScript to raster, you should use Ghostscript or one of the commercial host-based PostScript clones like Go-Script or Freedom of Press. Ken (shiva@well.sf.ca.us)