Path: utzoo!utgpu!water!watmath!clyde!rutgers!ll-xn!husc6!linus!philabs!ttidca!sa
From: sa@ttidca.TTI.COM (Steve Alter)
Newsgroups: comp.lang.postscript
Subject: Re: Encapsulated PostScript
Message-ID: <1572@ttidca.TTI.COM>
Date: 18 Dec 87 08:13:45 GMT
References: <488@tetons.UUCP>
Reply-To: sa@ttidca.tti.com (Steve Alter)
Organization: Citicorp/TTI, Santa Monica
Lines: 65

In article <488@tetons.UUCP> gnd@tetons.UUCP (Greg Darnell) writes:
} Can anyone tell me what "Encapsulated" PostScript is?  I have some
} PostScript files I would like to import into Ventura Publisher running
} under MS/DOS 3.2 to incorporate in a document.  When I try to load 
} them into VP it chokes.  VP insists on them being in encapsulated format
} with a default file type of .EPS but I don't know what has to be done.

My off-the-top-of-my-head belief is that you need one of the following:
A. An application that knows how to create a real .EPS (Encapsulated
   PostScript) file, or
B. You need for Ventura Publisher to know how to incorporate straight
   postscript.

I say this, because the format looks pretty hairy for someone to
incorporate manually.  Adobe Systems has published a document entitled
"Encapsulated PostScript File Format" with subtitle "For Apple Macintosh
and IBM PC Applications."  (PostScript is a registered trademark of Adobe
Systems, Incorporated.)  The date of this document is December 18, 1986,
for version 1.2 of the EPS format.

Since this might be proprietary stuff, I'll have to avoid technical
details (anybody from Adobe reading this?)

A failure in any one of the following could be the cause for Ventura
rejecting your PostScript file.

1. Structuring should follow the conventions listed in the PostScript
   Language Reference Manual (the "Red book") Appendix C, and also the
   PostScript Document Structuring Conventions, version 2.0 (available
   from Adobe.)

2. Files must be "well-behaved" in their use (or avoidance) of certain
   operators.

3. The file must include the "%%BoundingBox" comment (described in the
   Structuring Conventions.)

4. There are a bunch of "%%comments" that must or should be included
   if the file does any text work.

5. This last one is the worst.

   For the IBM PC (and its brothers in the universe of clones):
   "The recommended file extension is .EPS.  Other file extensions will
   also be allowed, but it will be assumed that these files are text only
   files with no screen metafile or TIFF section in them."

   This says to me that .EPS files might be required to have a screen
   metafiles or TIFF section!
   (A screen metafile is a Microsoft Windows feature.)
   (TIFF == Tag Image File Format.)
   The document goes on to describe, in explicit detail, the format of the
   .EPS file when a screen metafile or TIFF file is included; this is
   a binary format, with length/position headers and checksums.

Conclusions:
If you can get Ventura Publisher to accept a straight-text file, then
all you might have to do is make sure that the required comments are
in there and that the code is well-behaved.

Good Luck!

-- Steve Alter
...!{csun,rdlvax,trwrb,psivax}!ttidca!alter  or  alter@tti.com
Citicorp/TTI, Santa Monica CA  (213) 452-9191 x2541