Path: utzoo!attcan!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!wuarchive!julius.cs.uiuc.edu!apple!voder!pyramid!infmx!robertw From: robertw@informix.com (Rob Weinberg) Newsgroups: comp.sys.next Subject: Re: EPS Message-ID: <1990Dec20.215526.17957@informix.com> Date: 20 Dec 90 21:55:26 GMT References: Sender: news@informix.com (Usenet News) Organization: Informix Software, Inc. Lines: 42 In article aberno@questor.wimsey.bc.ca (Anthony Berno) writes: >Thank you to everyone who responded to my message about EPS non-editability. >However, I still think there is hope. > >So PostScript is like a full language, with routines and data structures >and such. Well, the thing is, when you print an EPS file, you *generally* >get a single, fixed, result, right? There are some exceptions - like those >silly new "random" fonts, but generally, you get the same output if >you do it twice in a row. > >As such, that output should be made up out of primitives, like squares, >polygons, bitmaps, Bezier curves, etc. Well, suppose you wrote a program >that simulated an EPS file printing out, but didn't send the results to >the printer. Instead, it intercepted them, and converted the print calls >into things like polygons or letters or bezier curves in some common, >sensible format. I think you could extend your exploration of PostScript by getting hold of a file created by Adobe Illustrator, and opening it from any word processor. After all, such a file is just a long text file, a PostScript program. What you WON'T find in the Illustrator file are many PostScript primitives. At the start of the file, you will find a long header. PostScript encourages the programmer to create definitions from the primitives, and to build on these to create other definitions, etc. Then, by the time a program such as Illustrator gets to the point where it needs to translate your mouse clickings and sketchings into code, it can call on these definitions to quickly generate compact code. Anyway, I know little more about PostScript then you do; but you might enjoy dissecting an Illustrator file, and get some idea of why it is not so easy to take any PostScript file and "reduce" it to editable primitives. And, an EPS file can consist of big, inscrutible bitmaps whose only "primitives" are definitions of points on a page. Also, the primitives which describe the shapes of letterforms of the fonts used by a PostScript file are contained in the fonts themselves, which reside in the printer's ROM or in seperate printer font files, not in the PostScript graphic file itself which is sent to the printer. Just take whatever PostScript files you can find lying around and poke into them a bit, and you will see some interesting things.