Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!uwm.edu!zaphod.mps.ohio-state.edu!tut.cis.ohio-state.edu!purdue!bu-cs!bloom-beacon!eru!luth!sunic!mcsun!ukc!icdoc!qmc-cs!harlqn!jcgs From: jcgs@wundt.uk.co.harlqn (John Sturdy) Newsgroups: comp.lang.postscript Subject: Re: encapsulated postscript Message-ID: Date: 30 Nov 89 03:45:39 GMT References: <288@peyote.cactus.org> Sender: news@harlqn.UUCP Organization: Harlequin Ltd, Cambridge, UK Lines: 92 This is a repost. The first one bounced somewhere. Organization lines etc may still be strange as on the previous one. >>I'm sick of dealing with Adobe's poorly written and changing structuring >>conventions, and even more so with applications that don't make even an >>effort to comply. Comments or thoughts? I agree! I wish the EPS spec didn't change/grow so gradually. At least it seems to have settled down to numberable versions now. I wrote an EPS-using application a while ago (basically an EPS editor, to give interactive/programmed access to most of the things the EPS is meant to allow). I'll try to summarise what I learnt from this: (1) EPS is great fun to work with, if done properly. There's nothing substantially wrong with the file format itself, although there are a few things I would prefer changed/tightened up. Just picky little things on the whole, for example: (1.1) The "%%Creator" line can indicate the person who drew the picture (or whatever) or the program they used to do it. It would be much more useful to give these separately - my program had to try to split them out. (1.2) Following from the above, it would be nice to know the version number of the producing package, so that when you merge several files, you could quickly tell whether they all require the same prologue. (2) The information you need is quite scattered (two documents from the Adobe infoserver, and assorted bits of the green book). (3) Some things are not specified well enough to use them. One I noticed is the {Begin/End}Object stuff. What constitutes the complete PS code for an object? Some of the EPS-producing packages I have written could easily produce "objects", if I thought anyone would read them as such. Should each object be positioned independently on the page (ie a moveto from the page origin) or is it OK for them to be relative to each other? OK, I could have asked Adobe, but for something I thought no-one would use anyway, I chose to drop the facility. (4) Some tools produce poor encapsulation of their PS. For example, one of the well-known packages put some necessary PS code between %%EndProlog and the first %%Page marker (to cope with this, I had to treat everything up to the start of the first page as the prologue - I don't like having to produce kludges like that to get round other people's kludges, especially when there is a written spec to follow). (5) Some tools that encapsulate their PS properly don't produce conformant PS. One popular word-processor from a company with a good public reputation, for example, re-encodes fonts the first time each font is used -- in line -- in the code for a *page*, not in the prologue at all. Because of this, you can't separate out pages for printing individually - you can't even print the document entire but in reverse page order! Not only is the guilty tool one that puts itself forward as supporting EPS, but it is one that is likely to be bought and used by end-users who will try to run it with WYSIWYG layout tools, and who will not all know how to fix things at the representation level when things go wrong. (I'm not going to name them here - so you authors of popular WP packages can all go and have a good look at your output now :-*) How about a validation service, as well as a program? The program is fine for those of us who can compile programs etc, but will be of little use to most end-users. A certificate that can be printed somewhere on the box for "shrink-wrapped software" could have more effect in making pressure to improve EPS quality -- perhaps Adobe could do this? (Rather them than me :-) And for those of us on the net, perhaps we could have a survey about EPS usage? My questions would be: * What features can you reasonably produce in your PS output? * What features do you want to read, parse and use when importing PS? * What things would you like to do using EPS if you had suitable tools? * What horror stories of bad PS do you have? (first-hand or local-site only). * What further things would you be interested to see in EPS (read the specs first - it might be there already, lurking in a dark corner)? * What things did you find difficult to understand or find in the documents from Adobe? Repeating from point (1): Well done overall, Adobe. But I think it now needs rescuing from misuse and disuse. -- __John When asked to attend a court case, Father Moses took with him a leaking jug of water. Asked about it, he said: "You ask me to judge the faults of another, while mine run out like water behind me." jcgs@uk.co.harlqn (UK notation) jcgs@harlqn.co.uk (most places) ...!mcvax!ukc!harlqn!jcgs (uucp - really has more stages, but ukc knows us) John Sturdy Telephone +44-223-872522 Harlequin Ltd, Barrington Hall, Barrington, Cambridge, UK