Path: utzoo!attcan!uunet!lll-winken!lll-lcc!lll-tis!ames!pacbell!att!alberta!ubc-cs!van-bc!lpami From: lphillips@lpami.van-bc.UUCP (Larry Phillips) Newsgroups: comp.sys.amiga Subject: Re: A Modest Proposal (IFF QuickDraw) Message-ID: <1767@van-bc.UUCP> Date: 18 May 88 00:49:33 GMT Sender: lpami@van-bc.UUCP Lines: 122 In <5967@well.UUCP>, ewhac@well.UUCP (Leo 'Bols Ewhac' Schwab) writes: >In article <1760@van-bc.UUCP> lphillips@lpami.van-bc.UUCP (Larry Phillips) writes: >> >>In <4607@super.upenn.edu>, ranjit@eniac.seas.upenn.edu (Ranjit Bhatnagar) writes: >> > By some coincidence, there already is such a standard: Apple >> >QuickDraw. So called "PICT" images consist of, effectively, a script >> >recording a sequence of calls to the graphics library. An additional >> >>By further coincidence, PostScript is an established standard, fits all the >>criteria, and in addition, is supported on a great many more machines than >>'PICT'. [ ... ] > > And. by an even more amazing coincidence, PostScript is just as >inappropriate a choice as QuickDraw. Well, it would appear that we are both all wet. It has been pointed out in few other messages that as a structured graphic standard, a display protocol such as PostScript or NAPLPS falls somewhat short of the mark. I don't know if QuickDraw is only a display protocol or a structured graphics description standard, so I don't have much to say about that, but do have more to say about NAPLPS vs. PostScript. > "PostScript: The Inefficient Document Layout Specification Language >for The Masses. Yes, PostScript is just the thing for you "power-users" with >disk space, transfer bandwidth, and money just begging to be needlessly >consumed. Why be efficient or clever, when you can have PostScript?" Disk space and transfer bandwidth? You wouldn't be confusing the resources required to store/send a bitmap with the interpreter to build it would you? If I were you, I'd check out the NAPLPS spec before coming down too hard on PostScript for these reasons. One of the biggest drawbacks of NAPLPS is that is it not a language. You can tell the display what to show, but there are no control structures or calculating abilities. This feature alone in PostScript makes it a better choice for bandwidth savings. > Enough immature flamage (something I'm trying to cut down on). Good idea. My IFF reader doesn't understand the FLAM chunk. >Here's some concrete minuses for PostScript: > o It's not public domain. No, it isn't, but any derivative work is. You can't call it PostScript, but what's in a name anyway? > o Adobe charges what I understand to be a hefty licensing fee for > the use of PostScript in any product. I don't know the details of Adobe's licensing fee, but you get what you pay for. With NAPLPS, it works out to at least the same proce/performance ratio. For your NAPLPS fee, you get a limited, fairly primitive, standard that not only is unacceptable to the rest of the world, but that has been tried and dropped by bigger outfits than CBM, Apple or Adobe. Last I heard there were probably three special purpose information services left in Canada, and maybe one in the US that still piss against the wind with NAPLPS, and perhaps a half dozen BBS's that still have some NAPLPS picture files hanging around. With PostScript, you get a fairly well thought out presentation protocol that is in wide use, and getting more popular all the time, on both hard media and video. > o PostScript files, from what I understand, can get very large very > quickly, even for relatively simple documents. Depends on what you're doing. Yes, a bitmap can get huge, but then so can the raw, or even the compressed representation of that same bitmap. Most PostScript files are quite small. I wrote a small PostScript program to output a PCB layout consisting of three, three-slot XT backplanes (just the bus connections and pads. I can't remember the exact figure, but the program was around 250 bytes. Try that in NAPLPS, where you would have to describe each individual element in the display. With PostScript, it was simply a matter of defining a pad (circuit board pad), two traces, and algorithmically drawing as many as I needed, where I needed them. > o PostScript, from what I understand, doesn't know about color yet. PostScript knows about colour. NeWS is effectively PostScript with extensions, and colour is included in the part of it that's compatible with PostScript. The reason you don't see colour mentioned much is for the same reason that you don't see IFF mentioned much. Apple and IBM users don't have much use for it. Be sure to attend SIGGRAPH this year and wander by the Ameristar stuff. Ask to see a typical NeWS program. Strap your socks on. > o PostScript **may** not properly address the "structured graphics" > need we're looking for, since PostScript was designed as a > document layout language (font creation, manipulation, etc.). NAPLPS does not support 'structured graphics', unless you limit yourself to the graphic primitives like arc, cirle, line, etc. PostScript at least allows you to define a procedure which describes a graphic object. Since we are speaking of a display protocol here only, it's sort of a moot point within the whole discussion of what's needed in a structured graphic standard. NAPLPS was designed as a TV display language. > o Adobe is coming out with something called "Display PostScript". > This implies that Display PostScript and vanilla PostScript found > in laser printers aren't quite the same thing. We want something > that works the same on all output devices. Don't know much about Display PostScript, except to say that since Apple rejected it, it can't be all bad. :-) > I still think NAPLPS is a better choice, if only that it will be >cheaper. I'm going to order the standard from ANSI, and check it out more >thoroughly. It will be cheaper alright. But then so are character set graphics. I have the spec right here beside me. I haul it out once in a while and attempt to wade through it. It's ANSI X3.110-1983, or CSA T500-1983. When you do get it, let me know when you are about to read it, so I can get out of the way when you barf. :-) -larry -- Janus? Well, look at it this way. If you squint a little, the J could be Amiga checkmark, and the rest of the word describes MsDos. +----------------------------------------------------------------+ | // Larry Phillips | | \X/ {ihnp4!alberta!ubc-vision,uunet}!van-bc!lpami!lphillips | | COMPUSERVE: 76703,4322 | +----------------------------------------------------------------+