Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ames!lll-winken!uunet!ficc!peter From: peter@ficc.uu.net (Peter da Silva) Newsgroups: comp.sys.next Subject: Re: NextStep and NeWS... Keywords: NextStep,NeWS,Postscript Message-ID: <3931@ficc.uu.net> Date: 20 Apr 89 14:39:18 GMT References: <1041@nixctc.DE> <8530@polya.Stanford.EDU> <3901@ficc.uu.net> <4779@pt.cs.cmu.edu> Organization: Xenix Support Lines: 78 In article <4779@pt.cs.cmu.edu>, avie@wb1.cs.cmu.edu (Avadis Tevanian) writes: > NextStep defines a user-interface, DPS/Objective-C/C provide a base > for an implementation of it. If you want to write your own user-interface, > then you can program it in DPS if you wish. We are just saying that > programming in DPS (or NeWS) is, in general, a pain. Mainly I'm talking about whether your UI is bound in with the application or not. More on this at the end of this article. > >The second advantage to this is that more of the processing of the user- > >interface can go on in the display server, freeing the host and communication > >channel of the burden. [ division of labor ] > The importance of this is somewhat questionable (I think). I disagree... it's pretty important. Not because... > The fact that > people even think about this these days is because the environment they > are used to (e.g., UNIX with sockets) just doesn't do message passing > fast enough. ...not because sockets are too slow, but because the communication channel may be. I can buy an Acer Xebra 1000 for $1000 and hook it onto an ethernet or SLIP serial port and run X remotely. It would be more efficient to run NeWS on the server instead... send menu selection events instead of bitmaps. The following is a digression... > When you are doing animations (for example), do you really > want to write your animation in Postscript, of course not, and we don't. Hell no. I'd rather do animations in Director's scripting language, or in forth. Write forth programs to generate videoscape 3-d animation files. Which takes me back to postscript, now doesn't it? > What if your animation needs to be synchronized with sound effects? What if it needs to be driven by MIDI? "What if" is a trademark of HP :->. > The basic problem with X/NeWS/... environments is that the generally > run on top of UNIX, and UNIX just doesn't have the [ high speed message > passing]. We have overcome this problem by using Mach ... about 10 times > faster than with traditional UNIX facilities. But it's still not real-time. How many messages a second could you pass through a pipeline containing say, a MIDI input port, a couple of filters, to a MIDI output port and the DSP? Not entirely relevant, but I do think that *as yet* the advantages of Mach haven't fully gelled. I believe it will eventually become the final solution to te real-time-UNIX problem... but it's not there yet. Anyway, back to the point. Animation really isn't a user-interface process so it's kind of a straw man... I'm not talking about doing EVERYTHING in DP or NeWS or VideoLisp or whatever. I'm talking about a division of labor between the UI and the application. This division of labor question is still wide open. I certainly haven't seen anyone claiming they've solved it. > >Personally, I think a lisp-like language would be better than postscript, but > >there is a certain historical advantage to sticking with PS. > Then you'll be happy to use Common Lisp with support for NextStep in our 1.0 > release. But I can't write Common Lisp code and change the global behaviour of my desktop. The interface policy decisions are still tied up in compiled code. What if I want to use pac-man menus? What if I want to use that second mouse button for something useful? Like having it pop up menus instead of leaving them around all the time? Pac-man menus? With the DSP going wocka-wocka- wocka... -- Peter da Silva, Xenix Support, Ferranti International Controls Corporation. Business: uunet.uu.net!ficc!peter, peter@ficc.uu.net, +1 713 274 5180. Personal: ...!texbell!sugar!peter, peter@sugar.hackercorp.com.