Path: utzoo!utgpu!watmath!clyde!att!pacbell!lll-tis!helios.ee.lbl.gov!pasteur!dent.Berkeley.EDU!davidh From: davidh@dent.Berkeley.EDU (David S. Harrison) Newsgroups: comp.sys.next Subject: Re : Display PS vs NeWS Keywords: NeWS is a superset of POSTSCRIPT! Message-ID: <7957@pasteur.Berkeley.EDU> Date: 3 Dec 88 02:44:57 GMT References: <2391@ssc-vax.UUCP> <941@riddle.UUCP> Sender: news@pasteur.Berkeley.EDU Organization: UC Berkeley Electronics Research Lab Lines: 35 (ed. Positive comments about NeWS; Negative comments about X. Plus the following debatable statements:) > I have a healthy respect for X11 but with the > exception of the networking it is the same old ten (or more) year old > techology ... it is no REAL breakthrough...X is a toy when compared > technically with NeWS...(you can emulate X from NeWS...the reverse is > not possible) ... > ... and if I want to have X do what NeWS > does ...sigh...well then I CAN'T DO THAT. (sorry for being obnoxious... > but consider it an education). I have often heard these opinions stated by NeWS advocates. Unfortunately, they are not entirely true. In its current form, NeWS *cannot* fully emulate X. This is because the NeWS color model *does not* support writable color tables. Furthermore, there are operations supported by X which cannot be efficiently emulated under NeWS. The prime example is stipple filled areas. The Postscript/NeWS display model does not support writing a certain pattern of bits onto the display without changing the bits not specified in the pattern. This can be emulated but the replacement operations are *very* slow. These two features alone rule out reasonable implementations of a wide class of color graphics editors under NeWS (including the one I have developed under X). Please don't misunderstand: I see many advantages in the NeWS model. However, the argument is far from one sided. There are several serious problems with NeWS in its current form. X, although low-level, addresses many of these problems. That is precisely the reason why Sun has decided to produce a combined X11/NeWS server (not just an X11 emulator above NeWS). David Harrison UC Berkeley Electronics Research Lab (davidh@ic.Berkely.EDU, ...!ucbvax!davidh)