Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cornell!uw-beaver!apollo!tbg From: tbg@apollo.COM (Tom Gross) Newsgroups: comp.graphics Subject: Michener's History of PHIGS Message-ID: <427e35c1.137b8@apollo.COM> Date: 7 Apr 89 17:10:00 GMT Organization: Apollo Computer, Chelmsford, Mass. Lines: 115 Mich's version of PHIGS early history Jim Michener 4/7/89 Written in response to a news group article (appended). In the U.S., PHIGS was the development of the Accredited Standards Committee X3H3 (Graphics). X3H3 started meeting in October 1979. There were discussions (like in 1980) of what should be done with the CORE System (SIGGRAPH 79), when somebody, I'm virtually certain it was Bert Herzog, said: Let's revisit, one more time, the assumption that there should be no hierarchy. The decision went in favor of hierarchy. Subsequent work, then, went in the direction of merging hierarchy and CORE System functionality. One subcommittee of X3H3, task group X3H3.1, worked simultaneously on standardizing GKS internationally (and nationally) and on PHIGS. The PHIGS attribute model at first was very similar to the CORE system's (attributes directly in structures). In contrast, early GKS had a table lookup model (index attributes, looked up in a "workstation table"). The collision between the two models in 1981 or 1982 created the Attribute Source Flag concept, which GKS and then PHIGS adopted. -- GKS-3D started in about 1983 or 1984 after (almost) all the work was done on GKS. It was an attempt to take some features from PHIGS and weld them onto GKS. After a while GKS-3D and PHIGS got into a moving-target situation: Most folks agreed that the 3D parts of the two should be the same (and that the primitives output onto workstations should be the same), so if some change was suggested for one of the systems, the other system would have to change too. -- The name PMIG (I do not believe it was ever called PMIGS) referred to the Programmer's Minimal Interface to Graphics. It was definitely not related to the development of PHIGS. It was an attempt to cut GKS functionality (which some judged to rich) down to about 30 functions. GKS at the time had over 100 functions. Today's GKS (X3.124-1985) has about 186 functions. I believe the name PHIGS was adopted after some discussion of PMIG, although I am not positive. In this light I would say that the "P.I.G." of PHIGS came from PMIG. The flow might have been in the opposite direction. PMIG was abondoned around 1982, I believe. -- Rensselaer Polytechnic Institute did one or more implementations of early drafts of PHIGS. Contact Salim Abi-Ezzi, still at RPI, for more info. I do not know at what point they started getting IBM support. I do recall in 1985 that Salim was giving the rest of the committee reports on their implementation experience. -- During the PHIGS discussions I recall a really minimal proposal (a joke) that had only five functions. I do not remember the proposal exactly but it was something like: INITIALZE DEVICE SET COLOR (R,G,B) DRAW LINE (4x4 matrix) - draws the unit line between (0,0,0) and (1,0,0) - after transformation by the specified 4x4. READ CURSOR POSITION(x,y) TERMINATE DEVICE -- The "real designer's" referred to the news group article below would have to include the CORE system designers, the GKS designers, and the X3H3.1 task group members. -- Submitted by Jim (Been-in-graphics-standards-since-1971) Michener mich@apollo.com ------------------------------------------------------------- Article 4905 of 4909, Thu 01:40. Subject: PHIGS early history? From: garry@batcomputer.tn.cornell.edu (Garry Wiegand as guest @ Cornell Engineering && Ithaca Software) (25 lines) More? [ynq] We are trying to track down the early design history of Phigs and get it straight. I had had a vague impression that Phigs was basically an IBM contract to RPI which later got promoted to being an ANSI committee, but that's all I knew. My partner has called ANSI and dug through the Siggraph proceedings of the early 80's. The information is very scanty there, but it sounds like: Phigs was an outgrowth of a GKS-3D group (which faded away upon not being able to reach agreement with the ISO GKS committee?); The first (ad hoc?) committee to meet called it "PMIGS", started meeting in 1980, (and did the design from scratch?); The first official standards committee called it "PHIGS" and started meeting in 1982. I don't know how the IBM/RPI work and the Megatek work fits into this, or who/when the real designers were. Can anyone who was there in the early days fill us in on the designers, the basic chronology, and the first implementations of PHIGS? How did it really happen? (merci) garry wiegand (garry@larch.cadif.cornell.edu - @tcgould won't work!)