From uchinews!vixen.cso.uiuc.edu!howland.reston.ans.net!usc!elroy.jpl.nasa.gov!decwrl!adobe!shore Mon Oct 4 16:43:08 CDT 1993 Article: 49502 of alt.folklore.computers Xref: uchinews alt.folklore.computers:49502 comp.fonts:9196 comp.lang.postscript:15717 Newsgroups: alt.folklore.computers,comp.fonts,comp.lang.postscript Path: uchinews!vixen.cso.uiuc.edu!howland.reston.ans.net!usc!elroy.jpl.nasa.gov!decwrl!adobe!shore From: shore@adobe.com (Andrew Shore) Subject: Re: Source of Adobe "blues" Message-ID: <1993Oct4.155110.19099@adobe.com> Sender: usenet@adobe.com (USENET NEWS) Organization: Adobe Systems Incorporated References: <26@fewmet.win.net> <1993Oct2.175921.21775@CSD-NewsHost.Stanford.EDU> Date: Mon, 4 Oct 1993 15:51:10 GMT Lines: 58 Status: R In article <1993Oct2.175921.21775@CSD-NewsHost.Stanford.EDU> bigelow@Sunburn.Stanford.EDU (Charles A. Bigelow) writes: >In article <26@fewmet.win.net> sbeyer@fewmet.win.net (Steve Beyer) writes: >>I am looking for a piece of cultural history -- the source >>of all the "blues" used in the keys in the Private >>dictionary in PostScript Type 1 fonts (BlueValues, >>FamilyBlues, BlueFuzz, and so on). Why "blue"? Was >>someone sad? Did someone use a blue pencil? Were "red" >>hints tried and discarded, like Type 2 fonts? Are there >>any Wise Old Men or Wise Old Women out there who can tell >>the story for future generations? Thanks in advance for >>any information. >> >>-- Steve >Someone at Adobe who worked on the font technology in the early days would be >able to provide the definitive answer, but my guess would be that this is a >holdover of some Xerox PARC nomenclature in which the different buttons of a >three button mouse were named by different colors (red, yellow, blue). In the >early Adobe font digitization process, the flagging of character elements for >stem control or alignment control, i.e. the "locking" of such elements to pixel >boundaries, etc., may have been named by different colors. Color terms like >yellow and red may have been lost in later developments of the font technology, >but blue, for horizontal alignment zones, may have survived. > >But dom't take this speculation as gospel. Let's wait for someone at Adobe to >set the record straight, and dispell this ignorant guessing. Chuck is almost but not quite right. (And I remember Chuck actually seeing the digitizing setup we were using at the time...) In the earliest days, Adobe was digitizing fonts on a tablet that had a four-button puck. These buttons were red, green, yellow, and blue. We used red and green to denote points along the character outlines themselves. Yellow was used to denote important vertical features (stems and such along the X axis). Blue was used to denote important horizontal features (serifs, and other such features along the Y axis). The blue values were the last to be tackled by our evolving scalable type technology, and seemed to be the only ones (at the time) that needed global handling across the font, hence all the "blues" in the font dictionaries and in the Type1 definition. These days, I think, there is also global info about stem weight (at least) for ATM to handle, so some global "yellow" information has crept in as well. I don't remember the manufacturer of the tablet, but I do remember that it had a serial interface to our VAX 11/750. The software at the other end (reading the codes from the tablet) was .... *POSTSCRIPT*. A very early incarnation of our interpreter was reading the ascii stuff coming from the tablet, decoding it, and writing out one file per character with the digitized data in it. Talk about bootstrapping your technology.... Hope that answers your question. Of course, a more appropriate query might have been titled "I am Curious Blue". --Andy Shore Adobe Old Timer