Xref: utzoo comp.lang.postscript:5710 comp.fonts:1391 Path: utzoo!attcan!uunet!samsung!zaphod.mps.ohio-state.edu!usc!apple!apple.com!kevina From: kevina@apple.com (This space for rent) Newsgroups: comp.lang.postscript,comp.fonts Subject: Re: PostScript vs TrueType? Message-ID: <9607@goofy.Apple.COM> Date: 7 Aug 90 17:18:21 GMT Sender: usenet@Apple.COM Organization: Apple Computer, Inc. Lines: 28 References:<1100.26af57d3@waikato.ac.nz> <1990Jul26.135834.9874@tsa.co.uk> <862@grenada.UUCP> <9583@goofy.Apple.COM> <3880@bwdls58.UUCP> In article <3880@bwdls58.UUCP> hwt@.bnr.ca (Henry Troup) writes: > I'm a veteran of Dick Rubenstein's Digital Typography course. I remember his > discussion of the interaction of device physics (electrostatics) and write- > white and write-black devices. How can anyone design low level hints without > knowing if the the device is write-white or write-black? And is there any > information in systemdict (PostScript) to know which way a laser printer is > set up? TrueType includes instructions which can be used to compensate for engine characteristics. Between write-white and write-black, the significant difference is the resulting size of the black spot. Those instructions modify points based on that size, independent of what the size actually is. (There seems to be a feeling that TrueType's "low-level" hints somehow make it device- or resolution-dependent. This is not the case.) Type 1 fonts have something called "Erode" (in the Private dictionary) and "ErodeSW" (in internaldict-- presumably used by stroked fonts) which appear to be functions to do some sort of engine compensation. Don't know how you can distinguish between write-white and write-black in general, though. --Kevin Andresen [kevina@apple.com] "Orange whip? Orange whip? Three orange whips."