🚀 go-pugleaf

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."