Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sun-barr!lll-winken!uunet!spool.mu.edu!think.com!huxley!arg From: arg@huxley.UUCP (Adam R. Grossman) Newsgroups: comp.lang.postscript Subject: Re: type 1 hint directions Message-ID: <660@huxley.UUCP> Date: 8 Feb 91 23:00:07 GMT References: Reply-To: arg@bitstream.com Distribution: comp Organization: Bitstream, Inc., Cambridge, MA Lines: 30 In-reply-to: leslie@book.dle.dg.com's message of 9 Feb 91 01:54:03 GMT leslie@book.dle.dg.com (Leslie French) asks: Does the direction of a hint make a difference, i.e. is there any difference between (say) 150 -10 hstem and 140 10 hstem if so, what? I've seen both 'positive' and 'negative' hints generated for a single character, and I'm curious as to whether or not there's a reason behind it. First, you must understand that Type 1 hinting is declarative by nature which means, as the Black Book ("Type 1 Font Format") points out, the "hint system depends on an intelligent rasterizing algorithm to render the character outlines... [and that c]onsequently the appearance of font characters created with declarative hints will... [change] as hint handling algorithms [change]." (p. 36) Therefore, the answer to your question is "it depends on which interpretter you are using" because different implementations will, by design, interpret the hints differently. However, two possible differences might be: (1) only part of the stem might lie in a BlueValue zone and perhaps the zone snapping is activated only when the stem starts/ends in the zone, or (2) since the "from" end may be anchored before the "to" end (e.g., "from 140 to 150" vs. "from 150 to 140"), the "from" end is likely to have a more accurate placement while the "to" end is likely to have a less accurate placement. -- Adam Grossman arg@bitstream.com