From: John Hudson (tiro@tiro.com)
Date: Wed Dec 03 2003 - 22:30:49 EST
At 06:20 PM 12/3/2003, Philippe Verdy wrote:
>Another way would be to develop another hinting system that does not include
>something claimed in the above patents. It will be hard even if the technics
>and formats used are completely different, because the terms of the patent
>are quite vague and seem to cover nearly all the aspects of font hinting,
>which is exactly a way to move control points that define glyphs.
Philippe, as it says on the FreeType site:
It's important to clarify that the patents only cover
a small subset of the TrueType instructions (not the
whole process of hinting glyphs with specific bytecode
programs). Unfortunately, the patented bytecodes
are relatively often used in high-quality glyph programs.
You are reading the patent filings in isolation, and ignoring the fact that
hinting technologies pre-exist the Apple TT patents and circumscribe the
extent of those patents. No matter how vague the language, Apple can't
claim a patent on something that is already patented by someone else or is
demonstrably not novel.
If you look at the graphic at http://freetype.sourceforge.net/patents.html
it should be pretty obvious that the patented bytecodes FreeType cannot
legally interpret are specifically those that *can be used* to control
diagonal stems. I stress 'can be used' because the TT instruction set is a
tool for designing bitmap output from vector outlines, and the tool can be
used in a number of different ways. There are at least three strategies for
controlling diagonal stems with the TT instruction set, only one of which
relies on the patented method. So it is perfectly possible to create TT
fonts that will render very nicely in FreeType. A lot of professional
hinters do not use the patented method anyway: not all font tools support
it, so hinters have long since developed other strategies using other
aspects of the TT instruction set.
I'm sure that more than most Unicoders wanted to know about hinting. This
discussion is way off-topic. I think we should drop it.
John Hudson
Tiro Typeworks www.tiro.com
Vancouver, BC tiro@tiro.com
Theory set out to produce texts that could not be processed successfully
by the commonsensical assumptions that ordinary language puts into play.
There are texts of theory that resist meaning so powerfully ... that the
very process of failing to comprehend the text is part of what it has to offer
- Lentricchia & Mclaughlin, _Critical terms for literary study_
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