[luatex] the hz algorithm

Hans Hagen pragma at wxs.nl
Tue Aug 24 00:28:45 CEST 2010

On 8-8-2010 12:42, Martin Schröder wrote:
> 2010/8/8 Pablo Rodríguez<oinos at web.de>:
>> I'm not a lawyer, but even in the legal side of this issue (when the the
>> European doesn't expire until 1/1/2011), there might be a related patent for
>> a line-breaking algorithm granted to Adobe
>> (http://www.freepatentsonline.com/6510441.pdf) that might involve the
>> hz-algorithm (http://typophile.com/node/16525).
> That patent should be easy to shoot down as TeX is clearly prior art.
> I didn't read it all, but on a cursory glance it looks much like TeX.

He situation around hz and the patent and who owns what is somewhat 
messy (urw breaking up etc). Anyhow, long ago Hermann Zapf explicitly 
gave his blessing over the hz as used in pdftex and (1) he's the main 
inventor and (2) was afaik not involved in selling the patent.

Also, the original implementation in pdftex assumes special fonts, for 
instance multiple instances generated by metafont in which case the 
fonts are scaled but strokes are preserved. Hz itself was inspired by 
gutenberg who used fonts with multiple alternatives for glyphs.

(In the oriental tex project we use variants to achieve simular effects.)

(Anyhow, stretching glyphs in the sense of scaling lines to fit is as 
old as computers do typesetting.)


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