[cairo] LCD filtering in cairo, use default filter?

[James Cloos]

Ideally, the default should be the light hinting with the light filter.

Except, if the bytecode interpreter is available, certain well
instructed glyf fonts should get ‘full’ hinting and the legacy
filter.

One thorny issue, though, is the case of document viewers  (such as
evince, xpdf, xdvi, et al).  When the goal it to read a document on
screen, the above continues to hold.  But when the goal is to check
(a simulation of) the document’s as-printed appearance, light auto-
hinting and filtering should be used exclusively.

The other thorny issue is treating the UI elements differently than
the document text.  In the simulated printout case, even if the doc
uses the same font as the UI, the UI should get the ‘full’ hints if
available and the document light auto.

As such, configurability is important.

-JimC
-- 
James Cloos <cloos at jhcloos.com>         OpenPGP: 1024D/ED7DAEA6