Re: Add usage of OpenType font feature to the documents (issue 328140043 by address@hidden)

[lemzwerg]

> I looked into the latest Harfbuzz internals, and it looks like
> the list of supported OpenType features is manually maintained.

Nope.

> Not all the features listed on the Microsoft feature registry
> are supported, but many are.

HarfBuzz is agnostic to most features; if you select a feature, and the
feature is available, and the other feature constraints are met, it
simply gets applied.

> This list [in HarfBuzz] covers pretty much all likely candidates
> a user is going to encounter or want to use in modern fonts, so it
> probably isn't worth listing each of the supported features.

You are mistaken.  What you are referring to is a special interface to
OS X's `coretext' implementation of OpenType.

There exist far more features than you will ever use.  Additionally, a
large deal of features is not to be set (or unset) by the end user – for
example, most of the Indic font features have to be always applied.
Similarly, Arabic features (`isol', `fina', `medi', `init', etc., etc.)
must be always applied in a specific order to get correct rendering
results.


https://codereview.appspot.com/328140043/