Before this change, the decoder would silently remove "redundant" values
when decompiling AAT lookups. However, it is perfectly valid for a lookup
to map a glyph ID to itself, and also not all AAT lookups have glyph IDs as
their value range.
With AAT, the same lookup data structure can be used for various
types of values. In the morx table, the values are glyph IDs or
glyph classes, which both are encoded as 16-bit unsigned integers.
In other AAT tables, however, the values can be different data types
with different encodings. By passing a `valueWriter` callback and
explicit `valueSize`, we prepare for eventually templatizing
the building of AATLookups.
Also, assert that the called writer wrote the exact number of bytes
that was predicted when figuring out what format should be used for
encoding an AATLookup.
On some Python builds, Unicode characters above U+FFFF get escaped
to two question marks ?? instead of just one ?. This is not a real
problem, but for testing it is a nuisance when the results depend
on the platform.
This class had been added in the `morx` branch, and I wanted
to merge it into master. While writing tests for it, I noticed
that `otConverters` has meanwhile been extended by an `UInt8`
converter. Therefore, only adding a test for the existing
implementation.
I've got some changes in the `morx` branch which I'd like to merge
into master. So I'm writing this unit test as an example how to
test `otConverter` code.
When the tests are run with `python setup.py test` (e.g. from the ./run-tests.sh
script), we can't have setuptools install pre-compiled wheels for extra test
requirements (e.g. Brotli, unicodedata2).
Instead of failing, it's better that we skip the tests that have such extra
requirements.
NOTE: The recommended way to run the full test suite is by using tox
(like we do on the CI), or by installing pytest and the rests of requirements.txt,
and then run `pytest` command directly.
* TupleVariationTest.test_compileDeltaValues(): also test floats
* TupleVariation: round deltas before encoding
Python 3 was raising 'struct.error: required argument is not an integer' and Python 2 was truncating when deltas are floats
Also fixes a bug where glyph alternates in MTI feature files were
wrongly sorted by glyph name. After this change, the output is using
the same ordering as in the input MTI feature file.
Fixes https://github.com/fonttools/fonttools/issues/833.
