otherwise it causes sides effects since logging state is global and should only
be done when __name__ == '__main__'.
We can capture logging messages via the caplog pytest fixture
continue checking subsequent condition tables in case the other may
be format=1 and may reference a pinned axis; in which case, these
conditions need to be dropped from the condition set, or the whole
record needs to be dropped if the instance coordinate is outside the
condition range.
Condition tables within a condition set are associated with a AND
boolean operator, so if any one doesn't match, the whole set doesn't
apply. Even if we don't recognize one condition format, if we do
ascertain that another condition table does not match the current
partial instance location, we can drop the FeatureVariation record
since it doesn't apply.
instead of reading off existing FeatureVars.ttx test file.
This gives us more flexibility to add more tests, and keeps the input
values closer to the expected results
this is done automatically upon compiling; however it's good to do it here
as well, in case one wants to pass the updated font directly to other modules
like 'subset' which requires these fields to be present -- without having
to first compile and decompile.
there was a logic issue in the function that checks whether a FeatureVariationRecord
has a unique set of condition (was returning False instead of True for unsupported condition).
It's safer to always keep such records with unknown condition formats as new formats
may be added in the future. A warning is already issued in these cases.
After partial instancing, multiple FeatureVariationRecords may end up with
the same set of conditions (e.g. if one references two axes, one of which
is dropped, and a subsequent one also references the same axis that was
kept in the preceding record's condition set, and the min/max values are
the same for both records).
Therefore, we make sure only the first unique record with a given
configuration of conditions is kept. Any additional records with identical
conditions will never match the current context so they can be dropped.
ConditionTable.AxisIndex needs to change when dropping axes, to
refer to the same axis in the modified fvar.axes array.
There was also another bug when a condition was not met,
and the `applies` flag (initialised to `True`) was not set to
`False`, thus substutions were incorrectly applied.
the buildGSUB function creates an empty GSUB with no FeatureRecords, so the
FeatureIndex list should be empty initially; the index of the newly created
rvrn feature record will be appended later on by addFeatureVariationsRaw
function.
Added new test VF font (a subset of NotoSans-VF only containing glyphs 'A', 'Agrave' and 'T');
the VF was instanced with varLib.mutator, producing a series of full instances, which are
included as ttx files as well.
The tests run the partial instancer twice, once only instancing wght, then again for wdth,
and assert that the generated instance is identical to those.
This allows to drop an axis (aka L1 instancing) without knowing the
axis' actual default value from fvar table. One can simply call
`instantiateVariableFont` function with a `None` value for a given
axis (i.e. axis_limits={'wght': None}); the `None` value is replaced
by the axis default value as per fvar table.
The same can be done from the console script as well.
The special string literal 'None' is parsed as the Python `None`
object. E.g.:
$ fonttools varLib.instancer MyFont-VF.ttf wght=None
The code was setting GlyphClassDef.classDefs for the base font to an
empty dict then reading it from all fonts. It accidentally works when
creating variable fonts because the GlyphClassDef of the other fonts
will be used, but when mutating there is only one font.
Fix by reading the glyph classes before assigning to an empty dict.
