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.
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.
Do not round them to integer, but let the caller do the rounding immediately before adding them to the default instance (or just before compiling the binary table as with glyf).
This ensures that the glyphs' left sidebearings are calculated in the same way as they were by varLib.mutator.
If we round deltas too early, then we may get off-by-one differences.
See the glyf table setCoordinates method where left sidebearings are computed.
varLib.mutator does the same.
Ideally we would keep STAT if has any extra (inter-family) DesignAxis or it font was only partially instanced. We can improve on this later as needed.
for avar, we drop segments of the axes being pinned.
for fvar, we drop the pinned axes and all the named instances whose coordinates are different from the pinned location.
if the original VarStore had any regions in VarRegionList that wasn't
even referenced in any VarData VarRegionIndex, this makes sure we
remove those as well from VarRegionList (and remap the VarRegionIndex
accordingly)
We don't actually apply deltas to hmtx since these have already been applied
from the gvar deltas when we call glyf.setCoordinates method using the glyf
phantom points.
We simply call instantiateItemVariationStore on HVAR.VarStore to remove
regions and scale remaining deltas, but ignore the return value.
We only run VarStore.optimize() if the HVAR originally has an AdvWidthMap,
if it does not then it uses a direct implicit GID->VariationIndex mapping
for advance widths deltas, and we keep the VariationIndex unchanged by
not optimizing VarStore.
If all axes in fvar are being instanced, then we simply delete HVAR
(just like varLib.mutator currently does).
VVAR is not supported yet because we do not set the 3rd and 4th phantom points
from gvar to the vmtx table yet (this should be done in glyf.setCoordinates).
Also, supporting CFF2 would need more work, in that HVAR there is required
and we need to apply the deltas to hmtx/vmtx in here.
* Added getter (in the form of a property decorator) for T2Charstring.vsindex. Fixes endless compile loop in some circumstances.
Fixed bug in mutator: need to remove vsindex from snapshotted charstrings, plus formatting clean up
* Fix for subsetting HVAR tables that have an AdvanceWidthMap when the --retain-gid option is used. Needed to make subset_test.py::test_retain_gids_cff2 tests pass.
* in varLib/cffLib.py, add support for sparse sources, and sources with more than one model, and hence more than one VarData element in the VarStore.
CFF2 source fonts with multiple FontDicts in the FDArray need some extra work. With sparse fonts, some of the source fonts may have a fewer FontDicts than the default font. The getfd_map function() builds a map from the FontDict indices in the default font to those in each region font. This is needed when building up the blend value lists in the master font FontDict PrivateDicts, in order to fetch PrivateDict values from the correct FontDict in each region font.
In specializer.py, add support for CFF2 CharStrings with blend operators. 1) In generalizeCommands, convert a blend op to a list of args that are blend lists for the following regular operator. A blend list as a default font value, followed by the delta tuple. 2) In specializeCommands(), convert these back to blend ops, combining as many successive blend lists as allowed by the stack limit.
Add test case for sparse CFF2 sources.
The test font has 55 glyphs. 2 glyphs use only 2 sources (weight = 0 and 100). The rest use 4 source fonts: the two end points of the weight axis, and two intermediate masters. The intermediate masters are only 1 design space unit apart, and are used to change glyph design at the point in design space. For the rest, at most 2 glyphs use the same set of source fonts. There are 12 source fonts.
Add test case for specializer programToCommands() and commandsToProgram by converting each CharString.program in the font to a command list, and back again, and comparing original and final versions.
deltas in VarData[0] are directly look up by GID so compacted
if any deltas are referenced by LsbMap / RsbMap but not used for advance widths, they are moved to the end of VarData[0]
updated expected test result expect_HVVAR.ttx accordingly
1. if AdvWidthMap/AdvHeightMap missing, deltas for unused (emptied) glyphs are zeroed
2. If indexMap exists and unused glyph ID <= last used glyph ID, then its major/minor number set to 0/0
3. If indexMap exists and unused glyph ID > last used glyph ID, then its major/minor number set to that of the last used glyph (removed from table)
code elsewhere assumes that all optional fields in OT tables are initialized
to None (that is the case when decompiling from a file).
This patch makes sure that the new GDEF table build by varLib when creating
a new VF is properly initialised.
Ideally we wouldn't have to do that manually, but the constructor would
take care of that. But otData-generated classes are special...
