In favor of separate VARC table.
ttGlyphSet does NOT yet know how to draw VARC table though.
The 9 failing tests are all VarComposite-related and need
to be updated with VARC equivalents eventually when we
add VARC support to subsetter and instancer.
The CFF2ToCFF module is rather solid, at least IMO.
This takes convertCFFToCFF2 from cffLib. Apparently there's a more
complete one in varLib.cff:
https://github.com/fonttools/fonttools/issues/1835
Should merge the two and finish them.
vsindex 0 is implied.
Also, add Unimplemented code for private-dict variable
values. I couldn't find any fonts using them, so for
now they remain unimplemented.
Imagine a font with current min/default/max of 100,700,1000. And new
setting of 100,400,1000. The current normalizeLocation will calculate
the new location for 700 to be +.33, whereas it should calculate +.5!
This is because 400 translates to -.5, so 700 will be normalized to
-1,-.5,+1 and get +.33...
We need a special normalizeLocation that is aware of the "distance"
between min/default/max, ie. the non-normalized values. Then it will be
clear that the distance from 400 to 700 is equal to 700 to 1000, and as
such 700 should be normalized to .5, not .33... I'm still trying to
figure out the case where avar is present.
Store this distance in NormalizeAxisLimit and reach it out in the
solver.
Fixes https://github.com/fonttools/fonttools/issues/3177
Previously we were only updating these when pinning wght/wdth/slnt axes.
Now we do whenever any of these axes defaults are changed, whether or not the axes are pinned or kept
Fixes https://github.com/fonttools/fonttools/issues/2885
Also renamed AxisTent => AxisTriple because I think "tent" is more appropriate to visualize master supports (i.e. a triangle with a peak in the middle), here it's simply the new desired min, default, max values of an axis, or the axis limits.
The public facing instantiateVariableFont continues to accept a hybrid map of axis tags to single values or 2- (and now also 3-) tuples, these are normalized to an AxisLimits mapping that contains only AxisTriples and passed around to the internal methods.
