copied from fontTools.varLib._DesignspaceAxis._map static method.
I place it here since it is also used by varLib.mutator, so makes sense
to have a public function
this is the mapping between the half of each percentage intervals and
the associated usWidthClass:
{56.25: 1,
68.75: 2,
81.25: 3,
93.75: 4,
106.25: 5,
118.75: 6,
137.5: 7,
175.0: 8}
Notice how wdth=80 (in the adjusted test case) will fall in width class
3, instead of 4, because it is < 81.25, thus closer to the nominal 75
than to 87.5.
Oops. Was introduced when I last changed modeling.
The problem was, for checking that a previous master m is outside the current
influence box of the current master, I was doing "not (lower < m[loc] < upper)".
This is wrong, where lower,peak,upper is the support of previous master.
This fails if lower == peak == m[loc], or m[loc] == peak == upper.
Fixes https://github.com/fonttools/fonttools/issues/1269#issuecomment-397655016
So we now round towards +Infinity in:
- floatToFixed (which fully examplify that quotes from OT spec)
- psCharStrings: when packing floats as fixed 16.16
- t2CharStringPen: when rounding coordinates and advance widths
- subset: when rounding advance widths to compute average
- TupleVariation: rounding gvar deltas
- _g_l_y_f: when rounding coordinates: both in GlyphComponent.{x,y}
and for GlyphCoordinates.toInt()
- _h_m_t_x: for rounding horiz/vert metrics
- varLib: rounding horiz metrics and deltas
Takes a template containing predefined strings {dirname}, {basename},
{stem}, {ext} and {fullname}, to customize the location of the binary
master TTFs in relation to the designspace source filenames.
and rename getPermutations to iterAllCombinations.
It's not really permutations we are after here, but more combinations
of indexes sorted by decreasing length, from more specific to less
