* Replaced all from ...py23 import * with explicit name imports, or removed completely when possible.
* Replaced tounicode() with tostr()
* Changed all BytesIO ans StringIO imports to from io import ..., replaced all UnicodeIO with StringIO.
* Replaced all unichr() with chr()
* Misc minor tweaks and fixes
- changed getCoordWidth method to use all if-stmt, ordered by ret value (0, 1, 2).
- added more info to TypeError message in getCoordWidth method.
- in round/scaleDeltas, chained if statements in one line to avoid writing the loop twice.
The instantiateTupleVariationStore function now groups TupleVariation
tables that have the same axes 'tents', then merges them into a single
TupleVariation by summing their deltas. The rounding to integer happens
after summing the scaled deltas as floats, to reduce off-by-one errors.
To be able to sum gvar TupleVariation, it needs to calculate the inferred
deltas so it now takes two optional lists (origCoords and endPts) that
are passed on to iup_delta function. These only make sense for gvar
type of TupleVariation, of course, and are unused for cvar tuples.
It also run iup_delta_optimize on the gvar deltas that are left after
partial instancing and whose inferred deltas had to be interpolated.
This can be disabled with --no-optimize CLI option.
Also added calcInferredDeltas and optimize methods to TupleVariation
class, which use functions from varLib.iup module, plus tests
that exercise them.
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
* 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
