Imported 9b7ecb4 from fontPens, which is the version modified to accept
a parameterized tolerance. Recent changes in fontTools such as 2831096,
186e461 and 7d5530e were considered so that the diff will be minimal.
* 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
The PointToSegmentPen translates between PointPen and (Segment)Pen
protocol.
In the SegmentPen protocol, closed contours always imply a final 'lineTo'
segment from the last oncurve point to the starting point.
So the PointToSegmentPen omits the final 'lineTo' segment for closed
contours -- unless the option 'outputImpliedClosingLine' is True
(it is False by default, and defcon.Glyph.draw method initializes the
converter pen without this option).
However, if the last oncurve point is on a "line" segment and has same
coordinates as the starting point of a closed contour, the converter pen must
always output the closing 'lineTo' explicitly (regardless of the value of the
'outputImpliedClosingLine' option) in order to disambiguate this case from
the implied closing 'lineTo'.
If it doesn't do that, a duplicate 'line' point at the end of a closed
contour gets lost in the conversion.
See https://github.com/googlefonts/fontmake/issues/572.
'identifier' param is part of the AbstractPointPen interface.
Even though it is unused by the segment pen protocol, the caller may attempt
to pass it by positional argument instead of keyword argument, e.g.
2920ddd07c/Lib/fontMath/mathGlyph.py (L486)
this patch avoids the resulting TypeError exception
