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Interpolating Ubuntu Mono fails with "Errors calculating 427 glyphs" due to IndexError in "fontMath/mathGlyph.py"
See original GitHub issueHi there,
This looks like a really cool project. I tried to get a feel of how it works by interpolating a semi-bold version of Ubuntu Mono. I used FontForge to convert the TTFs to UFO:
font = fontforge.open("UbuntuMono-R.ttf")
font.generate("UbuntuMono-R.ufo")
font.close()
Then I made the following designspace file:
<?xml version="1.0" ?>
<designspace format="3">
<sources>
<source filename="sources/ufos/UbuntuMono-R.ufo" name="ubuntu_mono_regular">
<lib copy="1"/>
<groups copy="1"/>
<info copy="1"/>
<location>
<dimension name="weight" xvalue="400"/>
</location>
</source>
<source filename="sources/ufos/UbuntuMono-B.ufo" name="ubuntu_mono_bold">
<location>
<dimension name="weight" xvalue="700"/>
</location>
</source>
</sources>
<instances>
<instance familyname="Ubuntu Mono" filename="outputs/UbuntuMono-M.ufo" stylename="Medium">
<location>
<dimension name="weight" xvalue="500"/>
</location>
<info/>
<kerning/>
</instance>
<instance familyname="Ubuntu Mono" filename="outputs/UbuntuMono-SB.ufo" stylename="SemiBold">
<location>
<dimension name="weight" xvalue="600"/>
</location>
<info/>
<kerning/>
</instance>
</instances>
</designspace>
Finally, I ran MutatorMath like this:
from mutatorMath.ufo import build
build("ubuntu-mono.designspace")
Unfortunately, this failed to generate a valid font; the log says:
2016-10-25 01:05:26,775 MutatorMath Executing designspace document: ubuntu-mono.designspace
2016-10-25 01:05:26,800 MutatorMath Writing UbuntuMono-M.ufo to outputs/UbuntuMono-M.ufo
2016-10-25 01:05:27,849 MutatorMath Multiple unicode values for glyph nonmarkingreturn: 9, 13
2016-10-25 01:05:27,850 MutatorMath Multiple unicode values for glyph .null: 8, 0, 29
2016-10-25 01:05:29,731 MutatorMath outputs/UbuntuMono-M.ufo:
Errors calculating 427 glyphs:
[…]
I removed the catch-all exception handler around _calculateGlyph in ufo/instance.py and got the following backtrace:
Traceback (most recent call last):
File "./buildinstances.py", line 19, in <module>
main()
File "./buildinstances.py", line 16, in main
build("ubuntu-mono.designspace")
File "./deps/MutatorMath/Lib/mutatorMath/ufo/__init__.py", line 56, in build
reader.process()
File "./deps/MutatorMath/Lib/mutatorMath/ufo/document.py", line 418, in process
self.readInstances(makeGlyphs=makeGlyphs, makeKerning=makeKerning, makeInfo=makeInfo)
File "./deps/MutatorMath/Lib/mutatorMath/ufo/document.py", line 572, in readInstances
self._readSingleInstanceElement(instanceElement, makeGlyphs=makeGlyphs, makeKerning=makeKerning, makeInfo=makeInfo)
File "./deps/MutatorMath/Lib/mutatorMath/ufo/document.py", line 631, in _readSingleInstanceElement
instanceObject.addGlyph(n, unicodeValue)
File "./deps/MutatorMath/Lib/mutatorMath/ufo/instance.py", line 345, in addGlyph
self._calculateGlyph(glyphObject, instanceLocation, glyphMasters)
File "./deps/MutatorMath/Lib/mutatorMath/ufo/instance.py", line 371, in _calculateGlyph
bias, m = buildMutator(items, warpDict=self.warpDict)
File "./deps/MutatorMath/Lib/mutatorMath/objects/mutator.py", line 46, in buildMutator
onx.append((lb, obj-m.getNeutral()))
File "./deps/fontMath/Lib/fontMath/mathGlyph.py", line 167, in __sub__
self._processMathOne(copiedGlyph, otherGlyph, subPt, sub)
File "./deps/fontMath/Lib/fontMath/mathGlyph.py", line 178, in _processMathOne
copiedGlyph.contours = _processMathOneContours(self.contours, otherGlyph.contours, ptFunc)
File "./deps/fontMath/Lib/fontMath/mathGlyph.py", line 516, in _processMathOneContours
pt2 = points2[index][1]
IndexError: list index out of range
Here’s the context in which this error occurred, courtesy of PDB:
(Pdb) pprint(locals())
{'contour1': {'identifier': None,
'points': [('qcurve', (249, 499), False, None, None),
(None, (239, 464), False, None, None),
(None, (222, 401), False, None, None),
(None, (207, 340), False, None, None),
(None, (194, 278), False, None, None),
('qcurve', (188, 245), False, None, None),
(None, (188, 245), False, None, None),
(None, (309, 245), False, None, None),
('curve', (309, 245), False, None, None),
(None, (303, 278), False, None, None),
(None, (291, 340), False, None, None),
(None, (276, 401), False, None, None),
(None, (259, 464), False, None, None)]},
'contourIdentifier': None,
'contours1': [{'identifier': None,
'points': [('curve', (359, 0), False, None, None),
(None, (359, 0), False, None, None),
(None, (330, 143), False, None, None),
('curve', (330, 143), False, None, None),
(None, (330, 143), False, None, None),
(None, (165, 143), False, None, None),
('curve', (165, 143), False, None, None),
(None, (165, 143), False, None, None),
(None, (137, 0), False, None, None),
('curve', (137, 0), False, None, None),
(None, (137, 0), False, None, None),
(None, (9, 0), False, None, None),
('curve', (9, 0), False, None, None),
(None, (53, 183), False, None, None),
(None, (143, 484), False, None, None),
('qcurve', (185, 619), False, None, None),
(None, (185, 619), False, None, None),
(None, (319, 619), False, None, None),
('curve', (319, 619), False, None, None),
(None, (363, 483), False, None, None),
(None, (450, 178), False, None, None),
('qcurve', (491, 0), False, None, None),
(None, (491, 0), False, None, None),
(None, (359, 0), False, None, None)]},
{'identifier': None,
'points': [('qcurve', (249, 499), False, None, None),
(None, (239, 464), False, None, None),
(None, (222, 401), False, None, None),
(None, (207, 340), False, None, None),
(None, (194, 278), False, None, None),
('qcurve', (188, 245), False, None, None),
(None, (188, 245), False, None, None),
(None, (309, 245), False, None, None),
('curve', (309, 245), False, None, None),
(None, (303, 278), False, None, None),
(None, (291, 340), False, None, None),
(None, (276, 401), False, None, None),
(None, (259, 464), False, None, None)]}],
'contours2': [{'identifier': None,
'points': [('curve', (404, 0), False, None, None),
(None, (404, 0), False, None, None),
(None, (367, 162), False, None, None),
('curve', (367, 162), False, None, None),
(None, (367, 162), False, None, None),
(None, (129, 162), False, None, None),
('curve', (129, 162), False, None, None),
(None, (129, 162), False, None, None),
(None, (93, 0), False, None, None),
('curve', (93, 0), False, None, None),
(None, (93, 0), False, None, None),
(None, (9, 0), False, None, None),
('curve', (9, 0), False, None, None),
(None, (26, 66), False, None, None),
(None, (68, 220), False, None, None),
(None, (117, 382), False, None, None),
(None, (171, 545), False, None, None),
('qcurve', (201, 619), False, None, None),
(None, (201, 619), False, None, None),
(None, (303, 619), False, None, None),
('curve', (303, 619), False, None, None),
(None, (332, 545), False, None, None),
(None, (385, 382), False, None, None),
(None, (432, 220), False, None, None),
(None, (474, 66), False, None, None),
('qcurve', (491, 0), False, None, None),
(None, (491, 0), False, None, None),
(None, (404, 0), False, None, None)]},
{'identifier': None,
'points': [('qcurve', (249, 547), False, None, None),
(None, (226, 484), False, None, None),
(None, (172, 318), False, None, None),
('qcurve', (148, 230), False, None, None),
(None, (148, 230), False, None, None),
(None, (348, 230), False, None, None),
('curve', (348, 230), False, None, None),
(None, (325, 320), False, None, None),
(None, (272, 487), False, None, None)]}],
'func': <function subPt at 0x7f7f3bbefc80>,
'identifier': None,
'index': 9,
'name': None,
'point': (None, (303, 278), False, None, None),
'points1': [('qcurve', (249, 499), False, None, None),
(None, (239, 464), False, None, None),
(None, (222, 401), False, None, None),
(None, (207, 340), False, None, None),
(None, (194, 278), False, None, None),
('qcurve', (188, 245), False, None, None),
(None, (188, 245), False, None, None),
(None, (309, 245), False, None, None),
('curve', (309, 245), False, None, None),
(None, (303, 278), False, None, None),
(None, (291, 340), False, None, None),
(None, (276, 401), False, None, None),
(None, (259, 464), False, None, None)],
'points2': [('qcurve', (249, 547), False, None, None),
(None, (226, 484), False, None, None),
(None, (172, 318), False, None, None),
('qcurve', (148, 230), False, None, None),
(None, (148, 230), False, None, None),
(None, (348, 230), False, None, None),
('curve', (348, 230), False, None, None),
(None, (325, 320), False, None, None),
(None, (272, 487), False, None, None)],
'pprint': <function pprint at 0x7f7f3a2fc378>,
'pt': (37, -242),
'pt1': (303, 278),
'pt2': (272, 487),
'result': [{'identifier': None,
'points': [('curve', (-45, 0), False, None, None),
(None, (-45, 0), False, None, None),
(None, (-37, -19), False, None, None),
('curve', (-37, -19), False, None, None),
(None, (-37, -19), False, None, None),
(None, (36, -19), False, None, None),
('curve', (36, -19), False, None, None),
(None, (36, -19), False, None, None),
(None, (44, 0), False, None, None),
('curve', (44, 0), False, None, None),
(None, (44, 0), False, None, None),
(None, (0, 0), False, None, None),
('curve', (0, 0), False, None, None),
(None, (27, 117), False, None, None),
(None, (75, 264), False, None, None),
('qcurve', (68, 237), False, None, None),
(None, (14, 74), False, None, None),
(None, (118, 0), False, None, None),
('curve', (118, 0), False, None, None),
(None, (60, -136), False, None, None),
(None, (147, -441), False, None, None),
('qcurve', (159, -545), False, None, None),
(None, (106, -382), False, None, None),
(None, (-73, -220), False, None, None)]}],
'resultPoints': [('qcurve', (0, -48), False, None, None),
(None, (13, -20), False, None, None),
(None, (50, 83), False, None, None),
(None, (59, 110), False, None, None),
(None, (46, 48), False, None, None),
('qcurve', (-160, 15), False, None, None),
(None, (-160, 15), False, None, None),
(None, (-16, -75), False, None, None),
('curve', (37, -242), False, None, None)],
'segmentType': None,
'smooth': False}
Am I doing something wrong? Thanks for this cool project!
Issue Analytics
- State:
- Created 7 years ago
- Comments:7 (2 by maintainers)
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It’s possible to do this, but it wasn’t a goal of fontMath back when I wrote it. My goal was to have extremely predictable interpolation. I’ve thought about adding support for forcing compatibility by inserting points + flattening to equal numbers of line segments, but I’ve never had time to write it. I’d be happy to accept a patch that implements this (as long as it is optional and off by default, to maintain existing behavior).
Thanks for explaining! I understand. I don’t think this is something I could figure out myself in a small amount of time, but hopefully someone will 😃