fonttools/Lib/fontTools/varLib/interpolatable.py

"""
Tool to find wrong contour order between different masters, and
other interpolatability (or lack thereof) issues.

Call as:
$ fonttools varLib.interpolatable font1 font2 ...
"""

from fontTools.pens.basePen import AbstractPen, BasePen
from fontTools.pens.pointPen import AbstractPointPen, SegmentToPointPen
from fontTools.pens.recordingPen import RecordingPen
from fontTools.pens.statisticsPen import StatisticsPen
from fontTools.pens.momentsPen import OpenContourError
from collections import defaultdict
import math
import itertools
import sys
import logging

log = logging.getLogger("fontTools.varLib.interpolatable")


def _rot_list(l, k):
    """Rotate list by k items forward.  Ie. item at position 0 will be
    at position k in returned list.  Negative k is allowed."""
    return l[-k:] + l[:-k]


class PerContourPen(BasePen):
    def __init__(self, Pen, glyphset=None):
        BasePen.__init__(self, glyphset)
        self._glyphset = glyphset
        self._Pen = Pen
        self._pen = None
        self.value = []

    def _moveTo(self, p0):
        self._newItem()
        self._pen.moveTo(p0)

    def _lineTo(self, p1):
        self._pen.lineTo(p1)

    def _qCurveToOne(self, p1, p2):
        self._pen.qCurveTo(p1, p2)

    def _curveToOne(self, p1, p2, p3):
        self._pen.curveTo(p1, p2, p3)

    def _closePath(self):
        self._pen.closePath()
        self._pen = None

    def _endPath(self):
        self._pen.endPath()
        self._pen = None

    def _newItem(self):
        self._pen = pen = self._Pen()
        self.value.append(pen)


class PerContourOrComponentPen(PerContourPen):
    def addComponent(self, glyphName, transformation):
        self._newItem()
        self.value[-1].addComponent(glyphName, transformation)


class RecordingPointPen(AbstractPointPen):
    def __init__(self):
        self.value = []

    def beginPath(self, identifier=None, **kwargs):
        pass

    def endPath(self) -> None:
        pass

    def addPoint(self, pt, segmentType=None):
        self.value.append((pt, False if segmentType is None else True))


def _vdiff_hypot2(v0, v1):
    s = 0
    for x0, x1 in zip(v0, v1):
        d = x1 - x0
        s += d * d
    return s


def _vdiff_hypot2_complex(v0, v1):
    s = 0
    for x0, x1 in zip(v0, v1):
        d = x1 - x0
        s += d.real * d.real + d.imag * d.imag
    return s


def _matching_cost(G, matching):
    return sum(G[i][j] for i, j in enumerate(matching))


def min_cost_perfect_bipartite_matching_scipy(G):
    n = len(G)
    rows, cols = linear_sum_assignment(G)
    assert (rows == list(range(n))).all()
    return list(cols), _matching_cost(G, cols)


def min_cost_perfect_bipartite_matching_munkres(G):
    n = len(G)
    cols = [None] * n
    for row, col in Munkres().compute(G):
        cols[row] = col
    return cols, _matching_cost(G, cols)


def min_cost_perfect_bipartite_matching_bruteforce(G):
    n = len(G)

    if n > 6:
        raise Exception("Install Python module 'munkres' or 'scipy >= 0.17.0'")

    # Otherwise just brute-force
    permutations = itertools.permutations(range(n))
    best = list(next(permutations))
    best_cost = _matching_cost(G, best)
    for p in permutations:
        cost = _matching_cost(G, p)
        if cost < best_cost:
            best, best_cost = list(p), cost
    return best, best_cost


try:
    from scipy.optimize import linear_sum_assignment

    min_cost_perfect_bipartite_matching = min_cost_perfect_bipartite_matching_scipy
except ImportError:
    try:
        from munkres import Munkres

        min_cost_perfect_bipartite_matching = (
            min_cost_perfect_bipartite_matching_munkres
        )
    except ImportError:
        min_cost_perfect_bipartite_matching = (
            min_cost_perfect_bipartite_matching_bruteforce
        )


def test_gen(glyphsets, glyphs=None, names=None, ignore_missing=False):
    if names is None:
        names = glyphsets
    if glyphs is None:
        # `glyphs = glyphsets[0].keys()` is faster, certainly, but doesn't allow for sparse TTFs/OTFs given out of order
        # ... risks the sparse master being the first one, and only processing a subset of the glyphs
        glyphs = {g for glyphset in glyphsets for g in glyphset.keys()}

    hist = []

    for glyph_name in glyphs:
        try:
            m0idx = 0
            allVectors = []
            allNodeTypes = []
            allContourIsomorphisms = []
            allGlyphs = [glyphset[glyph_name] for glyphset in glyphsets]
            if len([1 for glyph in allGlyphs if glyph is not None]) <= 1:
                continue
            for glyph, glyphset, name in zip(allGlyphs, glyphsets, names):
                if glyph is None:
                    if not ignore_missing:
                        yield (glyph_name, {"type": "missing", "master": name})
                    allNodeTypes.append(None)
                    allVectors.append(None)
                    allContourIsomorphisms.append(None)
                    continue

                perContourPen = PerContourOrComponentPen(
                    RecordingPen, glyphset=glyphset
                )
                try:
                    glyph.draw(perContourPen, outputImpliedClosingLine=True)
                except TypeError:
                    glyph.draw(perContourPen)
                contourPens = perContourPen.value
                del perContourPen

                contourVectors = []
                contourIsomorphisms = []
                nodeTypes = []
                allNodeTypes.append(nodeTypes)
                allVectors.append(contourVectors)
                allContourIsomorphisms.append(contourIsomorphisms)
                for ix, contour in enumerate(contourPens):
                    nodeVecs = tuple(instruction[0] for instruction in contour.value)
                    nodeTypes.append(nodeVecs)

                    stats = StatisticsPen(glyphset=glyphset)
                    try:
                        contour.replay(stats)
                    except OpenContourError as e:
                        yield (
                            glyph_name,
                            {"master": name, "contour": ix, "type": "open_path"},
                        )
                        continue
                    size = math.sqrt(abs(stats.area)) * 0.5
                    vector = (
                        int(size),
                        int(stats.meanX),
                        int(stats.meanY),
                        int(stats.stddevX * 2),
                        int(stats.stddevY * 2),
                        int(stats.correlation * size),
                    )
                    contourVectors.append(vector)
                    # print(vector)

                    # Check starting point
                    if nodeVecs[0] == "addComponent":
                        continue
                    assert nodeVecs[0] == "moveTo"
                    assert nodeVecs[-1] in ("closePath", "endPath")
                    points = RecordingPointPen()
                    converter = SegmentToPointPen(points, False)
                    contour.replay(converter)
                    # points.value is a list of pt,bool where bool is true if on-curve and false if off-curve;
                    # now check all rotations and mirror-rotations of the contour and build list of isomorphic
                    # possible starting points.
                    bits = 0
                    for pt, b in points.value:
                        bits = (bits << 1) | b
                    n = len(points.value)
                    mask = (1 << n) - 1
                    isomorphisms = []
                    contourIsomorphisms.append(isomorphisms)
                    complexPoints = [complex(*pt) for pt, bl in points.value]
                    for i in range(n):
                        b = ((bits << i) & mask) | ((bits >> (n - i)))
                        if b == bits:
                            isomorphisms.append(_rot_list(complexPoints, i))
                    # Add mirrored rotations
                    mirrored = list(reversed(points.value))
                    reversed_bits = 0
                    for pt, b in mirrored:
                        reversed_bits = (reversed_bits << 1) | b
                    complexPoints = list(reversed(complexPoints))
                    for i in range(n):
                        b = ((reversed_bits << i) & mask) | ((reversed_bits >> (n - i)))
                        if b == bits:
                            isomorphisms.append(_rot_list(complexPoints, i))

            # m0idx should be the index of the first non-None item in allNodeTypes,
            # else give it the last item.
            m0idx = next(
                (i for i, x in enumerate(allNodeTypes) if x is not None),
                len(allNodeTypes) - 1,
            )
            # m0 is the first non-None item in allNodeTypes, or last one if all None
            m0 = allNodeTypes[m0idx]
            for i, m1 in enumerate(allNodeTypes[m0idx + 1 :]):
                if m1 is None:
                    continue
                if len(m0) != len(m1):
                    yield (
                        glyph_name,
                        {
                            "type": "path_count",
                            "master_1": names[m0idx],
                            "master_2": names[m0idx + i + 1],
                            "value_1": len(m0),
                            "value_2": len(m1),
                        },
                    )
                if m0 == m1:
                    continue
                for pathIx, (nodes1, nodes2) in enumerate(zip(m0, m1)):
                    if nodes1 == nodes2:
                        continue
                    if len(nodes1) != len(nodes2):
                        yield (
                            glyph_name,
                            {
                                "type": "node_count",
                                "path": pathIx,
                                "master_1": names[m0idx],
                                "master_2": names[m0idx + i + 1],
                                "value_1": len(nodes1),
                                "value_2": len(nodes2),
                            },
                        )
                        continue
                    for nodeIx, (n1, n2) in enumerate(zip(nodes1, nodes2)):
                        if n1 != n2:
                            yield (
                                glyph_name,
                                {
                                    "type": "node_incompatibility",
                                    "path": pathIx,
                                    "node": nodeIx,
                                    "master_1": names[m0idx],
                                    "master_2": names[m0idx + i + 1],
                                    "value_1": n1,
                                    "value_2": n2,
                                },
                            )
                            continue

            # m0idx should be the index of the first non-None item in allVectors,
            # else give it the last item.
            m0idx = next(
                (i for i, x in enumerate(allVectors) if x is not None),
                len(allVectors) - 1,
            )
            # m0 is the first non-None item in allVectors, or last one if all None
            m0 = allVectors[m0idx]
            if m0 is not None and len(m0) > 1:
                for i, m1 in enumerate(allVectors[m0idx + 1 :]):
                    if m1 is None:
                        continue
                    if len(m0) != len(m1):
                        # We already reported this
                        continue
                    costs = [[_vdiff_hypot2(v0, v1) for v1 in m1] for v0 in m0]
                    matching, matching_cost = min_cost_perfect_bipartite_matching(costs)
                    identity_matching = list(range(len(m0)))
                    identity_cost = sum(costs[i][i] for i in range(len(m0)))
                    if (
                        matching != identity_matching
                        and matching_cost < identity_cost * 0.95
                    ):
                        yield (
                            glyph_name,
                            {
                                "type": "contour_order",
                                "master_1": names[m0idx],
                                "master_2": names[m0idx + i + 1],
                                "value_1": list(range(len(m0))),
                                "value_2": matching,
                            },
                        )
                        break

            # m0idx should be the index of the first non-None item in allContourIsomorphisms,
            # else give it the last item.
            m0idx = next(
                (i for i, x in enumerate(allContourIsomorphisms) if x is not None),
                len(allVectors) - 1,
            )
            # m0 is the first non-None item in allContourIsomorphisms, or last one if all None
            m0 = allContourIsomorphisms[m0idx]
            if m0:
                for i, m1 in enumerate(allContourIsomorphisms[m0idx + 1 :]):
                    if m1 is None:
                        continue
                    if len(m0) != len(m1):
                        # We already reported this
                        continue
                    for ix, (contour0, contour1) in enumerate(zip(m0, m1)):
                        c0 = contour0[0]
                        costs = [_vdiff_hypot2_complex(c0, c1) for c1 in contour1]
                        min_cost = min(costs)
                        first_cost = costs[0]
                        if min_cost < first_cost * 0.95:
                            yield (
                                glyph_name,
                                {
                                    "type": "wrong_start_point",
                                    "contour": ix,
                                    "master_1": names[m0idx],
                                    "master_2": names[m0idx + i + 1],
                                },
                            )

        except ValueError as e:
            yield (
                glyph_name,
                {"type": "math_error", "master": name, "error": e},
            )


def test(glyphsets, glyphs=None, names=None, ignore_missing=False):
    problems = defaultdict(list)
    for glyphname, problem in test_gen(glyphsets, glyphs, names, ignore_missing):
        problems[glyphname].append(problem)
    return problems


def recursivelyAddGlyph(glyphname, glyphset, ttGlyphSet, glyf):
    if glyphname in glyphset:
        return
    glyphset[glyphname] = ttGlyphSet[glyphname]

    for component in getattr(glyf[glyphname], "components", []):
        recursivelyAddGlyph(component.glyphName, glyphset, ttGlyphSet, glyf)


def main(args=None):
    """Test for interpolatability issues between fonts"""
    import argparse

    parser = argparse.ArgumentParser(
        "fonttools varLib.interpolatable",
        description=main.__doc__,
    )
    parser.add_argument(
        "--glyphs",
        action="store",
        help="Space-separate name of glyphs to check",
    )
    parser.add_argument(
        "--json",
        action="store_true",
        help="Output report in JSON format",
    )
    parser.add_argument(
        "--quiet",
        action="store_true",
        help="Only exit with code 1 or 0, no output",
    )
    parser.add_argument(
        "--ignore-missing",
        action="store_true",
        help="Will not report glyphs missing from sparse masters as errors",
    )
    parser.add_argument(
        "inputs",
        metavar="FILE",
        type=str,
        nargs="+",
        help="Input a single variable font / DesignSpace / Glyphs file, or multiple TTF/UFO files",
    )
    parser.add_argument("-v", "--verbose", action="store_true", help="Run verbosely.")

    args = parser.parse_args(args)

    from fontTools import configLogger

    configLogger(level=("INFO" if args.verbose else "ERROR"))

    glyphs = args.glyphs.split() if args.glyphs else None

    from os.path import basename

    fonts = []
    names = []

    if len(args.inputs) == 1:
        if args.inputs[0].endswith(".designspace"):
            from fontTools.designspaceLib import DesignSpaceDocument

            designspace = DesignSpaceDocument.fromfile(args.inputs[0])
            args.inputs = [master.path for master in designspace.sources]

        elif args.inputs[0].endswith(".glyphs"):
            from glyphsLib import GSFont, to_ufos

            gsfont = GSFont(args.inputs[0])
            fonts.extend(to_ufos(gsfont))
            names = ["%s-%s" % (f.info.familyName, f.info.styleName) for f in fonts]
            args.inputs = []

        elif args.inputs[0].endswith(".ttf"):
            from fontTools.ttLib import TTFont

            font = TTFont(args.inputs[0])
            if "gvar" in font:
                # Is variable font
                gvar = font["gvar"]
                glyf = font["glyf"]
                # Gather all glyphs at their "master" locations
                ttGlyphSets = {}
                glyphsets = defaultdict(dict)

                if glyphs is None:
                    glyphs = sorted(gvar.variations.keys())
                for glyphname in glyphs:
                    for var in gvar.variations[glyphname]:
                        locDict = {}
                        loc = []
                        for tag, val in sorted(var.axes.items()):
                            locDict[tag] = val[1]
                            loc.append((tag, val[1]))

                        locTuple = tuple(loc)
                        if locTuple not in ttGlyphSets:
                            ttGlyphSets[locTuple] = font.getGlyphSet(
                                location=locDict, normalized=True
                            )

                        recursivelyAddGlyph(
                            glyphname, glyphsets[locTuple], ttGlyphSets[locTuple], glyf
                        )

                names = ["()"]
                fonts = [font.getGlyphSet()]
                for locTuple in sorted(glyphsets.keys(), key=lambda v: (len(v), v)):
                    names.append(str(locTuple))
                    fonts.append(glyphsets[locTuple])
                args.ignore_missing = True
                args.inputs = []

    for filename in args.inputs:
        if filename.endswith(".ufo"):
            from fontTools.ufoLib import UFOReader

            fonts.append(UFOReader(filename))
        else:
            from fontTools.ttLib import TTFont

            fonts.append(TTFont(filename))

        names.append(basename(filename).rsplit(".", 1)[0])

    glyphsets = []
    for font in fonts:
        if hasattr(font, "getGlyphSet"):
            glyphset = font.getGlyphSet()
        else:
            glyphset = font
        glyphsets.append({k: glyphset[k] for k in glyphset.keys()})

    if not glyphs:
        glyphs = sorted(set([gn for glyphset in glyphsets for gn in glyphset.keys()]))

    glyphsSet = set(glyphs)
    for glyphset in glyphsets:
        glyphSetGlyphNames = set(glyphset.keys())
        diff = glyphsSet - glyphSetGlyphNames
        if diff:
            for gn in diff:
                glyphset[gn] = None

    log.info("Running on %d glyphsets", len(glyphsets))
    problems_gen = test_gen(
        glyphsets, glyphs=glyphs, names=names, ignore_missing=args.ignore_missing
    )
    problems = defaultdict(list)

    if not args.quiet:
        if args.json:
            import json

            for glyphname, problem in problems_gen:
                problems[glyphname].append(problem)

            print(json.dumps(problems))
        else:
            last_glyphname = None
            for glyphname, p in problems_gen:
                problems[glyphname].append(p)

                if glyphname != last_glyphname:
                    print(f"Glyph {glyphname} was not compatible: ")
                    last_glyphname = glyphname

                if p["type"] == "missing":
                    print("    Glyph was missing in master %s" % p["master"])
                if p["type"] == "open_path":
                    print("    Glyph has an open path in master %s" % p["master"])
                if p["type"] == "path_count":
                    print(
                        "    Path count differs: %i in %s, %i in %s"
                        % (p["value_1"], p["master_1"], p["value_2"], p["master_2"])
                    )
                if p["type"] == "node_count":
                    print(
                        "    Node count differs in path %i: %i in %s, %i in %s"
                        % (
                            p["path"],
                            p["value_1"],
                            p["master_1"],
                            p["value_2"],
                            p["master_2"],
                        )
                    )
                if p["type"] == "node_incompatibility":
                    print(
                        "    Node %o incompatible in path %i: %s in %s, %s in %s"
                        % (
                            p["node"],
                            p["path"],
                            p["value_1"],
                            p["master_1"],
                            p["value_2"],
                            p["master_2"],
                        )
                    )
                if p["type"] == "contour_order":
                    print(
                        "    Contour order differs: %s in %s, %s in %s"
                        % (
                            p["value_1"],
                            p["master_1"],
                            p["value_2"],
                            p["master_2"],
                        )
                    )
                if p["type"] == "wrong_start_point":
                    print(
                        "    Contour %d start point differs: %s, %s"
                        % (
                            p["contour"],
                            p["master_1"],
                            p["master_2"],
                        )
                    )
                if p["type"] == "math_error":
                    print(
                        "    Miscellaneous error in %s: %s"
                        % (
                            p["master"],
                            p["error"],
                        )
                    )
    else:
        for glyphname, problem in problems_gen:
            problems[glyphname].append(problem)

    if problems:
        return problems


if __name__ == "__main__":
    import sys

    problems = main()
    sys.exit(int(bool(problems)))