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 SegmentToPointPen
from fontTools.pens.recordingPen import RecordingPen
from fontTools.pens.statisticsPen import StatisticsPen
from fontTools.pens.momentsPen import OpenContourError
from collections import OrderedDict
import itertools
import sys

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."""
	n = len(l)
	k %= n
	if not k: return l
	return l[n-k:] + l[:n-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(BasePen):

    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(v0, v1):
    return tuple(b - a for a, b in zip(v0, v1))


def _vlen(vec):
    v = 0
    for x in vec:
        v += x * x
    return v

def _complex_vlen(vec):
    v = 0
    for x in vec:
        v += abs(x) * abs(x)
    return v


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


def min_cost_perfect_bipartite_matching(G):
    n = len(G)
    try:
        from scipy.optimize import linear_sum_assignment

        rows, cols = linear_sum_assignment(G)
        assert (rows == list(range(n))).all()
        return list(cols), _matching_cost(G, cols)
    except ImportError:
        pass

    try:
        from munkres import Munkres

        cols = [None] * n
        for row, col in Munkres().compute(G):
            cols[row] = col
        return cols, _matching_cost(G, cols)
    except ImportError:
        pass

    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


def test(glyphsets, glyphs=None, names=None):

    if names is None:
        names = glyphsets
    if glyphs is None:
        glyphs = glyphsets[0].keys()

    hist = []
    problems = OrderedDict()

    def add_problem(glyphname, problem):
        problems.setdefault(glyphname, []).append(problem)

    for glyph_name in glyphs:
        # print()
        # print(glyph_name)

        try:
            allVectors = []
            allNodeTypes = []
            allContourIsomorphisms = []
            for glyphset, name in zip(glyphsets, names):
                # print('.', end='')
                if glyph_name not in glyphset:
                    add_problem(glyph_name, {"type": "missing", "master": name})
                    continue
                glyph = glyphset[glyph_name]

                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:
                        add_problem(
                            glyph_name,
                            {"master": name, "contour": ix, "type": "open_path"},
                        )
                        continue
                    size = abs(stats.area) ** 0.5 * 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)
                    for i in range(n):
                        b = ((bits << i) & mask) | ((bits >> (n - i)))
                        if b == bits:
                            isomorphisms.append(_rot_list ([complex(*pt) for pt,bl in points.value], i))
                    # Add mirrored rotations
                    mirrored = list(reversed(points.value))
                    reversed_bits = 0
                    for pt,b in mirrored:
                        reversed_bits = (reversed_bits << 1) | b
                    for i in range(n):
                        b = ((reversed_bits << i) & mask) | ((reversed_bits >> (n - i)))
                        if b == bits:
                            isomorphisms.append(_rot_list ([complex(*pt) for pt,bl in mirrored], i))

            # Check each master against the next one in the list.
            for i, (m0, m1) in enumerate(zip(allNodeTypes[:-1], allNodeTypes[1:])):
                if len(m0) != len(m1):
                    add_problem(
                        glyph_name,
                        {
                            "type": "path_count",
                            "master_1": names[i],
                            "master_2": names[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):
                        add_problem(
                            glyph_name,
                            {
                                "type": "node_count",
                                "path": pathIx,
                                "master_1": names[i],
                                "master_2": names[i + 1],
                                "value_1": len(nodes1),
                                "value_2": len(nodes2),
                            },
                        )
                        continue
                    for nodeIx, (n1, n2) in enumerate(zip(nodes1, nodes2)):
                        if n1 != n2:
                            add_problem(
                                glyph_name,
                                {
                                    "type": "node_incompatibility",
                                    "path": pathIx,
                                    "node": nodeIx,
                                    "master_1": names[i],
                                    "master_2": names[i + 1],
                                    "value_1": n1,
                                    "value_2": n2,
                                },
                            )
                            continue

            for i, (m0, m1) in enumerate(zip(allVectors[:-1], allVectors[1:])):
                if len(m0) != len(m1):
                    # We already reported this
                    continue
                if not m0:
                    continue
                costs = [[_vlen(_vdiff(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 * .95:
                    add_problem(
                        glyph_name,
                        {
                            "type": "contour_order",
                            "master_1": names[i],
                            "master_2": names[i + 1],
                            "value_1": list(range(len(m0))),
                            "value_2": matching,
                        },
                    )
                    break

            for i, (m0, m1) in enumerate(zip(allContourIsomorphisms[:-1], allContourIsomorphisms[1:])):
                if len(m0) != len(m1):
                    # We already reported this
                    continue
                if not m0:
                    continue
                for contour0,contour1 in zip(m0,m1):
                    c0 = contour0[0]
                    costs = [v for v in (_complex_vlen(_vdiff(c0, c1)) for c1 in contour1)]
                    min_cost = min(costs)
                    first_cost = costs[0]
                    if min_cost < first_cost * .95:
                        add_problem(
                            glyph_name,
                            {
                                "type": "wrong_start_point",
                                "master_1": names[i],
                                "master_2": names[i + 1],
                            },
                        )

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


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

    parser = argparse.ArgumentParser(
        "fonttools varLib.interpolatable",
        description=main.__doc__,
    )
    parser.add_argument(
        "--json",
        action="store_true",
        help="Output report in JSON format",
    )
    parser.add_argument(
        "inputs", metavar="FILE", type=str, nargs="+", help="Input TTF/UFO files"
    )

    args = parser.parse_args(args)
    glyphs = None
    # glyphs = ['uni08DB', 'uniFD76']
    # glyphs = ['uni08DE', 'uni0034']
    # glyphs = ['uni08DE', 'uni0034', 'uni0751', 'uni0753', 'uni0754', 'uni08A4', 'uni08A4.fina', 'uni08A5.fina']

    from os.path import basename

    names = [basename(filename).rsplit(".", 1)[0] for filename in args.inputs]

    fonts = []
    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))

    glyphsets = [font.getGlyphSet() for font in fonts]
    problems = test(glyphsets, glyphs=glyphs, names=names)
    if args.json:
        import json

        print(json.dumps(problems))
    else:
        for glyph, glyph_problems in problems.items():
            print(f"Glyph {glyph} was not compatible: ")
            for p in glyph_problems:
                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 start point differs: %s, %s"
                        % (
                            p["master_1"],
                            p["master_2"],
                        )
                    )
    if problems:
        return problems


if __name__ == "__main__":
    import sys

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