# Source code for fontTools.subset

    # Copyright 2013 Google, Inc. All Rights Reserved.
    #
    # Google Author(s): Behdad Esfahbod

    from __future__ import annotations

    from fontTools import config
    from fontTools.misc.roundTools import otRound
    from fontTools import ttLib
    from fontTools.ttLib.tables import otTables
    from fontTools.ttLib.tables.otBase import USE_HARFBUZZ_REPACKER
    from fontTools.otlLib.maxContextCalc import maxCtxFont
    from fontTools.pens.basePen import NullPen
    from fontTools.misc.loggingTools import Timer
    from fontTools.misc.cliTools import makeOutputFileName
    from fontTools.subset.util import _add_method, _uniq_sort
    from fontTools.subset.cff import *
    from fontTools.subset.svg import *
    from fontTools.varLib import varStore, multiVarStore  # For monkey-patching
    from fontTools.ttLib.tables._n_a_m_e import NameRecordVisitor, makeName
    from fontTools.unicodedata import mirrored
    import sys
    import struct
    import array
    import logging
    from collections import Counter, defaultdict
    from functools import reduce
    from types import MethodType

    __usage__ = "fonttools subset font-file [glyph...] [--option=value]..."

    __doc__ = (
        """\
    fonttools subset -- OpenType font subsetter and optimizer

    fonttools subset is an OpenType font subsetter and optimizer, based on
    fontTools. It accepts any TT- or CFF-flavored OpenType (.otf or .ttf)
    or WOFF (.woff) font file. The subsetted glyph set is based on the
    specified glyphs or characters, and specified OpenType layout features.

    The tool also performs some size-reducing optimizations, aimed for using
    subset fonts as webfonts.  Individual optimizations can be enabled or
    disabled, and are enabled by default when they are safe.

    Usage: """
        + __usage__
        + """

    At least one glyph or one of --gids, --gids-file, --glyphs, --glyphs-file,
    --text, --text-file, --unicodes, or --unicodes-file, must be specified.

    Args:

    font-file
      The input font file.
    glyph
      Specify one or more glyph identifiers to include in the subset. Must be
      PS glyph names, or the special string '*' to keep the entire glyph set.

    Initial glyph set specification
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

    These options populate the initial glyph set. Same option can appear
    multiple times, and the results are accummulated.

    --gids=<NNN>[,<NNN>...]
      Specify comma/whitespace-separated list of glyph IDs or ranges as decimal
      numbers.  For example, --gids=10-12,14 adds glyphs with numbers 10, 11,
      12, and 14.

    --gids-file=<path>
      Like --gids but reads from a file. Anything after a '#' on any line is
      ignored as comments.

    --glyphs=<glyphname>[,<glyphname>...]
      Specify comma/whitespace-separated PS glyph names to add to the subset.
      Note that only PS glyph names are accepted, not gidNNN, U+XXXX, etc
      that are accepted on the command line.  The special string '*' will keep
      the entire glyph set.

    --glyphs-file=<path>
      Like --glyphs but reads from a file. Anything after a '#' on any line
      is ignored as comments.

    --text=<text>
      Specify characters to include in the subset, as UTF-8 string.

    --text-file=<path>
      Like --text but reads from a file. Newline character are not added to
      the subset.

    --unicodes=<XXXX>[,<XXXX>...]
      Specify comma/whitespace-separated list of Unicode codepoints or
      ranges as hex numbers, optionally prefixed with 'U+', 'u', etc.
      For example, --unicodes=41-5a,61-7a adds ASCII letters, so does
      the more verbose --unicodes=U+0041-005A,U+0061-007A.
      The special strings '*' will choose all Unicode characters mapped
      by the font.

    --unicodes-file=<path>
      Like --unicodes, but reads from a file. Anything after a '#' on any
      line in the file is ignored as comments.

    --ignore-missing-glyphs
      Do not fail if some requested glyphs or gids are not available in
      the font.

    --no-ignore-missing-glyphs
      Stop and fail if some requested glyphs or gids are not available
      in the font. [default]

    --ignore-missing-unicodes [default]
      Do not fail if some requested Unicode characters (including those
      indirectly specified using --text or --text-file) are not available
      in the font.

    --no-ignore-missing-unicodes
      Stop and fail if some requested Unicode characters are not available
      in the font.
      Note the default discrepancy between ignoring missing glyphs versus
      unicodes.  This is for historical reasons and in the future
      --no-ignore-missing-unicodes might become default.

    Other options
    ^^^^^^^^^^^^^

    For the other options listed below, to see the current value of the option,
    pass a value of '?' to it, with or without a '='. In some environments,
    you might need to escape the question mark, like this: '--glyph-names\\?'.

    Examples::

        $ fonttools subset --glyph-names?
        Current setting for 'glyph-names' is: False
        $ fonttools subset --name-IDs=?
        Current setting for 'name-IDs' is: [0, 1, 2, 3, 4, 5, 6]
        $ fonttools subset --hinting? --no-hinting --hinting?
        Current setting for 'hinting' is: True
        Current setting for 'hinting' is: False

    Output options
    ^^^^^^^^^^^^^^

    --output-file=<path>
      The output font file. If not specified, the subsetted font
      will be saved in as font-file.subset.

    --flavor=<type>
      Specify flavor of output font file. May be 'woff' or 'woff2'.
      Note that WOFF2 requires the Brotli Python extension, available
      at https://github.com/google/brotli

    --with-zopfli
      Use the Google Zopfli algorithm to compress WOFF. The output is 3-8 %
      smaller than pure zlib, but the compression speed is much slower.
      The Zopfli Python bindings are available at:
      https://pypi.python.org/pypi/zopfli

    --harfbuzz-repacker
      By default, we serialize GPOS/GSUB using the HarfBuzz Repacker when
      uharfbuzz can be imported and is successful, otherwise fall back to
      the pure-python serializer. Set the option to force using the HarfBuzz
      Repacker (raises an error if uharfbuzz can't be found or fails).

    --no-harfbuzz-repacker
      Always use the pure-python serializer even if uharfbuzz is available.

    Glyph set expansion
    ^^^^^^^^^^^^^^^^^^^

    These options control how additional glyphs are added to the subset.

    --retain-gids
      Retain glyph indices; just empty glyphs not needed in-place.

    --notdef-glyph
      Add the '.notdef' glyph to the subset (ie, keep it). [default]

    --no-notdef-glyph
      Drop the '.notdef' glyph unless specified in the glyph set. This
      saves a few bytes, but is not possible for Postscript-flavored
      fonts, as those require '.notdef'. For TrueType-flavored fonts,
      this works fine as long as no unsupported glyphs are requested
      from the font.

    --notdef-outline
      Keep the outline of '.notdef' glyph. The '.notdef' glyph outline is
      used when glyphs not supported by the font are to be shown. It is not
      needed otherwise.

    --no-notdef-outline
      When including a '.notdef' glyph, remove its outline. This saves
      a few bytes. [default]

    --recommended-glyphs
      Add glyphs 0, 1, 2, and 3 to the subset, as recommended for
      TrueType-flavored fonts: '.notdef', 'NULL' or '.null', 'CR', 'space'.
      Some legacy software might require this, but no modern system does.

    --no-recommended-glyphs
      Do not add glyphs 0, 1, 2, and 3 to the subset, unless specified in
      glyph set. [default]

    --no-layout-closure
      Do not expand glyph set to add glyphs produced by OpenType layout
      features.  Instead, OpenType layout features will be subset to only
      rules that are relevant to the otherwise-specified glyph set.

    --layout-features[+|-]=<feature>[,<feature>...]
      Specify (=), add to (+=) or exclude from (-=) the comma-separated
      set of OpenType layout feature tags that will be preserved.
      Glyph variants used by the preserved features are added to the
      specified subset glyph set. By default, 'calt', 'ccmp', 'clig', 'curs',
      'dnom', 'frac', 'kern', 'liga', 'locl', 'mark', 'mkmk', 'numr', 'rclt',
      'rlig', 'rvrn', and all features required for script shaping are
      preserved. To see the full list, try '--layout-features=?'.
      Use '*' to keep all features.
      Multiple --layout-features options can be provided if necessary.
      Examples:

        --layout-features+=onum,pnum,ss01
            * Keep the default set of features and 'onum', 'pnum', 'ss01'.
        --layout-features-='mark','mkmk'
            * Keep the default set of features but drop 'mark' and 'mkmk'.
        --layout-features='kern'
            * Only keep the 'kern' feature, drop all others.
        --layout-features=''
            * Drop all features.
        --layout-features='*'
            * Keep all features.
        --layout-features+=aalt --layout-features-=vrt2
            * Keep default set of features plus 'aalt', but drop 'vrt2'.

    --layout-scripts[+|-]=<script>[,<script>...]
      Specify (=), add to (+=) or exclude from (-=) the comma-separated
      set of OpenType layout script tags that will be preserved. LangSys tags
      can be appended to script tag, separated by '.', for example:
      'arab.dflt,arab.URD,latn.TRK'. By default all scripts are retained ('*').

    Hinting options
    ^^^^^^^^^^^^^^^

    --hinting
      Keep hinting [default]

    --no-hinting
      Drop glyph-specific hinting and font-wide hinting tables, as well
      as remove hinting-related bits and pieces from other tables (eg. GPOS).
      See --hinting-tables for list of tables that are dropped by default.
      Instructions and hints are stripped from 'glyf' and 'CFF ' tables
      respectively. This produces (sometimes up to 30%) smaller fonts that
      are suitable for extremely high-resolution systems, like high-end
      mobile devices and retina displays.

    Optimization options
    ^^^^^^^^^^^^^^^^^^^^

    --desubroutinize
      Remove CFF use of subroutinizes.  Subroutinization is a way to make CFF
      fonts smaller.  For small subsets however, desubroutinizing might make
      the font smaller.  It has even been reported that desubroutinized CFF
      fonts compress better (produce smaller output) WOFF and WOFF2 fonts.
      Also see note under --no-hinting.

    --no-desubroutinize [default]
      Leave CFF subroutinizes as is, only throw away unused subroutinizes.

    Font table options
    ^^^^^^^^^^^^^^^^^^

    --drop-tables[+|-]=<table>[,<table>...]
      Specify (=), add to (+=) or exclude from (-=) the comma-separated
      set of tables that will be be dropped.
      By default, the following tables are dropped:
      'JSTF', 'DSIG', 'EBDT', 'EBLC', 'EBSC', 'PCLT', 'LTSH'
      and Graphite tables: 'Feat', 'Glat', 'Gloc', 'Silf', 'Sill'.
      The tool will attempt to subset the remaining tables.

      Examples:

      --drop-tables-=BASE
          * Drop the default set of tables but keep 'BASE'.

      --drop-tables+=GSUB
          * Drop the default set of tables and 'GSUB'.

      --drop-tables=DSIG
          * Only drop the 'DSIG' table, keep all others.

      --drop-tables=
          * Keep all tables.

    --no-subset-tables+=<table>[,<table>...]
      Add to the set of tables that will not be subsetted.
      By default, the following tables are included in this list, as
      they do not need subsetting (ignore the fact that 'loca' is listed
      here): 'gasp', 'head', 'hhea', 'maxp', 'vhea', 'OS/2', 'loca', 'name',
      'cvt ', 'fpgm', 'prep', 'VMDX', 'DSIG', 'CPAL', 'MVAR', 'cvar', 'STAT'.
      By default, tables that the tool does not know how to subset and are not
      specified here will be dropped from the font, unless --passthrough-tables
      option is passed.

      Example:

       --no-subset-tables+=FFTM
          * Keep 'FFTM' table in the font by preventing subsetting.

    --passthrough-tables
      Do not drop tables that the tool does not know how to subset.

    --no-passthrough-tables
      Tables that the tool does not know how to subset and are not specified
      in --no-subset-tables will be dropped from the font. [default]

    --hinting-tables[-]=<table>[,<table>...]
      Specify (=), add to (+=) or exclude from (-=) the list of font-wide
      hinting tables that will be dropped if --no-hinting is specified.

      Examples:

      --hinting-tables-=VDMX
          * Drop font-wide hinting tables except 'VDMX'.
      --hinting-tables=
          * Keep all font-wide hinting tables (but strip hints from glyphs).

    --legacy-kern
      Keep TrueType 'kern' table even when OpenType 'GPOS' is available.

    --no-legacy-kern
      Drop TrueType 'kern' table if OpenType 'GPOS' is available. [default]

    Font naming options
    ^^^^^^^^^^^^^^^^^^^

    These options control what is retained in the 'name' table. For numerical
    codes, see: http://www.microsoft.com/typography/otspec/name.htm

    --name-IDs[+|-]=<nameID>[,<nameID>...]
      Specify (=), add to (+=) or exclude from (-=) the set of 'name' table
      entry nameIDs that will be preserved. By default, only nameIDs between 0
      and 6 are preserved, the rest are dropped. Use '*' to keep all entries.

      Examples:

      --name-IDs+=7,8,9
          * Also keep Trademark, Manufacturer and Designer name entries.
      --name-IDs=
          * Drop all 'name' table entries.
      --name-IDs=*
          * keep all 'name' table entries

    --name-legacy
      Keep legacy (non-Unicode) 'name' table entries (0.x, 1.x etc.).
      XXX Note: This might be needed for some fonts that have no Unicode name
      entires for English. See: https://github.com/fonttools/fonttools/issues/146

    --no-name-legacy
      Drop legacy (non-Unicode) 'name' table entries [default]

    --name-languages[+|-]=<langID>[,<langID>]
      Specify (=), add to (+=) or exclude from (-=) the set of 'name' table
      langIDs that will be preserved. By default only records with langID
      0x0409 (English) are preserved. Use '*' to keep all langIDs.

    --obfuscate-names
      Make the font unusable as a system font by replacing name IDs 1, 2, 3, 4,
      and 6 with dummy strings (it is still fully functional as webfont).

    Glyph naming and encoding options
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

    --glyph-names
      Keep PS glyph names in TT-flavored fonts. In general glyph names are
      not needed for correct use of the font. However, some PDF generators
      and PDF viewers might rely on glyph names to extract Unicode text
      from PDF documents.
    --no-glyph-names
      Drop PS glyph names in TT-flavored fonts, by using 'post' table
      version 3.0. [default]
    --legacy-cmap
      Keep the legacy 'cmap' subtables (0.x, 1.x, 4.x etc.).
    --no-legacy-cmap
      Drop the legacy 'cmap' subtables. [default]
    --symbol-cmap
      Keep the 3.0 symbol 'cmap'.
    --no-symbol-cmap
      Drop the 3.0 symbol 'cmap'. [default]

    Other font-specific options
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^

    --recalc-bounds
        Recalculate font bounding boxes.
    --no-recalc-bounds
        Keep original font bounding boxes. This is faster and still safe
        for all practical purposes. [default]
    --recalc-timestamp
        Set font 'modified' timestamp to current time.
    --no-recalc-timestamp
        Do not modify font 'modified' timestamp. [default]
    --canonical-order
        Order tables as recommended in the OpenType standard. This is not
        required by the standard, nor by any known implementation.
    --no-canonical-order
        Keep original order of font tables. This is faster. [default]
    --prune-unicode-ranges
        Update the 'OS/2 ulUnicodeRange*' bits after subsetting. The Unicode
        ranges defined in the OpenType specification v1.7 are intersected with
        the Unicode codepoints specified in the font's Unicode 'cmap' subtables:
        when no overlap is found, the bit will be switched off. However, it will
        *not* be switched on if an intersection is found.  [default]
    --no-prune-unicode-ranges
        Don't change the 'OS/2 ulUnicodeRange*' bits.
    --prune-codepage-ranges
        Update the 'OS/2 ulCodePageRange*' bits after subsetting.  [default]
    --no-prune-codepage-ranges
        Don't change the 'OS/2 ulCodePageRange*' bits.
    --recalc-average-width
        Update the 'OS/2 xAvgCharWidth' field after subsetting.
    --no-recalc-average-width
        Don't change the 'OS/2 xAvgCharWidth' field. [default]
    --recalc-max-context
        Update the 'OS/2 usMaxContext' field after subsetting.
    --no-recalc-max-context
        Don't change the 'OS/2 usMaxContext' field. [default]
    --font-number=<number>
        Select font number for TrueType Collection (.ttc/.otc), starting from 0.
    --pretty-svg
        When subsetting SVG table, use lxml pretty_print=True option to indent
        the XML output (only recommended for debugging purposes).

    Application options
    ^^^^^^^^^^^^^^^^^^^

    --verbose
        Display verbose information of the subsetting process.
    --timing
        Display detailed timing information of the subsetting process.
    --xml
        Display the TTX XML representation of subsetted font.

    Example
    ^^^^^^^

    Produce a subset containing the characters ' !"#$%' without performing
    size-reducing optimizations::

      $ fonttools subset font.ttf --unicodes="U+0020-0025" \\
        --layout-features=* --glyph-names --symbol-cmap --legacy-cmap \\
        --notdef-glyph --notdef-outline --recommended-glyphs \\
        --name-IDs=* --name-legacy --name-languages=*
    """
    )

    log = logging.getLogger("fontTools.subset")

    def _log_glyphs(self, glyphs, font=None):
        self.info("Glyph names: %s", sorted(glyphs))
        if font:
            reverseGlyphMap = font.getReverseGlyphMap()
            self.info("Glyph IDs:   %s", sorted(reverseGlyphMap[g] for g in glyphs))

    # bind "glyphs" function to 'log' object
    log.glyphs = MethodType(_log_glyphs, log)

    # I use a different timing channel so I can configure it separately from the
    # main module's logger
    timer = Timer(logger=logging.getLogger("fontTools.subset.timer"))

    def _dict_subset(d, glyphs):
        return {g: d[g] for g in glyphs}

    def _list_subset(l, indices):
        count = len(l)
        return [l[i] for i in indices if i < count]

    @_add_method(otTables.Coverage)
    def intersect(self, glyphs):
        """Returns ascending list of matching coverage values."""
        return [i for i, g in enumerate(self.glyphs) if g in glyphs]

    @_add_method(otTables.Coverage)
    def intersect_glyphs(self, glyphs):
        """Returns set of intersecting glyphs."""
        return set(g for g in self.glyphs if g in glyphs)

    @_add_method(otTables.Coverage)
    def subset(self, glyphs):
        """Returns ascending list of remaining coverage values."""
        indices = self.intersect(glyphs)
        self.glyphs = [g for g in self.glyphs if g in glyphs]
        return indices

    @_add_method(otTables.Coverage)
    def remap(self, coverage_map):
        """Remaps coverage."""
        self.glyphs = [self.glyphs[i] for i in coverage_map]

    @_add_method(otTables.ClassDef)
    def intersect(self, glyphs):
        """Returns ascending list of matching class values."""
        return _uniq_sort(
            ([0] if any(g not in self.classDefs for g in glyphs) else [])
            + [v for g, v in self.classDefs.items() if g in glyphs]
        )

    @_add_method(otTables.ClassDef)
    def intersect_class(self, glyphs, klass):
        """Returns set of glyphs matching class."""
        if klass == 0:
            return set(g for g in glyphs if g not in self.classDefs)
        return set(g for g, v in self.classDefs.items() if v == klass and g in glyphs)

    @_add_method(otTables.ClassDef)
    def subset(self, glyphs, remap=False, useClass0=True):
        """Returns ascending list of remaining classes."""
        self.classDefs = {g: v for g, v in self.classDefs.items() if g in glyphs}
        # Note: while class 0 has the special meaning of "not matched",
        # if no glyph will ever /not match/, we can optimize class 0 out too.
        # Only do this if allowed.
        indices = _uniq_sort(
            (
                [0]
                if ((not useClass0) or any(g not in self.classDefs for g in glyphs))
                else []
            )
            + list(self.classDefs.values())
        )
        if remap:
            self.remap(indices)
        return indices

    @_add_method(otTables.ClassDef)
    def remap(self, class_map):
        """Remaps classes."""
        self.classDefs = {g: class_map.index(v) for g, v in self.classDefs.items()}

    @_add_method(otTables.SingleSubst)
    def closure_glyphs(self, s, cur_glyphs):
        s.glyphs.update(v for g, v in self.mapping.items() if g in cur_glyphs)

    @_add_method(otTables.SingleSubst)
    def subset_glyphs(self, s):
        self.mapping = {
            g: v for g, v in self.mapping.items() if g in s.glyphs and v in s.glyphs
        }
        return bool(self.mapping)

    @_add_method(otTables.MultipleSubst)
    def closure_glyphs(self, s, cur_glyphs):
        for glyph, subst in self.mapping.items():
            if glyph in cur_glyphs:
                s.glyphs.update(subst)

    @_add_method(otTables.MultipleSubst)
    def subset_glyphs(self, s):
        self.mapping = {
            g: v
            for g, v in self.mapping.items()
            if g in s.glyphs and all(sub in s.glyphs for sub in v)
        }
        return bool(self.mapping)

    @_add_method(otTables.AlternateSubst)
    def closure_glyphs(self, s, cur_glyphs):
        s.glyphs.update(*(vlist for g, vlist in self.alternates.items() if g in cur_glyphs))

    @_add_method(otTables.AlternateSubst)
    def subset_glyphs(self, s):
        self.alternates = {
            g: [v for v in vlist if v in s.glyphs]
            for g, vlist in self.alternates.items()
            if g in s.glyphs and any(v in s.glyphs for v in vlist)
        }
        return bool(self.alternates)

    @_add_method(otTables.LigatureSubst)
    def closure_glyphs(self, s, cur_glyphs):
        s.glyphs.update(
            *(
                [seq.LigGlyph for seq in seqs if all(c in s.glyphs for c in seq.Component)]
                for g, seqs in self.ligatures.items()
                if g in cur_glyphs
            )
        )

    @_add_method(otTables.LigatureSubst)
    def subset_glyphs(self, s):
        self.ligatures = {g: v for g, v in self.ligatures.items() if g in s.glyphs}
        self.ligatures = {
            g: [
                seq
                for seq in seqs
                if seq.LigGlyph in s.glyphs and all(c in s.glyphs for c in seq.Component)
            ]
            for g, seqs in self.ligatures.items()
        }
        self.ligatures = {g: v for g, v in self.ligatures.items() if v}
        return bool(self.ligatures)

    @_add_method(otTables.ReverseChainSingleSubst)
    def closure_glyphs(self, s, cur_glyphs):
        if self.Format == 1:
            indices = self.Coverage.intersect(cur_glyphs)
            if not indices or not all(
                c.intersect(s.glyphs)
                for c in self.LookAheadCoverage + self.BacktrackCoverage
            ):
                return
            s.glyphs.update(self.Substitute[i] for i in indices)
        else:
            assert 0, "unknown format: %s" % self.Format

    @_add_method(otTables.ReverseChainSingleSubst)
    def subset_glyphs(self, s):
        if self.Format == 1:
            indices = self.Coverage.subset(s.glyphs)
            self.Substitute = _list_subset(self.Substitute, indices)
            # Now drop rules generating glyphs we don't want
            indices = [i for i, sub in enumerate(self.Substitute) if sub in s.glyphs]
            self.Substitute = _list_subset(self.Substitute, indices)
            self.Coverage.remap(indices)
            self.GlyphCount = len(self.Substitute)
            return bool(
                self.GlyphCount
                and all(
                    c.subset(s.glyphs)
                    for c in self.LookAheadCoverage + self.BacktrackCoverage
                )
            )
        else:
            assert 0, "unknown format: %s" % self.Format

    @_add_method(otTables.Device)
    def is_hinting(self):
        return self.DeltaFormat in (1, 2, 3)

    @_add_method(otTables.ValueRecord)
    def prune_hints(self):
        for name in ["XPlaDevice", "YPlaDevice", "XAdvDevice", "YAdvDevice"]:
            v = getattr(self, name, None)
            if v is not None and v.is_hinting():
                delattr(self, name)

    @_add_method(otTables.SinglePos)
    def subset_glyphs(self, s):
        if self.Format == 1:
            return len(self.Coverage.subset(s.glyphs))
        elif self.Format == 2:
            indices = self.Coverage.subset(s.glyphs)
            values = self.Value
            count = len(values)
            self.Value = [values[i] for i in indices if i < count]
            self.ValueCount = len(self.Value)
            return bool(self.ValueCount)
        else:
            assert 0, "unknown format: %s" % self.Format

    @_add_method(otTables.SinglePos)
    def prune_post_subset(self, font, options):
        if self.Value is None:
            assert self.ValueFormat == 0
            return True

        # Shrink ValueFormat
        if self.Format == 1:
            if not options.hinting:
                self.Value.prune_hints()
            self.ValueFormat = self.Value.getEffectiveFormat()
        elif self.Format == 2:
            if None in self.Value:
                assert self.ValueFormat == 0
                assert all(v is None for v in self.Value)
            else:
                if not options.hinting:
                    for v in self.Value:
                        v.prune_hints()
                self.ValueFormat = reduce(
                    int.__or__, [v.getEffectiveFormat() for v in self.Value], 0
                )

        # Downgrade to Format 1 if all ValueRecords are the same
        if self.Format == 2 and all(v == self.Value[0] for v in self.Value):
            self.Format = 1
            self.Value = self.Value[0] if self.ValueFormat != 0 else None
            del self.ValueCount

        return True

    @_add_method(otTables.PairPos)
    def subset_glyphs(self, s):
        if self.Format == 1:
            indices = self.Coverage.subset(s.glyphs)
            pairs = self.PairSet
            count = len(pairs)
            self.PairSet = [pairs[i] for i in indices if i < count]
            for p in self.PairSet:
                p.PairValueRecord = [
                    r for r in p.PairValueRecord if r.SecondGlyph in s.glyphs
                ]
                p.PairValueCount = len(p.PairValueRecord)
            # Remove empty pairsets
            indices = [i for i, p in enumerate(self.PairSet) if p.PairValueCount]
            self.Coverage.remap(indices)
            self.PairSet = _list_subset(self.PairSet, indices)
            self.PairSetCount = len(self.PairSet)
            return bool(self.PairSetCount)
        elif self.Format == 2:
            class1_map = [
                c
                for c in self.ClassDef1.subset(
                    s.glyphs.intersection(self.Coverage.glyphs), remap=True
                )
                if c < self.Class1Count
            ]
            class2_map = [
                c
                for c in self.ClassDef2.subset(s.glyphs, remap=True, useClass0=False)
                if c < self.Class2Count
            ]
            self.Class1Record = [self.Class1Record[i] for i in class1_map]
            for c in self.Class1Record:
                c.Class2Record = [c.Class2Record[i] for i in class2_map]
            self.Class1Count = len(class1_map)
            self.Class2Count = len(class2_map)
            # If only Class2 0 left, no need to keep anything.
            return bool(
                self.Class1Count
                and (self.Class2Count > 1)
                and self.Coverage.subset(s.glyphs)
            )
        else:
            assert 0, "unknown format: %s" % self.Format

    @_add_method(otTables.PairPos)
    def prune_post_subset(self, font, options):
        if not options.hinting:
            attr1, attr2 = {
                1: ("PairSet", "PairValueRecord"),
                2: ("Class1Record", "Class2Record"),
            }[self.Format]

            self.ValueFormat1 = self.ValueFormat2 = 0
            for row in getattr(self, attr1):
                for r in getattr(row, attr2):
                    if r.Value1:
                        r.Value1.prune_hints()
                        self.ValueFormat1 |= r.Value1.getEffectiveFormat()
                    if r.Value2:
                        r.Value2.prune_hints()
                        self.ValueFormat2 |= r.Value2.getEffectiveFormat()

        return bool(self.ValueFormat1 | self.ValueFormat2)

    @_add_method(otTables.CursivePos)
    def subset_glyphs(self, s):
        if self.Format == 1:
            indices = self.Coverage.subset(s.glyphs)
            records = self.EntryExitRecord
            count = len(records)
            self.EntryExitRecord = [records[i] for i in indices if i < count]
            self.EntryExitCount = len(self.EntryExitRecord)
            return bool(self.EntryExitCount)
        else:
            assert 0, "unknown format: %s" % self.Format

    @_add_method(otTables.Anchor)
    def prune_hints(self):
        if self.Format == 2:
            self.Format = 1
        elif self.Format == 3:
            for name in ("XDeviceTable", "YDeviceTable"):
                v = getattr(self, name, None)
                if v is not None and v.is_hinting():
                    setattr(self, name, None)
            if self.XDeviceTable is None and self.YDeviceTable is None:
                self.Format = 1

    @_add_method(otTables.CursivePos)
    def prune_post_subset(self, font, options):
        if not options.hinting:
            for rec in self.EntryExitRecord:
                if rec.EntryAnchor:
                    rec.EntryAnchor.prune_hints()
                if rec.ExitAnchor:
                    rec.ExitAnchor.prune_hints()
        return True

    @_add_method(otTables.MarkBasePos)
    def subset_glyphs(self, s):
        if self.Format == 1:
            mark_indices = self.MarkCoverage.subset(s.glyphs)
            self.MarkArray.MarkRecord = _list_subset(
                self.MarkArray.MarkRecord, mark_indices
            )
            self.MarkArray.MarkCount = len(self.MarkArray.MarkRecord)
            class_indices = _uniq_sort(v.Class for v in self.MarkArray.MarkRecord)

            intersect_base_indices = self.BaseCoverage.intersect(s.glyphs)
            base_records = self.BaseArray.BaseRecord
            num_base_records = len(base_records)
            base_indices = [
                i
                for i in intersect_base_indices
                if i < num_base_records
                and any(base_records[i].BaseAnchor[j] is not None for j in class_indices)
            ]
            if not base_indices:
                return False

            self.BaseCoverage.remap(base_indices)
            self.BaseArray.BaseRecord = _list_subset(
                self.BaseArray.BaseRecord, base_indices
            )
            self.BaseArray.BaseCount = len(self.BaseArray.BaseRecord)
            # Prune empty classes
            self.ClassCount = len(class_indices)
            for m in self.MarkArray.MarkRecord:
                m.Class = class_indices.index(m.Class)
            for b in self.BaseArray.BaseRecord:
                b.BaseAnchor = _list_subset(b.BaseAnchor, class_indices)
            return bool(
                self.ClassCount and self.MarkArray.MarkCount and self.BaseArray.BaseCount
            )
        else:
            assert 0, "unknown format: %s" % self.Format

    @_add_method(otTables.MarkBasePos)
    def prune_post_subset(self, font, options):
        if not options.hinting:
            for m in self.MarkArray.MarkRecord:
                if m.MarkAnchor:
                    m.MarkAnchor.prune_hints()
            for b in self.BaseArray.BaseRecord:
                for a in b.BaseAnchor:
                    if a:
                        a.prune_hints()
        return True

    @_add_method(otTables.MarkLigPos)
    def subset_glyphs(self, s):
        if self.Format == 1:
            mark_indices = self.MarkCoverage.subset(s.glyphs)
            self.MarkArray.MarkRecord = _list_subset(
                self.MarkArray.MarkRecord, mark_indices
            )
            self.MarkArray.MarkCount = len(self.MarkArray.MarkRecord)
            class_indices = _uniq_sort(v.Class for v in self.MarkArray.MarkRecord)

            intersect_ligature_indices = self.LigatureCoverage.intersect(s.glyphs)
            ligature_array = self.LigatureArray.LigatureAttach
            num_ligatures = self.LigatureArray.LigatureCount

            ligature_indices = [
                i
                for i in intersect_ligature_indices
                if i < num_ligatures
                and any(
                    any(component.LigatureAnchor[j] is not None for j in class_indices)
                    for component in ligature_array[i].ComponentRecord
                )
            ]

            if not ligature_indices:
                return False

            self.LigatureCoverage.remap(ligature_indices)
            self.LigatureArray.LigatureAttach = _list_subset(
                self.LigatureArray.LigatureAttach, ligature_indices
            )
            self.LigatureArray.LigatureCount = len(self.LigatureArray.LigatureAttach)
            # Prune empty classes
            self.ClassCount = len(class_indices)
            for m in self.MarkArray.MarkRecord:
                m.Class = class_indices.index(m.Class)
            for l in self.LigatureArray.LigatureAttach:
                if l is None:
                    continue
                for c in l.ComponentRecord:
                    c.LigatureAnchor = _list_subset(c.LigatureAnchor, class_indices)
            return bool(
                self.ClassCount
                and self.MarkArray.MarkCount
                and self.LigatureArray.LigatureCount
            )
        else:
            assert 0, "unknown format: %s" % self.Format

    @_add_method(otTables.MarkLigPos)
    def prune_post_subset(self, font, options):
        if not options.hinting:
            for m in self.MarkArray.MarkRecord:
                if m.MarkAnchor:
                    m.MarkAnchor.prune_hints()
            for l in self.LigatureArray.LigatureAttach:
                if l is None:
                    continue
                for c in l.ComponentRecord:
                    for a in c.LigatureAnchor:
                        if a:
                            a.prune_hints()
        return True

    @_add_method(otTables.MarkMarkPos)
    def subset_glyphs(self, s):
        if self.Format == 1:
            mark1_indices = self.Mark1Coverage.subset(s.glyphs)
            self.Mark1Array.MarkRecord = _list_subset(
                self.Mark1Array.MarkRecord, mark1_indices
            )
            self.Mark1Array.MarkCount = len(self.Mark1Array.MarkRecord)
            class_indices = _uniq_sort(v.Class for v in self.Mark1Array.MarkRecord)

            intersect_mark2_indices = self.Mark2Coverage.intersect(s.glyphs)
            mark2_records = self.Mark2Array.Mark2Record
            num_mark2_records = len(mark2_records)
            mark2_indices = [
                i
                for i in intersect_mark2_indices
                if i < num_mark2_records
                and any(mark2_records[i].Mark2Anchor[j] is not None for j in class_indices)
            ]
            if not mark2_indices:
                return False

            self.Mark2Coverage.remap(mark2_indices)
            self.Mark2Array.Mark2Record = _list_subset(
                self.Mark2Array.Mark2Record, mark2_indices
            )
            self.Mark2Array.MarkCount = len(self.Mark2Array.Mark2Record)
            # Prune empty classes
            self.ClassCount = len(class_indices)
            for m in self.Mark1Array.MarkRecord:
                m.Class = class_indices.index(m.Class)
            for b in self.Mark2Array.Mark2Record:
                b.Mark2Anchor = _list_subset(b.Mark2Anchor, class_indices)
            return bool(
                self.ClassCount and self.Mark1Array.MarkCount and self.Mark2Array.MarkCount
            )
        else:
            assert 0, "unknown format: %s" % self.Format

    @_add_method(otTables.MarkMarkPos)
    def prune_post_subset(self, font, options):
        if not options.hinting:
            for m in self.Mark1Array.MarkRecord:
                if m.MarkAnchor:
                    m.MarkAnchor.prune_hints()
            for b in self.Mark2Array.Mark2Record:
                for m in b.Mark2Anchor:
                    if m:
                        m.prune_hints()
        return True

    @_add_method(
        otTables.SingleSubst,
        otTables.MultipleSubst,
        otTables.AlternateSubst,
        otTables.LigatureSubst,
        otTables.ReverseChainSingleSubst,
        otTables.SinglePos,
        otTables.PairPos,
        otTables.CursivePos,
        otTables.MarkBasePos,
        otTables.MarkLigPos,
        otTables.MarkMarkPos,
    )
    def subset_lookups(self, lookup_indices):
        pass

    @_add_method(
        otTables.SingleSubst,
        otTables.MultipleSubst,
        otTables.AlternateSubst,
        otTables.LigatureSubst,
        otTables.ReverseChainSingleSubst,
        otTables.SinglePos,
        otTables.PairPos,
        otTables.CursivePos,
        otTables.MarkBasePos,
        otTables.MarkLigPos,
        otTables.MarkMarkPos,
    )
    def collect_lookups(self):
        return []

    @_add_method(
        otTables.SingleSubst,
        otTables.MultipleSubst,
        otTables.AlternateSubst,
        otTables.LigatureSubst,
        otTables.ReverseChainSingleSubst,
        otTables.ContextSubst,
        otTables.ChainContextSubst,
        otTables.ContextPos,
        otTables.ChainContextPos,
    )
    def prune_post_subset(self, font, options):
        return True

    @_add_method(
        otTables.SingleSubst, otTables.AlternateSubst, otTables.ReverseChainSingleSubst
    )
    def may_have_non_1to1(self):
        return False

    @_add_method(
        otTables.MultipleSubst,
        otTables.LigatureSubst,
        otTables.ContextSubst,
        otTables.ChainContextSubst,
    )
    def may_have_non_1to1(self):
        return True

    @_add_method(
        otTables.ContextSubst,
        otTables.ChainContextSubst,
        otTables.ContextPos,
        otTables.ChainContextPos,
    )
    def __subset_classify_context(self):
        class ContextHelper(object):
            def __init__(self, klass, Format):
                if klass.__name__.endswith("Subst"):
                    Typ = "Sub"
                    Type = "Subst"
                else:
                    Typ = "Pos"
                    Type = "Pos"
                if klass.__name__.startswith("Chain"):
                    Chain = "Chain"
                    InputIdx = 1
                    DataLen = 3
                else:
                    Chain = ""
                    InputIdx = 0
                    DataLen = 1
                ChainTyp = Chain + Typ

                self.Typ = Typ
                self.Type = Type
                self.Chain = Chain
                self.ChainTyp = ChainTyp
                self.InputIdx = InputIdx
                self.DataLen = DataLen

                self.LookupRecord = Type + "LookupRecord"

                if Format == 1:
                    Coverage = lambda r: r.Coverage
                    ChainCoverage = lambda r: r.Coverage
                    ContextData = lambda r: (None,)
                    ChainContextData = lambda r: (None, None, None)
                    SetContextData = None
                    SetChainContextData = None
                    RuleData = lambda r: (r.Input,)
                    ChainRuleData = lambda r: (r.Backtrack, r.Input, r.LookAhead)

                    def SetRuleData(r, d):
                        (r.Input,) = d
                        (r.GlyphCount,) = (len(x) + 1 for x in d)

                    def ChainSetRuleData(r, d):
                        (r.Backtrack, r.Input, r.LookAhead) = d
                        (
                            r.BacktrackGlyphCount,
                            r.InputGlyphCount,
                            r.LookAheadGlyphCount,
                        ) = (len(d[0]), len(d[1]) + 1, len(d[2]))

                elif Format == 2:
                    Coverage = lambda r: r.Coverage
                    ChainCoverage = lambda r: r.Coverage
                    ContextData = lambda r: (r.ClassDef,)
                    ChainContextData = lambda r: (
                        r.BacktrackClassDef,
                        r.InputClassDef,
                        r.LookAheadClassDef,
                    )

                    def SetContextData(r, d):
                        (r.ClassDef,) = d

                    def SetChainContextData(r, d):
                        (r.BacktrackClassDef, r.InputClassDef, r.LookAheadClassDef) = d

                    RuleData = lambda r: (r.Class,)
                    ChainRuleData = lambda r: (r.Backtrack, r.Input, r.LookAhead)

                    def SetRuleData(r, d):
                        (r.Class,) = d
                        (r.GlyphCount,) = (len(x) + 1 for x in d)

                    def ChainSetRuleData(r, d):
                        (r.Backtrack, r.Input, r.LookAhead) = d
                        (
                            r.BacktrackGlyphCount,
                            r.InputGlyphCount,
                            r.LookAheadGlyphCount,
                        ) = (len(d[0]), len(d[1]) + 1, len(d[2]))

                elif Format == 3:
                    Coverage = lambda r: r.Coverage[0]
                    ChainCoverage = lambda r: r.InputCoverage[0]
                    ContextData = None
                    ChainContextData = None
                    SetContextData = None
                    SetChainContextData = None
                    RuleData = lambda r: r.Coverage
                    ChainRuleData = lambda r: (
                        r.BacktrackCoverage + r.InputCoverage + r.LookAheadCoverage
                    )

                    def SetRuleData(r, d):
                        (r.Coverage,) = d
                        (r.GlyphCount,) = (len(x) for x in d)

                    def ChainSetRuleData(r, d):
                        (r.BacktrackCoverage, r.InputCoverage, r.LookAheadCoverage) = d
                        (
                            r.BacktrackGlyphCount,
                            r.InputGlyphCount,
                            r.LookAheadGlyphCount,
                        ) = (len(x) for x in d)

                else:
                    assert 0, "unknown format: %s" % Format

                if Chain:
                    self.Coverage = ChainCoverage
                    self.ContextData = ChainContextData
                    self.SetContextData = SetChainContextData
                    self.RuleData = ChainRuleData
                    self.SetRuleData = ChainSetRuleData
                else:
                    self.Coverage = Coverage
                    self.ContextData = ContextData
                    self.SetContextData = SetContextData
                    self.RuleData = RuleData
                    self.SetRuleData = SetRuleData

                if Format == 1:
                    self.Rule = ChainTyp + "Rule"
                    self.RuleCount = ChainTyp + "RuleCount"
                    self.RuleSet = ChainTyp + "RuleSet"
                    self.RuleSetCount = ChainTyp + "RuleSetCount"
                    self.Intersect = lambda glyphs, c, r: [r] if r in glyphs else []
                elif Format == 2:
                    self.Rule = ChainTyp + "ClassRule"
                    self.RuleCount = ChainTyp + "ClassRuleCount"
                    self.RuleSet = ChainTyp + "ClassSet"
                    self.RuleSetCount = ChainTyp + "ClassSetCount"
                    self.Intersect = lambda glyphs, c, r: (
                        c.intersect_class(glyphs, r)
                        if c
                        else (set(glyphs) if r == 0 else set())
                    )

                    self.ClassDef = "InputClassDef" if Chain else "ClassDef"
                    self.ClassDefIndex = 1 if Chain else 0
                    self.Input = "Input" if Chain else "Class"
                elif Format == 3:
                    self.Input = "InputCoverage" if Chain else "Coverage"

        if self.Format not in [1, 2, 3]:
            return None  # Don't shoot the messenger; let it go
        if not hasattr(self.__class__, "_subset__ContextHelpers"):
            self.__class__._subset__ContextHelpers = {}
        if self.Format not in self.__class__._subset__ContextHelpers:
            helper = ContextHelper(self.__class__, self.Format)
            self.__class__._subset__ContextHelpers[self.Format] = helper
        return self.__class__._subset__ContextHelpers[self.Format]

    @_add_method(otTables.ContextSubst, otTables.ChainContextSubst)
    def closure_glyphs(self, s, cur_glyphs):
        c = self.__subset_classify_context()

        indices = c.Coverage(self).intersect(cur_glyphs)
        if not indices:
            return []
        cur_glyphs = c.Coverage(self).intersect_glyphs(cur_glyphs)

        if self.Format == 1:
            ContextData = c.ContextData(self)
            rss = getattr(self, c.RuleSet)
            rssCount = getattr(self, c.RuleSetCount)
            for i in indices:
                if i >= rssCount or not rss[i]:
                    continue
                for r in getattr(rss[i], c.Rule):
                    if not r:
                        continue
                    if not all(
                        all(c.Intersect(s.glyphs, cd, k) for k in klist)
                        for cd, klist in zip(ContextData, c.RuleData(r))
                    ):
                        continue
                    chaos = set()
                    for ll in getattr(r, c.LookupRecord):
                        if not ll:
                            continue
                        seqi = ll.SequenceIndex
                        if seqi in chaos:
                            # TODO Can we improve this?
                            pos_glyphs = None
                        else:
                            if seqi == 0:
                                pos_glyphs = frozenset([c.Coverage(self).glyphs[i]])
                            else:
                                pos_glyphs = frozenset([r.Input[seqi - 1]])
                        lookup = s.table.LookupList.Lookup[ll.LookupListIndex]
                        chaos.add(seqi)
                        if lookup.may_have_non_1to1():
                            chaos.update(range(seqi, len(r.Input) + 2))
                        lookup.closure_glyphs(s, cur_glyphs=pos_glyphs)
        elif self.Format == 2:
            ClassDef = getattr(self, c.ClassDef)
            indices = ClassDef.intersect(cur_glyphs)
            ContextData = c.ContextData(self)
            rss = getattr(self, c.RuleSet)
            rssCount = getattr(self, c.RuleSetCount)
            for i in indices:
                if i >= rssCount or not rss[i]:
                    continue
                for r in getattr(rss[i], c.Rule):
                    if not r:
                        continue
                    if not all(
                        all(c.Intersect(s.glyphs, cd, k) for k in klist)
                        for cd, klist in zip(ContextData, c.RuleData(r))
                    ):
                        continue
                    chaos = set()
                    for ll in getattr(r, c.LookupRecord):
                        if not ll:
                            continue
                        seqi = ll.SequenceIndex
                        if seqi in chaos:
                            # TODO Can we improve this?
                            pos_glyphs = None
                        else:
                            if seqi == 0:
                                pos_glyphs = frozenset(
                                    ClassDef.intersect_class(cur_glyphs, i)
                                )
                            else:
                                pos_glyphs = frozenset(
                                    ClassDef.intersect_class(
                                        s.glyphs, getattr(r, c.Input)[seqi - 1]
                                    )
                                )
                        lookup = s.table.LookupList.Lookup[ll.LookupListIndex]
                        chaos.add(seqi)
                        if lookup.may_have_non_1to1():
                            chaos.update(range(seqi, len(getattr(r, c.Input)) + 2))
                        lookup.closure_glyphs(s, cur_glyphs=pos_glyphs)
        elif self.Format == 3:
            if not all(x is not None and x.intersect(s.glyphs) for x in c.RuleData(self)):
                return []
            r = self
            input_coverages = getattr(r, c.Input)
            chaos = set()
            for ll in getattr(r, c.LookupRecord):
                if not ll:
                    continue
                seqi = ll.SequenceIndex
                if seqi in chaos:
                    # TODO Can we improve this?
                    pos_glyphs = None
                else:
                    if seqi == 0:
                        pos_glyphs = frozenset(cur_glyphs)
                    else:
                        pos_glyphs = frozenset(
                            input_coverages[seqi].intersect_glyphs(s.glyphs)
                        )
                lookup = s.table.LookupList.Lookup[ll.LookupListIndex]
                chaos.add(seqi)
                if lookup.may_have_non_1to1():
                    chaos.update(range(seqi, len(input_coverages) + 1))
                lookup.closure_glyphs(s, cur_glyphs=pos_glyphs)
        else:
            assert 0, "unknown format: %s" % self.Format

    @_add_method(
        otTables.ContextSubst,
        otTables.ContextPos,
        otTables.ChainContextSubst,
        otTables.ChainContextPos,
    )
    def subset_glyphs(self, s):
        c = self.__subset_classify_context()

        if self.Format == 1:
            indices = self.Coverage.subset(s.glyphs)
            rss = getattr(self, c.RuleSet)
            rssCount = getattr(self, c.RuleSetCount)
            rss = [rss[i] for i in indices if i < rssCount]
            for rs in rss:
                if not rs:
                    continue
                ss = getattr(rs, c.Rule)
                ss = [
                    r
                    for r in ss
                    if r
                    and all(all(g in s.glyphs for g in glist) for glist in c.RuleData(r))
                ]
                setattr(rs, c.Rule, ss)
                setattr(rs, c.RuleCount, len(ss))
            # Prune empty rulesets
            indices = [i for i, rs in enumerate(rss) if rs and getattr(rs, c.Rule)]
            self.Coverage.remap(indices)
            rss = _list_subset(rss, indices)
            setattr(self, c.RuleSet, rss)
            setattr(self, c.RuleSetCount, len(rss))
            return bool(rss)
        elif self.Format == 2:
            if not self.Coverage.subset(s.glyphs):
                return False
            ContextData = c.ContextData(self)
            klass_maps = [
                x.subset(s.glyphs, remap=True) if x else None for x in ContextData
            ]

            # Keep rulesets for class numbers that survived.
            indices = klass_maps[c.ClassDefIndex]
            rss = getattr(self, c.RuleSet)
            rssCount = getattr(self, c.RuleSetCount)
            rss = [rss[i] for i in indices if i < rssCount]
            del rssCount
            # Delete, but not renumber, unreachable rulesets.
            indices = getattr(self, c.ClassDef).intersect(self.Coverage.glyphs)
            rss = [rss if i in indices else None for i, rss in enumerate(rss)]

            for rs in rss:
                if not rs:
                    continue
                ss = getattr(rs, c.Rule)
                ss = [
                    r
                    for r in ss
                    if r
                    and all(
                        all(k in klass_map for k in klist)
                        for klass_map, klist in zip(klass_maps, c.RuleData(r))
                    )
                ]
                setattr(rs, c.Rule, ss)
                setattr(rs, c.RuleCount, len(ss))

                # Remap rule classes
                for r in ss:
                    c.SetRuleData(
                        r,
                        [
                            [klass_map.index(k) for k in klist]
                            for klass_map, klist in zip(klass_maps, c.RuleData(r))
                        ],
                    )

            # Prune empty rulesets
            rss = [rs if rs and getattr(rs, c.Rule) else None for rs in rss]
            while rss and rss[-1] is None:
                del rss[-1]
            setattr(self, c.RuleSet, rss)
            setattr(self, c.RuleSetCount, len(rss))

            # TODO: We can do a second round of remapping class values based
            # on classes that are actually used in at least one rule.	Right
            # now we subset classes to c.glyphs only.	Or better, rewrite
            # the above to do that.

            return bool(rss)
        elif self.Format == 3:
            return all(x is not None and x.subset(s.glyphs) for x in c.RuleData(self))
        else:
            assert 0, "unknown format: %s" % self.Format

    @_add_method(
        otTables.ContextSubst,
        otTables.ChainContextSubst,
        otTables.ContextPos,
        otTables.ChainContextPos,
    )
    def subset_lookups(self, lookup_indices):
        c = self.__subset_classify_context()

        if self.Format in [1, 2]:
            for rs in getattr(self, c.RuleSet):
                if not rs:
                    continue
                for r in getattr(rs, c.Rule):
                    if not r:
                        continue
                    setattr(
                        r,
                        c.LookupRecord,
                        [
                            ll
                            for ll in getattr(r, c.LookupRecord)
                            if ll and ll.LookupListIndex in lookup_indices
                        ],
                    )
                    for ll in getattr(r, c.LookupRecord):
                        if not ll:
                            continue
                        ll.LookupListIndex = lookup_indices.index(ll.LookupListIndex)
        elif self.Format == 3:
            setattr(
                self,
                c.LookupRecord,
                [
                    ll
                    for ll in getattr(self, c.LookupRecord)
                    if ll and ll.LookupListIndex in lookup_indices
                ],
            )
            for ll in getattr(self, c.LookupRecord):
                if not ll:
                    continue
                ll.LookupListIndex = lookup_indices.index(ll.LookupListIndex)
        else:
            assert 0, "unknown format: %s" % self.Format

    @_add_method(
        otTables.ContextSubst,
        otTables.ChainContextSubst,
        otTables.ContextPos,
        otTables.ChainContextPos,
    )
    def collect_lookups(self):
        c = self.__subset_classify_context()

        if self.Format in [1, 2]:
            return [
                ll.LookupListIndex
                for rs in getattr(self, c.RuleSet)
                if rs
                for r in getattr(rs, c.Rule)
                if r
                for ll in getattr(r, c.LookupRecord)
                if ll
            ]
        elif self.Format == 3:
            return [ll.LookupListIndex for ll in getattr(self, c.LookupRecord) if ll]
        else:
            assert 0, "unknown format: %s" % self.Format

    @_add_method(otTables.ExtensionSubst)
    def closure_glyphs(self, s, cur_glyphs):
        if self.Format == 1:
            self.ExtSubTable.closure_glyphs(s, cur_glyphs)
        else:
            assert 0, "unknown format: %s" % self.Format

    @_add_method(otTables.ExtensionSubst)
    def may_have_non_1to1(self):
        if self.Format == 1:
            return self.ExtSubTable.may_have_non_1to1()
        else:
            assert 0, "unknown format: %s" % self.Format

    @_add_method(otTables.ExtensionSubst, otTables.ExtensionPos)
    def subset_glyphs(self, s):
        if self.Format == 1:
            return self.ExtSubTable.subset_glyphs(s)
        else:
            assert 0, "unknown format: %s" % self.Format

    @_add_method(otTables.ExtensionSubst, otTables.ExtensionPos)
    def prune_post_subset(self, font, options):
        if self.Format == 1:
            return self.ExtSubTable.prune_post_subset(font, options)
        else:
            assert 0, "unknown format: %s" % self.Format

    @_add_method(otTables.ExtensionSubst, otTables.ExtensionPos)
    def subset_lookups(self, lookup_indices):
        if self.Format == 1:
            return self.ExtSubTable.subset_lookups(lookup_indices)
        else:
            assert 0, "unknown format: %s" % self.Format

    @_add_method(otTables.ExtensionSubst, otTables.ExtensionPos)
    def collect_lookups(self):
        if self.Format == 1:
            return self.ExtSubTable.collect_lookups()
        else:
            assert 0, "unknown format: %s" % self.Format

    @_add_method(otTables.Lookup)
    def closure_glyphs(self, s, cur_glyphs=None):
        if cur_glyphs is None:
            cur_glyphs = frozenset(s.glyphs)

        # Memoize
        key = id(self)
        doneLookups = s._doneLookups
        count, covered = doneLookups.get(key, (0, None))
        if count != len(s.glyphs):
            count, covered = doneLookups[key] = (len(s.glyphs), set())
        if cur_glyphs.issubset(covered):
            return
        covered.update(cur_glyphs)

        for st in self.SubTable:
            if not st:
                continue
            st.closure_glyphs(s, cur_glyphs)

    @_add_method(otTables.Lookup)
    def subset_glyphs(self, s):
        self.SubTable = [st for st in self.SubTable if st and st.subset_glyphs(s)]
        self.SubTableCount = len(self.SubTable)
        if hasattr(self, "MarkFilteringSet") and self.MarkFilteringSet is not None:
            if self.MarkFilteringSet not in s.used_mark_sets:
                self.MarkFilteringSet = None
                self.LookupFlag &= ~0x10
                self.LookupFlag |= 0x8
            else:
                self.MarkFilteringSet = s.used_mark_sets.index(self.MarkFilteringSet)
        return bool(self.SubTableCount)

    @_add_method(otTables.Lookup)
    def prune_post_subset(self, font, options):
        ret = False
        for st in self.SubTable:
            if not st:
                continue
            if st.prune_post_subset(font, options):
                ret = True
        return ret

    @_add_method(otTables.Lookup)
    def subset_lookups(self, lookup_indices):
        for s in self.SubTable:
            s.subset_lookups(lookup_indices)

    @_add_method(otTables.Lookup)
    def collect_lookups(self):
        return sum((st.collect_lookups() for st in self.SubTable if st), [])

    @_add_method(otTables.Lookup)
    def may_have_non_1to1(self):
        return any(st.may_have_non_1to1() for st in self.SubTable if st)

    @_add_method(otTables.LookupList)
    def subset_glyphs(self, s):
        """Returns the indices of nonempty lookups."""
        return [i for i, l in enumerate(self.Lookup) if l and l.subset_glyphs(s)]

    @_add_method(otTables.LookupList)
    def prune_post_subset(self, font, options):
        ret = False
        for l in self.Lookup:
            if not l:
                continue
            if l.prune_post_subset(font, options):
                ret = True
        return ret

    @_add_method(otTables.LookupList)
    def subset_lookups(self, lookup_indices):
        self.ensureDecompiled()
        self.Lookup = [self.Lookup[i] for i in lookup_indices if i < self.LookupCount]
        self.LookupCount = len(self.Lookup)
        for l in self.Lookup:
            l.subset_lookups(lookup_indices)

    @_add_method(otTables.LookupList)
    def neuter_lookups(self, lookup_indices):
        """Sets lookups not in lookup_indices to None."""
        self.ensureDecompiled()
        self.Lookup = [
            l if i in lookup_indices else None for i, l in enumerate(self.Lookup)
        ]

    @_add_method(otTables.LookupList)
    def closure_lookups(self, lookup_indices):
        """Returns sorted index of all lookups reachable from lookup_indices."""
        lookup_indices = _uniq_sort(lookup_indices)
        recurse = lookup_indices
        while True:
            recurse_lookups = sum(
                (self.Lookup[i].collect_lookups() for i in recurse if i < self.LookupCount),
                [],
            )
            recurse_lookups = [
                l
                for l in recurse_lookups
                if l not in lookup_indices and l < self.LookupCount
            ]
            if not recurse_lookups:
                return _uniq_sort(lookup_indices)
            recurse_lookups = _uniq_sort(recurse_lookups)
            lookup_indices.extend(recurse_lookups)
            recurse = recurse_lookups

    @_add_method(otTables.Feature)
    def subset_lookups(self, lookup_indices):
        """ "Returns True if feature is non-empty afterwards."""
        self.LookupListIndex = [l for l in self.LookupListIndex if l in lookup_indices]
        # Now map them.
        self.LookupListIndex = [lookup_indices.index(l) for l in self.LookupListIndex]
        self.LookupCount = len(self.LookupListIndex)
        # keep 'size' feature even if it contains no lookups; but drop any other
        # empty feature (e.g. FeatureParams for stylistic set names)
        # https://github.com/fonttools/fonttools/issues/2324
        return self.LookupCount or isinstance(
            self.FeatureParams, otTables.FeatureParamsSize
        )

    @_add_method(otTables.FeatureList)
    def subset_lookups(self, lookup_indices):
        """Returns the indices of nonempty features."""
        # Note: Never ever drop feature 'pref', even if it's empty.
        # HarfBuzz chooses shaper for Khmer based on presence of this
        # feature.	See thread at:
        # http://lists.freedesktop.org/archives/harfbuzz/2012-November/002660.html
        return [
            i
            for i, f in enumerate(self.FeatureRecord)
            if (f.Feature.subset_lookups(lookup_indices) or f.FeatureTag == "pref")
        ]

    @_add_method(otTables.FeatureList)
    def collect_lookups(self, feature_indices):
        return sum(
            (
                self.FeatureRecord[i].Feature.LookupListIndex
                for i in feature_indices
                if i < self.FeatureCount
            ),
            [],
        )

    @_add_method(otTables.FeatureList)
    def subset_features(self, feature_indices):
        self.ensureDecompiled()
        self.FeatureRecord = _list_subset(self.FeatureRecord, feature_indices)
        self.FeatureCount = len(self.FeatureRecord)
        return bool(self.FeatureCount)

    @_add_method(otTables.FeatureTableSubstitution)
    def subset_lookups(self, lookup_indices):
        """Returns the indices of nonempty features."""
        return [
            r.FeatureIndex
            for r in self.SubstitutionRecord
            if r.Feature.subset_lookups(lookup_indices)
        ]

    @_add_method(otTables.FeatureVariations)
    def subset_lookups(self, lookup_indices):
        """Returns the indices of nonempty features."""
        return sum(
            (
                f.FeatureTableSubstitution.subset_lookups(lookup_indices)
                for f in self.FeatureVariationRecord
            ),
            [],
        )

    @_add_method(otTables.FeatureVariations)
    def collect_lookups(self, feature_indices):
        return sum(
            (
                r.Feature.LookupListIndex
                for vr in self.FeatureVariationRecord
                for r in vr.FeatureTableSubstitution.SubstitutionRecord
                if r.FeatureIndex in feature_indices
            ),
            [],
        )

    @_add_method(otTables.FeatureTableSubstitution)
    def subset_features(self, feature_indices):
        self.ensureDecompiled()
        self.SubstitutionRecord = [
            r for r in self.SubstitutionRecord if r.FeatureIndex in feature_indices
        ]
        # remap feature indices
        for r in self.SubstitutionRecord:
            r.FeatureIndex = feature_indices.index(r.FeatureIndex)
        self.SubstitutionCount = len(self.SubstitutionRecord)
        return bool(self.SubstitutionCount)

    @_add_method(otTables.FeatureTableSubstitution)
    def prune_features(self, feature_index_map):
        self.ensureDecompiled()
        self.SubstitutionRecord = [
            r for r in self.SubstitutionRecord if r.FeatureIndex in feature_index_map.keys()
        ]
        # remap feature indices
        for r in self.SubstitutionRecord:
            r.FeatureIndex = feature_index_map[r.FeatureIndex]
        self.SubstitutionCount = len(self.SubstitutionRecord)
        return bool(self.SubstitutionCount)

    @_add_method(otTables.FeatureVariations)
    def subset_features(self, feature_indices):
        self.ensureDecompiled()
        for r in self.FeatureVariationRecord:
            r.FeatureTableSubstitution.subset_features(feature_indices)
        # Prune empty records at the end only
        # https://github.com/fonttools/fonttools/issues/1881
        while (
            self.FeatureVariationRecord
            and not self.FeatureVariationRecord[
                -1
            ].FeatureTableSubstitution.SubstitutionCount
        ):
            self.FeatureVariationRecord.pop()
        self.FeatureVariationCount = len(self.FeatureVariationRecord)
        return bool(self.FeatureVariationCount)

    @_add_method(otTables.FeatureVariations)
    def prune_features(self, feature_index_map):
        self.ensureDecompiled()
        for r in self.FeatureVariationRecord:
            r.FeatureTableSubstitution.prune_features(feature_index_map)
        # Prune empty records at the end only
        # https://github.com/fonttools/fonttools/issues/1881
        while (
            self.FeatureVariationRecord
            and not self.FeatureVariationRecord[
                -1
            ].FeatureTableSubstitution.SubstitutionCount
        ):
            self.FeatureVariationRecord.pop()
        self.FeatureVariationCount = len(self.FeatureVariationRecord)
        return bool(self.FeatureVariationCount)

    @_add_method(otTables.DefaultLangSys, otTables.LangSys)
    def subset_features(self, feature_indices):
        if self.ReqFeatureIndex in feature_indices:
            self.ReqFeatureIndex = feature_indices.index(self.ReqFeatureIndex)
        else:
            self.ReqFeatureIndex = 65535
        self.FeatureIndex = [f for f in self.FeatureIndex if f in feature_indices]
        # Now map them.
        self.FeatureIndex = [
            feature_indices.index(f) for f in self.FeatureIndex if f in feature_indices
        ]
        self.FeatureCount = len(self.FeatureIndex)
        return bool(self.FeatureCount or self.ReqFeatureIndex != 65535)

    @_add_method(otTables.DefaultLangSys, otTables.LangSys)
    def prune_features(self, feature_index_map):
        self.ReqFeatureIndex = feature_index_map.get(self.ReqFeatureIndex, 65535)
        self.FeatureIndex = [
            feature_index_map[f] for f in self.FeatureIndex if f in feature_index_map.keys()
        ]
        self.FeatureCount = len(self.FeatureIndex)
        return bool(self.FeatureCount or self.ReqFeatureIndex != 65535)

    @_add_method(otTables.DefaultLangSys, otTables.LangSys)
    def collect_features(self):
        feature_indices = self.FeatureIndex[:]
        if self.ReqFeatureIndex != 65535:
            feature_indices.append(self.ReqFeatureIndex)
        return _uniq_sort(feature_indices)

    @_add_method(otTables.Script)
    def subset_features(self, feature_indices, keepEmptyDefaultLangSys=False):
        if (
            self.DefaultLangSys
            and not self.DefaultLangSys.subset_features(feature_indices)
            and not keepEmptyDefaultLangSys
        ):
            self.DefaultLangSys = None
        self.LangSysRecord = [
            l for l in self.LangSysRecord if l.LangSys.subset_features(feature_indices)
        ]
        self.LangSysCount = len(self.LangSysRecord)
        return bool(self.LangSysCount or self.DefaultLangSys)

    @_add_method(otTables.Script)
    def prune_features(self, feature_index_map, keepEmptyDefaultLangSys=False):
        if (
            self.DefaultLangSys
            and not self.DefaultLangSys.prune_features(feature_index_map)
            and not keepEmptyDefaultLangSys
        ):
            self.DefaultLangSys = None
        self.LangSysRecord = [
            l for l in self.LangSysRecord if l.LangSys.prune_features(feature_index_map)
        ]
        self.LangSysCount = len(self.LangSysRecord)
        return bool(self.LangSysCount or self.DefaultLangSys)

    @_add_method(otTables.Script)
    def collect_features(self):
        feature_indices = [l.LangSys.collect_features() for l in self.LangSysRecord]
        if self.DefaultLangSys:
            feature_indices.append(self.DefaultLangSys.collect_features())
        return _uniq_sort(sum(feature_indices, []))

    @_add_method(otTables.ScriptList)
    def subset_features(self, feature_indices, retain_empty):
        # https://bugzilla.mozilla.org/show_bug.cgi?id=1331737#c32
        self.ScriptRecord = [
            s
            for s in self.ScriptRecord
            if s.Script.subset_features(feature_indices, s.ScriptTag == "DFLT")
            or retain_empty
        ]
        self.ScriptCount = len(self.ScriptRecord)
        return bool(self.ScriptCount)

    @_add_method(otTables.ScriptList)
    def prune_features(self, feature_index_map, retain_empty):
        # https://bugzilla.mozilla.org/show_bug.cgi?id=1331737#c32
        self.ScriptRecord = [
            s
            for s in self.ScriptRecord
            if s.Script.prune_features(feature_index_map, s.ScriptTag == "DFLT")
            or retain_empty
        ]
        self.ScriptCount = len(self.ScriptRecord)
        return bool(self.ScriptCount)

    @_add_method(otTables.ScriptList)
    def collect_features(self):
        return _uniq_sort(sum((s.Script.collect_features() for s in self.ScriptRecord), []))

    # CBLC will inherit it
    @_add_method(ttLib.getTableClass("EBLC"))
    def subset_glyphs(self, s):
        for strike in self.strikes:
            for indexSubTable in strike.indexSubTables:
                indexSubTable.names = [n for n in indexSubTable.names if n in s.glyphs]
            strike.indexSubTables = [i for i in strike.indexSubTables if i.names]
        self.strikes = [s for s in self.strikes if s.indexSubTables]

        return True

    # CBDT will inherit it
    @_add_method(ttLib.getTableClass("EBDT"))
    def subset_glyphs(self, s):
        strikeData = [
            {g: strike[g] for g in s.glyphs if g in strike} for strike in self.strikeData
        ]
        # Prune empty strikes
        # https://github.com/fonttools/fonttools/issues/1633
        self.strikeData = [strike for strike in strikeData if strike]
        return True

    @_add_method(ttLib.getTableClass("sbix"))
    def subset_glyphs(self, s):
        for strike in self.strikes.values():
            strike.glyphs = {g: strike.glyphs[g] for g in s.glyphs if g in strike.glyphs}

        return True

    @_add_method(ttLib.getTableClass("GSUB"))
    def closure_glyphs(self, s):
        s.table = self.table
        if self.table.ScriptList:
            feature_indices = self.table.ScriptList.collect_features()
        else:
            feature_indices = []
        if self.table.FeatureList:
            lookup_indices = self.table.FeatureList.collect_lookups(feature_indices)
        else:
            lookup_indices = []
        if getattr(self.table, "FeatureVariations", None):
            lookup_indices += self.table.FeatureVariations.collect_lookups(feature_indices)
        lookup_indices = _uniq_sort(lookup_indices)
        if self.table.LookupList:
            s._doneLookups = {}
            while True:
                orig_glyphs = frozenset(s.glyphs)
                for i in lookup_indices:
                    if i >= self.table.LookupList.LookupCount:
                        continue
                    if not self.table.LookupList.Lookup[i]:
                        continue
                    self.table.LookupList.Lookup[i].closure_glyphs(s)
                if orig_glyphs == s.glyphs:
                    break
            del s._doneLookups
        del s.table

    @_add_method(ttLib.getTableClass("GSUB"), ttLib.getTableClass("GPOS"))
    def subset_glyphs(self, s):
        s.glyphs = s.glyphs_gsubed
        if self.table.LookupList:
            lookup_indices = self.table.LookupList.subset_glyphs(s)
        else:
            lookup_indices = []
        self.subset_lookups(lookup_indices)
        return True

    @_add_method(ttLib.getTableClass("GSUB"), ttLib.getTableClass("GPOS"))
    def retain_empty_scripts(self):
        # https://github.com/fonttools/fonttools/issues/518
        # https://bugzilla.mozilla.org/show_bug.cgi?id=1080739#c15
        return self.__class__ == ttLib.getTableClass("GSUB")

    @_add_method(ttLib.getTableClass("GSUB"), ttLib.getTableClass("GPOS"))
    def subset_lookups(self, lookup_indices):
        """Retains specified lookups, then removes empty features, language
        systems, and scripts."""
        if self.table.LookupList:
            self.table.LookupList.subset_lookups(lookup_indices)
        if self.table.FeatureList:
            feature_indices = self.table.FeatureList.subset_lookups(lookup_indices)
        else:
            feature_indices = []
        if getattr(self.table, "FeatureVariations", None):
            feature_indices += self.table.FeatureVariations.subset_lookups(lookup_indices)
        feature_indices = _uniq_sort(feature_indices)
        if self.table.FeatureList:
            self.table.FeatureList.subset_features(feature_indices)
        if getattr(self.table, "FeatureVariations", None):
            self.table.FeatureVariations.subset_features(feature_indices)
        if self.table.ScriptList:
            self.table.ScriptList.subset_features(
                feature_indices, self.retain_empty_scripts()
            )

    @_add_method(ttLib.getTableClass("GSUB"), ttLib.getTableClass("GPOS"))
    def neuter_lookups(self, lookup_indices):
        """Sets lookups not in lookup_indices to None."""
        if self.table.LookupList:
            self.table.LookupList.neuter_lookups(lookup_indices)

    @_add_method(ttLib.getTableClass("GSUB"), ttLib.getTableClass("GPOS"))
    def prune_lookups(self, remap=True):
        """Remove (default) or neuter unreferenced lookups"""
        if self.table.ScriptList:
            feature_indices = self.table.ScriptList.collect_features()
        else:
            feature_indices = []
        if self.table.FeatureList:
            lookup_indices = self.table.FeatureList.collect_lookups(feature_indices)
        else:
            lookup_indices = []
        if getattr(self.table, "FeatureVariations", None):
            lookup_indices += self.table.FeatureVariations.collect_lookups(feature_indices)
        lookup_indices = _uniq_sort(lookup_indices)
        if self.table.LookupList:
            lookup_indices = self.table.LookupList.closure_lookups(lookup_indices)
        else:
            lookup_indices = []
        if remap:
            self.subset_lookups(lookup_indices)
        else:
            self.neuter_lookups(lookup_indices)

    @_add_method(ttLib.getTableClass("GSUB"), ttLib.getTableClass("GPOS"))
    def subset_feature_tags(self, feature_tags):
        if self.table.FeatureList:
            feature_indices = [
                i
                for i, f in enumerate(self.table.FeatureList.FeatureRecord)
                if f.FeatureTag in feature_tags
            ]
            self.table.FeatureList.subset_features(feature_indices)
            if getattr(self.table, "FeatureVariations", None):
                self.table.FeatureVariations.subset_features(feature_indices)
        else:
            feature_indices = []
        if self.table.ScriptList:
            self.table.ScriptList.subset_features(
                feature_indices, self.retain_empty_scripts()
            )

    @_add_method(ttLib.getTableClass("GSUB"), ttLib.getTableClass("GPOS"))
    def subset_script_tags(self, tags):
        langsys = {}
        script_tags = set()
        for tag in tags:
            script_tag, lang_tag = tag.split(".") if "." in tag else (tag, "*")
            script_tags.add(script_tag.ljust(4))
            langsys.setdefault(script_tag, set()).add(lang_tag.ljust(4))

        if self.table.ScriptList:
            self.table.ScriptList.ScriptRecord = [
                s for s in self.table.ScriptList.ScriptRecord if s.ScriptTag in script_tags
            ]
            self.table.ScriptList.ScriptCount = len(self.table.ScriptList.ScriptRecord)

            for record in self.table.ScriptList.ScriptRecord:
                if record.ScriptTag in langsys and "*   " not in langsys[record.ScriptTag]:
                    record.Script.LangSysRecord = [
                        l
                        for l in record.Script.LangSysRecord
                        if l.LangSysTag in langsys[record.ScriptTag]
                    ]
                    record.Script.LangSysCount = len(record.Script.LangSysRecord)
                    if "dflt" not in langsys[record.ScriptTag]:
                        record.Script.DefaultLangSys = None

    @_add_method(ttLib.getTableClass("GSUB"), ttLib.getTableClass("GPOS"))
    def prune_features(self):
        """Remove unreferenced and duplicate features in FeatureList
        Remove unreferenced features and remap duplicate feature indices in ScriptList and FeatureVariations
        """
        if self.table.ScriptList:
            feature_indices = self.table.ScriptList.collect_features()
        else:
            feature_indices = []
        (feature_indices, feature_index_map) = self.remap_duplicate_features(
            feature_indices
        )

        if self.table.FeatureList:
            self.table.FeatureList.subset_features(feature_indices)
        if getattr(self.table, "FeatureVariations", None):
            self.table.FeatureVariations.prune_features(feature_index_map)
        if self.table.ScriptList:
            self.table.ScriptList.prune_features(
                feature_index_map, self.retain_empty_scripts()
            )

    @_add_method(ttLib.getTableClass("GSUB"), ttLib.getTableClass("GPOS"))
    def remap_duplicate_features(self, feature_indices):
        """Return retained feature indices(without duplicates) and remapped feature indices"""
        features = self.table.FeatureList.FeatureRecord

        unique_features = {}
        duplicate_features = {}
        for i in feature_indices:
            f = features[i]
            tag = f.FeatureTag

            same_tag_features = unique_features.get(tag)
            if same_tag_features is None:
                unique_features[tag] = set([i])
                duplicate_features[i] = i
                continue

            found = False
            for other_i in same_tag_features:
                if features[other_i] == f:
                    found = True
                    duplicate_features[i] = other_i
                    break

            if not found:
                same_tag_features.add(i)
                duplicate_features[i] = i

        ## remap retained feature indices
        feature_map = {}
        new_idx = 0

        for i in feature_indices:
            unique_i = duplicate_features.get(i, i)
            v = feature_map.get(unique_i)
            if v is None:
                feature_map[i] = new_idx
                new_idx += 1
            else:
                feature_map[i] = v

        retained_feature_indices = _uniq_sort(
            sum((list(s) for s in unique_features.values()), [])
        )
        return (retained_feature_indices, feature_map)

    @_add_method(ttLib.getTableClass("GSUB"), ttLib.getTableClass("GPOS"))
    def prune_pre_subset(self, font, options):
        # Drop undesired features
        if "*" not in options.layout_scripts:
            self.subset_script_tags(options.layout_scripts)
        if "*" not in options.layout_features:
            self.subset_feature_tags(options.layout_features)
        # Neuter unreferenced lookups
        self.prune_lookups(remap=False)
        return True

    @_add_method(ttLib.getTableClass("GSUB"), ttLib.getTableClass("GPOS"))
    def remove_redundant_langsys(self):
        table = self.table
        if not table.ScriptList or not table.FeatureList:
            return

        features = table.FeatureList.FeatureRecord

        for s in table.ScriptList.ScriptRecord:
            d = s.Script.DefaultLangSys
            if not d:
                continue
            for lr in s.Script.LangSysRecord[:]:
                l = lr.LangSys
                # Compare d and l
                if len(d.FeatureIndex) != len(l.FeatureIndex):
                    continue
                if (d.ReqFeatureIndex == 65535) != (l.ReqFeatureIndex == 65535):
                    continue

                if d.ReqFeatureIndex != 65535:
                    if features[d.ReqFeatureIndex] != features[l.ReqFeatureIndex]:
                        continue

                for i in range(len(d.FeatureIndex)):
                    if features[d.FeatureIndex[i]] != features[l.FeatureIndex[i]]:
                        break
                else:
                    # LangSys and default are equal; delete LangSys
                    s.Script.LangSysRecord.remove(lr)

    @_add_method(ttLib.getTableClass("GSUB"), ttLib.getTableClass("GPOS"))
    def prune_post_subset(self, font, options):
        table = self.table

        self.prune_lookups()  # XXX Is this actually needed?!

        if table.LookupList:
            table.LookupList.prune_post_subset(font, options)
            # XXX Next two lines disabled because OTS is stupid and
            # doesn't like NULL offsets here.
            # if not table.LookupList.Lookup:
            # 	table.LookupList = None

        if not table.LookupList:
            table.FeatureList = None

        if table.FeatureList:
            self.remove_redundant_langsys()
            # Remove unreferenced features
            self.prune_features()

        # XXX Next two lines disabled because OTS is stupid and
        # doesn't like NULL offsets here.
        # if table.FeatureList and not table.FeatureList.FeatureRecord:
        # 	table.FeatureList = None

        # Never drop scripts themselves as them just being available
        # holds semantic significance.
        # XXX Next two lines disabled because OTS is stupid and
        # doesn't like NULL offsets here.
        # if table.ScriptList and not table.ScriptList.ScriptRecord:
        # 	table.ScriptList = None

        if hasattr(table, "FeatureVariations"):
            # drop FeatureVariations if there are no features to substitute
            if table.FeatureVariations and not (
                table.FeatureList and table.FeatureVariations.FeatureVariationRecord
            ):
                table.FeatureVariations = None

            # downgrade table version if there are no FeatureVariations
            if not table.FeatureVariations and table.Version == 0x00010001:
                table.Version = 0x00010000

        return True

    @_add_method(ttLib.getTableClass("GDEF"))
    def subset_glyphs(self, s):
        glyphs = s.glyphs_gsubed
        table = self.table
        if table.LigCaretList:
            indices = table.LigCaretList.Coverage.subset(glyphs)
            table.LigCaretList.LigGlyph = _list_subset(table.LigCaretList.LigGlyph, indices)
            table.LigCaretList.LigGlyphCount = len(table.LigCaretList.LigGlyph)
        if table.MarkAttachClassDef:
            table.MarkAttachClassDef.classDefs = {
                g: v for g, v in table.MarkAttachClassDef.classDefs.items() if g in glyphs
            }
        if table.GlyphClassDef:
            table.GlyphClassDef.classDefs = {
                g: v for g, v in table.GlyphClassDef.classDefs.items() if g in glyphs
            }
        if table.AttachList:
            indices = table.AttachList.Coverage.subset(glyphs)
            GlyphCount = table.AttachList.GlyphCount
            table.AttachList.AttachPoint = [
                table.AttachList.AttachPoint[i] for i in indices if i < GlyphCount
            ]
            table.AttachList.GlyphCount = len(table.AttachList.AttachPoint)
        if hasattr(table, "MarkGlyphSetsDef") and table.MarkGlyphSetsDef:
            markGlyphSets = table.MarkGlyphSetsDef
            for coverage in markGlyphSets.Coverage:
                if coverage:
                    coverage.subset(glyphs)

            s.used_mark_sets = [i for i, c in enumerate(markGlyphSets.Coverage) if c.glyphs]
            markGlyphSets.Coverage = [c for c in markGlyphSets.Coverage if c.glyphs]

        return True

    def _pruneGDEF(font):
        if "GDEF" not in font:
            return
        gdef = font["GDEF"]
        table = gdef.table
        if not hasattr(table, "VarStore"):
            return

        store = table.VarStore

        usedVarIdxes = set()

        # Collect.
        table.collect_device_varidxes(usedVarIdxes)
        if "GPOS" in font:
            font["GPOS"].table.collect_device_varidxes(usedVarIdxes)

        # Subset.
        varidx_map = store.subset_varidxes(usedVarIdxes)

        # Map.
        table.remap_device_varidxes(varidx_map)
        if "GPOS" in font:
            font["GPOS"].table.remap_device_varidxes(varidx_map)

    @_add_method(ttLib.getTableClass("GDEF"))
    def prune_post_subset(self, font, options):
        table = self.table
        # XXX check these against OTS
        if table.LigCaretList and not table.LigCaretList.LigGlyphCount:
            table.LigCaretList = None
        if table.MarkAttachClassDef and not table.MarkAttachClassDef.classDefs:
            table.MarkAttachClassDef = None
        if table.GlyphClassDef and not table.GlyphClassDef.classDefs:
            table.GlyphClassDef = None
        if table.AttachList and not table.AttachList.GlyphCount:
            table.AttachList = None
        if hasattr(table, "VarStore"):
            _pruneGDEF(font)
            if table.VarStore.VarDataCount == 0:
                if table.Version == 0x00010003:
                    table.Version = 0x00010002
        if (
            not hasattr(table, "MarkGlyphSetsDef")
            or not table.MarkGlyphSetsDef
            or not table.MarkGlyphSetsDef.Coverage
        ):
            table.MarkGlyphSetsDef = None
            if table.Version == 0x00010002:
                table.Version = 0x00010000
        return bool(
            table.LigCaretList
            or table.MarkAttachClassDef
            or table.GlyphClassDef
            or table.AttachList
            or (table.Version >= 0x00010002 and table.MarkGlyphSetsDef)
            or (table.Version >= 0x00010003 and table.VarStore)
        )

    @_add_method(ttLib.getTableClass("kern"))
    def prune_pre_subset(self, font, options):
        # Prune unknown kern table types
        self.kernTables = [t for t in self.kernTables if hasattr(t, "kernTable")]
        return bool(self.kernTables)

    @_add_method(ttLib.getTableClass("kern"))
    def subset_glyphs(self, s):
        glyphs = s.glyphs_gsubed
        for t in self.kernTables:
            t.kernTable = {
                (a, b): v
                for (a, b), v in t.kernTable.items()
                if a in glyphs and b in glyphs
            }
        self.kernTables = [t for t in self.kernTables if t.kernTable]
        return bool(self.kernTables)

    @_add_method(ttLib.getTableClass("vmtx"))
    def subset_glyphs(self, s):
        self.metrics = _dict_subset(self.metrics, s.glyphs)
        for g in s.glyphs_emptied:
            self.metrics[g] = (0, 0)
        return bool(self.metrics)

    @_add_method(ttLib.getTableClass("hmtx"))
    def subset_glyphs(self, s):
        self.metrics = _dict_subset(self.metrics, s.glyphs)
        for g in s.glyphs_emptied:
            self.metrics[g] = (0, 0)
        return True  # Required table

    @_add_method(ttLib.getTableClass("hdmx"))
    def subset_glyphs(self, s):
        self.hdmx = {sz: _dict_subset(l, s.glyphs) for sz, l in self.hdmx.items()}
        for sz in self.hdmx:
            for g in s.glyphs_emptied:
                self.hdmx[sz][g] = 0
        return bool(self.hdmx)

    @_add_method(ttLib.getTableClass("ankr"))
    def subset_glyphs(self, s):
        table = self.table.AnchorPoints
        assert table.Format == 0, "unknown 'ankr' format %s" % table.Format
        table.Anchors = {
            glyph: table.Anchors[glyph] for glyph in s.glyphs if glyph in table.Anchors
        }
        return len(table.Anchors) > 0

    @_add_method(ttLib.getTableClass("bsln"))
    def closure_glyphs(self, s):
        table = self.table.Baseline
        if table.Format in (2, 3):
            s.glyphs.add(table.StandardGlyph)

    @_add_method(ttLib.getTableClass("bsln"))
    def subset_glyphs(self, s):
        table = self.table.Baseline
        if table.Format in (1, 3):
            baselines = {
                glyph: table.BaselineValues.get(glyph, table.DefaultBaseline)
                for glyph in s.glyphs
            }
            if len(baselines) > 0:
                mostCommon, _cnt = Counter(baselines.values()).most_common(1)[0]
                table.DefaultBaseline = mostCommon
                baselines = {glyph: b for glyph, b in baselines.items() if b != mostCommon}
            if len(baselines) > 0:
                table.BaselineValues = baselines
            else:
                table.Format = {1: 0, 3: 2}[table.Format]
                del table.BaselineValues
        return True

    @_add_method(ttLib.getTableClass("lcar"))
    def subset_glyphs(self, s):
        table = self.table.LigatureCarets
        if table.Format in (0, 1):
            table.Carets = {
                glyph: table.Carets[glyph] for glyph in s.glyphs if glyph in table.Carets
            }
            return len(table.Carets) > 0
        else:
            assert False, "unknown 'lcar' format %s" % table.Format

    @_add_method(ttLib.getTableClass("gvar"))
    def prune_pre_subset(self, font, options):
        if options.notdef_glyph and not options.notdef_outline:
            self.variations[font.glyphOrder[0]] = []
        return True

    @_add_method(ttLib.getTableClass("gvar"))
    def subset_glyphs(self, s):
        self.variations = _dict_subset(self.variations, s.glyphs)
        self.glyphCount = len(self.variations)
        return bool(self.variations)

    def _remap_index_map(s, varidx_map, table_map):
        map_ = {k: varidx_map[v] for k, v in table_map.mapping.items()}
        # Emptied glyphs are remapped to:
        # if GID <= last retained GID, 0/0: delta set for 0/0 is expected to exist & zeros compress well
        # if GID > last retained GID, major/minor of the last retained glyph: will be optimized out by table compiler
        last_idx = varidx_map[table_map.mapping[s.last_retained_glyph]]
        for g, i in s.reverseEmptiedGlyphMap.items():
            map_[g] = last_idx if i > s.last_retained_order else 0
        return map_

    @_add_method(ttLib.getTableClass("HVAR"))
    def subset_glyphs(self, s):
        table = self.table

        used = set()
        advIdxes_ = set()
        retainAdvMap = False

        if table.AdvWidthMap:
            table.AdvWidthMap.mapping = _dict_subset(table.AdvWidthMap.mapping, s.glyphs)
            used.update(table.AdvWidthMap.mapping.values())
        else:
            used.update(s.reverseOrigGlyphMap.values())
            advIdxes_ = used.copy()
            retainAdvMap = s.options.retain_gids

        if table.LsbMap:
            table.LsbMap.mapping = _dict_subset(table.LsbMap.mapping, s.glyphs)
            used.update(table.LsbMap.mapping.values())
        if table.RsbMap:
            table.RsbMap.mapping = _dict_subset(table.RsbMap.mapping, s.glyphs)
            used.update(table.RsbMap.mapping.values())

        varidx_map = table.VarStore.subset_varidxes(
            used, retainFirstMap=retainAdvMap, advIdxes=advIdxes_
        )

        if table.AdvWidthMap:
            table.AdvWidthMap.mapping = _remap_index_map(s, varidx_map, table.AdvWidthMap)
        if table.LsbMap:
            table.LsbMap.mapping = _remap_index_map(s, varidx_map, table.LsbMap)
        if table.RsbMap:
            table.RsbMap.mapping = _remap_index_map(s, varidx_map, table.RsbMap)

        # TODO Return emptiness...
        return True

    @_add_method(ttLib.getTableClass("VVAR"))
    def subset_glyphs(self, s):
        table = self.table

        used = set()
        advIdxes_ = set()
        retainAdvMap = False

        if table.AdvHeightMap:
            table.AdvHeightMap.mapping = _dict_subset(table.AdvHeightMap.mapping, s.glyphs)
            used.update(table.AdvHeightMap.mapping.values())
        else:
            used.update(s.reverseOrigGlyphMap.values())
            advIdxes_ = used.copy()
            retainAdvMap = s.options.retain_gids

        if table.TsbMap:
            table.TsbMap.mapping = _dict_subset(table.TsbMap.mapping, s.glyphs)
            used.update(table.TsbMap.mapping.values())
        if table.BsbMap:
            table.BsbMap.mapping = _dict_subset(table.BsbMap.mapping, s.glyphs)
            used.update(table.BsbMap.mapping.values())
        if table.VOrgMap:
            table.VOrgMap.mapping = _dict_subset(table.VOrgMap.mapping, s.glyphs)
            used.update(table.VOrgMap.mapping.values())

        varidx_map = table.VarStore.subset_varidxes(
            used, retainFirstMap=retainAdvMap, advIdxes=advIdxes_
        )

        if table.AdvHeightMap:
            table.AdvHeightMap.mapping = _remap_index_map(s, varidx_map, table.AdvHeightMap)
        if table.TsbMap:
            table.TsbMap.mapping = _remap_index_map(s, varidx_map, table.TsbMap)
        if table.BsbMap:
            table.BsbMap.mapping = _remap_index_map(s, varidx_map, table.BsbMap)
        if table.VOrgMap:
            table.VOrgMap.mapping = _remap_index_map(s, varidx_map, table.VOrgMap)

        # TODO Return emptiness...
        return True

    @_add_method(ttLib.getTableClass("VORG"))
    def subset_glyphs(self, s):
        self.VOriginRecords = {
            g: v for g, v in self.VOriginRecords.items() if g in s.glyphs
        }
        self.numVertOriginYMetrics = len(self.VOriginRecords)
        return True  # Never drop; has default metrics

    @_add_method(ttLib.getTableClass("opbd"))
    def subset_glyphs(self, s):
        table = self.table.OpticalBounds
        if table.Format == 0:
            table.OpticalBoundsDeltas = {
                glyph: table.OpticalBoundsDeltas[glyph]
                for glyph in s.glyphs
                if glyph in table.OpticalBoundsDeltas
            }
            return len(table.OpticalBoundsDeltas) > 0
        elif table.Format == 1:
            table.OpticalBoundsPoints = {
                glyph: table.OpticalBoundsPoints[glyph]
                for glyph in s.glyphs
                if glyph in table.OpticalBoundsPoints
            }
            return len(table.OpticalBoundsPoints) > 0
        else:
            assert False, "unknown 'opbd' format %s" % table.Format

    @_add_method(ttLib.getTableClass("post"))
    def prune_pre_subset(self, font, options):
        if not options.glyph_names:
            self.formatType = 3.0
        return True  # Required table

    @_add_method(ttLib.getTableClass("post"))
    def subset_glyphs(self, s):
        self.extraNames = []  # This seems to do it
        return True  # Required table

    @_add_method(ttLib.getTableClass("prop"))
    def subset_glyphs(self, s):
        prop = self.table.GlyphProperties
        if prop.Format == 0:
            return prop.DefaultProperties != 0
        elif prop.Format == 1:
            prop.Properties = {
                g: prop.Properties.get(g, prop.DefaultProperties) for g in s.glyphs
            }
            mostCommon, _cnt = Counter(prop.Properties.values()).most_common(1)[0]
            prop.DefaultProperties = mostCommon
            prop.Properties = {
                g: prop for g, prop in prop.Properties.items() if prop != mostCommon
            }
            if len(prop.Properties) == 0:
                del prop.Properties
                prop.Format = 0
                return prop.DefaultProperties != 0
            return True
        else:
            assert False, "unknown 'prop' format %s" % prop.Format

    def _paint_glyph_names(paint, colr):
        result = set()

        def callback(paint):
            if paint.Format in {
                otTables.PaintFormat.PaintGlyph,
                otTables.PaintFormat.PaintColrGlyph,
            }:
                result.add(paint.Glyph)

        paint.traverse(colr, callback)
        return result

    @_add_method(ttLib.getTableClass("COLR"))
    def closure_glyphs(self, s):
        if self.version > 0:
            # on decompiling COLRv1, we only keep around the raw otTables
            # but for subsetting we need dicts with fully decompiled layers;
            # we store them temporarily in the C_O_L_R_ instance and delete
            # them after we have finished subsetting.
            self.ColorLayers = self._decompileColorLayersV0(self.table)
            self.ColorLayersV1 = {
                rec.BaseGlyph: rec.Paint
                for rec in self.table.BaseGlyphList.BaseGlyphPaintRecord
            }

        decompose = s.glyphs
        while decompose:
            layers = set()
            for g in decompose:
                for layer in self.ColorLayers.get(g, []):
                    layers.add(layer.name)

                if self.version > 0:
                    paint = self.ColorLayersV1.get(g)
                    if paint is not None:
                        layers.update(_paint_glyph_names(paint, self.table))

            layers -= s.glyphs
            s.glyphs.update(layers)
            decompose = layers

    @_add_method(ttLib.getTableClass("COLR"))
    def subset_glyphs(self, s):
        from fontTools.colorLib.unbuilder import unbuildColrV1
        from fontTools.colorLib.builder import buildColrV1, populateCOLRv0

        # only include glyphs after COLR closure, which in turn comes after cmap and GSUB
        # closure, but importantly before glyf/CFF closures. COLR layers can refer to
        # composite glyphs, and that's ok, since glyf/CFF closures happen after COLR closure
        # and take care of those. If we also included glyphs resulting from glyf/CFF closures
        # when deciding which COLR base glyphs to retain, then we may end up with a situation
        # whereby a COLR base glyph is kept, not because directly requested (cmap)
        # or substituted (GSUB) or referenced by another COLRv1 PaintColrGlyph, but because
        # it corresponds to (has same GID as) a non-COLR glyph that happens to be used as a
        # component in glyf or CFF table. Best case scenario we retain more glyphs than
        # required; worst case we retain incomplete COLR records that try to reference
        # glyphs that are no longer in the final subset font.
        # https://github.com/fonttools/fonttools/issues/2461
        s.glyphs = s.glyphs_colred

        self.ColorLayers = {
            g: self.ColorLayers[g] for g in s.glyphs if g in self.ColorLayers
        }
        if self.version == 0:
            return bool(self.ColorLayers)

        colorGlyphsV1 = unbuildColrV1(self.table.LayerList, self.table.BaseGlyphList)
        self.table.LayerList, self.table.BaseGlyphList = buildColrV1(
            {g: colorGlyphsV1[g] for g in colorGlyphsV1 if g in s.glyphs}
        )
        del self.ColorLayersV1

        if self.table.ClipList is not None:
            clips = self.table.ClipList.clips
            self.table.ClipList.clips = {g: clips[g] for g in clips if g in s.glyphs}

        layersV0 = self.ColorLayers
        if not self.table.BaseGlyphList.BaseGlyphPaintRecord:
            # no more COLRv1 glyphs: downgrade to version 0
            self.version = 0
            del self.table
            return bool(layersV0)

        populateCOLRv0(
            self.table,
            {g: [(layer.name, layer.colorID) for layer in layersV0[g]] for g in layersV0},
        )
        del self.ColorLayers

        # TODO: also prune ununsed varIndices in COLR.VarStore
        return True

    @_add_method(ttLib.getTableClass("CPAL"))
    def prune_post_subset(self, font, options):
        # Keep whole "CPAL" if "SVG " is present as it may be referenced by the latter
        # via 'var(--color{palette_entry_index}, ...)' CSS color variables.
        # For now we just assume this is the case by the mere presence of "SVG " table,
        # for parsing SVG to collect all the used indices is too much work...
        # TODO(anthrotype): Do The Right Thing (TM).
        if "SVG " in font:
            return True

        colr = font.get("COLR")
        if not colr:  # drop CPAL if COLR was subsetted to empty
            return False

        colors_by_index = defaultdict(list)

        def collect_colors_by_index(paint):
            if hasattr(paint, "PaletteIndex"):  # either solid colors...
                colors_by_index[paint.PaletteIndex].append(paint)
            elif hasattr(paint, "ColorLine"):  # ... or gradient color stops
                for stop in paint.ColorLine.ColorStop:
                    colors_by_index[stop.PaletteIndex].append(stop)

        if colr.version == 0:
            for layers in colr.ColorLayers.values():
                for layer in layers:
                    colors_by_index[layer.colorID].append(layer)
        else:
            if colr.table.LayerRecordArray:
                for layer in colr.table.LayerRecordArray.LayerRecord:
                    colors_by_index[layer.PaletteIndex].append(layer)
            for record in colr.table.BaseGlyphList.BaseGlyphPaintRecord:
                record.Paint.traverse(colr.table, collect_colors_by_index)

        # don't remap palette entry index 0xFFFF, this is always the foreground color
        # https://github.com/fonttools/fonttools/issues/2257
        retained_palette_indices = set(colors_by_index.keys()) - {0xFFFF}
        for palette in self.palettes:
            palette[:] = [c for i, c in enumerate(palette) if i in retained_palette_indices]
            assert len(palette) == len(retained_palette_indices)

        for new_index, old_index in enumerate(sorted(retained_palette_indices)):
            for record in colors_by_index[old_index]:
                if hasattr(record, "colorID"):  # v0
                    record.colorID = new_index
                elif hasattr(record, "PaletteIndex"):  # v1
                    record.PaletteIndex = new_index
                else:
                    raise AssertionError(record)

        self.numPaletteEntries = len(self.palettes[0])

        if self.version == 1:
            kept_labels = []
            for i, label in enumerate(self.paletteEntryLabels):
                if i in retained_palette_indices:
                    kept_labels.append(label)
            self.paletteEntryLabels = kept_labels
        return bool(self.numPaletteEntries)

    @_add_method(otTables.MathGlyphConstruction)
    def closure_glyphs(self, glyphs):
        variants = set()
        for v in self.MathGlyphVariantRecord:
            variants.add(v.VariantGlyph)
        if self.GlyphAssembly:
            for p in self.GlyphAssembly.PartRecords:
                variants.add(p.glyph)
        return variants

    @_add_method(otTables.MathVariants)
    def closure_glyphs(self, s):
        glyphs = frozenset(s.glyphs)
        variants = set()

        if self.VertGlyphCoverage:
            indices = self.VertGlyphCoverage.intersect(glyphs)
            for i in indices:
                variants.update(self.VertGlyphConstruction[i].closure_glyphs(glyphs))

        if self.HorizGlyphCoverage:
            indices = self.HorizGlyphCoverage.intersect(glyphs)
            for i in indices:
                variants.update(self.HorizGlyphConstruction[i].closure_glyphs(glyphs))

        s.glyphs.update(variants)

    @_add_method(ttLib.getTableClass("VARC"))
    def subset_glyphs(self, s):
        indices = self.table.Coverage.subset(s.glyphs)
        self.table.VarCompositeGlyphs.VarCompositeGlyph = _list_subset(
            self.table.VarCompositeGlyphs.VarCompositeGlyph, indices
        )
        return bool(self.table.VarCompositeGlyphs.VarCompositeGlyph)

    @_add_method(ttLib.getTableClass("VARC"))
    def closure_glyphs(self, s):
        if self.table.VarCompositeGlyphs is None:
            return

        glyphMap = {glyphName: i for i, glyphName in enumerate(self.table.Coverage.glyphs)}
        glyphRecords = self.table.VarCompositeGlyphs.VarCompositeGlyph

        glyphs = s.glyphs
        covered = set()
        new = set(glyphs)
        while new:
            oldNew = new
            new = set()
            for glyphName in oldNew:
                if glyphName in covered:
                    continue
                idx = glyphMap.get(glyphName)
                if idx is None:
                    continue
                glyph = glyphRecords[idx]
                for comp in glyph.components:
                    name = comp.glyphName
                    glyphs.add(name)
                    if name not in covered:
                        new.add(name)

    @_add_method(ttLib.getTableClass("VARC"))
    def prune_post_subset(self, font, options):
        table = self.table

        store = table.MultiVarStore
        if store is not None:
            usedVarIdxes = set()
            table.collect_varidxes(usedVarIdxes)
            varidx_map = store.subset_varidxes(usedVarIdxes)
            table.remap_varidxes(varidx_map)

        axisIndicesList = table.AxisIndicesList.Item
        if axisIndicesList is not None:
            usedIndices = set()
            for glyph in table.VarCompositeGlyphs.VarCompositeGlyph:
                for comp in glyph.components:
                    if comp.axisIndicesIndex is not None:
                        usedIndices.add(comp.axisIndicesIndex)
            usedIndices = sorted(usedIndices)
            table.AxisIndicesList.Item = _list_subset(axisIndicesList, usedIndices)
            mapping = {old: new for new, old in enumerate(usedIndices)}
            for glyph in table.VarCompositeGlyphs.VarCompositeGlyph:
                for comp in glyph.components:
                    if comp.axisIndicesIndex is not None:
                        comp.axisIndicesIndex = mapping[comp.axisIndicesIndex]

        conditionList = table.ConditionList
        if conditionList is not None:
            conditionTables = conditionList.ConditionTable
            usedIndices = set()
            for glyph in table.VarCompositeGlyphs.VarCompositeGlyph:
                for comp in glyph.components:
                    if comp.conditionIndex is not None:
                        usedIndices.add(comp.conditionIndex)
            usedIndices = sorted(usedIndices)
            conditionList.ConditionTable = _list_subset(conditionTables, usedIndices)
            mapping = {old: new for new, old in enumerate(usedIndices)}
            for glyph in table.VarCompositeGlyphs.VarCompositeGlyph:
                for comp in glyph.components:
                    if comp.conditionIndex is not None:
                        comp.conditionIndex = mapping[comp.conditionIndex]

        return True

    @_add_method(ttLib.getTableClass("MATH"))
    def closure_glyphs(self, s):
        if self.table.MathVariants:
            self.table.MathVariants.closure_glyphs(s)

    @_add_method(otTables.MathItalicsCorrectionInfo)
    def subset_glyphs(self, s):
        indices = self.Coverage.subset(s.glyphs)
        self.ItalicsCorrection = _list_subset(self.ItalicsCorrection, indices)
        self.ItalicsCorrectionCount = len(self.ItalicsCorrection)
        return bool(self.ItalicsCorrectionCount)

    @_add_method(otTables.MathTopAccentAttachment)
    def subset_glyphs(self, s):
        indices = self.TopAccentCoverage.subset(s.glyphs)
        self.TopAccentAttachment = _list_subset(self.TopAccentAttachment, indices)
        self.TopAccentAttachmentCount = len(self.TopAccentAttachment)
        return bool(self.TopAccentAttachmentCount)

    @_add_method(otTables.MathKernInfo)
    def subset_glyphs(self, s):
        indices = self.MathKernCoverage.subset(s.glyphs)
        self.MathKernInfoRecords = _list_subset(self.MathKernInfoRecords, indices)
        self.MathKernCount = len(self.MathKernInfoRecords)
        return bool(self.MathKernCount)

    @_add_method(otTables.MathGlyphInfo)
    def subset_glyphs(self, s):
        if self.MathItalicsCorrectionInfo:
            self.MathItalicsCorrectionInfo.subset_glyphs(s)
        if self.MathTopAccentAttachment:
            self.MathTopAccentAttachment.subset_glyphs(s)
        if self.MathKernInfo:
            self.MathKernInfo.subset_glyphs(s)
        if self.ExtendedShapeCoverage:
            self.ExtendedShapeCoverage.subset(s.glyphs)
        return True

    @_add_method(otTables.MathVariants)
    def subset_glyphs(self, s):
        if self.VertGlyphCoverage:
            indices = self.VertGlyphCoverage.subset(s.glyphs)
            self.VertGlyphConstruction = _list_subset(self.VertGlyphConstruction, indices)
            self.VertGlyphCount = len(self.VertGlyphConstruction)

        if self.HorizGlyphCoverage:
            indices = self.HorizGlyphCoverage.subset(s.glyphs)
            self.HorizGlyphConstruction = _list_subset(self.HorizGlyphConstruction, indices)
            self.HorizGlyphCount = len(self.HorizGlyphConstruction)

        return True

    @_add_method(ttLib.getTableClass("MATH"))
    def subset_glyphs(self, s):
        s.glyphs = s.glyphs_mathed
        if self.table.MathGlyphInfo:
            self.table.MathGlyphInfo.subset_glyphs(s)
        if self.table.MathVariants:
            self.table.MathVariants.subset_glyphs(s)
        return True

    @_add_method(ttLib.getTableModule("glyf").Glyph)
    def remapComponentsFast(self, glyphidmap):
        if not self.data or struct.unpack(">h", self.data[:2])[0] >= 0:
            return  # Not composite
        data = self.data = bytearray(self.data)
        i = 10
        more = 1
        while more:
            flags = (data[i] << 8) | data[i + 1]
            glyphID = (data[i + 2] << 8) | data[i + 3]
            # Remap
            glyphID = glyphidmap[glyphID]
            data[i + 2] = glyphID >> 8
            data[i + 3] = glyphID & 0xFF
            i += 4
            flags = int(flags)

            if flags & 0x0001:
                i += 4  # ARG_1_AND_2_ARE_WORDS
            else:
                i += 2
            if flags & 0x0008:
                i += 2  # WE_HAVE_A_SCALE
            elif flags & 0x0040:
                i += 4  # WE_HAVE_AN_X_AND_Y_SCALE
            elif flags & 0x0080:
                i += 8  # WE_HAVE_A_TWO_BY_TWO
            more = flags & 0x0020  # MORE_COMPONENTS

    @_add_method(ttLib.getTableClass("glyf"))
    def closure_glyphs(self, s):
        glyphSet = self.glyphs
        decompose = s.glyphs
        while decompose:
            components = set()
            for g in decompose:
                if g not in glyphSet:
                    continue
                gl = glyphSet[g]
                for c in gl.getComponentNames(self):
                    components.add(c)
            components -= s.glyphs
            s.glyphs.update(components)
            decompose = components

    @_add_method(ttLib.getTableClass("glyf"))
    def prune_pre_subset(self, font, options):
        if options.notdef_glyph and not options.notdef_outline:
            g = self[self.glyphOrder[0]]
            # Yay, easy!
            g.__dict__.clear()
            g.data = b""
        return True

    @_add_method(ttLib.getTableClass("glyf"))
    def subset_glyphs(self, s):
        self.glyphs = _dict_subset(self.glyphs, s.glyphs)
        if not s.options.retain_gids:
            indices = [i for i, g in enumerate(self.glyphOrder) if g in s.glyphs]
            glyphmap = {o: n for n, o in enumerate(indices)}
            for v in self.glyphs.values():
                if hasattr(v, "data"):
                    v.remapComponentsFast(glyphmap)
        Glyph = ttLib.getTableModule("glyf").Glyph
        for g in s.glyphs_emptied:
            self.glyphs[g] = Glyph()
            self.glyphs[g].data = b""
        self.glyphOrder = [
            g for g in self.glyphOrder if g in s.glyphs or g in s.glyphs_emptied
        ]
        # Don't drop empty 'glyf' tables, otherwise 'loca' doesn't get subset.
        return True

    @_add_method(ttLib.getTableClass("glyf"))
    def prune_post_subset(self, font, options):
        remove_hinting = not options.hinting
        for v in self.glyphs.values():
            v.trim(remove_hinting=remove_hinting)
        return True

    @_add_method(ttLib.getTableClass("cmap"))
    def closure_glyphs(self, s):
        tables = [t for t in self.tables if t.isUnicode()]

        # Closure unicodes, which for now is pulling in bidi mirrored variants
        if s.options.bidi_closure:
            additional_unicodes = set()
            for u in s.unicodes_requested:
                mirror_u = mirrored(u)
                if mirror_u is not None:
                    additional_unicodes.add(mirror_u)
            s.unicodes_requested.update(additional_unicodes)

        # Close glyphs
        for table in tables:
            if table.format == 14:
                for varSelector, cmap in table.uvsDict.items():
                    if varSelector not in s.unicodes_requested:
                        continue
                    glyphs = {g for u, g in cmap if u in s.unicodes_requested}
                    if None in glyphs:
                        glyphs.remove(None)
                    s.glyphs.update(glyphs)
            else:
                cmap = table.cmap
                intersection = s.unicodes_requested.intersection(cmap.keys())
                s.glyphs.update(cmap[u] for u in intersection)

        # Calculate unicodes_missing
        s.unicodes_missing = s.unicodes_requested.copy()
        for table in tables:
            s.unicodes_missing.difference_update(table.cmap)

    @_add_method(ttLib.getTableClass("cmap"))
    def prune_pre_subset(self, font, options):
        if not options.legacy_cmap:
            # Drop non-Unicode / non-Symbol cmaps
            self.tables = [t for t in self.tables if t.isUnicode() or t.isSymbol()]
        if not options.symbol_cmap:
            self.tables = [t for t in self.tables if not t.isSymbol()]
        # TODO(behdad) Only keep one subtable?
        # For now, drop format=0 which can't be subset_glyphs easily?
        self.tables = [t for t in self.tables if t.format != 0]
        self.numSubTables = len(self.tables)
        return True  # Required table

    @_add_method(ttLib.getTableClass("cmap"))
    def subset_glyphs(self, s):
        s.glyphs = None  # We use s.glyphs_requested and s.unicodes_requested only

        tables_format12_bmp = []
        table_plat0_enc3 = {}  # Unicode platform, Unicode BMP only, keyed by language
        table_plat3_enc1 = {}  # Windows platform, Unicode BMP, keyed by language

        for t in self.tables:
            if t.platformID == 0 and t.platEncID == 3:
                table_plat0_enc3[t.language] = t
            if t.platformID == 3 and t.platEncID == 1:
                table_plat3_enc1[t.language] = t

            if t.format == 14:
                # TODO(behdad) We drop all the default-UVS mappings
                # for glyphs_requested.  So it's the caller's responsibility to make
                # sure those are included.
                t.uvsDict = {
                    v: [
                        (u, g)
                        for u, g in l
                        if g in s.glyphs_requested or u in s.unicodes_requested
                    ]
                    for v, l in t.uvsDict.items()
                    if v in s.unicodes_requested
                }
                t.uvsDict = {v: l for v, l in t.uvsDict.items() if l}
            elif t.isUnicode():
                t.cmap = {
                    u: g
                    for u, g in t.cmap.items()
                    if g in s.glyphs_requested or u in s.unicodes_requested
                }
                # Collect format 12 tables that hold only basic multilingual plane
                # codepoints.
                if t.format == 12 and t.cmap and max(t.cmap.keys()) < 0x10000:
                    tables_format12_bmp.append(t)
            else:
                t.cmap = {u: g for u, g in t.cmap.items() if g in s.glyphs_requested}

        # Fomat 12 tables are redundant if they contain just the same BMP codepoints
        # their little BMP-only encoding siblings contain.
        for t in tables_format12_bmp:
            if (
                t.platformID == 0  # Unicode platform
                and t.platEncID == 4  # Unicode full repertoire
                and t.language in table_plat0_enc3  # Have a BMP-only sibling?
                and table_plat0_enc3[t.language].cmap == t.cmap
            ):
                t.cmap.clear()
            elif (
                t.platformID == 3  # Windows platform
                and t.platEncID == 10  # Unicode full repertoire
                and t.language in table_plat3_enc1  # Have a BMP-only sibling?
                and table_plat3_enc1[t.language].cmap == t.cmap
            ):
                t.cmap.clear()

        self.tables = [t for t in self.tables if (t.cmap if t.format != 14 else t.uvsDict)]
        self.numSubTables = len(self.tables)
        # TODO(behdad) Convert formats when needed.
        # In particular, if we have a format=12 without non-BMP
        # characters, convert it to format=4 if there's not one.
        return True  # Required table

    @_add_method(ttLib.getTableClass("DSIG"))
    def prune_pre_subset(self, font, options):
        # Drop all signatures since they will be invalid
        self.usNumSigs = 0
        self.signatureRecords = []
        return True

    @_add_method(ttLib.getTableClass("maxp"))
    def prune_pre_subset(self, font, options):
        if not options.hinting:
            if self.tableVersion == 0x00010000:
                self.maxZones = 1
                self.maxTwilightPoints = 0
                self.maxStorage = 0
                self.maxFunctionDefs = 0
                self.maxInstructionDefs = 0
                self.maxStackElements = 0
                self.maxSizeOfInstructions = 0
        return True

    NAME_IDS_TO_OBFUSCATE = {1, 2, 3, 4, 6, 16, 17, 18}

    @_add_method(ttLib.getTableClass("name"))
    def prune_post_subset(self, font, options):
        visitor = NameRecordVisitor()
        visitor.visit(font)
        nameIDs = set(options.name_IDs) | visitor.seen
        if "*" in options.name_IDs:
            nameIDs |= {n.nameID for n in self.names if n.nameID < 256}
        self.names = [n for n in self.names if n.nameID in nameIDs]
        if not options.name_legacy:
            # TODO(behdad) Sometimes (eg Apple Color Emoji) there's only a macroman
            # entry for Latin and no Unicode names.
            self.names = [n for n in self.names if n.isUnicode()]
        # TODO(behdad) Option to keep only one platform's
        if "*" not in options.name_languages:
            # TODO(behdad) This is Windows-platform specific!
            self.names = [n for n in self.names if n.langID in options.name_languages]
        if options.obfuscate_names:
            namerecs = []
            # Preserve names to be scrambled or dropped elsewhere so that other
            # parts of the font don't break.
            needRemapping = visitor.seen.intersection(NAME_IDS_TO_OBFUSCATE)
            if needRemapping:
                _remap_select_name_ids(font, needRemapping)
            for n in self.names:
                if n.nameID in [1, 4]:
                    n.string = ".\x7f".encode("utf_16_be") if n.isUnicode() else ".\x7f"
                elif n.nameID in [2, 6]:
                    n.string = "\x7f".encode("utf_16_be") if n.isUnicode() else "\x7f"
                elif n.nameID == 3:
                    n.string = ""
                elif n.nameID in [16, 17, 18]:
                    continue
                namerecs.append(n)
            self.names = namerecs
        return True  # Required table

    def _remap_select_name_ids(font: ttLib.TTFont, needRemapping: set[int]) -> None:
        """Remap a set of IDs so that the originals can be safely scrambled or
        dropped.

        For each name record whose name id is in the `needRemapping` set, make a copy
        and allocate a new unused name id in the font-specific range (> 255).

        Finally update references to these in the `fvar` and `STAT` tables.
        """

        if "fvar" not in font and "STAT" not in font:
            return

        name = font["name"]

        # 1. Assign new IDs for names to be preserved.
        existingIds = {record.nameID for record in name.names}
        remapping = {}
        nextId = name._findUnusedNameID() - 1  # Should skip gaps in name IDs.
        for nameId in needRemapping:
            nextId += 1  # We should have complete freedom until 32767.
            assert nextId not in existingIds, "_findUnusedNameID did not skip gaps"
            if nextId > 32767:
                raise ValueError("Ran out of name IDs while trying to remap existing ones.")
            remapping[nameId] = nextId

        # 2. Copy records to use the new ID. We can't rewrite them in place, because
        #    that could make IDs 1 to 6 "disappear" from code that follows. Some
        #    tools that produce EOT fonts expect them to exist, even when they're
        #    scrambled. See https://github.com/fonttools/fonttools/issues/165.
        copiedRecords = []
        for record in name.names:
            if record.nameID not in needRemapping:
                continue
            recordCopy = makeName(
                record.string,
                remapping[record.nameID],
                record.platformID,
                record.platEncID,
                record.langID,
            )
            copiedRecords.append(recordCopy)
        name.names.extend(copiedRecords)

        # 3. Rewrite the corresponding IDs in other tables. For now, care only about
        #    STAT and fvar. If more tables need to be changed, consider adapting
        #    NameRecordVisitor to rewrite IDs wherever it finds them.
        fvar = font.get("fvar")
        if fvar is not None:
            for axis in fvar.axes:
                axis.axisNameID = remapping.get(axis.axisNameID, axis.axisNameID)
            for instance in fvar.instances:
                nameID = instance.subfamilyNameID
                instance.subfamilyNameID = remapping.get(nameID, nameID)
                nameID = instance.postscriptNameID
                instance.postscriptNameID = remapping.get(nameID, nameID)

        stat = font.get("STAT")
        if stat is None:
            return
        elidedNameID = stat.table.ElidedFallbackNameID
        stat.table.ElidedFallbackNameID = remapping.get(elidedNameID, elidedNameID)
        if stat.table.DesignAxisRecord:
            for axis in stat.table.DesignAxisRecord.Axis:
                axis.AxisNameID = remapping.get(axis.AxisNameID, axis.AxisNameID)
        if stat.table.AxisValueArray:
            for value in stat.table.AxisValueArray.AxisValue:
                value.ValueNameID = remapping.get(value.ValueNameID, value.ValueNameID)

    @_add_method(ttLib.getTableClass("head"))
    def prune_post_subset(self, font, options):
        # Force re-compiling head table, to update any recalculated values.
        return True

    # TODO(behdad) OS/2 ulCodePageRange?
    # TODO(behdad) Drop AAT tables.
    # TODO(behdad) Drop unneeded GSUB/GPOS Script/LangSys entries.
    # TODO(behdad) Drop empty GSUB/GPOS, and GDEF if no GSUB/GPOS left
    # TODO(behdad) Drop GDEF subitems if unused by lookups
    # TODO(behdad) Avoid recursing too much (in GSUB/GPOS and in CFF)
    # TODO(behdad) Text direction considerations.
    # TODO(behdad) Text script / language considerations.
    # TODO(behdad) Optionally drop 'kern' table if GPOS available
    # TODO(behdad) Implement --unicode='*' to choose all cmap'ed
    # TODO(behdad) Drop old-spec Indic scripts

    class Options(object):

        class OptionError(Exception):
            pass

        class UnknownOptionError(OptionError):
            pass

        # spaces in tag names (e.g. "SVG ", "cvt ") are stripped by the argument parser
        _drop_tables_default = [
            "JSTF",
            "DSIG",
            "EBDT",
            "EBLC",
            "EBSC",
            "PCLT",
            "LTSH",
        ]
        _drop_tables_default += ["Feat", "Glat", "Gloc", "Silf", "Sill"]  # Graphite
        _no_subset_tables_default = [
            "avar",
            "BASE",
            "fvar",
            "gasp",
            "head",
            "hhea",
            "maxp",
            "vhea",
            "OS/2",
            "loca",
            "name",
            "cvt",
            "fpgm",
            "prep",
            "VDMX",
            "DSIG",
            "CPAL",
            "MVAR",
            "cvar",
            "STAT",
        ]
        _hinting_tables_default = ["cvt", "cvar", "fpgm", "prep", "hdmx", "VDMX"]

        # Based on HarfBuzz shapers
        _layout_features_groups = {
            # Default shaper
            "common": ["rvrn", "ccmp", "liga", "locl", "mark", "mkmk", "rlig"],
            "fractions": ["frac", "numr", "dnom"],
            "horizontal": ["calt", "clig", "curs", "kern", "rclt"],
            "vertical": ["valt", "vert", "vkrn", "vpal", "vrt2"],
            "ltr": ["ltra", "ltrm"],
            "rtl": ["rtla", "rtlm"],
            "rand": ["rand"],
            "justify": ["jalt"],
            "private": ["Harf", "HARF", "Buzz", "BUZZ"],
            "east_asian_spacing": ["chws", "vchw", "halt", "vhal"],
            # Complex shapers
            "arabic": [
                "init",
                "medi",
                "fina",
                "isol",
                "med2",
                "fin2",
                "fin3",
                "cswh",
                "mset",
                "stch",
            ],
            "hangul": ["ljmo", "vjmo", "tjmo"],
            "tibetan": ["abvs", "blws", "abvm", "blwm"],
            "indic": [
                "nukt",
                "akhn",
                "rphf",
                "rkrf",
                "pref",
                "blwf",
                "half",
                "abvf",
                "pstf",
                "cfar",
                "vatu",
                "cjct",
                "init",
                "pres",
                "abvs",
                "blws",
                "psts",
                "haln",
                "dist",
                "abvm",
                "blwm",
            ],
        }
        _layout_features_default = _uniq_sort(
            sum(iter(_layout_features_groups.values()), [])
        )

        def __init__(self, **kwargs):
            self.drop_tables = self._drop_tables_default[:]
            self.no_subset_tables = self._no_subset_tables_default[:]
            self.passthrough_tables = False  # keep/drop tables we can't subset
            self.hinting_tables = self._hinting_tables_default[:]
            self.legacy_kern = False  # drop 'kern' table if GPOS available
            self.layout_closure = True
            self.layout_features = self._layout_features_default[:]
            self.layout_scripts = ["*"]
            self.ignore_missing_glyphs = False
            self.ignore_missing_unicodes = True
            self.hinting = True
            self.glyph_names = False
            self.legacy_cmap = False
            self.symbol_cmap = False
            self.name_IDs = [
                0,
                1,
                2,
                3,
                4,
                5,
                6,
            ]  # https://github.com/fonttools/fonttools/issues/1170#issuecomment-364631225
            self.name_legacy = False
            self.name_languages = [0x0409]  # English
            self.obfuscate_names = False  # to make webfont unusable as a system font
            self.retain_gids = False
            self.notdef_glyph = True  # gid0 for TrueType / .notdef for CFF
            self.notdef_outline = False  # No need for notdef to have an outline really
            self.recommended_glyphs = False  # gid1, gid2, gid3 for TrueType
            self.recalc_bounds = False  # Recalculate font bounding boxes
            self.recalc_timestamp = False  # Recalculate font modified timestamp
            self.prune_unicode_ranges = True  # Clear unused 'ulUnicodeRange' bits
            self.prune_codepage_ranges = True  # Clear unused 'ulCodePageRange' bits
            self.recalc_average_width = False  # update 'xAvgCharWidth'
            self.recalc_max_context = False  # update 'usMaxContext'
            self.canonical_order = None  # Order tables as recommended
            self.flavor = None  # May be 'woff' or 'woff2'
            self.with_zopfli = False  # use zopfli instead of zlib for WOFF 1.0
            self.desubroutinize = False  # Desubroutinize CFF CharStrings
            self.harfbuzz_repacker = USE_HARFBUZZ_REPACKER.default
            self.verbose = False
            self.timing = False
            self.xml = False
            self.font_number = -1
            self.pretty_svg = False
            self.lazy = True
            self.bidi_closure = True

            self.set(**kwargs)

        def set(self, **kwargs):
            for k, v in kwargs.items():
                if not hasattr(self, k):
                    raise self.UnknownOptionError("Unknown option '%s'" % k)
                setattr(self, k, v)

        def parse_opts(self, argv, ignore_unknown=[]):
            posargs = []
            passthru_options = []
            for a in argv:
                orig_a = a
                if not a.startswith("--"):
                    posargs.append(a)
                    continue
                a = a[2:]
                i = a.find("=")
                op = "="
                if i == -1:
                    if a.startswith("no-"):
                        k = a[3:]
                        if k == "canonical-order":
                            # reorderTables=None is faster than False (the latter
                            # still reorders to "keep" the original table order)
                            v = None
                        else:
                            v = False
                    else:
                        k = a
                        v = True
                    if k.endswith("?"):
                        k = k[:-1]
                        v = "?"
                else:
                    k = a[:i]
                    if k[-1] in "-+":
                        op = k[-1] + "="  # Op is '-=' or '+=' now.
                        k = k[:-1]
                    v = a[i + 1 :]
                ok = k
                k = k.replace("-", "_")
                if not hasattr(self, k):
                    if ignore_unknown is True or ok in ignore_unknown:
                        passthru_options.append(orig_a)
                        continue
                    else:
                        raise self.UnknownOptionError("Unknown option '%s'" % a)

                ov = getattr(self, k)
                if v == "?":
                    print("Current setting for '%s' is: %s" % (ok, ov))
                    continue
                if isinstance(ov, bool):
                    v = bool(v)
                elif isinstance(ov, int):
                    v = int(v)
                elif isinstance(ov, str):
                    v = str(v)  # redundant
                elif isinstance(ov, list):
                    if isinstance(v, bool):
                        raise self.OptionError(
                            "Option '%s' requires values to be specified using '='" % a
                        )
                    vv = v.replace(",", " ").split()
                    if vv == [""]:
                        vv = []
                    vv = [int(x, 0) if len(x) and x[0] in "0123456789" else x for x in vv]
                    if op == "=":
                        v = vv
                    elif op == "+=":
                        v = ov
                        v.extend(vv)
                    elif op == "-=":
                        v = ov
                        for x in vv:
                            if x in v:
                                v.remove(x)
                    else:
                        assert False

                setattr(self, k, v)

            return posargs + passthru_options

    class Subsetter(object):

        class SubsettingError(Exception):
            pass

        class MissingGlyphsSubsettingError(SubsettingError):
            pass

        class MissingUnicodesSubsettingError(SubsettingError):
            pass

        def __init__(self, options=None):
            if not options:
                options = Options()

            self.options = options
            self.unicodes_requested = set()
            self.glyph_names_requested = set()
            self.glyph_ids_requested = set()

        def populate(self, glyphs=[], gids=[], unicodes=[], text=""):
            self.unicodes_requested.update(unicodes)
            if isinstance(text, bytes):
                text = text.decode("utf_8")
            text_utf32 = text.encode("utf-32-be")
            nchars = len(text_utf32) // 4
            for u in struct.unpack(">%dL" % nchars, text_utf32):
                self.unicodes_requested.add(u)
            self.glyph_names_requested.update(glyphs)
            self.glyph_ids_requested.update(gids)

        def _prune_pre_subset(self, font):
            for tag in self._sort_tables(font):
                if (
                    tag.strip() in self.options.drop_tables
                    or (
                        tag.strip() in self.options.hinting_tables
                        and not self.options.hinting
                    )
                    or (tag == "kern" and (not self.options.legacy_kern and "GPOS" in font))
                ):
                    log.info("%s dropped", tag)
                    del font[tag]
                    continue

                clazz = ttLib.getTableClass(tag)

                if hasattr(clazz, "prune_pre_subset"):
                    with timer("load '%s'" % tag):
                        table = font[tag]
                    with timer("prune '%s'" % tag):
                        retain = table.prune_pre_subset(font, self.options)
                    if not retain:
                        log.info("%s pruned to empty; dropped", tag)
                        del font[tag]
                        continue
                    else:
                        log.info("%s pruned", tag)

        def _closure_glyphs(self, font):
            realGlyphs = set(font.getGlyphOrder())
            self.orig_glyph_order = glyph_order = font.getGlyphOrder()

            self.glyphs_requested = set()
            self.glyphs_requested.update(self.glyph_names_requested)
            self.glyphs_requested.update(
                glyph_order[i] for i in self.glyph_ids_requested if i < len(glyph_order)
            )

            self.glyphs_missing = set()
            self.glyphs_missing.update(self.glyphs_requested.difference(realGlyphs))
            self.glyphs_missing.update(
                i for i in self.glyph_ids_requested if i >= len(glyph_order)
            )
            if self.glyphs_missing:
                log.info("Missing requested glyphs: %s", self.glyphs_missing)
                if not self.options.ignore_missing_glyphs:
                    raise self.MissingGlyphsSubsettingError(self.glyphs_missing)

            self.glyphs = self.glyphs_requested.copy()

            self.unicodes_missing = set()
            if "cmap" in font:
                with timer("close glyph list over 'cmap'"):
                    font["cmap"].closure_glyphs(self)
                    self.glyphs.intersection_update(realGlyphs)
            self.glyphs_cmaped = frozenset(self.glyphs)
            if self.unicodes_missing:
                missing = ["U+%04X" % u for u in self.unicodes_missing]
                log.info("Missing glyphs for requested Unicodes: %s", missing)
                if not self.options.ignore_missing_unicodes:
                    raise self.MissingUnicodesSubsettingError(missing)
                del missing

            if self.options.notdef_glyph:
                if "glyf" in font:
                    self.glyphs.add(font.getGlyphName(0))
                    log.info("Added gid0 to subset")
                else:
                    self.glyphs.add(".notdef")
                    log.info("Added .notdef to subset")
            if self.options.recommended_glyphs:
                if "glyf" in font:
                    for i in range(min(4, len(font.getGlyphOrder()))):
                        self.glyphs.add(font.getGlyphName(i))
                    log.info("Added first four glyphs to subset")

            if "MATH" in font:
                with timer("close glyph list over 'MATH'"):
                    log.info(
                        "Closing glyph list over 'MATH': %d glyphs before", len(self.glyphs)
                    )
                    log.glyphs(self.glyphs, font=font)
                    font["MATH"].closure_glyphs(self)
                    self.glyphs.intersection_update(realGlyphs)
                    log.info(
                        "Closed glyph list over 'MATH': %d glyphs after", len(self.glyphs)
                    )
                    log.glyphs(self.glyphs, font=font)
            self.glyphs_mathed = frozenset(self.glyphs)

            if self.options.layout_closure and "GSUB" in font:
                with timer("close glyph list over 'GSUB'"):
                    log.info(
                        "Closing glyph list over 'GSUB': %d glyphs before", len(self.glyphs)
                    )
                    log.glyphs(self.glyphs, font=font)
                    font["GSUB"].closure_glyphs(self)
                    self.glyphs.intersection_update(realGlyphs)
                    log.info(
                        "Closed glyph list over 'GSUB': %d glyphs after", len(self.glyphs)
                    )
                    log.glyphs(self.glyphs, font=font)
            self.glyphs_gsubed = frozenset(self.glyphs)

            for table in ("COLR", "bsln"):
                if table in font:
                    with timer("close glyph list over '%s'" % table):
                        log.info(
                            "Closing glyph list over '%s': %d glyphs before",
                            table,
                            len(self.glyphs),
                        )
                        log.glyphs(self.glyphs, font=font)
                        font[table].closure_glyphs(self)
                        self.glyphs.intersection_update(realGlyphs)
                        log.info(
                            "Closed glyph list over '%s': %d glyphs after",
                            table,
                            len(self.glyphs),
                        )
                        log.glyphs(self.glyphs, font=font)
                setattr(self, f"glyphs_{table.lower()}ed", frozenset(self.glyphs))

            if "VARC" in font:
                with timer("close glyph list over 'VARC'"):
                    log.info(
                        "Closing glyph list over 'VARC': %d glyphs before", len(self.glyphs)
                    )
                    log.glyphs(self.glyphs, font=font)
                    font["VARC"].closure_glyphs(self)
                    self.glyphs.intersection_update(realGlyphs)
                    log.info(
                        "Closed glyph list over 'VARC': %d glyphs after", len(self.glyphs)
                    )
                    log.glyphs(self.glyphs, font=font)
            self.glyphs_glyfed = frozenset(self.glyphs)

            if "glyf" in font:
                with timer("close glyph list over 'glyf'"):
                    log.info(
                        "Closing glyph list over 'glyf': %d glyphs before", len(self.glyphs)
                    )
                    log.glyphs(self.glyphs, font=font)
                    font["glyf"].closure_glyphs(self)
                    self.glyphs.intersection_update(realGlyphs)
                    log.info(
                        "Closed glyph list over 'glyf': %d glyphs after", len(self.glyphs)
                    )
                    log.glyphs(self.glyphs, font=font)
            self.glyphs_glyfed = frozenset(self.glyphs)

            if "CFF " in font:
                with timer("close glyph list over 'CFF '"):
                    log.info(
                        "Closing glyph list over 'CFF ': %d glyphs before", len(self.glyphs)
                    )
                    log.glyphs(self.glyphs, font=font)
                    font["CFF "].closure_glyphs(self)
                    self.glyphs.intersection_update(realGlyphs)
                    log.info(
                        "Closed glyph list over 'CFF ': %d glyphs after", len(self.glyphs)
                    )
                    log.glyphs(self.glyphs, font=font)
            self.glyphs_cffed = frozenset(self.glyphs)

            self.glyphs_retained = frozenset(self.glyphs)

            order = font.getReverseGlyphMap()
            self.reverseOrigGlyphMap = {g: order[g] for g in self.glyphs_retained}

            self.last_retained_order = max(self.reverseOrigGlyphMap.values())
            self.last_retained_glyph = font.getGlyphOrder()[self.last_retained_order]

            self.glyphs_emptied = frozenset()
            if self.options.retain_gids:
                self.glyphs_emptied = {
                    g
                    for g in realGlyphs - self.glyphs_retained
                    if order[g] <= self.last_retained_order
                }

            self.reverseEmptiedGlyphMap = {g: order[g] for g in self.glyphs_emptied}

            if not self.options.retain_gids:
                new_glyph_order = [g for g in glyph_order if g in self.glyphs_retained]
            else:
                new_glyph_order = [
                    g for g in glyph_order if font.getGlyphID(g) <= self.last_retained_order
                ]
            # We'll call font.setGlyphOrder() at the end of _subset_glyphs when all
            # tables have been subsetted. Below, we use the new glyph order to get
            # a map from old to new glyph indices, which can be useful when
            # subsetting individual tables (e.g. SVG) that refer to GIDs.
            self.new_glyph_order = new_glyph_order
            self.glyph_index_map = {
                order[new_glyph_order[i]]: i for i in range(len(new_glyph_order))
            }

            log.info("Retaining %d glyphs", len(self.glyphs_retained))

            del self.glyphs

        def _subset_glyphs(self, font):
            self.used_mark_sets = []
            for tag in self._sort_tables(font):
                clazz = ttLib.getTableClass(tag)

                if tag.strip() in self.options.no_subset_tables:
                    log.info("%s subsetting not needed", tag)
                elif hasattr(clazz, "subset_glyphs"):
                    with timer("subset '%s'" % tag):
                        table = font[tag]
                        self.glyphs = self.glyphs_retained
                        retain = table.subset_glyphs(self)
                        del self.glyphs
                    if not retain:
                        log.info("%s subsetted to empty; dropped", tag)
                        del font[tag]
                    else:
                        log.info("%s subsetted", tag)
                elif self.options.passthrough_tables:
                    log.info("%s NOT subset; don't know how to subset", tag)
                else:
                    log.warning("%s NOT subset; don't know how to subset; dropped", tag)
                    del font[tag]

            with timer("subset GlyphOrder"):
                font.setGlyphOrder(self.new_glyph_order)

        def _prune_post_subset(self, font):
            tableTags = font.keys()
            # Prune the name table last because when we're pruning the name table,
            # we visit each table in the font to see what name table records are
            # still in use.
            if "name" in tableTags:
                tableTags.remove("name")
                tableTags.append("name")
            for tag in tableTags:
                if tag == "GlyphOrder":
                    continue
                if tag == "OS/2":
                    if self.options.prune_unicode_ranges:
                        old_uniranges = font[tag].getUnicodeRanges()
                        new_uniranges = font[tag].recalcUnicodeRanges(font, pruneOnly=True)
                        if old_uniranges != new_uniranges:
                            log.info(
                                "%s Unicode ranges pruned: %s", tag, sorted(new_uniranges)
                            )
                    if self.options.prune_codepage_ranges and font[tag].version >= 1:
                        # codepage range fields were added with OS/2 format 1
                        # https://learn.microsoft.com/en-us/typography/opentype/spec/os2#version-1
                        old_codepages = font[tag].getCodePageRanges()
                        new_codepages = font[tag].recalcCodePageRanges(font, pruneOnly=True)
                        if old_codepages != new_codepages:
                            log.info(
                                "%s CodePage ranges pruned: %s",
                                tag,
                                sorted(new_codepages),
                            )
                    if self.options.recalc_average_width:
                        old_avg_width = font[tag].xAvgCharWidth
                        new_avg_width = font[tag].recalcAvgCharWidth(font)
                        if old_avg_width != new_avg_width:
                            log.info("%s xAvgCharWidth updated: %d", tag, new_avg_width)
                    if self.options.recalc_max_context:
                        max_context = maxCtxFont(font)
                        if max_context != font[tag].usMaxContext:
                            font[tag].usMaxContext = max_context
                            log.info("%s usMaxContext updated: %d", tag, max_context)
                clazz = ttLib.getTableClass(tag)
                if hasattr(clazz, "prune_post_subset"):
                    with timer("prune '%s'" % tag):
                        table = font[tag]
                        retain = table.prune_post_subset(font, self.options)
                    if not retain:
                        log.info("%s pruned to empty; dropped", tag)
                        del font[tag]
                    else:
                        log.info("%s pruned", tag)

        def _sort_tables(self, font):
            tagOrder = ["GDEF", "GPOS", "GSUB", "fvar", "avar", "gvar", "name", "glyf"]
            tagOrder = {t: i + 1 for i, t in enumerate(tagOrder)}
            tags = sorted(font.keys(), key=lambda tag: tagOrder.get(tag, 0))
            return [t for t in tags if t != "GlyphOrder"]

        def subset(self, font):
            self._prune_pre_subset(font)
            self._closure_glyphs(font)
            self._subset_glyphs(font)
            self._prune_post_subset(font)

    @timer("load font")
    def load_font(fontFile, options, checkChecksums=0, dontLoadGlyphNames=False, lazy=True):
        font = ttLib.TTFont(
            fontFile,
            checkChecksums=checkChecksums,
            recalcBBoxes=options.recalc_bounds,
            recalcTimestamp=options.recalc_timestamp,
            lazy=lazy,
            fontNumber=options.font_number,
        )

        # Hack:
        #
        # If we don't need glyph names, change 'post' class to not try to
        # load them.	It avoid lots of headache with broken fonts as well
        # as loading time.
        #
        # Ideally ttLib should provide a way to ask it to skip loading
        # glyph names.	But it currently doesn't provide such a thing.
        #
        if dontLoadGlyphNames:
            post = ttLib.getTableClass("post")
            saved = post.decode_format_2_0
            post.decode_format_2_0 = post.decode_format_3_0
            f = font["post"]
            if f.formatType == 2.0:
                f.formatType = 3.0
            post.decode_format_2_0 = saved

        return font

    @timer("compile and save font")
    def save_font(font, outfile, options):
        if options.with_zopfli and options.flavor == "woff":
            from fontTools.ttLib import sfnt

            sfnt.USE_ZOPFLI = True
        font.flavor = options.flavor
        font.cfg[USE_HARFBUZZ_REPACKER] = options.harfbuzz_repacker
        font.save(outfile, reorderTables=options.canonical_order)

    def parse_unicodes(s):
        import re

        s = re.sub(r"0[xX]", " ", s)
        s = re.sub(r"[<+>,;&#\\xXuU\n	]", " ", s)
        l = []
        for item in s.split():
            fields = item.split("-")
            if len(fields) == 1:
                l.append(int(item, 16))
            else:
                start, end = fields
                l.extend(range(int(start, 16), int(end, 16) + 1))
        return l

    def parse_gids(s):
        l = []
        for item in s.replace(",", " ").split():
            fields = item.split("-")
            if len(fields) == 1:
                l.append(int(fields[0]))
            else:
                l.extend(range(int(fields[0]), int(fields[1]) + 1))
        return l

    def parse_glyphs(s):
        return s.replace(",", " ").split()

    def usage():
        print("usage:", __usage__, file=sys.stderr)
        print("Try fonttools subset --help for more information.\n", file=sys.stderr)

    @timer("make one with everything (TOTAL TIME)")
    def main(args=None):
        """OpenType font subsetter and optimizer"""
        from os.path import splitext
        from fontTools import configLogger

        if args is None:
            args = sys.argv[1:]

        if "--help" in args:
            print(__doc__)
            return 0

        options = Options()
        try:
            args = options.parse_opts(
                args,
                ignore_unknown=[
                    "gids",
                    "gids-file",
                    "glyphs",
                    "glyphs-file",
                    "text",
                    "text-file",
                    "unicodes",
                    "unicodes-file",
                    "output-file",
                ],
            )
        except options.OptionError as e:
            usage()
            print("ERROR:", e, file=sys.stderr)
            return 2

        if len(args) < 2:
            usage()
            return 1

        configLogger(level=logging.INFO if options.verbose else logging.WARNING)
        if options.timing:
            timer.logger.setLevel(logging.DEBUG)
        else:
            timer.logger.disabled = True

        fontfile = args[0]
        args = args[1:]

        subsetter = Subsetter(options=options)
        outfile = None
        glyphs = []
        gids = []
        unicodes = []
        wildcard_glyphs = False
        wildcard_unicodes = False
        text = ""
        for g in args:
            if g == "*":
                wildcard_glyphs = True
                continue
            if g.startswith("--output-file="):
                outfile = g[14:]
                continue
            if g.startswith("--text="):
                text += g[7:]
                continue
            if g.startswith("--text-file="):
                with open(g[12:], encoding="utf-8-sig") as f:
                    text += f.read().replace("\n", "")
                continue
            if g.startswith("--unicodes="):
                if g[11:] == "*":
                    wildcard_unicodes = True
                else:
                    unicodes.extend(parse_unicodes(g[11:]))
                continue
            if g.startswith("--unicodes-file="):
                with open(g[16:]) as f:
                    for line in f.readlines():
                        unicodes.extend(parse_unicodes(line.split("#")[0]))
                continue
            if g.startswith("--gids="):
                gids.extend(parse_gids(g[7:]))
                continue
            if g.startswith("--gids-file="):
                with open(g[12:]) as f:
                    for line in f.readlines():
                        gids.extend(parse_gids(line.split("#")[0]))
                continue
            if g.startswith("--glyphs="):
                if g[9:] == "*":
                    wildcard_glyphs = True
                else:
                    glyphs.extend(parse_glyphs(g[9:]))
                continue
            if g.startswith("--glyphs-file="):
                with open(g[14:]) as f:
                    for line in f.readlines():
                        glyphs.extend(parse_glyphs(line.split("#")[0]))
                continue
            glyphs.append(g)

        dontLoadGlyphNames = not options.glyph_names and not glyphs
        lazy = options.lazy
        font = load_font(
            fontfile, options, dontLoadGlyphNames=dontLoadGlyphNames, lazy=lazy
        )

        if outfile is None:
            ext = "." + options.flavor.lower() if options.flavor is not None else None
            outfile = makeOutputFileName(
                fontfile, extension=ext, overWrite=True, suffix=".subset"
            )

        with timer("compile glyph list"):
            if wildcard_glyphs:
                glyphs.extend(font.getGlyphOrder())
            if wildcard_unicodes:
                for t in font["cmap"].tables:
                    if t.isUnicode():
                        unicodes.extend(t.cmap.keys())
                        if t.format == 14:
                            unicodes.extend(t.uvsDict.keys())
            assert "" not in glyphs

        log.info("Text: '%s'" % text)
        log.info("Unicodes: %s", unicodes)
        log.info("Glyphs: %s", glyphs)
        log.info("Gids: %s", gids)

        subsetter.populate(glyphs=glyphs, gids=gids, unicodes=unicodes, text=text)
        subsetter.subset(font)

        save_font(font, outfile, options)

        if options.verbose:
            import os

            log.info("Input font:% 7d bytes: %s" % (os.path.getsize(fontfile), fontfile))
            log.info("Subset font:% 7d bytes: %s" % (os.path.getsize(outfile), outfile))

        if options.xml:
            font.saveXML(sys.stdout)

        font.close()

    __all__ = [
        "Options",
        "Subsetter",
        "load_font",
        "save_font",
        "parse_gids",
        "parse_glyphs",
        "parse_unicodes",
        "main",
    ]