index : qt/qtbase.git	5.10 5.11 5.12 5.12.5 5.12.7 5.13 5.14 5.15 5.3 5.4 5.5 5.6 5.7 5.8 5.9 6.0 6.1 6.2 6.2.0 6.2.4 6.3 6.4 6.4.0 6.4.1 6.4.2 6.4.3 6.5 6.5.0 6.5.1 6.5.2 6.5.3 6.6 6.6.0 6.6.1 6.6.2 6.6.3 6.7 6.7.0 6.7.1 dev old/5.0 old/5.1 old/5.2 wip/cmake wip/highdpi wip/lite wip/mir wip/nacl wip/network-test-server wip/remac wip/tizen wip/webassembly
	Qt Base (Core, Gui, Widgets, Network, ...)

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path: root/tests/auto/widgets/graphicsview

	Commit message (Expand)	Author	Age	Files	Lines
*	Fix spurious XPASS in tst_QGraphicsAnchorLayout.	Friedemann Kleint	2014-03-14	1	-12/+19
*	expand tabs and related whitespace fixes in *.{cpp,h,qdoc}	Oswald Buddenhagen	2014-01-13	3	-21/+21
*	Merge remote-tracking branch 'origin/stable' into dev	Frederik Gladhorn	2013-12-16	1	-0/+1
|\
| *	Stabilize tst_QGraphicsItem	Marc Mutz	2013-12-03	1	-0/+1
* |	Add proper abstractions to the grid layout engine.	Jan Arve Saether	2013-12-05	1	-2/+0
* |	Add test for default (style dependent) spacings	Jan Arve Saether	2013-11-28	1	-0/+94
* |	Merge remote-tracking branch 'origin/stable' into dev	Frederik Gladhorn	2013-11-26	4	-9/+28
|\|
| *	Stabilize tst_QGraphicsWidget::updateFocusChainWhenChildDie().	Friedemann Kleint	2013-11-20	1	-2/+10
| *	Stabilize tst_QGraphicsView::hoverLeave().	Friedemann Kleint	2013-11-20	1	-6/+8
| *	Stabilize tst_QGraphicsScene::isActive().	Friedemann Kleint	2013-11-20	1	-1/+4
| *	Skip tst_QGraphicsItem::ensureUpdateOnTextItem() on OSX 10.7	Gunnar Sletta	2013-11-14	1	-0/+6
* |	Merge remote-tracking branch 'origin/stable' into dev	Frederik Gladhorn	2013-10-24	1	-0/+4
|\|
| *	Skip tst_QGraphicsItem::paint() on Mac OS X 10.7	Simo Fält	2013-10-15	1	-0/+4
* |	WinRT: Fix various test compilations	Andrew Knight	2013-10-02	4	-4/+4
|/
*	Merge remote-tracking branch 'origin/stable' into dev	Sergio Ahumada	2013-09-07	1	-5/+109
|\
| *	Forward QGraphicsView::mouseDoubleClickEvent	Marcel Krems	2013-09-06	1	-5/+109
* |	Skip tst_QGraphicsProxyWidget::popup_subwidget on Windows.	Friedemann Kleint	2013-09-03	1	-0/+3
* |	Merge "Merge remote-tracking branch 'origin/stable' into dev" into refs/stagi...	Thiago Macieira	2013-08-22	1	-4/+7
|\ \
| * |	Merge remote-tracking branch 'origin/stable' into dev	Frederik Gladhorn	2013-08-21	1	-4/+7
| |\|
| | *	Fix QGraphics(Ellipse)Item autotest	Giuseppe D'Angelo	2013-08-19	1	-4/+7
* | |	tst_qgraphicsproxywidget: fix memory leak	David Faure	2013-08-21	1	-0/+5
|/ /
* |	Skip tst_QGraphicsProxyWidget::deleteProxyForChildWidget on Win	Frederik Gladhorn	2013-08-20	1	-0/+4
* |	tst_qgraphicsproxywidget: skip crashing test on Mac/Windows.	David Faure	2013-08-20	1	-0/+3
* |	Merge remote-tracking branch 'origin/stable' into dev	Frederik Gladhorn	2013-08-14	1	-0/+61
|\|
| *	Fix double transform for items ignoring parent transformations.	Andreas Aardal Hanssen	2013-08-05	1	-0/+61
* |	Re-enable tests tst_qgraphicsproxywidget, tst_qgraphicswidget.	Friedemann Kleint	2013-07-24	1	-2/+2
* |	Merge remote-tracking branch 'origin/stable' into dev	Frederik Gladhorn	2013-07-23	1	-0/+52
|\|
| *	Make *ItemBoundingRect modes work with custom shapes.	Mitch Curtis	2013-07-16	1	-0/+52
* |	Merge remote-tracking branch 'origin/stable' into dev	Frederik Gladhorn	2013-06-04	1	-0/+12
|\|
| *	Made sure items with preferred width of 0 could also stretch	Jan Arve Saether	2013-05-27	1	-0/+12
* |	widget/graphicsview: Do not run tests showing windows in parallel.	Friedemann Kleint	2013-06-03	5	-6/+0
* |	Remove XFAIL from tst_qgraphicswidget::initialShow2().	Friedemann Kleint	2013-05-27	2	-4/+0
* |	Merge remote-tracking branch 'origin/stable' into dev	Frederik Gladhorn	2013-05-23	4	-17/+61
|\|
| *	Stabilize tst_qgraphicssceneindex.	Friedemann Kleint	2013-05-23	1	-1/+1
| *	QGV: fix items not to be selected on right mouse button release	J-P Nurmi	2013-05-14	1	-0/+28
| *	Stabilize QGraphicsWidget test.	Friedemann Kleint	2013-05-09	1	-15/+12
| *	Fix tabFocusFirst when that item is removed from QGraphicsScene	Miikka Heikkinen	2013-05-08	1	-0/+18
| *	Add QSKIP to hoverenter-test in tst_qgraphicsproxywidget.	Friedemann Kleint	2013-05-07	1	-0/+1
| *	Fix XPASS in tst_qgraphicswidget (Windows).	Friedemann Kleint	2013-05-07	1	-1/+1
* |	Merge remote-tracking branch 'origin/stable' into dev	Frederik Gladhorn	2013-04-22	1	-1/+1
|\|
| *	Fix qgraphicsview autotest build for WEC7.	Janne Anttila	2013-04-17	1	-1/+1
* |	Fixed a bug where the MaximumSizeHint of a layout with spans was wrong	Jan Arve Saether	2013-04-04	1	-5/+5
* |	Fixed a bug where spans across empty cells got broken.	Jan Arve Saether	2013-04-03	1	-0/+28
|/
*	QtWidgets tests: Remove DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0	Debao Zhang	2013-03-28	12	-12/+0
*	QtWidgets tests: Replace qFindChild{ren} with QObject::findChild{ren}	Debao Zhang	2013-03-27	2	-2/+2
*	QtWidgets tests: Don't use the deprecated QTest::qWaitForWindowShown()	Debao Zhang	2013-03-27	1	-1/+1
*	tst_qgraphicseffectsource: Don't use the deprecated QGraphicsItem::children()	Debao Zhang	2013-03-27	2	-21/+21
*	Whitespace cleanup: remove trailing whitespace	Axel Waggershauser	2013-03-16	1	-1/+1
*	Fix warnings about overloaded virtuals in tests (CLANG).	Friedemann Kleint	2013-03-12	1	-2/+2
*	Merge remote-tracking branch 'origin/stable' into dev	Frederik Gladhorn	2013-01-24	1	-0/+57
|\

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generated by cgit v1.2.3 (git 2.25.1) at 2024-05-06 21:54:07 +0000

/*
 * Copyright © 2007,2008,2009  Red Hat, Inc.
 * Copyright © 2010,2012  Google, Inc.
 *
 *  This is part of HarfBuzz, a text shaping library.
 *
 * Permission is hereby granted, without written agreement and without
 * license or royalty fees, to use, copy, modify, and distribute this
 * software and its documentation for any purpose, provided that the
 * above copyright notice and the following two paragraphs appear in
 * all copies of this software.
 *
 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
 * DAMAGE.
 *
 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
 * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
 *
 * Red Hat Author(s): Behdad Esfahbod
 * Google Author(s): Behdad Esfahbod
 */

#ifndef HB_OT_LAYOUT_COMMON_HH
#define HB_OT_LAYOUT_COMMON_HH

#include "hb.hh"
#include "hb-ot-layout.hh"
#include "hb-open-type.hh"
#include "hb-set.hh"
#include "hb-bimap.hh"

#include "OT/Layout/Common/Coverage.hh"
#include "OT/Layout/types.hh"

// TODO(garretrieger): cleanup these after migration.
using OT::Layout::Common::Coverage;
using OT::Layout::Common::RangeRecord;
using OT::Layout::SmallTypes;
using OT::Layout::MediumTypes;


namespace OT {

template<typename Iterator>
static inline bool ClassDef_serialize (hb_serialize_context_t *c,
				       Iterator it);

static bool ClassDef_remap_and_serialize (
    hb_serialize_context_t *c,
    const hb_set_t &klasses,
    bool use_class_zero,
    hb_sorted_vector_t<hb_codepoint_pair_t> &glyph_and_klass, /* IN/OUT */
    hb_map_t *klass_map /*IN/OUT*/);

struct hb_collect_feature_substitutes_with_var_context_t
{
  const hb_map_t *axes_index_tag_map;
  const hb_hashmap_t<hb_tag_t, Triple> *axes_location;
  hb_hashmap_t<unsigned, hb::shared_ptr<hb_set_t>> *record_cond_idx_map;
  hb_hashmap_t<unsigned, const Feature*> *feature_substitutes_map;
  bool& insert_catch_all_feature_variation_record;

  // not stored in subset_plan
  hb_set_t *feature_indices;
  bool apply;
  bool variation_applied;
  bool universal;
  unsigned cur_record_idx;
  hb_hashmap_t<hb::shared_ptr<hb_map_t>, unsigned> *conditionset_map;
};

struct hb_prune_langsys_context_t
{
  hb_prune_langsys_context_t (const void         *table_,
                              hb_hashmap_t<unsigned, hb::unique_ptr<hb_set_t>> *script_langsys_map_,
                              const hb_map_t     *duplicate_feature_map_,
                              hb_set_t           *new_collected_feature_indexes_)
      :table (table_),
      script_langsys_map (script_langsys_map_),
      duplicate_feature_map (duplicate_feature_map_),
      new_feature_indexes (new_collected_feature_indexes_),
      script_count (0),langsys_feature_count (0) {}

  bool visitScript ()
  { return script_count++ < HB_MAX_SCRIPTS; }

  bool visitLangsys (unsigned feature_count)
  {
    langsys_feature_count += feature_count;
    return langsys_feature_count < HB_MAX_LANGSYS_FEATURE_COUNT;
  }

  public:
  const void *table;
  hb_hashmap_t<unsigned, hb::unique_ptr<hb_set_t>> *script_langsys_map;
  const hb_map_t     *duplicate_feature_map;
  hb_set_t           *new_feature_indexes;

  private:
  unsigned script_count;
  unsigned langsys_feature_count;
};

struct hb_subset_layout_context_t :
  hb_dispatch_context_t<hb_subset_layout_context_t, hb_empty_t, HB_DEBUG_SUBSET>
{
  const char *get_name () { return "SUBSET_LAYOUT"; }
  static return_t default_return_value () { return hb_empty_t (); }

  bool visitScript ()
  {
    return script_count++ < HB_MAX_SCRIPTS;
  }

  bool visitLangSys ()
  {
    return langsys_count++ < HB_MAX_LANGSYS;
  }

  bool visitFeatureIndex (int count)
  {
    feature_index_count += count;
    return feature_index_count < HB_MAX_FEATURE_INDICES;
  }

  bool visitLookupIndex()
  {
    lookup_index_count++;
    return lookup_index_count < HB_MAX_LOOKUP_VISIT_COUNT;
  }

  hb_subset_context_t *subset_context;
  const hb_tag_t table_tag;
  const hb_map_t *lookup_index_map;
  const hb_hashmap_t<unsigned, hb::unique_ptr<hb_set_t>> *script_langsys_map;
  const hb_map_t *feature_index_map;
  const hb_hashmap_t<unsigned, const Feature*> *feature_substitutes_map;
  hb_hashmap_t<unsigned, hb::shared_ptr<hb_set_t>> *feature_record_cond_idx_map;

  unsigned cur_script_index;
  unsigned cur_feature_var_record_idx;

  hb_subset_layout_context_t (hb_subset_context_t *c_,
			      hb_tag_t tag_) :
				subset_context (c_),
				table_tag (tag_),
				cur_script_index (0xFFFFu),
				cur_feature_var_record_idx (0u),
				script_count (0),
				langsys_count (0),
				feature_index_count (0),
				lookup_index_count (0)
  {
    if (tag_ == HB_OT_TAG_GSUB)
    {
      lookup_index_map = &c_->plan->gsub_lookups;
      script_langsys_map = &c_->plan->gsub_langsys;
      feature_index_map = &c_->plan->gsub_features;
      feature_substitutes_map = &c_->plan->gsub_feature_substitutes_map;
      feature_record_cond_idx_map = c_->plan->user_axes_location.is_empty () ? nullptr : &c_->plan->gsub_feature_record_cond_idx_map;
    }
    else
    {
      lookup_index_map = &c_->plan->gpos_lookups;
      script_langsys_map = &c_->plan->gpos_langsys;
      feature_index_map = &c_->plan->gpos_features;
      feature_substitutes_map = &c_->plan->gpos_feature_substitutes_map;
      feature_record_cond_idx_map = c_->plan->user_axes_location.is_empty () ? nullptr : &c_->plan->gpos_feature_record_cond_idx_map;
    }
  }

  private:
  unsigned script_count;
  unsigned langsys_count;
  unsigned feature_index_count;
  unsigned lookup_index_count;
};

struct VariationStore;
struct hb_collect_variation_indices_context_t :
       hb_dispatch_context_t<hb_collect_variation_indices_context_t>
{
  template <typename T>
  return_t dispatch (const T &obj) { obj.collect_variation_indices (this); return hb_empty_t (); }
  static return_t default_return_value () { return hb_empty_t (); }

  hb_set_t *layout_variation_indices;
  const hb_set_t *glyph_set;
  const hb_map_t *gpos_lookups;

  hb_collect_variation_indices_context_t (hb_set_t *layout_variation_indices_,
					  const hb_set_t *glyph_set_,
					  const hb_map_t *gpos_lookups_) :
					layout_variation_indices (layout_variation_indices_),
					glyph_set (glyph_set_),
					gpos_lookups (gpos_lookups_) {}
};

template<typename OutputArray>
struct subset_offset_array_t
{
  subset_offset_array_t (hb_subset_context_t *subset_context_,
			 OutputArray& out_,
			 const void *base_) : subset_context (subset_context_),
					      out (out_), base (base_) {}

  template <typename T>
  bool operator () (T&& offset)
  {
    auto snap = subset_context->serializer->snapshot ();
    auto *o = out.serialize_append (subset_context->serializer);
    if (unlikely (!o)) return false;
    bool ret = o->serialize_subset (subset_context, offset, base);
    if (!ret)
    {
      out.pop ();
      subset_context->serializer->revert (snap);
    }
    return ret;
  }

  private:
  hb_subset_context_t *subset_context;
  OutputArray &out;
  const void *base;
};


template<typename OutputArray, typename Arg>
struct subset_offset_array_arg_t
{
  subset_offset_array_arg_t (hb_subset_context_t *subset_context_,
			     OutputArray& out_,
			     const void *base_,
			     Arg &&arg_) : subset_context (subset_context_), out (out_),
					  base (base_), arg (arg_) {}

  template <typename T>
  bool operator () (T&& offset)
  {
    auto snap = subset_context->serializer->snapshot ();
    auto *o = out.serialize_append (subset_context->serializer);
    if (unlikely (!o)) return false;
    bool ret = o->serialize_subset (subset_context, offset, base, arg);
    if (!ret)
    {
      out.pop ();
      subset_context->serializer->revert (snap);
    }
    return ret;
  }

  private:
  hb_subset_context_t *subset_context;
  OutputArray &out;
  const void *base;
  Arg &&arg;
};

/*
 * Helper to subset an array of offsets. Subsets the thing pointed to by each offset
 * and discards the offset in the array if the subset operation results in an empty
 * thing.
 */
struct
{
  template<typename OutputArray>
  subset_offset_array_t<OutputArray>
  operator () (hb_subset_context_t *subset_context, OutputArray& out,
	       const void *base) const
  { return subset_offset_array_t<OutputArray> (subset_context, out, base); }

  /* Variant with one extra argument passed to serialize_subset */
  template<typename OutputArray, typename Arg>
  subset_offset_array_arg_t<OutputArray, Arg>
  operator () (hb_subset_context_t *subset_context, OutputArray& out,
	       const void *base, Arg &&arg) const
  { return subset_offset_array_arg_t<OutputArray, Arg> (subset_context, out, base, arg); }
}
HB_FUNCOBJ (subset_offset_array);

template<typename OutputArray>
struct subset_record_array_t
{
  subset_record_array_t (hb_subset_layout_context_t *c_, OutputArray* out_,
			 const void *base_) : subset_layout_context (c_),
					      out (out_), base (base_) {}

  template <typename T>
  void
  operator () (T&& record)
  {
    auto snap = subset_layout_context->subset_context->serializer->snapshot ();
    bool ret = record.subset (subset_layout_context, base);
    if (!ret) subset_layout_context->subset_context->serializer->revert (snap);
    else out->len++;
  }

  private:
  hb_subset_layout_context_t *subset_layout_context;
  OutputArray *out;
  const void *base;
};

template<typename OutputArray, typename Arg>
struct subset_record_array_arg_t
{
  subset_record_array_arg_t (hb_subset_layout_context_t *c_, OutputArray* out_,
			     const void *base_,
			     Arg &&arg_) : subset_layout_context (c_),
					   out (out_), base (base_), arg (arg_) {}

  template <typename T>
  void
  operator () (T&& record)
  {
    auto snap = subset_layout_context->subset_context->serializer->snapshot ();
    bool ret = record.subset (subset_layout_context, base, arg);
    if (!ret) subset_layout_context->subset_context->serializer->revert (snap);
    else out->len++;
  }

  private:
  hb_subset_layout_context_t *subset_layout_context;
  OutputArray *out;
  const void *base;
  Arg &&arg;
};

/*
 * Helper to subset a RecordList/record array. Subsets each Record in the array and
 * discards the record if the subset operation returns false.
 */
struct
{
  template<typename OutputArray>
  subset_record_array_t<OutputArray>
  operator () (hb_subset_layout_context_t *c, OutputArray* out,
	       const void *base) const
  { return subset_record_array_t<OutputArray> (c, out, base); }

  /* Variant with one extra argument passed to subset */
  template<typename OutputArray, typename Arg>
  subset_record_array_arg_t<OutputArray, Arg>
  operator () (hb_subset_layout_context_t *c, OutputArray* out,
               const void *base, Arg &&arg) const
  { return subset_record_array_arg_t<OutputArray, Arg> (c, out, base, arg); }
}
HB_FUNCOBJ (subset_record_array);


template<typename OutputArray>
struct serialize_math_record_array_t
{
  serialize_math_record_array_t (hb_serialize_context_t *serialize_context_,
                         OutputArray& out_,
                         const void *base_) : serialize_context (serialize_context_),
                                              out (out_), base (base_) {}

  template <typename T>
  bool operator () (T&& record)
  {
    if (!serialize_context->copy (record, base)) return false;
    out.len++;
    return true;
  }

  private:
  hb_serialize_context_t *serialize_context;
  OutputArray &out;
  const void *base;
};

/*
 * Helper to serialize an array of MATH records.
 */
struct
{
  template<typename OutputArray>
  serialize_math_record_array_t<OutputArray>
  operator () (hb_serialize_context_t *serialize_context, OutputArray& out,
               const void *base) const
  { return serialize_math_record_array_t<OutputArray> (serialize_context, out, base); }

}
HB_FUNCOBJ (serialize_math_record_array);

/*
 *
 * OpenType Layout Common Table Formats
 *
 */


/*
 * Script, ScriptList, LangSys, Feature, FeatureList, Lookup, LookupList
 */

struct IndexArray : Array16Of<Index>
{
  bool intersects (const hb_map_t *indexes) const
  { return hb_any (*this, indexes); }

  template <typename Iterator,
	    hb_requires (hb_is_iterator (Iterator))>
  void serialize (hb_serialize_context_t *c,
		  hb_subset_layout_context_t *l,
		  Iterator it)
  {
    if (!it) return;
    if (unlikely (!c->extend_min ((*this)))) return;

    for (const auto _ : it)
    {
      if (!l->visitLookupIndex()) break;

      Index i;
      i = _;
      c->copy (i);
      this->len++;
    }
  }

  unsigned int get_indexes (unsigned int start_offset,
			    unsigned int *_count /* IN/OUT */,
			    unsigned int *_indexes /* OUT */) const
  {
    if (_count)
    {
      + this->as_array ().sub_array (start_offset, _count)
      | hb_sink (hb_array (_indexes, *_count))
      ;
    }
    return this->len;
  }

  void add_indexes_to (hb_set_t* output /* OUT */) const
  {
    output->add_array (as_array ());
  }
};


/* https://docs.microsoft.com/en-us/typography/opentype/spec/features_pt#size */
struct FeatureParamsSize
{
  bool sanitize (hb_sanitize_context_t *c) const
  {
    TRACE_SANITIZE (this);
    if (unlikely (!c->check_struct (this))) return_trace (false);

    /* This subtable has some "history", if you will.  Some earlier versions of
     * Adobe tools calculated the offset of the FeatureParams subtable from the
     * beginning of the FeatureList table!  Now, that is dealt with in the
     * Feature implementation.  But we still need to be able to tell junk from
     * real data.  Note: We don't check that the nameID actually exists.
     *
     * Read Roberts wrote on 9/15/06 on opentype-list@indx.co.uk :
     *
     * Yes, it is correct that a new version of the AFDKO (version 2.0) will be
     * coming out soon, and that the makeotf program will build a font with a
     * 'size' feature that is correct by the specification.
     *
     * The specification for this feature tag is in the "OpenType Layout Tag
     * Registry". You can see a copy of this at:
     * https://docs.microsoft.com/en-us/typography/opentype/spec/features_pt#tag-size
     *
     * Here is one set of rules to determine if the 'size' feature is built
     * correctly, or as by the older versions of MakeOTF. You may be able to do
     * better.
     *
     * Assume that the offset to the size feature is according to specification,
     * and make the following value checks. If it fails, assume the size
     * feature is calculated as versions of MakeOTF before the AFDKO 2.0 built it.
     * If this fails, reject the 'size' feature. The older makeOTF's calculated the
     * offset from the beginning of the FeatureList table, rather than from the
     * beginning of the 'size' Feature table.
     *
     * If "design size" == 0:
     *     fails check
     *
     * Else if ("subfamily identifier" == 0 and
     *     "range start" == 0 and
     *     "range end" == 0 and
     *     "range start" == 0 and
     *     "menu name ID" == 0)
     *     passes check: this is the format used when there is a design size
     * specified, but there is no recommended size range.
     *
     * Else if ("design size" <  "range start" or
     *     "design size" >   "range end" or
     *     "range end" <= "range start" or
     *     "menu name ID"  < 256 or
     *     "menu name ID"  > 32767 or
     *     menu name ID is not a name ID which is actually in the name table)
     *     fails test
     * Else
     *     passes test.
     */

    if (!designSize)
      return_trace (false);
    else if (subfamilyID == 0 &&
	     subfamilyNameID == 0 &&
	     rangeStart == 0 &&
	     rangeEnd == 0)
      return_trace (true);
    else if (designSize < rangeStart ||
	     designSize > rangeEnd ||
	     subfamilyNameID < 256 ||
	     subfamilyNameID > 32767)
      return_trace (false);
    else
      return_trace (true);
  }

  void collect_name_ids (hb_set_t *nameids_to_retain /* OUT */) const
  { nameids_to_retain->add (subfamilyNameID); }

  bool subset (hb_subset_context_t *c) const
  {
    TRACE_SUBSET (this);
    return_trace ((bool) c->serializer->embed (*this));
  }

  HBUINT16	designSize;	/* Represents the design size in 720/inch
				 * units (decipoints).  The design size entry
				 * must be non-zero.  When there is a design
				 * size but no recommended size range, the
				 * rest of the array will consist of zeros. */
  HBUINT16	subfamilyID;	/* Has no independent meaning, but serves
				 * as an identifier that associates fonts
				 * in a subfamily. All fonts which share a
				 * Preferred or Font Family name and which
				 * differ only by size range shall have the
				 * same subfamily value, and no fonts which
				 * differ in weight or style shall have the
				 * same subfamily value. If this value is
				 * zero, the remaining fields in the array
				 * will be ignored. */
  NameID	subfamilyNameID;/* If the preceding value is non-zero, this
				 * value must be set in the range 256 - 32767
				 * (inclusive). It records the value of a
				 * field in the name table, which must
				 * contain English-language strings encoded
				 * in Windows Unicode and Macintosh Roman,
				 * and may contain additional strings
				 * localized to other scripts and languages.
				 * Each of these strings is the name an
				 * application should use, in combination
				 * with the family name, to represent the
				 * subfamily in a menu.  Applications will
				 * choose the appropriate version based on
				 * their selection criteria. */
  HBUINT16	rangeStart;	/* Large end of the recommended usage range
				 * (inclusive), stored in 720/inch units
				 * (decipoints). */
  HBUINT16	rangeEnd;	/* Small end of the recommended usage range
				   (exclusive), stored in 720/inch units
				 * (decipoints). */
  public:
  DEFINE_SIZE_STATIC (10);
};

/* https://docs.microsoft.com/en-us/typography/opentype/spec/features_pt#ssxx */
struct FeatureParamsStylisticSet
{
  bool sanitize (hb_sanitize_context_t *c) const
  {
    TRACE_SANITIZE (this);
    /* Right now minorVersion is at zero.  Which means, any table supports
     * the uiNameID field. */
    return_trace (c->check_struct (this));
  }

  void collect_name_ids (hb_set_t *nameids_to_retain /* OUT */) const
  { nameids_to_retain->add (uiNameID); }

  bool subset (hb_subset_context_t *c) const
  {
    TRACE_SUBSET (this);
    return_trace ((bool) c->serializer->embed (*this));
  }

  HBUINT16	version;	/* (set to 0): This corresponds to a “minor”
				 * version number. Additional data may be
				 * added to the end of this Feature Parameters
				 * table in the future. */

  NameID	uiNameID;	/* The 'name' table name ID that specifies a
				 * string (or strings, for multiple languages)
				 * for a user-interface label for this
				 * feature.  The values of uiLabelNameId and
				 * sampleTextNameId are expected to be in the
				 * font-specific name ID range (256-32767),
				 * though that is not a requirement in this
				 * Feature Parameters specification. The
				 * user-interface label for the feature can
				 * be provided in multiple languages. An
				 * English string should be included as a
				 * fallback. The string should be kept to a
				 * minimal length to fit comfortably with
				 * different application interfaces. */
  public:
  DEFINE_SIZE_STATIC (4);
};

/* https://docs.microsoft.com/en-us/typography/opentype/spec/features_ae#cv01-cv99 */
struct FeatureParamsCharacterVariants
{
  unsigned
  get_characters (unsigned start_offset, unsigned *char_count, hb_codepoint_t *chars) const
  {
    if (char_count)
    {
      + characters.as_array ().sub_array (start_offset, char_count)
      | hb_sink (hb_array (chars, *char_count))
      ;
    }
    return characters.len;
  }

  unsigned get_size () const
  { return min_size + characters.len * HBUINT24::static_size; }

  void collect_name_ids (hb_set_t *nameids_to_retain /* OUT */) const
  {
    if (featUILableNameID) nameids_to_retain->add (featUILableNameID);
    if (featUITooltipTextNameID) nameids_to_retain->add (featUITooltipTextNameID);
    if (sampleTextNameID) nameids_to_retain->add (sampleTextNameID);

    if (!firstParamUILabelNameID || !numNamedParameters || numNamedParameters >= 0x7FFF)
      return;

    unsigned last_name_id = (unsigned) firstParamUILabelNameID + (unsigned) numNamedParameters - 1;
    if (last_name_id >= 256 && last_name_id <= 32767)
      nameids_to_retain->add_range (firstParamUILabelNameID, last_name_id);
  }

  bool subset (hb_subset_context_t *c) const
  {
    TRACE_SUBSET (this);
    return_trace ((bool) c->serializer->embed (*this));
  }

  bool sanitize (hb_sanitize_context_t *c) const
  {
    TRACE_SANITIZE (this);
    return_trace (c->check_struct (this) &&
		  characters.sanitize (c));
  }

  HBUINT16	format;			/* Format number is set to 0. */
  NameID	featUILableNameID;	/* The ‘name’ table name ID that
					 * specifies a string (or strings,
					 * for multiple languages) for a
					 * user-interface label for this
					 * feature. (May be NULL.) */
  NameID	featUITooltipTextNameID;/* The ‘name’ table name ID that
					 * specifies a string (or strings,
					 * for multiple languages) that an
					 * application can use for tooltip
					 * text for this feature. (May be
					 * nullptr.) */
  NameID	sampleTextNameID;	/* The ‘name’ table name ID that
					 * specifies sample text that
					 * illustrates the effect of this
					 * feature. (May be NULL.) */
  HBUINT16	numNamedParameters;	/* Number of named parameters. (May
					 * be zero.) */
  NameID	firstParamUILabelNameID;/* The first ‘name’ table name ID
					 * used to specify strings for
					 * user-interface labels for the
					 * feature parameters. (Must be zero
					 * if numParameters is zero.) */
  Array16Of<HBUINT24>
		characters;		/* Array of the Unicode Scalar Value
					 * of the characters for which this
					 * feature provides glyph variants.
					 * (May be zero.) */
  public:
  DEFINE_SIZE_ARRAY (14, characters);
};

struct FeatureParams
{
  bool sanitize (hb_sanitize_context_t *c, hb_tag_t tag) const
  {
#ifdef HB_NO_LAYOUT_FEATURE_PARAMS
    return true;
#endif
    TRACE_SANITIZE (this);
    if (tag == HB_TAG ('s','i','z','e'))
      return_trace (u.size.sanitize (c));
    if ((tag & 0xFFFF0000u) == HB_TAG ('s','s','\0','\0')) /* ssXX */
      return_trace (u.stylisticSet.sanitize (c));
    if ((tag & 0xFFFF0000u) == HB_TAG ('c','v','\0','\0')) /* cvXX */
      return_trace (u.characterVariants.sanitize (c));
    return_trace (true);
  }

  void collect_name_ids (hb_tag_t tag, hb_set_t *nameids_to_retain /* OUT */) const
  {
#ifdef HB_NO_LAYOUT_FEATURE_PARAMS
    return;
#endif
    if (tag == HB_TAG ('s','i','z','e'))
      return (u.size.collect_name_ids (nameids_to_retain));
    if ((tag & 0xFFFF0000u) == HB_TAG ('s','s','\0','\0')) /* ssXX */
      return (u.stylisticSet.collect_name_ids (nameids_to_retain));
    if ((tag & 0xFFFF0000u) == HB_TAG ('c','v','\0','\0')) /* cvXX */
      return (u.characterVariants.collect_name_ids (nameids_to_retain));
  }

  bool subset (hb_subset_context_t *c, const Tag* tag) const
  {
    TRACE_SUBSET (this);
    if (!tag) return_trace (false);
    if (*tag == HB_TAG ('s','i','z','e'))
      return_trace (u.size.subset (c));
    if ((*tag & 0xFFFF0000u) == HB_TAG ('s','s','\0','\0')) /* ssXX */
      return_trace (u.stylisticSet.subset (c));
    if ((*tag & 0xFFFF0000u) == HB_TAG ('c','v','\0','\0')) /* cvXX */
      return_trace (u.characterVariants.subset (c));
    return_trace (false);
  }

#ifndef HB_NO_LAYOUT_FEATURE_PARAMS
  const FeatureParamsSize& get_size_params (hb_tag_t tag) const
  {
    if (tag == HB_TAG ('s','i','z','e'))
      return u.size;
    return Null (FeatureParamsSize);
  }
  const FeatureParamsStylisticSet& get_stylistic_set_params (hb_tag_t tag) const
  {
    if ((tag & 0xFFFF0000u) == HB_TAG ('s','s','\0','\0')) /* ssXX */
      return u.stylisticSet;
    return Null (FeatureParamsStylisticSet);
  }
  const FeatureParamsCharacterVariants& get_character_variants_params (hb_tag_t tag) const
  {
    if ((tag & 0xFFFF0000u) == HB_TAG ('c','v','\0','\0')) /* cvXX */
      return u.characterVariants;
    return Null (FeatureParamsCharacterVariants);
  }
#endif

  private:
  union {
  FeatureParamsSize			size;
  FeatureParamsStylisticSet		stylisticSet;
  FeatureParamsCharacterVariants	characterVariants;
  } u;
  public:
  DEFINE_SIZE_MIN (0);
};

struct Record_sanitize_closure_t {
  hb_tag_t tag;
  const void *list_base;
};

struct Feature
{
  unsigned int get_lookup_count () const
  { return lookupIndex.len; }
  hb_tag_t get_lookup_index (unsigned int i) const
  { return lookupIndex[i]; }
  unsigned int get_lookup_indexes (unsigned int start_index,
				   unsigned int *lookup_count /* IN/OUT */,
				   unsigned int *lookup_tags /* OUT */) const
  { return lookupIndex.get_indexes (start_index, lookup_count, lookup_tags); }
  void add_lookup_indexes_to (hb_set_t *lookup_indexes) const
  { lookupIndex.add_indexes_to (lookup_indexes); }

  const FeatureParams &get_feature_params () const
  { return this+featureParams; }

  bool intersects_lookup_indexes (const hb_map_t *lookup_indexes) const
  { return lookupIndex.intersects (lookup_indexes); }

  void collect_name_ids (hb_tag_t tag, hb_set_t *nameids_to_retain /* OUT */) const
  {
    if (featureParams)
      get_feature_params ().collect_name_ids (tag, nameids_to_retain);
  }

  bool subset (hb_subset_context_t         *c,
	       hb_subset_layout_context_t  *l,
	       const Tag                   *tag = nullptr) const
  {
    TRACE_SUBSET (this);
    auto *out = c->serializer->start_embed (*this);
    if (unlikely (!c->serializer->extend_min (out))) return_trace (false);

    out->featureParams.serialize_subset (c, featureParams, this, tag);

    auto it =
    + hb_iter (lookupIndex)
    | hb_filter (l->lookup_index_map)
    | hb_map (l->lookup_index_map)
    ;

    out->lookupIndex.serialize (c->serializer, l, it);
    // The decision to keep or drop this feature is already made before we get here
    // so always retain it.
    return_trace (true);
  }

  bool sanitize (hb_sanitize_context_t *c,
		 const Record_sanitize_closure_t *closure = nullptr) const
  {
    TRACE_SANITIZE (this);
    if (unlikely (!(c->check_struct (this) && lookupIndex.sanitize (c))))
      return_trace (false);

    /* Some earlier versions of Adobe tools calculated the offset of the
     * FeatureParams subtable from the beginning of the FeatureList table!
     *
     * If sanitizing "failed" for the FeatureParams subtable, try it with the
     * alternative location.  We would know sanitize "failed" if old value
     * of the offset was non-zero, but it's zeroed now.
     *
     * Only do this for the 'size' feature, since at the time of the faulty
     * Adobe tools, only the 'size' feature had FeatureParams defined.
     */

    if (likely (featureParams.is_null ()))
      return_trace (true);

    unsigned int orig_offset = featureParams;
    if (unlikely (!featureParams.sanitize (c, this, closure ? closure->tag : HB_TAG_NONE)))
      return_trace (false);

    if (featureParams == 0 && closure &&
	closure->tag == HB_TAG ('s','i','z','e') &&
	closure->list_base && closure->list_base < this)
    {
      unsigned int new_offset_int = orig_offset -
				    (((char *) this) - ((char *) closure->list_base));

      Offset16To<FeatureParams> new_offset;
      /* Check that it would not overflow. */
      new_offset = new_offset_int;
      if (new_offset == new_offset_int &&
	  c->try_set (&featureParams, new_offset_int) &&
	  !featureParams.sanitize (c, this, closure ? closure->tag : HB_TAG_NONE))
	return_trace (false);
    }

    return_trace (true);
  }

  Offset16To<FeatureParams>
		 featureParams;	/* Offset to Feature Parameters table (if one
				 * has been defined for the feature), relative
				 * to the beginning of the Feature Table; = Null
				 * if not required */
  IndexArray	 lookupIndex;	/* Array of LookupList indices */
  public:
  DEFINE_SIZE_ARRAY_SIZED (4, lookupIndex);
};

template <typename Type>
struct Record
{
  int cmp (hb_tag_t a) const { return tag.cmp (a); }

  bool subset (hb_subset_layout_context_t *c, const void *base, const void *f_sub = nullptr) const
  {
    TRACE_SUBSET (this);
    auto *out = c->subset_context->serializer->embed (this);
    if (unlikely (!out)) return_trace (false);

    if (!f_sub)
      return_trace (out->offset.serialize_subset (c->subset_context, offset, base, c, &tag));

    const Feature& f = *reinterpret_cast<const Feature *> (f_sub);
    auto *s = c->subset_context->serializer;
    s->push ();

    out->offset = 0;
    bool ret = f.subset (c->subset_context, c, &tag);
    if (ret)
      s->add_link (out->offset, s->pop_pack ());
    else
      s->pop_discard ();

    return_trace (ret);
  }

  bool sanitize (hb_sanitize_context_t *c, const void *base) const
  {
    TRACE_SANITIZE (this);
    const Record_sanitize_closure_t closure = {tag, base};
    return_trace (c->check_struct (this) && offset.sanitize (c, base, &closure));
  }

  Tag           tag;            /* 4-byte Tag identifier */
  Offset16To<Type>
                offset;         /* Offset from beginning of object holding
                                 * the Record */
  public:
  DEFINE_SIZE_STATIC (6);
};

template <typename Type>
struct RecordArrayOf : SortedArray16Of<Record<Type>>
{
  const Offset16To<Type>& get_offset (unsigned int i) const
  { return (*this)[i].offset; }
  Offset16To<Type>& get_offset (unsigned int i)
  { return (*this)[i].offset; }
  const Tag& get_tag (unsigned int i) const
  { return (*this)[i].tag; }
  unsigned int get_tags (unsigned int start_offset,
                         unsigned int *record_count /* IN/OUT */,
                         hb_tag_t     *record_tags /* OUT */) const
  {
    if (record_count)
    {
      + this->as_array ().sub_array (start_offset, record_count)
      | hb_map (&Record<Type>::tag)
      | hb_sink (hb_array (record_tags, *record_count))
      ;
    }
    return this->len;
  }
  bool find_index (hb_tag_t tag, unsigned int *index) const
  {
    return this->bfind (tag, index, HB_NOT_FOUND_STORE, Index::NOT_FOUND_INDEX);
  }
};

template <typename Type>
struct RecordListOf : RecordArrayOf<Type>
{
  const Type& operator [] (unsigned int i) const
  { return this+this->get_offset (i); }

  bool subset (hb_subset_context_t *c,
               hb_subset_layout_context_t *l) const
  {
    TRACE_SUBSET (this);
    auto *out = c->serializer->start_embed (*this);
    if (unlikely (!c->serializer->extend_min (out))) return_trace (false);

    + this->iter ()
    | hb_apply (subset_record_array (l, out, this))
    ;
    return_trace (true);
  }

  bool sanitize (hb_sanitize_context_t *c) const
  {
    TRACE_SANITIZE (this);
    return_trace (RecordArrayOf<Type>::sanitize (c, this));
  }
};

struct RecordListOfFeature : RecordListOf<Feature>
{
  bool subset (hb_subset_context_t *c,
	       hb_subset_layout_context_t *l) const
  {
    TRACE_SUBSET (this);
    auto *out = c->serializer->start_embed (*this);
    if (unlikely (!c->serializer->extend_min (out))) return_trace (false);

    + hb_enumerate (*this)
    | hb_filter (l->feature_index_map, hb_first)
    | hb_apply ([l, out, this] (const hb_pair_t<unsigned, const Record<Feature>&>& _)
                {
                  const Feature *f_sub = nullptr;
                  const Feature **f = nullptr;
                  if (l->feature_substitutes_map->has (_.first, &f))
                    f_sub = *f;

                  subset_record_array (l, out, this, f_sub) (_.second);
                })
    ;

    return_trace (true);
  }
};

typedef RecordListOf<Feature> FeatureList;


struct LangSys
{
  unsigned int get_feature_count () const
  { return featureIndex.len; }
  hb_tag_t get_feature_index (unsigned int i) const
  { return featureIndex[i]; }
  unsigned int get_feature_indexes (unsigned int start_offset,
				    unsigned int *feature_count /* IN/OUT */,
				    unsigned int *feature_indexes /* OUT */) const
  { return featureIndex.get_indexes (start_offset, feature_count, feature_indexes); }
  void add_feature_indexes_to (hb_set_t *feature_indexes) const
  { featureIndex.add_indexes_to (feature_indexes); }

  bool has_required_feature () const { return reqFeatureIndex != 0xFFFFu; }
  unsigned int get_required_feature_index () const
  {
    if (reqFeatureIndex == 0xFFFFu)
      return Index::NOT_FOUND_INDEX;
   return reqFeatureIndex;
  }

  LangSys* copy (hb_serialize_context_t *c) const
  {
    TRACE_SERIALIZE (this);
    return_trace (c->embed (*this));
  }

  bool compare (const LangSys& o, const hb_map_t *feature_index_map) const
  {
    if (reqFeatureIndex != o.reqFeatureIndex)
      return false;

    auto iter =
    + hb_iter (featureIndex)
    | hb_filter (feature_index_map)
    | hb_map (feature_index_map)
    ;

    auto o_iter =
    + hb_iter (o.featureIndex)
    | hb_filter (feature_index_map)
    | hb_map (feature_index_map)
    ;

    for (; iter && o_iter; iter++, o_iter++)
    {
      unsigned a = *iter;
      unsigned b = *o_iter;
      if (a != b) return false;
    }

    if (iter || o_iter) return false;

    return true;
  }

  void collect_features (hb_prune_langsys_context_t *c) const
  {
    if (!has_required_feature () && !get_feature_count ()) return;
    if (has_required_feature () &&
        c->duplicate_feature_map->has (reqFeatureIndex))
      c->new_feature_indexes->add (get_required_feature_index ());

    + hb_iter (featureIndex)
    | hb_filter (c->duplicate_feature_map)
    | hb_sink (c->new_feature_indexes)
    ;
  }

  bool subset (hb_subset_context_t        *c,
	       hb_subset_layout_context_t *l,
	       const Tag                  *tag = nullptr) const
  {
    TRACE_SUBSET (this);
    auto *out = c->serializer->start_embed (*this);
    if (unlikely (!c->serializer->extend_min (out))) return_trace (false);

    const uint32_t *v;
    out->reqFeatureIndex = l->feature_index_map->has (reqFeatureIndex, &v) ? *v : 0xFFFFu;

    if (!l->visitFeatureIndex (featureIndex.len))
      return_trace (false);

    auto it =
    + hb_iter (featureIndex)
    | hb_filter (l->feature_index_map)
    | hb_map (l->feature_index_map)
    ;

    bool ret = bool (it);
    out->featureIndex.serialize (c->serializer, l, it);
    return_trace (ret);
  }

  bool sanitize (hb_sanitize_context_t *c,
		 const Record_sanitize_closure_t * = nullptr) const
  {
    TRACE_SANITIZE (this);
    return_trace (c->check_struct (this) && featureIndex.sanitize (c));
  }

  Offset16	lookupOrderZ;	/* = Null (reserved for an offset to a
				 * reordering table) */
  HBUINT16	reqFeatureIndex;/* Index of a feature required for this
				 * language system--if no required features
				 * = 0xFFFFu */
  IndexArray	featureIndex;	/* Array of indices into the FeatureList */
  public:
  DEFINE_SIZE_ARRAY_SIZED (6, featureIndex);
};
DECLARE_NULL_NAMESPACE_BYTES (OT, LangSys);

struct Script
{
  unsigned int get_lang_sys_count () const
  { return langSys.len; }
  const Tag& get_lang_sys_tag (unsigned int i) const
  { return langSys.get_tag (i); }
  unsigned int get_lang_sys_tags (unsigned int start_offset,
				  unsigned int *lang_sys_count /* IN/OUT */,
				  hb_tag_t     *lang_sys_tags /* OUT */) const
  { return langSys.get_tags (start_offset, lang_sys_count, lang_sys_tags); }
  const LangSys& get_lang_sys (unsigned int i) const
  {
    if (i == Index::NOT_FOUND_INDEX) return get_default_lang_sys ();
    return this+langSys[i].offset;
  }
  bool find_lang_sys_index (hb_tag_t tag, unsigned int *index) const
  { return langSys.find_index (tag, index); }

  bool has_default_lang_sys () const           { return defaultLangSys != 0; }
  const LangSys& get_default_lang_sys () const { return this+defaultLangSys; }

  void prune_langsys (hb_prune_langsys_context_t *c,
                      unsigned script_index) const
  {
    if (!has_default_lang_sys () && !get_lang_sys_count ()) return;
    if (!c->visitScript ()) return;

    if (!c->script_langsys_map->has (script_index))
    {
      if (unlikely (!c->script_langsys_map->set (script_index, hb::unique_ptr<hb_set_t> {hb_set_create ()})))
	return;
    }

    if (has_default_lang_sys ())
    {
      //only collect features from non-redundant langsys
      const LangSys& d = get_default_lang_sys ();
      if (c->visitLangsys (d.get_feature_count ())) {
        d.collect_features (c);
      }

      for (auto _ : + hb_enumerate (langSys))
      {
        const LangSys& l = this+_.second.offset;
        if (!c->visitLangsys (l.get_feature_count ())) continue;
        if (l.compare (d, c->duplicate_feature_map)) continue;

        l.collect_features (c);
        c->script_langsys_map->get (script_index)->add (_.first);
      }
    }
    else
    {
      for (auto _ : + hb_enumerate (langSys))
      {
        const LangSys& l = this+_.second.offset;
        if (!c->visitLangsys (l.get_feature_count ())) continue;
        l.collect_features (c);
        c->script_langsys_map->get (script_index)->add (_.first);
      }
    }
  }

  bool subset (hb_subset_context_t         *c,
	       hb_subset_layout_context_t  *l,
	       const Tag                   *tag) const
  {
    TRACE_SUBSET (this);
    if (!l->visitScript ()) return_trace (false);
    if (tag && !c->plan->layout_scripts.has (*tag))
      return false;

    auto *out = c->serializer->start_embed (*this);
    if (unlikely (!c->serializer->extend_min (out))) return_trace (false);

    bool defaultLang = false;
    if (has_default_lang_sys ())
    {
      c->serializer->push ();
      const LangSys& ls = this+defaultLangSys;
      bool ret = ls.subset (c, l);
      if (!ret && tag && *tag != HB_TAG ('D', 'F', 'L', 'T'))
      {
	c->serializer->pop_discard ();
	out->defaultLangSys = 0;
      }
      else
      {
	c->serializer->add_link (out->defaultLangSys, c->serializer->pop_pack ());
	defaultLang = true;
      }
    }

    const hb_set_t *active_langsys = l->script_langsys_map->get (l->cur_script_index);
    if (active_langsys)
    {
      + hb_enumerate (langSys)
      | hb_filter (active_langsys, hb_first)
      | hb_map (hb_second)
      | hb_filter ([=] (const Record<LangSys>& record) {return l->visitLangSys (); })
      | hb_apply (subset_record_array (l, &(out->langSys), this))
      ;
    }

    return_trace (bool (out->langSys.len) || defaultLang || l->table_tag == HB_OT_TAG_GSUB);
  }

  bool sanitize (hb_sanitize_context_t *c,
		 const Record_sanitize_closure_t * = nullptr) const
  {
    TRACE_SANITIZE (this);
    return_trace (defaultLangSys.sanitize (c, this) && langSys.sanitize (c, this));
  }

  protected:
  Offset16To<LangSys>
		defaultLangSys;	/* Offset to DefaultLangSys table--from
				 * beginning of Script table--may be Null */
  RecordArrayOf<LangSys>
		langSys;	/* Array of LangSysRecords--listed
				 * alphabetically by LangSysTag */
  public:
  DEFINE_SIZE_ARRAY_SIZED (4, langSys);
};

struct RecordListOfScript : RecordListOf<Script>
{
  bool subset (hb_subset_context_t *c,
               hb_subset_layout_context_t *l) const
  {
    TRACE_SUBSET (this);
    auto *out = c->serializer->start_embed (*this);
    if (unlikely (!c->serializer->extend_min (out))) return_trace (false);

    for (auto _ : + hb_enumerate (*this))
    {
      auto snap = c->serializer->snapshot ();
      l->cur_script_index = _.first;
      bool ret = _.second.subset (l, this);
      if (!ret) c->serializer->revert (snap);
      else out->len++;
    }

    return_trace (true);
  }
};

typedef RecordListOfScript ScriptList;



struct LookupFlag : HBUINT16
{
  enum Flags {
    RightToLeft		= 0x0001u,
    IgnoreBaseGlyphs	= 0x0002u,
    IgnoreLigatures	= 0x0004u,
    IgnoreMarks		= 0x0008u,
    IgnoreFlags		= 0x000Eu,
    UseMarkFilteringSet	= 0x0010u,
    Reserved		= 0x00E0u,
    MarkAttachmentType	= 0xFF00u
  };
  public:
  DEFINE_SIZE_STATIC (2);
};

} /* namespace OT */
/* This has to be outside the namespace. */
HB_MARK_AS_FLAG_T (OT::LookupFlag::Flags);
namespace OT {

struct Lookup
{
  unsigned int get_subtable_count () const { return subTable.len; }

  template <typename TSubTable>
  const Array16OfOffset16To<TSubTable>& get_subtables () const
  { return reinterpret_cast<const Array16OfOffset16To<TSubTable> &> (subTable); }
  template <typename TSubTable>
  Array16OfOffset16To<TSubTable>& get_subtables ()
  { return reinterpret_cast<Array16OfOffset16To<TSubTable> &> (subTable); }

  template <typename TSubTable>
  const TSubTable& get_subtable (unsigned int i) const
  { return this+get_subtables<TSubTable> ()[i]; }
  template <typename TSubTable>
  TSubTable& get_subtable (unsigned int i)
  { return this+get_subtables<TSubTable> ()[i]; }

  unsigned int get_size () const
  {
    const HBUINT16 &markFilteringSet = StructAfter<const HBUINT16> (subTable);
    if (lookupFlag & LookupFlag::UseMarkFilteringSet)
      return (const char *) &StructAfter<const char> (markFilteringSet) - (const char *) this;
    return (const char *) &markFilteringSet - (const char *) this;
  }

  unsigned int get_type () const { return lookupType; }

  /* lookup_props is a 32-bit integer where the lower 16-bit is LookupFlag and
   * higher 16-bit is mark-filtering-set if the lookup uses one.
   * Not to be confused with glyph_props which is very similar. */
  uint32_t get_props () const
  {
    unsigned int flag = lookupFlag;
    if (unlikely (flag & LookupFlag::UseMarkFilteringSet))
    {
      const HBUINT16 &markFilteringSet = StructAfter<HBUINT16> (subTable);
      flag += (markFilteringSet << 16);
    }
    return flag;
  }

  template <typename TSubTable, typename context_t, typename ...Ts>
  typename context_t::return_t dispatch (context_t *c, Ts&&... ds) const
  {
    unsigned int lookup_type = get_type ();
    TRACE_DISPATCH (this, lookup_type);
    unsigned int count = get_subtable_count ();
    for (unsigned int i = 0; i < count; i++) {
      typename context_t::return_t r = get_subtable<TSubTable> (i).dispatch (c, lookup_type, std::forward<Ts> (ds)...);
      if (c->stop_sublookup_iteration (r))
	return_trace (r);
    }
    return_trace (c->default_return_value ());
  }

  bool serialize (hb_serialize_context_t *c,
		  unsigned int lookup_type,
		  uint32_t lookup_props,
		  unsigned int num_subtables)
  {
    TRACE_SERIALIZE (this);
    if (unlikely (!c->extend_min (this))) return_trace (false);
    lookupType = lookup_type;
    lookupFlag = lookup_props & 0xFFFFu;
    if (unlikely (!subTable.serialize (c, num_subtables))) return_trace (false);
    if (lookupFlag & LookupFlag::UseMarkFilteringSet)
    {
      if (unlikely (!c->extend (this))) return_trace (false);
      HBUINT16 &markFilteringSet = StructAfter<HBUINT16> (subTable);
      markFilteringSet = lookup_props >> 16;
    }
    return_trace (true);
  }

  template <typename TSubTable>
  bool subset (hb_subset_context_t *c) const
  {
    TRACE_SUBSET (this);
    auto *out = c->serializer->start_embed (*this);
    if (unlikely (!c->serializer->extend_min (out))) return_trace (false);
    out->lookupType = lookupType;
    out->lookupFlag = lookupFlag;

    const hb_set_t *glyphset = c->plan->glyphset_gsub ();
    unsigned int lookup_type = get_type ();
    + hb_iter (get_subtables <TSubTable> ())
    | hb_filter ([this, glyphset, lookup_type] (const Offset16To<TSubTable> &_) { return (this+_).intersects (glyphset, lookup_type); })
    | hb_apply (subset_offset_array (c, out->get_subtables<TSubTable> (), this, lookup_type))
    ;

    if (lookupFlag & LookupFlag::UseMarkFilteringSet)
    {
      if (unlikely (!c->serializer->extend (out))) return_trace (false);
      const HBUINT16 &markFilteringSet = StructAfter<HBUINT16> (subTable);
      HBUINT16 &outMarkFilteringSet = StructAfter<HBUINT16> (out->subTable);
      outMarkFilteringSet = markFilteringSet;
    }

    // Always keep the lookup even if it's empty. The rest of layout subsetting depends on lookup
    // indices being consistent with those computed during planning. So if an empty lookup is
    // discarded during the subset phase it will invalidate all subsequent lookup indices.
    // Generally we shouldn't end up with an empty lookup as we pre-prune them during the planning
    // phase, but it can happen in rare cases such as when during closure subtable is considered
    // degenerate (see: https://github.com/harfbuzz/harfbuzz/issues/3853)
    return_trace (true);
  }

  template <typename TSubTable>
  bool sanitize (hb_sanitize_context_t *c) const
  {
    TRACE_SANITIZE (this);
    if (!(c->check_struct (this) && subTable.sanitize (c))) return_trace (false);

    unsigned subtables = get_subtable_count ();
    if (unlikely (!c->visit_subtables (subtables))) return_trace (false);

    if (lookupFlag & LookupFlag::UseMarkFilteringSet)
    {
      const HBUINT16 &markFilteringSet = StructAfter<HBUINT16> (subTable);
      if (!markFilteringSet.sanitize (c)) return_trace (false);
    }

    if (unlikely (!get_subtables<TSubTable> ().sanitize (c, this, get_type ())))
      return_trace (false);

    if (unlikely (get_type () == TSubTable::Extension && !c->get_edit_count ()))
    {
      /* The spec says all subtables of an Extension lookup should
       * have the same type, which shall not be the Extension type
       * itself (but we already checked for that).
       * This is specially important if one has a reverse type!
       *
       * We only do this if sanitizer edit_count is zero.  Otherwise,
       * some of the subtables might have become insane after they
       * were sanity-checked by the edits of subsequent subtables.
       * https://bugs.chromium.org/p/chromium/issues/detail?id=960331
       */
      unsigned int type = get_subtable<TSubTable> (0).u.extension.get_type ();
      for (unsigned int i = 1; i < subtables; i++)
	if (get_subtable<TSubTable> (i).u.extension.get_type () != type)
	  return_trace (false);
    }
    return_trace (true);
  }

  protected:
  HBUINT16	lookupType;		/* Different enumerations for GSUB and GPOS */
  HBUINT16	lookupFlag;		/* Lookup qualifiers */
  Array16Of<Offset16>
		subTable;		/* Array of SubTables */
/*HBUINT16	markFilteringSetX[HB_VAR_ARRAY];*//* Index (base 0) into GDEF mark glyph sets
					 * structure. This field is only present if bit
					 * UseMarkFilteringSet of lookup flags is set. */
  public:
  DEFINE_SIZE_ARRAY (6, subTable);
};

template <typename Types>
using LookupList = List16OfOffsetTo<Lookup, typename Types::HBUINT>;

template <typename TLookup, typename OffsetType>
struct LookupOffsetList : List16OfOffsetTo<TLookup, OffsetType>
{
  bool subset (hb_subset_context_t        *c,
	       hb_subset_layout_context_t *l) const
  {
    TRACE_SUBSET (this);
    auto *out = c->serializer->start_embed (this);
    if (unlikely (!c->serializer->extend_min (out))) return_trace (false);

    + hb_enumerate (*this)
    | hb_filter (l->lookup_index_map, hb_first)
    | hb_map (hb_second)
    | hb_apply (subset_offset_array (c, *out, this))
    ;
    return_trace (true);
  }

  bool sanitize (hb_sanitize_context_t *c) const
  {
    TRACE_SANITIZE (this);
    return_trace (List16OfOffset16To<TLookup>::sanitize (c, this));
  }
};


/*
 * Coverage Table
 */


static bool ClassDef_remap_and_serialize (hb_serialize_context_t *c,
					  const hb_set_t &klasses,
                                          bool use_class_zero,
                                          hb_sorted_vector_t<hb_codepoint_pair_t> &glyph_and_klass, /* IN/OUT */
					  hb_map_t *klass_map /*IN/OUT*/)
{
  if (!klass_map)
    return ClassDef_serialize (c, glyph_and_klass.iter ());

  /* any glyph not assigned a class value falls into Class zero (0),
   * if any glyph assigned to class 0, remapping must start with 0->0*/
  if (!use_class_zero)
    klass_map->set (0, 0);

  unsigned idx = klass_map->has (0) ? 1 : 0;
  for (const unsigned k: klasses)
  {
    if (klass_map->has (k)) continue;
    klass_map->set (k, idx);
    idx++;
  }


  for (unsigned i = 0; i < glyph_and_klass.length; i++)
  {
    hb_codepoint_t klass = glyph_and_klass[i].second;
    glyph_and_klass[i].second = klass_map->get (klass);
  }

  c->propagate_error (glyph_and_klass, klasses);
  return ClassDef_serialize (c, glyph_and_klass.iter ());
}

/*
 * Class Definition Table
 */

template <typename Types>
struct ClassDefFormat1_3
{
  friend struct ClassDef;

  private:
  unsigned int get_class (hb_codepoint_t glyph_id) const
  {
    return classValue[(unsigned int) (glyph_id - startGlyph)];
  }

  unsigned get_population () const
  {
    return classValue.len;
  }

  template<typename Iterator,
	   hb_requires (hb_is_sorted_source_of (Iterator, hb_codepoint_t))>
  bool serialize (hb_serialize_context_t *c,
		  Iterator it)
  {
    TRACE_SERIALIZE (this);
    if (unlikely (!c->extend_min (this))) return_trace (false);

    if (unlikely (!it))
    {
      classFormat = 1;
      startGlyph = 0;
      classValue.len = 0;
      return_trace (true);
    }

    hb_codepoint_t glyph_min = (*it).first;
    hb_codepoint_t glyph_max = + it
			       | hb_map (hb_first)
			       | hb_reduce (hb_max, 0u);
    unsigned glyph_count = glyph_max - glyph_min + 1;

    startGlyph = glyph_min;
    if (unlikely (!classValue.serialize (c, glyph_count))) return_trace (false);
    for (const hb_pair_t<hb_codepoint_t, uint32_t> gid_klass_pair : + it)
    {
      unsigned idx = gid_klass_pair.first - glyph_min;
      classValue[idx] = gid_klass_pair.second;
    }
    return_trace (true);
  }

  bool subset (hb_subset_context_t *c,
	       hb_map_t *klass_map = nullptr /*OUT*/,
               bool keep_empty_table = true,
               bool use_class_zero = true,
               const Coverage* glyph_filter = nullptr) const
  {
    TRACE_SUBSET (this);
    const hb_map_t &glyph_map = c->plan->glyph_map_gsub;

    hb_sorted_vector_t<hb_codepoint_pair_t> glyph_and_klass;
    hb_set_t orig_klasses;

    hb_codepoint_t start = startGlyph;
    hb_codepoint_t end   = start + classValue.len;

    for (const hb_codepoint_t gid : + hb_range (start, end))
    {
      hb_codepoint_t new_gid = glyph_map[gid];
      if (new_gid == HB_MAP_VALUE_INVALID) continue;
      if (glyph_filter && !glyph_filter->has(gid)) continue;

      unsigned klass = classValue[gid - start];
      if (!klass) continue;

      glyph_and_klass.push (hb_pair (new_gid, klass));
      orig_klasses.add (klass);
    }

    if (use_class_zero)
    {
      unsigned glyph_count = glyph_filter
			     ? hb_len (hb_iter (glyph_map.keys()) | hb_filter (glyph_filter))
			     : glyph_map.get_population ();
      use_class_zero = glyph_count <= glyph_and_klass.length;
    }
    if (!ClassDef_remap_and_serialize (c->serializer,
                                       orig_klasses,
                                       use_class_zero,
                                       glyph_and_klass,
                                       klass_map))
      return_trace (false);
    return_trace (keep_empty_table || (bool) glyph_and_klass);
  }

  bool sanitize (hb_sanitize_context_t *c) const
  {
    TRACE_SANITIZE (this);
    return_trace (c->check_struct (this) && classValue.sanitize (c));
  }

  unsigned cost () const { return 1; }

  template <typename set_t>
  bool collect_coverage (set_t *glyphs) const
  {
    unsigned int start = 0;
    unsigned int count = classValue.len;
    for (unsigned int i = 0; i < count; i++)
    {
      if (classValue[i])
	continue;

      if (start != i)
	if (unlikely (!glyphs->add_range (startGlyph + start, startGlyph + i)))
	  return false;

      start = i + 1;
    }
    if (start != count)
      if (unlikely (!glyphs->add_range (startGlyph + start, startGlyph + count)))
	return false;

    return true;
  }

  template <typename set_t>
  bool collect_class (set_t *glyphs, unsigned klass) const
  {
    unsigned int count = classValue.len;
    for (unsigned int i = 0; i < count; i++)
      if (classValue[i] == klass) glyphs->add (startGlyph + i);
    return true;
  }

  bool intersects (const hb_set_t *glyphs) const
  {
    hb_codepoint_t start = startGlyph;
    hb_codepoint_t end = startGlyph + classValue.len;
    for (hb_codepoint_t iter = startGlyph - 1;
	 glyphs->next (&iter) && iter < end;)
      if (classValue[iter - start]) return true;
    return false;
  }
  bool intersects_class (const hb_set_t *glyphs, uint16_t klass) const
  {
    unsigned int count = classValue.len;
    if (klass == 0)
    {
      /* Match if there's any glyph that is not listed! */
      hb_codepoint_t g = HB_SET_VALUE_INVALID;
      if (!glyphs->next (&g)) return false;
      if (g < startGlyph) return true;
      g = startGlyph + count - 1;
      if (glyphs->next (&g)) return true;
      /* Fall through. */
    }
    /* TODO Speed up, using set overlap first? */
    /* TODO(iter) Rewrite as dagger. */
    const HBUINT16 *arr = classValue.arrayZ;
    for (unsigned int i = 0; i < count; i++)
      if (arr[i] == klass && glyphs->has (startGlyph + i))
	return true;
    return false;
  }

  void intersected_class_glyphs (const hb_set_t *glyphs, unsigned klass, hb_set_t *intersect_glyphs) const
  {
    unsigned count = classValue.len;
    if (klass == 0)
    {
      unsigned start_glyph = startGlyph;
      for (uint32_t g = HB_SET_VALUE_INVALID;
	   glyphs->next (&g) && g < start_glyph;)
	intersect_glyphs->add (g);

      for (uint32_t g = startGlyph + count - 1;
	   glyphs-> next (&g);)
	intersect_glyphs->add (g);

      return;
    }

    for (unsigned i = 0; i < count; i++)
      if (classValue[i] == klass && glyphs->has (startGlyph + i))
	intersect_glyphs->add (startGlyph + i);

#if 0
    /* The following implementation is faster asymptotically, but slower
     * in practice. */
    unsigned start_glyph = startGlyph;
    unsigned end_glyph = start_glyph + count;
    for (unsigned g = startGlyph - 1;
	 glyphs->next (&g) && g < end_glyph;)
      if (classValue.arrayZ[g - start_glyph] == klass)
        intersect_glyphs->add (g);
#endif
  }

  void intersected_classes (const hb_set_t *glyphs, hb_set_t *intersect_classes) const
  {
    if (glyphs->is_empty ()) return;
    hb_codepoint_t end_glyph = startGlyph + classValue.len - 1;
    if (glyphs->get_min () < startGlyph ||
        glyphs->get_max () > end_glyph)
      intersect_classes->add (0);

    for (const auto& _ : + hb_enumerate (classValue))
    {
      hb_codepoint_t g = startGlyph + _.first;
      if (glyphs->has (g))
        intersect_classes->add (_.second);
    }
  }

  protected:
  HBUINT16	classFormat;	/* Format identifier--format = 1 */
  typename Types::HBGlyphID
		 startGlyph;	/* First GlyphID of the classValueArray */
  typename Types::template ArrayOf<HBUINT16>
		classValue;	/* Array of Class Values--one per GlyphID */
  public:
  DEFINE_SIZE_ARRAY (2 + 2 * Types::size, classValue);
};

template <typename Types>
struct ClassDefFormat2_4
{
  friend struct ClassDef;

  private:
  unsigned int get_class (hb_codepoint_t glyph_id) const
  {
    return rangeRecord.bsearch (glyph_id).value;
  }

  unsigned get_population () const
  {
    typename Types::large_int ret = 0;
    for (const auto &r : rangeRecord)
      ret += r.get_population ();
    return ret > UINT_MAX ? UINT_MAX : (unsigned) ret;
  }

  template<typename Iterator,
	   hb_requires (hb_is_sorted_source_of (Iterator, hb_codepoint_t))>
  bool serialize (hb_serialize_context_t *c,
		  Iterator it)
  {
    TRACE_SERIALIZE (this);
    if (unlikely (!c->extend_min (this))) return_trace (false);

    if (unlikely (!it))
    {
      classFormat = 2;
      rangeRecord.len = 0;
      return_trace (true);
    }

    unsigned unsorted = false;
    unsigned num_ranges = 1;
    hb_codepoint_t prev_gid = (*it).first;
    unsigned prev_klass = (*it).second;

    RangeRecord<Types> range_rec;
    range_rec.first = prev_gid;
    range_rec.last = prev_gid;
    range_rec.value = prev_klass;

    auto *record = c->copy (range_rec);
    if (unlikely (!record)) return_trace (false);

    for (const auto gid_klass_pair : + (++it))
    {
      hb_codepoint_t cur_gid = gid_klass_pair.first;
      unsigned cur_klass = gid_klass_pair.second;

      if (cur_gid != prev_gid + 1 ||
	  cur_klass != prev_klass)
      {

	if (unlikely (cur_gid < prev_gid))
	  unsorted = true;

	if (unlikely (!record)) break;
	record->last = prev_gid;
	num_ranges++;

	range_rec.first = cur_gid;
	range_rec.last = cur_gid;
	range_rec.value = cur_klass;

	record = c->copy (range_rec);
      }

      prev_klass = cur_klass;
      prev_gid = cur_gid;
    }

    if (unlikely (c->in_error ())) return_trace (false);

    if (likely (record)) record->last = prev_gid;
    rangeRecord.len = num_ranges;

    if (unlikely (unsorted))
      rangeRecord.as_array ().qsort (RangeRecord<Types>::cmp_range);

    return_trace (true);
  }

  bool subset (hb_subset_context_t *c,
	       hb_map_t *klass_map = nullptr /*OUT*/,
               bool keep_empty_table = true,
               bool use_class_zero = true,
               const Coverage* glyph_filter = nullptr) const
  {
    TRACE_SUBSET (this);
    const hb_map_t &glyph_map = c->plan->glyph_map_gsub;
    const hb_set_t &glyph_set = *c->plan->glyphset_gsub ();

    hb_sorted_vector_t<hb_codepoint_pair_t> glyph_and_klass;
    hb_set_t orig_klasses;

    if (glyph_set.get_population () * hb_bit_storage ((unsigned) rangeRecord.len) / 2
	< get_population ())
    {
      for (hb_codepoint_t g : glyph_set)
      {
	unsigned klass = get_class (g);
	if (!klass) continue;
	hb_codepoint_t new_gid = glyph_map[g];
	if (new_gid == HB_MAP_VALUE_INVALID) continue;
	if (glyph_filter && !glyph_filter->has (g)) continue;
	glyph_and_klass.push (hb_pair (new_gid, klass));
	orig_klasses.add (klass);
      }
    }
    else
    {
      unsigned num_source_glyphs = c->plan->source->get_num_glyphs ();
      for (auto &range : rangeRecord)
      {
	unsigned klass = range.value;
	if (!klass) continue;
	hb_codepoint_t start = range.first;
	hb_codepoint_t end   = hb_min (range.last + 1, num_source_glyphs);
	for (hb_codepoint_t g = start; g < end; g++)
	{
	  hb_codepoint_t new_gid = glyph_map[g];
	  if (new_gid == HB_MAP_VALUE_INVALID) continue;
	  if (glyph_filter && !glyph_filter->has (g)) continue;

	  glyph_and_klass.push (hb_pair (new_gid, klass));
	  orig_klasses.add (klass);
	}
      }
    }

    const hb_set_t& glyphset = *c->plan->glyphset_gsub ();
    unsigned glyph_count = glyph_filter
                           ? hb_len (hb_iter (glyphset) | hb_filter (glyph_filter))
                           : glyph_map.get_population ();
    use_class_zero = use_class_zero && glyph_count <= glyph_and_klass.length;
    if (!ClassDef_remap_and_serialize (c->serializer,
                                       orig_klasses,
                                       use_class_zero,
                                       glyph_and_klass,
                                       klass_map))
      return_trace (false);
    return_trace (keep_empty_table || (bool) glyph_and_klass);
  }

  bool sanitize (hb_sanitize_context_t *c) const
  {
    TRACE_SANITIZE (this);
    return_trace (rangeRecord.sanitize (c));
  }

  unsigned cost () const { return hb_bit_storage ((unsigned) rangeRecord.len); /* bsearch cost */ }

  template <typename set_t>
  bool collect_coverage (set_t *glyphs) const
  {
    for (auto &range : rangeRecord)
      if (range.value)
	if (unlikely (!range.collect_coverage (glyphs)))
	  return false;
    return true;
  }

  template <typename set_t>
  bool collect_class (set_t *glyphs, unsigned int klass) const
  {
    for (auto &range : rangeRecord)
    {
      if (range.value == klass)
	if (unlikely (!range.collect_coverage (glyphs)))
	  return false;
    }
    return true;
  }

  bool intersects (const hb_set_t *glyphs) const
  {
    if (rangeRecord.len > glyphs->get_population () * hb_bit_storage ((unsigned) rangeRecord.len) / 2)
    {
      for (auto g : *glyphs)
        if (get_class (g))
	  return true;
      return false;
    }

    return hb_any (+ hb_iter (rangeRecord)
                   | hb_map ([glyphs] (const RangeRecord<Types> &range) { return range.intersects (*glyphs) && range.value; }));
  }
  bool intersects_class (const hb_set_t *glyphs, uint16_t klass) const
  {
    if (klass == 0)
    {
      /* Match if there's any glyph that is not listed! */
      hb_codepoint_t g = HB_SET_VALUE_INVALID;
      hb_codepoint_t last = HB_SET_VALUE_INVALID;
      auto it = hb_iter (rangeRecord);
      for (auto &range : it)
      {
        if (it->first == last + 1)
	{
	  it++;
	  continue;
	}

	if (!glyphs->next (&g))
	  break;
	if (g < range.first)
	  return true;
	g = range.last;
	last = g;
      }
      if (g != HB_SET_VALUE_INVALID && glyphs->next (&g))
	return true;
      /* Fall through. */
    }
    for (const auto &range : rangeRecord)
      if (range.value == klass && range.intersects (*glyphs))
	return true;
    return false;
  }

  void intersected_class_glyphs (const hb_set_t *glyphs, unsigned klass, hb_set_t *intersect_glyphs) const
  {
    if (klass == 0)
    {
      hb_codepoint_t g = HB_SET_VALUE_INVALID;
      for (auto &range : rangeRecord)
      {
	if (!glyphs->next (&g))
	  goto done;
	while (g < range.first)
	{
	  intersect_glyphs->add (g);
	  if (!glyphs->next (&g))
	    goto done;
        }
        g = range.last;
      }
      while (glyphs->next (&g))
	intersect_glyphs->add (g);
      done:

      return;
    }

    unsigned count = rangeRecord.len;
    if (count > glyphs->get_population () * hb_bit_storage (count) * 8)
    {
      for (auto g : *glyphs)
      {
        unsigned i;
        if (rangeRecord.as_array ().bfind (g, &i) &&
	    rangeRecord.arrayZ[i].value == klass)
	  intersect_glyphs->add (g);
      }
      return;
    }

    for (auto &range : rangeRecord)
    {
      if (range.value != klass) continue;

      unsigned end = range.last + 1;
      for (hb_codepoint_t g = range.first - 1;
	   glyphs->next (&g) && g < end;)
	intersect_glyphs->add (g);
    }
  }

  void intersected_classes (const hb_set_t *glyphs, hb_set_t *intersect_classes) const
  {
    if (glyphs->is_empty ()) return;

    hb_codepoint_t g = HB_SET_VALUE_INVALID;
    for (auto &range : rangeRecord)
    {
      if (!glyphs->next (&g))
        break;
      if (g < range.first)
      {
        intersect_classes->add (0);
        break;
      }
      g = range.last;
    }
    if (g != HB_SET_VALUE_INVALID && glyphs->next (&g))
      intersect_classes->add (0);

    for (const auto& range : rangeRecord)
      if (range.intersects (*glyphs))
        intersect_classes->add (range.value);
  }

  protected:
  HBUINT16	classFormat;	/* Format identifier--format = 2 */
  typename Types::template SortedArrayOf<RangeRecord<Types>>
		rangeRecord;	/* Array of glyph ranges--ordered by
				 * Start GlyphID */
  public:
  DEFINE_SIZE_ARRAY (2 + Types::size, rangeRecord);
};

struct ClassDef
{
  /* Has interface. */
  unsigned operator [] (hb_codepoint_t k) const { return get (k); }
  bool has (hb_codepoint_t k) const { return (*this)[k]; }
  /* Projection. */
  hb_codepoint_t operator () (hb_codepoint_t k) const { return get (k); }

  unsigned int get (hb_codepoint_t k) const { return get_class (k); }
  unsigned int get_class (hb_codepoint_t glyph_id) const
  {
    switch (u.format) {
    case 1: return u.format1.get_class (glyph_id);
    case 2: return u.format2.get_class (glyph_id);
#ifndef HB_NO_BEYOND_64K
    case 3: return u.format3.get_class (glyph_id);
    case 4: return u.format4.get_class (glyph_id);
#endif
    default:return 0;
    }
  }

  unsigned get_population () const
  {
    switch (u.format) {
    case 1: return u.format1.get_population ();
    case 2: return u.format2.get_population ();
#ifndef HB_NO_BEYOND_64K
    case 3: return u.format3.get_population ();
    case 4: return u.format4.get_population ();
#endif
    default:return NOT_COVERED;
    }
  }

  template<typename Iterator,
	   hb_requires (hb_is_sorted_source_of (Iterator, hb_codepoint_t))>
  bool serialize (hb_serialize_context_t *c, Iterator it_with_class_zero)
  {
    TRACE_SERIALIZE (this);
    if (unlikely (!c->extend_min (this))) return_trace (false);

    auto it = + it_with_class_zero | hb_filter (hb_second);

    unsigned format = 2;
    hb_codepoint_t glyph_max = 0;
    if (likely (it))
    {
      hb_codepoint_t glyph_min = (*it).first;
      glyph_max = glyph_min;

      unsigned num_glyphs = 0;
      unsigned num_ranges = 1;
      hb_codepoint_t prev_gid = glyph_min;
      unsigned prev_klass = (*it).second;

      for (const auto gid_klass_pair : it)
      {
	hb_codepoint_t cur_gid = gid_klass_pair.first;
	unsigned cur_klass = gid_klass_pair.second;
        num_glyphs++;
	if (cur_gid == glyph_min) continue;
        if (cur_gid > glyph_max) glyph_max = cur_gid;
	if (cur_gid != prev_gid + 1 ||
	    cur_klass != prev_klass)
	  num_ranges++;

	prev_gid = cur_gid;
	prev_klass = cur_klass;
      }

      if (num_glyphs && 1 + (glyph_max - glyph_min + 1) <= num_ranges * 3)
	format = 1;
    }

#ifndef HB_NO_BEYOND_64K
    if (glyph_max > 0xFFFFu)
      u.format += 2;
    if (unlikely (glyph_max > 0xFFFFFFu))
#else
    if (unlikely (glyph_max > 0xFFFFu))
#endif
    {
      c->check_success (false, HB_SERIALIZE_ERROR_INT_OVERFLOW);
      return_trace (false);
    }

    u.format = format;

    switch (u.format)
    {
    case 1: return_trace (u.format1.serialize (c, it));
    case 2: return_trace (u.format2.serialize (c, it));
#ifndef HB_NO_BEYOND_64K
    case 3: return_trace (u.format3.serialize (c, it));
    case 4: return_trace (u.format4.serialize (c, it));
#endif
    default:return_trace (false);
    }
  }

  bool subset (hb_subset_context_t *c,
	       hb_map_t *klass_map = nullptr /*OUT*/,
               bool keep_empty_table = true,
               bool use_class_zero = true,
               const Coverage* glyph_filter = nullptr) const
  {
    TRACE_SUBSET (this);
    switch (u.format) {
    case 1: return_trace (u.format1.subset (c, klass_map, keep_empty_table, use_class_zero, glyph_filter));
    case 2: return_trace (u.format2.subset (c, klass_map, keep_empty_table, use_class_zero, glyph_filter));
#ifndef HB_NO_BEYOND_64K
    case 3: return_trace (u.format3.subset (c, klass_map, keep_empty_table, use_class_zero, glyph_filter));
    case 4: return_trace (u.format4.subset (c, klass_map, keep_empty_table, use_class_zero, glyph_filter));
#endif
    default:return_trace (false);
    }
  }

  bool sanitize (hb_sanitize_context_t *c) const
  {
    TRACE_SANITIZE (this);
    if (!u.format.sanitize (c)) return_trace (false);
    switch (u.format) {
    case 1: return_trace (u.format1.sanitize (c));
    case 2: return_trace (u.format2.sanitize (c));
#ifndef HB_NO_BEYOND_64K
    case 3: return_trace (u.format3.sanitize (c));
    case 4: return_trace (u.format4.sanitize (c));
#endif
    default:return_trace (true);
    }
  }

  unsigned cost () const
  {
    switch (u.format) {
    case 1: return u.format1.cost ();
    case 2: return u.format2.cost ();
#ifndef HB_NO_BEYOND_64K
    case 3: return u.format3.cost ();
    case 4: return u.format4.cost ();
#endif
    default:return 0u;
    }
  }

  /* Might return false if array looks unsorted.
   * Used for faster rejection of corrupt data. */
  template <typename set_t>
  bool collect_coverage (set_t *glyphs) const
  {
    switch (u.format) {
    case 1: return u.format1.collect_coverage (glyphs);
    case 2: return u.format2.collect_coverage (glyphs);
#ifndef HB_NO_BEYOND_64K
    case 3: return u.format3.collect_coverage (glyphs);
    case 4: return u.format4.collect_coverage (glyphs);
#endif
    default:return false;
    }
  }

  /* Might return false if array looks unsorted.
   * Used for faster rejection of corrupt data. */
  template <typename set_t>
  bool collect_class (set_t *glyphs, unsigned int klass) const
  {
    switch (u.format) {
    case 1: return u.format1.collect_class (glyphs, klass);
    case 2: return u.format2.collect_class (glyphs, klass);
#ifndef HB_NO_BEYOND_64K
    case 3: return u.format3.collect_class (glyphs, klass);
    case 4: return u.format4.collect_class (glyphs, klass);
#endif
    default:return false;
    }
  }

  bool intersects (const hb_set_t *glyphs) const
  {
    switch (u.format) {
    case 1: return u.format1.intersects (glyphs);
    case 2: return u.format2.intersects (glyphs);
#ifndef HB_NO_BEYOND_64K
    case 3: return u.format3.intersects (glyphs);
    case 4: return u.format4.intersects (glyphs);
#endif
    default:return false;
    }
  }
  bool intersects_class (const hb_set_t *glyphs, unsigned int klass) const
  {
    switch (u.format) {
    case 1: return u.format1.intersects_class (glyphs, klass);
    case 2: return u.format2.intersects_class (glyphs, klass);
#ifndef HB_NO_BEYOND_64K
    case 3: return u.format3.intersects_class (glyphs, klass);
    case 4: return u.format4.intersects_class (glyphs, klass);
#endif
    default:return false;
    }
  }

  void intersected_class_glyphs (const hb_set_t *glyphs, unsigned klass, hb_set_t *intersect_glyphs) const
  {
    switch (u.format) {
    case 1: return u.format1.intersected_class_glyphs (glyphs, klass, intersect_glyphs);
    case 2: return u.format2.intersected_class_glyphs (glyphs, klass, intersect_glyphs);
#ifndef HB_NO_BEYOND_64K
    case 3: return u.format3.intersected_class_glyphs (glyphs, klass, intersect_glyphs);
    case 4: return u.format4.intersected_class_glyphs (glyphs, klass, intersect_glyphs);
#endif
    default:return;
    }
  }

  void intersected_classes (const hb_set_t *glyphs, hb_set_t *intersect_classes) const
  {
    switch (u.format) {
    case 1: return u.format1.intersected_classes (glyphs, intersect_classes);
    case 2: return u.format2.intersected_classes (glyphs, intersect_classes);
#ifndef HB_NO_BEYOND_64K
    case 3: return u.format3.intersected_classes (glyphs, intersect_classes);
    case 4: return u.format4.intersected_classes (glyphs, intersect_classes);
#endif
    default:return;
    }
  }


  protected:
  union {
  HBUINT16			format;		/* Format identifier */
  ClassDefFormat1_3<SmallTypes>	format1;
  ClassDefFormat2_4<SmallTypes>	format2;
#ifndef HB_NO_BEYOND_64K
  ClassDefFormat1_3<MediumTypes>format3;
  ClassDefFormat2_4<MediumTypes>format4;
#endif
  } u;
  public:
  DEFINE_SIZE_UNION (2, format);
};

template<typename Iterator>
static inline bool ClassDef_serialize (hb_serialize_context_t *c,
				       Iterator it)
{ return (c->start_embed<ClassDef> ()->serialize (c, it)); }


/*
 * Item Variation Store
 */

/* ported from fonttools (class _Encoding) */
struct delta_row_encoding_t
{
  /* each byte represents a region, value is one of 0/1/2/4, which means bytes
   * needed for this region */
  hb_vector_t<uint8_t> chars;
  unsigned width = 0;
  hb_vector_t<uint8_t> columns;
  unsigned overhead = 0;
  hb_vector_t<const hb_vector_t<int>*> items;

  delta_row_encoding_t () = default;
  delta_row_encoding_t (hb_vector_t<uint8_t>&& chars_,
                        const hb_vector_t<int>* row = nullptr) :
                        delta_row_encoding_t ()

  {
    chars = std::move (chars_);
    width = get_width ();
    columns = get_columns ();
    overhead = get_chars_overhead (columns);
    if (row) items.push (row);
  }

  bool is_empty () const
  { return !items; }

  static hb_vector_t<uint8_t> get_row_chars (const hb_vector_t<int>& row)
  {
    hb_vector_t<uint8_t> ret;
    if (!ret.alloc (row.length)) return ret;

    bool long_words = false;

    /* 0/1/2 byte encoding */
    for (int i = row.length - 1; i >= 0; i--)
    {
      int v =  row.arrayZ[i];
      if (v == 0)
        ret.push (0);
      else if (v > 32767 || v < -32768)
      {
        long_words = true;
        break;
      }
      else if (v > 127 || v < -128)
        ret.push (2);
      else
        ret.push (1);
    }

    if (!long_words)
      return ret;

    /* redo, 0/2/4 bytes encoding */
    ret.reset ();
    for (int i = row.length - 1; i >= 0; i--)
    {
      int v =  row.arrayZ[i];
      if (v == 0)
        ret.push (0);
      else if (v > 32767 || v < -32768)
        ret.push (4);
      else
        ret.push (2);
    }
    return ret;
  }

  inline unsigned get_width ()
  {
    unsigned ret = + hb_iter (chars)
                   | hb_reduce (hb_add, 0u)
                   ;
    return ret;
  }

  hb_vector_t<uint8_t> get_columns ()
  {
    hb_vector_t<uint8_t> cols;
    cols.alloc (chars.length);
    for (auto v : chars)
    {
      uint8_t flag = v ? 1 : 0;
      cols.push (flag);
    }
    return cols;
  }

  static inline unsigned get_chars_overhead (const hb_vector_t<uint8_t>& cols)
  {
    unsigned c = 4 + 6; // 4 bytes for LOffset, 6 bytes for VarData header
    unsigned cols_bit_count = 0;
    for (auto v : cols)
      if (v) cols_bit_count++;
    return c + cols_bit_count * 2;
  }

  unsigned get_gain () const
  {
    int count = items.length;
    return hb_max (0, (int) overhead - count);
  }

  int gain_from_merging (const delta_row_encoding_t& other_encoding) const
  {
    int combined_width = 0;
    for (unsigned i = 0; i < chars.length; i++)
      combined_width += hb_max (chars.arrayZ[i], other_encoding.chars.arrayZ[i]);
   
    hb_vector_t<uint8_t> combined_columns;
    combined_columns.alloc (columns.length);
    for (unsigned i = 0; i < columns.length; i++)
      combined_columns.push (columns.arrayZ[i] | other_encoding.columns.arrayZ[i]);
    
    int combined_overhead = get_chars_overhead (combined_columns);
    int combined_gain = (int) overhead + (int) other_encoding.overhead - combined_overhead
                        - (combined_width - (int) width) * items.length
                        - (combined_width - (int) other_encoding.width) * other_encoding.items.length;

    return combined_gain;
  }

  static int cmp (const void *pa, const void *pb)
  {
    const delta_row_encoding_t *a = (const delta_row_encoding_t *)pa;
    const delta_row_encoding_t *b = (const delta_row_encoding_t *)pb;

    int gain_a = a->get_gain ();
    int gain_b = b->get_gain ();

    if (gain_a != gain_b)
      return gain_a - gain_b;

    return (b->chars).as_array ().cmp ((a->chars).as_array ());
  }

  static int cmp_width (const void *pa, const void *pb)
  {
    const delta_row_encoding_t *a = (const delta_row_encoding_t *)pa;
    const delta_row_encoding_t *b = (const delta_row_encoding_t *)pb;

    if (a->width != b->width)
      return (int) a->width - (int) b->width;

    return (b->chars).as_array ().cmp ((a->chars).as_array ());
  }

  bool add_row (const hb_vector_t<int>* row)
  { return items.push (row); }
};

struct VarRegionAxis
{
  float evaluate (int coord) const
  {
    int peak = peakCoord.to_int ();
    if (peak == 0 || coord == peak)
      return 1.f;

    int start = startCoord.to_int (), end = endCoord.to_int ();

    /* TODO Move these to sanitize(). */
    if (unlikely (start > peak || peak > end))
      return 1.f;
    if (unlikely (start < 0 && end > 0 && peak != 0))
      return 1.f;

    if (coord <= start || end <= coord)
      return 0.f;

    /* Interpolate */
    if (coord < peak)
      return float (coord - start) / (peak - start);
    else
      return float (end - coord) / (end - peak);
  }

  bool sanitize (hb_sanitize_context_t *c) const
  {
    TRACE_SANITIZE (this);
    return_trace (c->check_struct (this));
    /* TODO Handle invalid start/peak/end configs, so we don't
     * have to do that at runtime. */
  }

  bool serialize (hb_serialize_context_t *c) const
  {
    TRACE_SERIALIZE (this);
    return_trace (c->embed (this));
  }

  public:
  F2DOT14	startCoord;
  F2DOT14	peakCoord;
  F2DOT14	endCoord;
  public:
  DEFINE_SIZE_STATIC (6);
};

#define REGION_CACHE_ITEM_CACHE_INVALID 2.f

struct VarRegionList
{
  using cache_t = float;

  float evaluate (unsigned int region_index,
		  const int *coords, unsigned int coord_len,
		  cache_t *cache = nullptr) const
  {
    if (unlikely (region_index >= regionCount))
      return 0.;

    float *cached_value = nullptr;
    if (cache)
    {
      cached_value = &(cache[region_index]);
      if (likely (*cached_value != REGION_CACHE_ITEM_CACHE_INVALID))
	return *cached_value;
    }

    const VarRegionAxis *axes = axesZ.arrayZ + (region_index * axisCount);

    float v = 1.;
    unsigned int count = axisCount;
    for (unsigned int i = 0; i < count; i++)
    {
      int coord = i < coord_len ? coords[i] : 0;
      float factor = axes[i].evaluate (coord);
      if (factor == 0.f)
      {
        if (cache)
	  *cached_value = 0.;
	return 0.;
      }
      v *= factor;
    }

    if (cache)
      *cached_value = v;
    return v;
  }

  bool sanitize (hb_sanitize_context_t *c) const
  {
    TRACE_SANITIZE (this);
    return_trace (c->check_struct (this) && axesZ.sanitize (c, axisCount * regionCount));
  }

  bool serialize (hb_serialize_context_t *c,
                  const hb_vector_t<hb_tag_t>& axis_tags,
                  const hb_vector_t<const hb_hashmap_t<hb_tag_t, Triple>*>& regions)
  {
    TRACE_SERIALIZE (this);
    unsigned axis_count = axis_tags.length;
    unsigned region_count = regions.length;
    if (!axis_count || !region_count) return_trace (false);
    if (unlikely (hb_unsigned_mul_overflows (axis_count * region_count,
                                             VarRegionAxis::static_size))) return_trace (false);
    if (unlikely (!c->extend_min (this))) return_trace (false);
    axisCount = axis_count;
    regionCount = region_count;

    for (unsigned r = 0; r < region_count; r++)
    {
      const auto& region = regions[r];
      for (unsigned i = 0; i < axis_count; i++)
      {
        hb_tag_t tag = axis_tags.arrayZ[i];
        VarRegionAxis var_region_rec;
        Triple *coords;
        if (region->has (tag, &coords))
        {
          var_region_rec.startCoord.set_float (coords->minimum);
          var_region_rec.peakCoord.set_float (coords->middle);
          var_region_rec.endCoord.set_float (coords->maximum);
        }
        else
        {
          var_region_rec.startCoord.set_int (0);
          var_region_rec.peakCoord.set_int (0);
          var_region_rec.endCoord.set_int (0);
        }
        if (!var_region_rec.serialize (c))
          return_trace (false);
      }
    }
    return_trace (true);
  }

  bool serialize (hb_serialize_context_t *c, const VarRegionList *src, const hb_inc_bimap_t &region_map)
  {
    TRACE_SERIALIZE (this);
    if (unlikely (!c->extend_min (this))) return_trace (false);
    axisCount = src->axisCount;
    regionCount = region_map.get_population ();
    if (unlikely (hb_unsigned_mul_overflows (axisCount * regionCount,
					     VarRegionAxis::static_size))) return_trace (false);
    if (unlikely (!c->extend (this))) return_trace (false);
    unsigned int region_count = src->regionCount;
    for (unsigned int r = 0; r < regionCount; r++)
    {
      unsigned int backward = region_map.backward (r);
      if (backward >= region_count) return_trace (false);
      hb_memcpy (&axesZ[axisCount * r], &src->axesZ[axisCount * backward], VarRegionAxis::static_size * axisCount);
    }

    return_trace (true);
  }

  bool get_var_region (unsigned region_index,
                       const hb_map_t& axes_old_index_tag_map,
                       hb_hashmap_t<hb_tag_t, Triple>& axis_tuples /* OUT */) const
  {
    if (region_index >= regionCount) return false;
    const VarRegionAxis* axis_region = axesZ.arrayZ + (region_index * axisCount);
    for (unsigned i = 0; i < axisCount; i++)
    {
      hb_tag_t *axis_tag;
      if (!axes_old_index_tag_map.has (i, &axis_tag))
        return false;

      float min_val = axis_region->startCoord.to_float ();
      float def_val = axis_region->peakCoord.to_float ();
      float max_val = axis_region->endCoord.to_float ();

      if (def_val != 0.f)
        axis_tuples.set (*axis_tag, Triple (min_val, def_val, max_val));
      axis_region++;
    }
    return !axis_tuples.in_error ();
  }

  bool get_var_regions (const hb_map_t& axes_old_index_tag_map,
                        hb_vector_t<hb_hashmap_t<hb_tag_t, Triple>>& regions /* OUT */) const
  {
    if (!regions.alloc (regionCount))
      return false;

    for (unsigned i = 0; i < regionCount; i++)
    {
      hb_hashmap_t<hb_tag_t, Triple> axis_tuples;
      if (!get_var_region (i, axes_old_index_tag_map, axis_tuples))
        return false;
      regions.push (std::move (axis_tuples));
    }
    return !regions.in_error ();
  }

  unsigned int get_size () const { return min_size + VarRegionAxis::static_size * axisCount * regionCount; }

  public:
  HBUINT16	axisCount;
  HBUINT15	regionCount;
  protected:
  UnsizedArrayOf<VarRegionAxis>
		axesZ;
  public:
  DEFINE_SIZE_ARRAY (4, axesZ);
};

struct VarData
{
  unsigned int get_item_count () const
  { return itemCount; }

  unsigned int get_region_index_count () const
  { return regionIndices.len; }
  
  unsigned get_region_index (unsigned i) const
  { return i >= regionIndices.len ? -1 : regionIndices[i]; }

  unsigned int get_row_size () const
  { return (wordCount () + regionIndices.len) * (longWords () ? 2 : 1); }

  unsigned int get_size () const
  { return min_size
	 - regionIndices.min_size + regionIndices.get_size ()
	 + itemCount * get_row_size ();
  }

  float get_delta (unsigned int inner,
		   const int *coords, unsigned int coord_count,
		   const VarRegionList &regions,
		   VarRegionList::cache_t *cache = nullptr) const
  {
    if (unlikely (inner >= itemCount))
      return 0.;

   unsigned int count = regionIndices.len;
   bool is_long = longWords ();
   unsigned word_count = wordCount ();
   unsigned int scount = is_long ? count : word_count;
   unsigned int lcount = is_long ? word_count : 0;

   const HBUINT8 *bytes = get_delta_bytes ();
   const HBUINT8 *row = bytes + inner * get_row_size ();

   float delta = 0.;
   unsigned int i = 0;

   const HBINT32 *lcursor = reinterpret_cast<const HBINT32 *> (row);
   for (; i < lcount; i++)
   {
     float scalar = regions.evaluate (regionIndices.arrayZ[i], coords, coord_count, cache);
     delta += scalar * *lcursor++;
   }
   const HBINT16 *scursor = reinterpret_cast<const HBINT16 *> (lcursor);
   for (; i < scount; i++)
   {
     float scalar = regions.evaluate (regionIndices.arrayZ[i], coords, coord_count, cache);
     delta += scalar * *scursor++;
   }
   const HBINT8 *bcursor = reinterpret_cast<const HBINT8 *> (scursor);
   for (; i < count; i++)
   {
     float scalar = regions.evaluate (regionIndices.arrayZ[i], coords, coord_count, cache);
     delta += scalar * *bcursor++;
   }

   return delta;
  }

  void get_region_scalars (const int *coords, unsigned int coord_count,
			   const VarRegionList &regions,
			   float *scalars /*OUT */,
			   unsigned int num_scalars) const
  {
    unsigned count = hb_min (num_scalars, regionIndices.len);
    for (unsigned int i = 0; i < count; i++)
      scalars[i] = regions.evaluate (regionIndices.arrayZ[i], coords, coord_count);
    for (unsigned int i = count; i < num_scalars; i++)
      scalars[i] = 0.f;
  }

  bool sanitize (hb_sanitize_context_t *c) const
  {
    TRACE_SANITIZE (this);
    return_trace (c->check_struct (this) &&
		  regionIndices.sanitize (c) &&
		  wordCount () <= regionIndices.len &&
		  c->check_range (get_delta_bytes (),
				  itemCount,
				  get_row_size ()));
  }

  bool serialize (hb_serialize_context_t *c,
                  bool has_long,
                  const hb_vector_t<const hb_vector_t<int>*>& rows)
  {
    TRACE_SERIALIZE (this);
    if (unlikely (!c->extend_min (this))) return_trace (false);
    unsigned row_count = rows.length;
    itemCount = row_count;

    int min_threshold = has_long ? -65536 : -128;
    int max_threshold = has_long ? +65535 : +127;
    enum delta_size_t { kZero=0, kNonWord, kWord };
    hb_vector_t<delta_size_t> delta_sz;
    unsigned num_regions = rows[0]->length;
    if (!delta_sz.resize (num_regions))
      return_trace (false);

    unsigned word_count = 0;
    for (unsigned r = 0; r < num_regions; r++)
    {
      for (unsigned i = 0; i < row_count; i++)
      {
        int delta = rows[i]->arrayZ[r];
        if (delta < min_threshold || delta > max_threshold)
        {
          delta_sz[r] = kWord;
          word_count++;
          break;
        }
        else if (delta != 0)
        {
          delta_sz[r] = kNonWord;
        }
      }
    }

    /* reorder regions: words and then non-words*/
    unsigned word_index = 0;
    unsigned non_word_index = word_count;
    hb_map_t ri_map;
    for (unsigned r = 0; r < num_regions; r++)
    {
      if (!delta_sz[r]) continue;
      unsigned new_r = (delta_sz[r] == kWord)? word_index++ : non_word_index++;
      if (!ri_map.set (new_r, r))
        return_trace (false);
    }

    wordSizeCount = word_count | (has_long ? 0x8000u /* LONG_WORDS */ : 0);

    unsigned ri_count = ri_map.get_population ();
    regionIndices.len = ri_count;
    if (unlikely (!c->extend (this))) return_trace (false);

    for (unsigned r = 0; r < ri_count; r++)
    {
      hb_codepoint_t *idx;
      if (!ri_map.has (r, &idx))
        return_trace (false);
      regionIndices[r] = *idx;
    }

    HBUINT8 *delta_bytes = get_delta_bytes ();
    unsigned row_size = get_row_size ();
    for (unsigned int i = 0; i < row_count; i++)
    {
      for (unsigned int r = 0; r < ri_count; r++)
      {
        int delta = rows[i]->arrayZ[ri_map[r]];
        set_item_delta_fast (i, r, delta, delta_bytes, row_size);
      }
    }
    return_trace (true);
  }

  bool serialize (hb_serialize_context_t *c,
		  const VarData *src,
		  const hb_inc_bimap_t &inner_map,
		  const hb_inc_bimap_t &region_map)
  {
    TRACE_SERIALIZE (this);
    if (unlikely (!c->extend_min (this))) return_trace (false);
    itemCount = inner_map.get_next_value ();

    /* Optimize word count */
    unsigned ri_count = src->regionIndices.len;
    enum delta_size_t { kZero=0, kNonWord, kWord };
    hb_vector_t<delta_size_t> delta_sz;
    hb_vector_t<unsigned int> ri_map;	/* maps new index to old index */
    delta_sz.resize (ri_count);
    ri_map.resize (ri_count);
    unsigned int new_word_count = 0;
    unsigned int r;

    const HBUINT8 *src_delta_bytes = src->get_delta_bytes ();
    unsigned src_row_size = src->get_row_size ();
    unsigned src_word_count = src->wordCount ();
    bool     src_long_words = src->longWords ();

    bool has_long = false;
    if (src_long_words)
    {
      for (r = 0; r < src_word_count; r++)
      {
        for (unsigned old_gid : inner_map.keys())
	{
	  int32_t delta = src->get_item_delta_fast (old_gid, r, src_delta_bytes, src_row_size);
	  if (delta < -65536 || 65535 < delta)
	  {
	    has_long = true;
	    break;
	  }
        }
      }
    }

    signed min_threshold = has_long ? -65536 : -128;
    signed max_threshold = has_long ? +65535 : +127;
    for (r = 0; r < ri_count; r++)
    {
      bool short_circuit = src_long_words == has_long && src_word_count <= r;

      delta_sz[r] = kZero;
      for (unsigned old_gid : inner_map.keys())
      {
	int32_t delta = src->get_item_delta_fast (old_gid, r, src_delta_bytes, src_row_size);
	if (delta < min_threshold || max_threshold < delta)
	{
	  delta_sz[r] = kWord;
	  new_word_count++;
	  break;
	}
	else if (delta != 0)
	{
	  delta_sz[r] = kNonWord;
	  if (short_circuit)
	    break;
	}
      }
    }

    unsigned int word_index = 0;
    unsigned int non_word_index = new_word_count;
    unsigned int new_ri_count = 0;
    for (r = 0; r < ri_count; r++)
      if (delta_sz[r])
      {
	unsigned new_r = (delta_sz[r] == kWord)? word_index++ : non_word_index++;
	ri_map[new_r] = r;
	new_ri_count++;
      }

    wordSizeCount = new_word_count | (has_long ? 0x8000u /* LONG_WORDS */ : 0);

    regionIndices.len = new_ri_count;

    if (unlikely (!c->extend (this))) return_trace (false);

    for (r = 0; r < new_ri_count; r++)
      regionIndices[r] = region_map[src->regionIndices[ri_map[r]]];

    HBUINT8 *delta_bytes = get_delta_bytes ();
    unsigned row_size = get_row_size ();
    unsigned count = itemCount;
    for (unsigned int i = 0; i < count; i++)
    {
      unsigned int old = inner_map.backward (i);
      for (unsigned int r = 0; r < new_ri_count; r++)
	set_item_delta_fast (i, r,
			     src->get_item_delta_fast (old, ri_map[r],
						       src_delta_bytes, src_row_size),
			     delta_bytes, row_size);
    }

    return_trace (true);
  }

  void collect_region_refs (hb_set_t &region_indices, const hb_inc_bimap_t &inner_map) const
  {
    const HBUINT8 *delta_bytes = get_delta_bytes ();
    unsigned row_size = get_row_size ();

    for (unsigned int r = 0; r < regionIndices.len; r++)
    {
      unsigned int region = regionIndices.arrayZ[r];
      if (region_indices.has (region)) continue;
      for (hb_codepoint_t old_gid : inner_map.keys())
	if (get_item_delta_fast (old_gid, r, delta_bytes, row_size) != 0)
	{
	  region_indices.add (region);
	  break;
	}
    }
  }

  public:
  const HBUINT8 *get_delta_bytes () const
  { return &StructAfter<HBUINT8> (regionIndices); }

  protected:
  HBUINT8 *get_delta_bytes ()
  { return &StructAfter<HBUINT8> (regionIndices); }

  public:
  int32_t get_item_delta_fast (unsigned int item, unsigned int region,
			       const HBUINT8 *delta_bytes, unsigned row_size) const
  {
    if (unlikely (item >= itemCount || region >= regionIndices.len)) return 0;

    const HBINT8 *p = (const HBINT8 *) delta_bytes + item * row_size;
    unsigned word_count = wordCount ();
    bool is_long = longWords ();
    if (is_long)
    {
      if (region < word_count)
	return ((const HBINT32 *) p)[region];
      else
	return ((const HBINT16 *)(p + HBINT32::static_size * word_count))[region - word_count];
    }
    else
    {
      if (region < word_count)
	return ((const HBINT16 *) p)[region];
      else
	return (p + HBINT16::static_size * word_count)[region - word_count];
    }
  }
  int32_t get_item_delta (unsigned int item, unsigned int region) const
  {
     return get_item_delta_fast (item, region,
				 get_delta_bytes (),
				 get_row_size ());
  }

  protected:
  void set_item_delta_fast (unsigned int item, unsigned int region, int32_t delta,
			    HBUINT8 *delta_bytes, unsigned row_size)
  {
    HBINT8 *p = (HBINT8 *) delta_bytes + item * row_size;
    unsigned word_count = wordCount ();
    bool is_long = longWords ();
    if (is_long)
    {
      if (region < word_count)
	((HBINT32 *) p)[region] = delta;
      else
	((HBINT16 *)(p + HBINT32::static_size * word_count))[region - word_count] = delta;
    }
    else
    {
      if (region < word_count)
	((HBINT16 *) p)[region] = delta;
      else
	(p + HBINT16::static_size * word_count)[region - word_count] = delta;
    }
  }
  void set_item_delta (unsigned int item, unsigned int region, int32_t delta)
  {
    set_item_delta_fast (item, region, delta,
			 get_delta_bytes (),
			 get_row_size ());
  }

  bool longWords () const { return wordSizeCount & 0x8000u /* LONG_WORDS */; }
  unsigned wordCount () const { return wordSizeCount & 0x7FFFu /* WORD_DELTA_COUNT_MASK */; }

  protected:
  HBUINT16		itemCount;
  HBUINT16		wordSizeCount;
  Array16Of<HBUINT16>	regionIndices;
/*UnsizedArrayOf<HBUINT8>bytesX;*/
  public:
  DEFINE_SIZE_ARRAY (6, regionIndices);
};

struct VariationStore
{
  friend struct item_variations_t;
  using cache_t = VarRegionList::cache_t;

  cache_t *create_cache () const
  {
#ifdef HB_NO_VAR
    return nullptr;
#endif
    auto &r = this+regions;
    unsigned count = r.regionCount;

    float *cache = (float *) hb_malloc (sizeof (float) * count);
    if (unlikely (!cache)) return nullptr;

    for (unsigned i = 0; i < count; i++)
      cache[i] = REGION_CACHE_ITEM_CACHE_INVALID;

    return cache;
  }

  static void destroy_cache (cache_t *cache) { hb_free (cache); }

  private:
  float get_delta (unsigned int outer, unsigned int inner,
		   const int *coords, unsigned int coord_count,
		   VarRegionList::cache_t *cache = nullptr) const
  {
#ifdef HB_NO_VAR
    return 0.f;
#endif

    if (unlikely (outer >= dataSets.len))
      return 0.f;

    return (this+dataSets[outer]).get_delta (inner,
					     coords, coord_count,
					     this+regions,
					     cache);
  }

  public:
  float get_delta (unsigned int index,
		   const int *coords, unsigned int coord_count,
		   VarRegionList::cache_t *cache = nullptr) const
  {
    unsigned int outer = index >> 16;
    unsigned int inner = index & 0xFFFF;
    return get_delta (outer, inner, coords, coord_count, cache);
  }
  float get_delta (unsigned int index,
		   hb_array_t<int> coords,
		   VarRegionList::cache_t *cache = nullptr) const
  {
    return get_delta (index,
		      coords.arrayZ, coords.length,
		      cache);
  }

  bool sanitize (hb_sanitize_context_t *c) const
  {
#ifdef HB_NO_VAR
    return true;
#endif

    TRACE_SANITIZE (this);
    return_trace (c->check_struct (this) &&
		  format == 1 &&
		  regions.sanitize (c, this) &&
		  dataSets.sanitize (c, this));
  }

  bool serialize (hb_serialize_context_t *c,
                  bool has_long,
                  const hb_vector_t<hb_tag_t>& axis_tags,
                  const hb_vector_t<const hb_hashmap_t<hb_tag_t, Triple>*>& region_list,
                  const hb_vector_t<delta_row_encoding_t>& vardata_encodings)
  {
    TRACE_SERIALIZE (this);
#ifdef HB_NO_VAR
    return_trace (false);
#endif
    if (unlikely (!c->extend_min (this))) return_trace (false);
    
    format = 1;
    if (!regions.serialize_serialize (c, axis_tags, region_list))
      return_trace (false);

    unsigned num_var_data = vardata_encodings.length;
    if (!num_var_data) return_trace (false);
    if (unlikely (!c->check_assign (dataSets.len, num_var_data,
                                    HB_SERIALIZE_ERROR_INT_OVERFLOW)))
      return_trace (false);

    if (unlikely (!c->extend (dataSets))) return_trace (false);
    for (unsigned i = 0; i < num_var_data; i++)
      if (!dataSets[i].serialize_serialize (c, has_long, vardata_encodings[i].items))
        return_trace (false);
    
    return_trace (true);
  }

  bool serialize (hb_serialize_context_t *c,
		  const VariationStore *src,
		  const hb_array_t <const hb_inc_bimap_t> &inner_maps)
  {
    TRACE_SERIALIZE (this);
#ifdef HB_NO_VAR
    return_trace (false);
#endif

    if (unlikely (!c->extend_min (this))) return_trace (false);

    unsigned int set_count = 0;
    for (unsigned int i = 0; i < inner_maps.length; i++)
      if (inner_maps[i].get_population ())
	set_count++;

    format = 1;

    const auto &src_regions = src+src->regions;

    hb_set_t region_indices;
    for (unsigned int i = 0; i < inner_maps.length; i++)
      (src+src->dataSets[i]).collect_region_refs (region_indices, inner_maps[i]);

    if (region_indices.in_error ())
      return_trace (false);

    region_indices.del_range ((src_regions).regionCount, hb_set_t::INVALID);

    /* TODO use constructor when our data-structures support that. */
    hb_inc_bimap_t region_map;
    + hb_iter (region_indices)
    | hb_apply ([&region_map] (unsigned _) { region_map.add(_); })
    ;
    if (region_map.in_error())
      return_trace (false);

    if (unlikely (!regions.serialize_serialize (c, &src_regions, region_map)))
      return_trace (false);

    dataSets.len = set_count;
    if (unlikely (!c->extend (dataSets))) return_trace (false);

    /* TODO: The following code could be simplified when
     * List16OfOffset16To::subset () can take a custom param to be passed to VarData::serialize () */
    unsigned int set_index = 0;
    for (unsigned int i = 0; i < inner_maps.length; i++)
    {
      if (!inner_maps[i].get_population ()) continue;
      if (unlikely (!dataSets[set_index++]
		     .serialize_serialize (c, &(src+src->dataSets[i]), inner_maps[i], region_map)))
	return_trace (false);
    }

    return_trace (true);
  }

  VariationStore *copy (hb_serialize_context_t *c) const
  {
    TRACE_SERIALIZE (this);
    auto *out = c->start_embed (this);
    if (unlikely (!out)) return_trace (nullptr);

    hb_vector_t <hb_inc_bimap_t> inner_maps;
    unsigned count = dataSets.len;
    for (unsigned i = 0; i < count; i++)
    {
      hb_inc_bimap_t *map = inner_maps.push ();
      auto &data = this+dataSets[i];

      unsigned itemCount = data.get_item_count ();
      for (unsigned j = 0; j < itemCount; j++)
	map->add (j);
    }

    if (unlikely (!out->serialize (c, this, inner_maps))) return_trace (nullptr);

    return_trace (out);
  }

  bool subset (hb_subset_context_t *c, const hb_array_t<const hb_inc_bimap_t> &inner_maps) const
  {
    TRACE_SUBSET (this);
#ifdef HB_NO_VAR
    return_trace (false);
#endif

    VariationStore *varstore_prime = c->serializer->start_embed<VariationStore> ();
    if (unlikely (!varstore_prime)) return_trace (false);

    varstore_prime->serialize (c->serializer, this, inner_maps);

    return_trace (
        !c->serializer->in_error()
        && varstore_prime->dataSets);
  }

  unsigned int get_region_index_count (unsigned int major) const
  {
#ifdef HB_NO_VAR
    return 0;
#endif
    return (this+dataSets[major]).get_region_index_count ();
  }

  void get_region_scalars (unsigned int major,
			   const int *coords, unsigned int coord_count,
			   float *scalars /*OUT*/,
			   unsigned int num_scalars) const
  {
#ifdef HB_NO_VAR
    for (unsigned i = 0; i < num_scalars; i++)
      scalars[i] = 0.f;
    return;
#endif

    (this+dataSets[major]).get_region_scalars (coords, coord_count,
					       this+regions,
					       &scalars[0], num_scalars);
  }

  unsigned int get_sub_table_count () const
   {
#ifdef HB_NO_VAR
     return 0;
#endif
     return dataSets.len;
   }

  const VarData& get_sub_table (unsigned i) const
  {
#ifdef HB_NO_VAR
     return Null (VarData);
#endif
     return this+dataSets[i];
  }

  const VarRegionList& get_region_list () const
  {
#ifdef HB_NO_VAR
     return Null (VarRegionList);
#endif
     return this+regions;
  }

  protected:
  HBUINT16				format;
  Offset32To<VarRegionList>		regions;
  Array16OfOffset32To<VarData>		dataSets;
  public:
  DEFINE_SIZE_ARRAY_SIZED (8, dataSets);
};

#undef REGION_CACHE_ITEM_CACHE_INVALID

/*
 * Feature Variations
 */
enum Cond_with_Var_flag_t
{
  KEEP_COND_WITH_VAR = 0,
  KEEP_RECORD_WITH_VAR = 1,
  DROP_COND_WITH_VAR = 2,
  DROP_RECORD_WITH_VAR = 3,
};

struct ConditionFormat1
{
  friend struct Condition;

  bool subset (hb_subset_context_t *c) const
  {
    TRACE_SUBSET (this);
    auto *out = c->serializer->embed (this);
    if (unlikely (!out)) return_trace (false);

    const hb_map_t *index_map = &c->plan->axes_index_map;
    if (index_map->is_empty ()) return_trace (true);

    const hb_map_t& axes_old_index_tag_map = c->plan->axes_old_index_tag_map;
    hb_codepoint_t *axis_tag;
    if (!axes_old_index_tag_map.has (axisIndex, &axis_tag) ||
        !index_map->has (axisIndex))
      return_trace (false);

    const hb_hashmap_t<hb_tag_t, Triple>& normalized_axes_location = c->plan->axes_location;
    Triple axis_limit{-1.f, 0.f, 1.f};
    Triple *normalized_limit;
    if (normalized_axes_location.has (*axis_tag, &normalized_limit))
      axis_limit = *normalized_limit;

    const hb_hashmap_t<hb_tag_t, TripleDistances>& axes_triple_distances = c->plan->axes_triple_distances;
    TripleDistances axis_triple_distances{1.f, 1.f};
    TripleDistances *triple_dists;
    if (axes_triple_distances.has (*axis_tag, &triple_dists))
      axis_triple_distances = *triple_dists;

    float normalized_min = renormalizeValue (filterRangeMinValue.to_float (), axis_limit, axis_triple_distances, false);
    float normalized_max = renormalizeValue (filterRangeMaxValue.to_float (), axis_limit, axis_triple_distances, false);
    out->filterRangeMinValue.set_float (normalized_min);
    out->filterRangeMaxValue.set_float (normalized_max);

    return_trace (c->serializer->check_assign (out->axisIndex, index_map->get (axisIndex),
                                               HB_SERIALIZE_ERROR_INT_OVERFLOW));
  }

  private:
  Cond_with_Var_flag_t keep_with_variations (hb_collect_feature_substitutes_with_var_context_t *c,
                                             hb_map_t *condition_map /* OUT */) const
  {
    //invalid axis index, drop the entire record
    if (!c->axes_index_tag_map->has (axisIndex))
      return DROP_RECORD_WITH_VAR;

    hb_tag_t axis_tag = c->axes_index_tag_map->get (axisIndex);

    Triple axis_range (-1.f, 0.f, 1.f);
    Triple *axis_limit;
    if (c->axes_location->has (axis_tag, &axis_limit))
      axis_range = *axis_limit;

    float axis_min_val = axis_range.minimum;
    float axis_default_val = axis_range.middle;
    float axis_max_val = axis_range.maximum;

    float filter_min_val = filterRangeMinValue.to_float ();
    float filter_max_val = filterRangeMaxValue.to_float ();

    if (axis_default_val < filter_min_val ||
        axis_default_val > filter_max_val)
      c->apply = false;

    //condition not met, drop the entire record
    if (axis_min_val > filter_max_val || axis_max_val < filter_min_val ||
        filter_min_val > filter_max_val)
      return DROP_RECORD_WITH_VAR;

    //condition met and axis pinned, drop the condition
    if (c->axes_location->has (axis_tag) &&
        c->axes_location->get (axis_tag).is_point ())
      return DROP_COND_WITH_VAR;

    if (filter_max_val != axis_max_val || filter_min_val != axis_min_val)
    {
      // add axisIndex->value into the hashmap so we can check if the record is
      // unique with variations
      int16_t int_filter_max_val = filterRangeMaxValue.to_int ();
      int16_t int_filter_min_val = filterRangeMinValue.to_int ();
      hb_codepoint_t val = (int_filter_max_val << 16) + int_filter_min_val;

      condition_map->set (axisIndex, val);
      return KEEP_COND_WITH_VAR;
    }

    return KEEP_RECORD_WITH_VAR;
  }

  bool evaluate (const int *coords, unsigned int coord_len) const
  {
    int coord = axisIndex < coord_len ? coords[axisIndex] : 0;
    return filterRangeMinValue.to_int () <= coord && coord <= filterRangeMaxValue.to_int ();
  }

  bool sanitize (hb_sanitize_context_t *c) const
  {
    TRACE_SANITIZE (this);
    return_trace (c->check_struct (this));
  }

  protected:
  HBUINT16	format;		/* Format identifier--format = 1 */
  HBUINT16	axisIndex;
  F2DOT14	filterRangeMinValue;
  F2DOT14	filterRangeMaxValue;
  public:
  DEFINE_SIZE_STATIC (8);
};

struct Condition
{
  bool evaluate (const int *coords, unsigned int coord_len) const
  {
    switch (u.format) {
    case 1: return u.format1.evaluate (coords, coord_len);
    default:return false;
    }
  }

  Cond_with_Var_flag_t keep_with_variations (hb_collect_feature_substitutes_with_var_context_t *c,
                                             hb_map_t *condition_map /* OUT */) const
  {
    switch (u.format) {
    case 1: return u.format1.keep_with_variations (c, condition_map);
    default: c->apply = false; return KEEP_COND_WITH_VAR;
    }
  }

  template <typename context_t, typename ...Ts>
  typename context_t::return_t dispatch (context_t *c, Ts&&... ds) const
  {
    if (unlikely (!c->may_dispatch (this, &u.format))) return c->no_dispatch_return_value ();
    TRACE_DISPATCH (this, u.format);
    switch (u.format) {
    case 1: return_trace (c->dispatch (u.format1, std::forward<Ts> (ds)...));
    default:return_trace (c->default_return_value ());
    }
  }

  bool sanitize (hb_sanitize_context_t *c) const
  {
    TRACE_SANITIZE (this);
    if (!u.format.sanitize (c)) return_trace (false);
    switch (u.format) {
    case 1: return_trace (u.format1.sanitize (c));
    default:return_trace (true);
    }
  }

  protected:
  union {
  HBUINT16		format;		/* Format identifier */
  ConditionFormat1	format1;
  } u;
  public:
  DEFINE_SIZE_UNION (2, format);
};

struct ConditionSet
{
  bool evaluate (const int *coords, unsigned int coord_len) const
  {
    unsigned int count = conditions.len;
    for (unsigned int i = 0; i < count; i++)
      if (!(this+conditions.arrayZ[i]).evaluate (coords, coord_len))
	return false;
    return true;
  }

  void keep_with_variations (hb_collect_feature_substitutes_with_var_context_t *c) const
  {
    hb_map_t *condition_map = hb_map_create ();
    if (unlikely (!condition_map)) return;
    hb::shared_ptr<hb_map_t> p {condition_map};

    hb_set_t *cond_set = hb_set_create ();
    if (unlikely (!cond_set)) return;
    hb::shared_ptr<hb_set_t> s {cond_set};

    c->apply = true;
    bool should_keep = false;
    unsigned num_kept_cond = 0, cond_idx = 0;
    for (const auto& offset : conditions)
    {
      Cond_with_Var_flag_t ret = (this+offset).keep_with_variations (c, condition_map);
      // condition is not met or condition out of range, drop the entire record
      if (ret == DROP_RECORD_WITH_VAR)
        return;

      if (ret == KEEP_COND_WITH_VAR)
      {
        should_keep = true;
        cond_set->add (cond_idx);
        num_kept_cond++;
      }

      if (ret == KEEP_RECORD_WITH_VAR)
        should_keep = true;

      cond_idx++;
    }

    if (!should_keep) return;

    //check if condition_set is unique with variations
    if (c->conditionset_map->has (p))
      //duplicate found, drop the entire record
      return;

    c->conditionset_map->set (p, 1);
    c->record_cond_idx_map->set (c->cur_record_idx, s);
    if (should_keep && num_kept_cond == 0)
      c->universal = true;
  }

  bool subset (hb_subset_context_t *c,
               hb_subset_layout_context_t *l) const
  {
    TRACE_SUBSET (this);
    auto *out = c->serializer->start_embed (this);
    if (unlikely (!out || !c->serializer->extend_min (out))) return_trace (false);

    hb_set_t *retained_cond_set = nullptr;
    if (l->feature_record_cond_idx_map != nullptr)
      retained_cond_set = l->feature_record_cond_idx_map->get (l->cur_feature_var_record_idx);

    unsigned int count = conditions.len;
    for (unsigned int i = 0; i < count; i++)
    {
      if (retained_cond_set != nullptr && !retained_cond_set->has (i))
        continue;
      subset_offset_array (c, out->conditions, this) (conditions[i]);
    }

    return_trace (bool (out->conditions));
  }

  bool sanitize (hb_sanitize_context_t *c) const
  {
    TRACE_SANITIZE (this);
    return_trace (conditions.sanitize (c, this));
  }

  protected:
  Array16OfOffset32To<Condition>	conditions;
  public:
  DEFINE_SIZE_ARRAY (2, conditions);
};

struct FeatureTableSubstitutionRecord
{
  friend struct FeatureTableSubstitution;

  void collect_lookups (const void *base, hb_set_t *lookup_indexes /* OUT */) const
  {
    return (base+feature).add_lookup_indexes_to (lookup_indexes);
  }

  void closure_features (const void *base,
			 const hb_map_t *lookup_indexes,
			 hb_set_t       *feature_indexes /* OUT */) const
  {
    if ((base+feature).intersects_lookup_indexes (lookup_indexes))
      feature_indexes->add (featureIndex);
  }

  void collect_feature_substitutes_with_variations (hb_hashmap_t<unsigned, const Feature*> *feature_substitutes_map,
                                                    const hb_set_t *feature_indices,
                                                    const void *base) const
  {
    if (feature_indices->has (featureIndex))
      feature_substitutes_map->set (featureIndex, &(base+feature));
  }

  bool subset (hb_subset_layout_context_t *c, const void *base) const
  {
    TRACE_SUBSET (this);
    if (!c->feature_index_map->has (featureIndex) ||
        c->feature_substitutes_map->has (featureIndex)) {
      // Feature that is being substituted is not being retained, so we don't
      // need this.
      return_trace (false);
    }

    auto *out = c->subset_context->serializer->embed (this);
    if (unlikely (!out)) return_trace (false);

    out->featureIndex = c->feature_index_map->get (featureIndex);
    return_trace (out->feature.serialize_subset (c->subset_context, feature, base, c));
  }

  bool sanitize (hb_sanitize_context_t *c, const void *base) const
  {
    TRACE_SANITIZE (this);
    return_trace (c->check_struct (this) && feature.sanitize (c, base));
  }

  protected:
  HBUINT16		featureIndex;
  Offset32To<Feature>	feature;
  public:
  DEFINE_SIZE_STATIC (6);
};

struct FeatureTableSubstitution
{
  const Feature *find_substitute (unsigned int feature_index) const
  {
    unsigned int count = substitutions.len;
    for (unsigned int i = 0; i < count; i++)
    {
      const FeatureTableSubstitutionRecord &record = substitutions.arrayZ[i];
      if (record.featureIndex == feature_index)
	return &(this+record.feature);
    }
    return nullptr;
  }

  void collect_lookups (const hb_set_t *feature_indexes,
			const hb_hashmap_t<unsigned, const Feature*> *feature_substitutes_map,
			hb_set_t       *lookup_indexes /* OUT */) const
  {
    + hb_iter (substitutions)
    | hb_filter (feature_indexes, &FeatureTableSubstitutionRecord::featureIndex)
    | hb_filter ([feature_substitutes_map] (const FeatureTableSubstitutionRecord& record)
                 {
                   if (feature_substitutes_map == nullptr) return true;
                   return !feature_substitutes_map->has (record.featureIndex);
                 })
    | hb_apply ([this, lookup_indexes] (const FeatureTableSubstitutionRecord& r)
		{ r.collect_lookups (this, lookup_indexes); })
    ;
  }

  void closure_features (const hb_map_t *lookup_indexes,
			 hb_set_t       *feature_indexes /* OUT */) const
  {
    for (const FeatureTableSubstitutionRecord& record : substitutions)
      record.closure_features (this, lookup_indexes, feature_indexes);
  }

  bool intersects_features (const hb_map_t *feature_index_map) const
  {
    for (const FeatureTableSubstitutionRecord& record : substitutions)
    {
      if (feature_index_map->has (record.featureIndex)) return true;
    }
    return false;
  }

  void collect_feature_substitutes_with_variations (hb_collect_feature_substitutes_with_var_context_t *c) const
  {
    for (const FeatureTableSubstitutionRecord& record : substitutions)
      record.collect_feature_substitutes_with_variations (c->feature_substitutes_map, c->feature_indices, this);
  }

  bool subset (hb_subset_context_t        *c,
	       hb_subset_layout_context_t *l) const
  {
    TRACE_SUBSET (this);
    auto *out = c->serializer->start_embed (*this);
    if (unlikely (!out || !c->serializer->extend_min (out))) return_trace (false);

    out->version.major = version.major;
    out->version.minor = version.minor;

    + substitutions.iter ()
    | hb_apply (subset_record_array (l, &(out->substitutions), this))
    ;

    return_trace (bool (out->substitutions));
  }

  bool sanitize (hb_sanitize_context_t *c) const
  {
    TRACE_SANITIZE (this);
    return_trace (version.sanitize (c) &&
		  likely (version.major == 1) &&
		  substitutions.sanitize (c, this));
  }

  protected:
  FixedVersion<>	version;	/* Version--0x00010000u */
  Array16Of<FeatureTableSubstitutionRecord>
			substitutions;
  public:
  DEFINE_SIZE_ARRAY (6, substitutions);
};

struct FeatureVariationRecord
{
  friend struct FeatureVariations;

  void collect_lookups (const void     *base,
			const hb_set_t *feature_indexes,
			const hb_hashmap_t<unsigned, const Feature*> *feature_substitutes_map,
			hb_set_t       *lookup_indexes /* OUT */) const
  {
    return (base+substitutions).collect_lookups (feature_indexes, feature_substitutes_map, lookup_indexes);
  }

  void closure_features (const void     *base,
			 const hb_map_t *lookup_indexes,
			 hb_set_t       *feature_indexes /* OUT */) const
  {
    (base+substitutions).closure_features (lookup_indexes, feature_indexes);
  }

  bool intersects_features (const void *base, const hb_map_t *feature_index_map) const
  {
    return (base+substitutions).intersects_features (feature_index_map);
  }

  void collect_feature_substitutes_with_variations (hb_collect_feature_substitutes_with_var_context_t *c,
                                                    const void *base) const
  {
    (base+conditions).keep_with_variations (c);
    if (c->apply && !c->variation_applied)
    {
      (base+substitutions).collect_feature_substitutes_with_variations (c);
      c->variation_applied = true; // set variations only once
    }
  }

  bool subset (hb_subset_layout_context_t *c, const void *base) const
  {
    TRACE_SUBSET (this);
    auto *out = c->subset_context->serializer->embed (this);
    if (unlikely (!out)) return_trace (false);

    out->conditions.serialize_subset (c->subset_context, conditions, base, c);
    out->substitutions.serialize_subset (c->subset_context, substitutions, base, c);

    return_trace (true);
  }

  bool sanitize (hb_sanitize_context_t *c, const void *base) const
  {
    TRACE_SANITIZE (this);
    return_trace (conditions.sanitize (c, base) &&
		  substitutions.sanitize (c, base));
  }

  protected:
  Offset32To<ConditionSet>
			conditions;
  Offset32To<FeatureTableSubstitution>
			substitutions;
  public:
  DEFINE_SIZE_STATIC (8);
};

struct FeatureVariations
{
  static constexpr unsigned NOT_FOUND_INDEX = 0xFFFFFFFFu;

  bool find_index (const int *coords, unsigned int coord_len,
		   unsigned int *index) const
  {
    unsigned int count = varRecords.len;
    for (unsigned int i = 0; i < count; i++)
    {
      const FeatureVariationRecord &record = varRecords.arrayZ[i];
      if ((this+record.conditions).evaluate (coords, coord_len))
      {
	*index = i;
	return true;
      }
    }
    *index = NOT_FOUND_INDEX;
    return false;
  }

  const Feature *find_substitute (unsigned int variations_index,
				  unsigned int feature_index) const
  {
    const FeatureVariationRecord &record = varRecords[variations_index];
    return (this+record.substitutions).find_substitute (feature_index);
  }

  void collect_feature_substitutes_with_variations (hb_collect_feature_substitutes_with_var_context_t *c) const
  {
    unsigned int count = varRecords.len;
    for (unsigned int i = 0; i < count; i++)
    {
      c->cur_record_idx = i;
      varRecords[i].collect_feature_substitutes_with_variations (c, this);
      if (c->universal)
        break;
    }
    if (c->variation_applied && !c->universal &&
        !c->record_cond_idx_map->is_empty ())
      c->insert_catch_all_feature_variation_record = true;
  }

  FeatureVariations* copy (hb_serialize_context_t *c) const
  {
    TRACE_SERIALIZE (this);
    return_trace (c->embed (*this));
  }

  void collect_lookups (const hb_set_t *feature_indexes,
			const hb_hashmap_t<unsigned, const Feature*> *feature_substitutes_map,
			hb_set_t       *lookup_indexes /* OUT */) const
  {
    for (const FeatureVariationRecord& r : varRecords)
      r.collect_lookups (this, feature_indexes, feature_substitutes_map, lookup_indexes);
  }

  void closure_features (const hb_map_t *lookup_indexes,
			 const hb_hashmap_t<unsigned, hb::shared_ptr<hb_set_t>> *feature_record_cond_idx_map,
			 hb_set_t       *feature_indexes /* OUT */) const
  {
    unsigned int count = varRecords.len;
    for (unsigned int i = 0; i < count; i++)
    {
      if (feature_record_cond_idx_map != nullptr &&
          !feature_record_cond_idx_map->has (i))
        continue;
      varRecords[i].closure_features (this, lookup_indexes, feature_indexes);
    }
  }

  bool subset (hb_subset_context_t *c,
	       hb_subset_layout_context_t *l) const
  {
    TRACE_SUBSET (this);
    auto *out = c->serializer->start_embed (*this);
    if (unlikely (!out || !c->serializer->extend_min (out))) return_trace (false);

    out->version.major = version.major;
    out->version.minor = version.minor;

    int keep_up_to = -1;
    for (int i = varRecords.len - 1; i >= 0; i--) {
      if (varRecords[i].intersects_features (this, l->feature_index_map)) {
        keep_up_to = i;
        break;
      }
    }

    unsigned count = (unsigned) (keep_up_to + 1);
    for (unsigned i = 0; i < count; i++)
    {
      if (l->feature_record_cond_idx_map != nullptr &&
          !l->feature_record_cond_idx_map->has (i))
        continue;

      l->cur_feature_var_record_idx = i;
      subset_record_array (l, &(out->varRecords), this) (varRecords[i]);
    }
    return_trace (bool (out->varRecords));
  }

  bool sanitize (hb_sanitize_context_t *c) const
  {
    TRACE_SANITIZE (this);
    return_trace (version.sanitize (c) &&
		  likely (version.major == 1) &&
		  varRecords.sanitize (c, this));
  }

  protected:
  FixedVersion<>	version;	/* Version--0x00010000u */
  Array32Of<FeatureVariationRecord>
			varRecords;
  public:
  DEFINE_SIZE_ARRAY_SIZED (8, varRecords);
};


/*
 * Device Tables
 */

struct HintingDevice
{
  friend struct Device;

  private:

  hb_position_t get_x_delta (hb_font_t *font) const
  { return get_delta (font->x_ppem, font->x_scale); }

  hb_position_t get_y_delta (hb_font_t *font) const
  { return get_delta (font->y_ppem, font->y_scale); }

  public:

  unsigned int get_size () const
  {
    unsigned int f = deltaFormat;
    if (unlikely (f < 1 || f > 3 || startSize > endSize)) return 3 * HBUINT16::static_size;
    return HBUINT16::static_size * (4 + ((endSize - startSize) >> (4 - f)));
  }

  bool sanitize (hb_sanitize_context_t *c) const
  {
    TRACE_SANITIZE (this);
    return_trace (c->check_struct (this) && c->check_range (this, this->get_size ()));
  }

  HintingDevice* copy (hb_serialize_context_t *c) const
  {
    TRACE_SERIALIZE (this);
    return_trace (c->embed<HintingDevice> (this));
  }

  private:

  int get_delta (unsigned int ppem, int scale) const
  {
    if (!ppem) return 0;

    int pixels = get_delta_pixels (ppem);

    if (!pixels) return 0;

    return (int) (pixels * (int64_t) scale / ppem);
  }
  int get_delta_pixels (unsigned int ppem_size) const
  {
    unsigned int f = deltaFormat;
    if (unlikely (f < 1 || f > 3))
      return 0;

    if (ppem_size < startSize || ppem_size > endSize)
      return 0;

    unsigned int s = ppem_size - startSize;

    unsigned int byte = deltaValueZ[s >> (4 - f)];
    unsigned int bits = (byte >> (16 - (((s & ((1 << (4 - f)) - 1)) + 1) << f)));
    unsigned int mask = (0xFFFFu >> (16 - (1 << f)));

    int delta = bits & mask;

    if ((unsigned int) delta >= ((mask + 1) >> 1))
      delta -= mask + 1;

    return delta;
  }

  protected:
  HBUINT16	startSize;		/* Smallest size to correct--in ppem */
  HBUINT16	endSize;		/* Largest size to correct--in ppem */
  HBUINT16	deltaFormat;		/* Format of DeltaValue array data: 1, 2, or 3
					 * 1	Signed 2-bit value, 8 values per uint16
					 * 2	Signed 4-bit value, 4 values per uint16
					 * 3	Signed 8-bit value, 2 values per uint16
					 */
  UnsizedArrayOf<HBUINT16>
		deltaValueZ;		/* Array of compressed data */
  public:
  DEFINE_SIZE_ARRAY (6, deltaValueZ);
};

struct VariationDevice
{
  friend struct Device;

  private:

  hb_position_t get_x_delta (hb_font_t *font,
			     const VariationStore &store,
			     VariationStore::cache_t *store_cache = nullptr) const
  { return font->em_scalef_x (get_delta (font, store, store_cache)); }

  hb_position_t get_y_delta (hb_font_t *font,
			     const VariationStore &store,
			     VariationStore::cache_t *store_cache = nullptr) const
  { return font->em_scalef_y (get_delta (font, store, store_cache)); }

  VariationDevice* copy (hb_serialize_context_t *c,
                         const hb_hashmap_t<unsigned, hb_pair_t<unsigned, int>> *layout_variation_idx_delta_map) const
  {
    TRACE_SERIALIZE (this);
    if (!layout_variation_idx_delta_map) return_trace (nullptr);

    hb_pair_t<unsigned, int> *v;
    if (!layout_variation_idx_delta_map->has (varIdx, &v))
      return_trace (nullptr);

    c->start_zerocopy (this->static_size);
    auto *out = c->embed (this);
    if (unlikely (!out)) return_trace (nullptr);

    if (!c->check_assign (out->varIdx, hb_first (*v), HB_SERIALIZE_ERROR_INT_OVERFLOW))
      return_trace (nullptr);
    return_trace (out);
  }

  void collect_variation_index (hb_collect_variation_indices_context_t *c) const
  { c->layout_variation_indices->add (varIdx); }

  bool sanitize (hb_sanitize_context_t *c) const
  {
    TRACE_SANITIZE (this);
    return_trace (c->check_struct (this));
  }

  private:

  float get_delta (hb_font_t *font,
		   const VariationStore &store,
		   VariationStore::cache_t *store_cache = nullptr) const
  {
    return store.get_delta (varIdx, font->coords, font->num_coords, (VariationStore::cache_t *) store_cache);
  }

  protected:
  VarIdx	varIdx;
  HBUINT16	deltaFormat;	/* Format identifier for this table: 0x0x8000 */
  public:
  DEFINE_SIZE_STATIC (6);
};

struct DeviceHeader
{
  protected:
  HBUINT16		reserved1;
  HBUINT16		reserved2;
  public:
  HBUINT16		format;		/* Format identifier */
  public:
  DEFINE_SIZE_STATIC (6);
};

struct Device
{
  hb_position_t get_x_delta (hb_font_t *font,
			     const VariationStore &store=Null (VariationStore),
			     VariationStore::cache_t *store_cache = nullptr) const
  {
    switch (u.b.format)
    {
#ifndef HB_NO_HINTING
    case 1: case 2: case 3:
      return u.hinting.get_x_delta (font);
#endif
#ifndef HB_NO_VAR
    case 0x8000:
      return u.variation.get_x_delta (font, store, store_cache);
#endif
    default:
      return 0;
    }
  }
  hb_position_t get_y_delta (hb_font_t *font,
			     const VariationStore &store=Null (VariationStore),
			     VariationStore::cache_t *store_cache = nullptr) const
  {
    switch (u.b.format)
    {
    case 1: case 2: case 3:
#ifndef HB_NO_HINTING
      return u.hinting.get_y_delta (font);
#endif
#ifndef HB_NO_VAR
    case 0x8000:
      return u.variation.get_y_delta (font, store, store_cache);
#endif
    default:
      return 0;
    }
  }

  bool sanitize (hb_sanitize_context_t *c) const
  {
    TRACE_SANITIZE (this);
    if (!u.b.format.sanitize (c)) return_trace (false);
    switch (u.b.format) {
#ifndef HB_NO_HINTING
    case 1: case 2: case 3:
      return_trace (u.hinting.sanitize (c));
#endif
#ifndef HB_NO_VAR
    case 0x8000:
      return_trace (u.variation.sanitize (c));
#endif
    default:
      return_trace (true);
    }
  }

  Device* copy (hb_serialize_context_t *c,
                const hb_hashmap_t<unsigned, hb_pair_t<unsigned, int>> *layout_variation_idx_delta_map=nullptr) const
  {
    TRACE_SERIALIZE (this);
    switch (u.b.format) {
#ifndef HB_NO_HINTING
    case 1:
    case 2:
    case 3:
      return_trace (reinterpret_cast<Device *> (u.hinting.copy (c)));
#endif
#ifndef HB_NO_VAR
    case 0x8000:
      return_trace (reinterpret_cast<Device *> (u.variation.copy (c, layout_variation_idx_delta_map)));
#endif
    default:
      return_trace (nullptr);
    }
  }

  void collect_variation_indices (hb_collect_variation_indices_context_t *c) const
  {
    switch (u.b.format) {
#ifndef HB_NO_HINTING
    case 1:
    case 2:
    case 3:
      return;
#endif
#ifndef HB_NO_VAR
    case 0x8000:
      u.variation.collect_variation_index (c);
      return;
#endif
    default:
      return;
    }
  }

  unsigned get_variation_index () const
  {
    switch (u.b.format) {
#ifndef HB_NO_VAR
    case 0x8000:
      return u.variation.varIdx;
#endif
    default:
      return HB_OT_LAYOUT_NO_VARIATIONS_INDEX;
    }
  }

  protected:
  union {
  DeviceHeader		b;
  HintingDevice		hinting;
#ifndef HB_NO_VAR
  VariationDevice	variation;
#endif
  } u;
  public:
  DEFINE_SIZE_UNION (6, b);
};


} /* namespace OT */


#endif /* HB_OT_LAYOUT_COMMON_HH */