src/java.desktop/share/native/libfontmanager/harfbuzz/hb-ot-layout-common.hh
changeset 54232 7c11a7cc7c1d
parent 51000 7c8841474f57
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/java.desktop/share/native/libfontmanager/harfbuzz/hb-ot-layout-common.hh	Fri Mar 01 16:59:19 2019 -0800
@@ -0,0 +1,2178 @@
+/*
+ * 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"
+
+
+#ifndef HB_MAX_NESTING_LEVEL
+#define HB_MAX_NESTING_LEVEL    6
+#endif
+#ifndef HB_MAX_CONTEXT_LENGTH
+#define HB_MAX_CONTEXT_LENGTH   64
+#endif
+#ifndef HB_CLOSURE_MAX_STAGES
+/*
+ * The maximum number of times a lookup can be applied during shaping.
+ * Used to limit the number of iterations of the closure algorithm.
+ * This must be larger than the number of times add_pause() is
+ * called in a collect_features call of any shaper.
+ */
+#define HB_CLOSURE_MAX_STAGES   32
+#endif
+
+#ifndef HB_MAX_SCRIPTS
+#define HB_MAX_SCRIPTS  500
+#endif
+
+#ifndef HB_MAX_LANGSYS
+#define HB_MAX_LANGSYS  2000
+#endif
+
+
+namespace OT {
+
+
+#define NOT_COVERED             ((unsigned int) -1)
+
+
+
+/*
+ *
+ * OpenType Layout Common Table Formats
+ *
+ */
+
+
+/*
+ * Script, ScriptList, LangSys, Feature, FeatureList, Lookup, LookupList
+ */
+
+struct Record_sanitize_closure_t {
+  hb_tag_t tag;
+  const void *list_base;
+};
+
+template <typename Type>
+struct Record
+{
+  int cmp (hb_tag_t a) const { return tag.cmp (a); }
+
+  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 */
+  OffsetTo<Type>
+                offset;         /* Offset from beginning of object holding
+                                 * the Record */
+  public:
+  DEFINE_SIZE_STATIC (6);
+};
+
+template <typename Type>
+struct RecordArrayOf : SortedArrayOf<Record<Type> >
+{
+  const OffsetTo<Type>& get_offset (unsigned int i) const
+  { return (*this)[i].offset; }
+  OffsetTo<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) {
+      const Record<Type> *arr = this->sub_array (start_offset, record_count);
+      unsigned int count = *record_count;
+      for (unsigned int i = 0; i < count; i++)
+        record_tags[i] = arr[i].tag;
+    }
+    return this->len;
+  }
+  bool find_index (hb_tag_t tag, unsigned int *index) const
+  {
+    return this->bfind (tag, index, HB_BFIND_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) const
+  {
+    TRACE_SUBSET (this);
+    struct RecordListOf<Type> *out = c->serializer->embed (*this);
+    if (unlikely (!out)) return_trace (false);
+    unsigned int count = this->len;
+    for (unsigned int i = 0; i < count; i++)
+      out->get_offset (i).serialize_subset (c, (*this)[i], out);
+    return_trace (true);
+  }
+
+  bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (RecordArrayOf<Type>::sanitize (c, this));
+  }
+};
+
+
+struct RangeRecord
+{
+  int cmp (hb_codepoint_t g) const
+  { return g < start ? -1 : g <= end ? 0 : +1; }
+
+  bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (c->check_struct (this));
+  }
+
+  bool intersects (const hb_set_t *glyphs) const
+  { return glyphs->intersects (start, end); }
+
+  template <typename set_t>
+  bool add_coverage (set_t *glyphs) const
+  { return glyphs->add_range (start, end); }
+
+  GlyphID       start;          /* First GlyphID in the range */
+  GlyphID       end;            /* Last GlyphID in the range */
+  HBUINT16      value;          /* Value */
+  public:
+  DEFINE_SIZE_STATIC (6);
+};
+DECLARE_NULL_NAMESPACE_BYTES (OT, RangeRecord);
+
+
+struct IndexArray : ArrayOf<Index>
+{
+  unsigned int get_indexes (unsigned int start_offset,
+                            unsigned int *_count /* IN/OUT */,
+                            unsigned int *_indexes /* OUT */) const
+  {
+    if (_count) {
+      const HBUINT16 *arr = this->sub_array (start_offset, _count);
+      unsigned int count = *_count;
+      for (unsigned int i = 0; i < count; i++)
+        _indexes[i] = arr[i];
+    }
+    return this->len;
+  }
+
+  void add_indexes_to (hb_set_t* output /* OUT */) const
+  {
+    output->add_array (arrayZ, len);
+  }
+};
+
+
+struct Script;
+struct LangSys;
+struct Feature;
+
+
+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;;
+  }
+
+  bool subset (hb_subset_context_t *c) const
+  {
+    TRACE_SUBSET (this);
+    return_trace (c->serializer->embed (*this));
+  }
+
+  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; }
+
+  bool subset (hb_subset_context_t *c) const
+  {
+    TRACE_SUBSET (this);
+    struct Script *out = c->serializer->embed (*this);
+    if (unlikely (!out)) return_trace (false);
+    out->defaultLangSys.serialize_subset (c, this+defaultLangSys, out);
+    unsigned int count = langSys.len;
+    for (unsigned int i = 0; i < count; i++)
+      out->langSys.arrayZ[i].offset.serialize_subset (c, this+langSys[i].offset, out);
+    return_trace (true);
+  }
+
+  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:
+  OffsetTo<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);
+};
+
+typedef RecordListOf<Script> ScriptList;
+
+
+/* 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 sutable 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);
+  }
+
+  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));
+  }
+
+  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
+{
+  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.) */
+  ArrayOf<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
+  {
+    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);
+  }
+
+  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);
+  }
+
+  private:
+  union {
+  FeatureParamsSize                     size;
+  FeatureParamsStylisticSet             stylisticSet;
+  FeatureParamsCharacterVariants        characterVariants;
+  } u;
+  public:
+  DEFINE_SIZE_STATIC (17);
+};
+
+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 subset (hb_subset_context_t *c) const
+  {
+    TRACE_SUBSET (this);
+    struct Feature *out = c->serializer->embed (*this);
+    if (unlikely (!out)) return_trace (false);
+    out->featureParams.set (0); /* TODO(subset) FeatureParams. */
+    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.
+     */
+
+    OffsetTo<FeatureParams> orig_offset = featureParams;
+    if (unlikely (!featureParams.sanitize (c, this, closure ? closure->tag : HB_TAG_NONE)))
+      return_trace (false);
+
+    if (likely (orig_offset.is_null ()))
+      return_trace (true);
+
+    if (featureParams == 0 && closure &&
+        closure->tag == HB_TAG ('s','i','z','e') &&
+        closure->list_base && closure->list_base < this)
+    {
+      unsigned int new_offset_int = (unsigned int) orig_offset -
+                                    (((char *) this) - ((char *) closure->list_base));
+
+      OffsetTo<FeatureParams> new_offset;
+      /* Check that it did not overflow. */
+      new_offset.set (new_offset_int);
+      if (new_offset == new_offset_int &&
+          c->try_set (&featureParams, new_offset) &&
+          !featureParams.sanitize (c, this, closure ? closure->tag : HB_TAG_NONE))
+        return_trace (false);
+    }
+
+    return_trace (true);
+  }
+
+  OffsetTo<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);
+};
+
+typedef RecordListOf<Feature> FeatureList;
+
+
+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 TSubTable& get_subtable (unsigned int i) const
+  { return this+CastR<OffsetArrayOf<TSubTable> > (subTable)[i]; }
+
+  template <typename TSubTable>
+  const OffsetArrayOf<TSubTable>& get_subtables () const
+  { return CastR<OffsetArrayOf<TSubTable> > (subTable); }
+  template <typename TSubTable>
+  OffsetArrayOf<TSubTable>& get_subtables ()
+  { return CastR<OffsetArrayOf<TSubTable> > (subTable); }
+
+  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 context_t::return_t dispatch (context_t *c) 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);
+      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.set (lookup_type);
+    lookupFlag.set (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.set (lookup_props >> 16);
+    }
+    return_trace (true);
+  }
+
+  /* Older compilers need this to NOT be locally defined in a function. */
+  template <typename TSubTable>
+  struct SubTableSubsetWrapper
+  {
+    SubTableSubsetWrapper (const TSubTable &subtable_,
+                           unsigned int lookup_type_) :
+                             subtable (subtable_),
+                             lookup_type (lookup_type_) {}
+
+    bool subset (hb_subset_context_t *c) const
+    { return subtable.dispatch (c, lookup_type); }
+
+    private:
+    const TSubTable &subtable;
+    unsigned int lookup_type;
+  };
+
+  template <typename TSubTable>
+  bool subset (hb_subset_context_t *c) const
+  {
+    TRACE_SUBSET (this);
+    struct Lookup *out = c->serializer->embed (*this);
+    if (unlikely (!out)) return_trace (false);
+
+    /* Subset the actual subtables. */
+    /* TODO Drop empty ones, either by calling intersects() beforehand,
+     * or just dropping null offsets after. */
+    const OffsetArrayOf<TSubTable>& subtables = get_subtables<TSubTable> ();
+    OffsetArrayOf<TSubTable>& out_subtables = out->get_subtables<TSubTable> ();
+    unsigned int count = subTable.len;
+    for (unsigned int i = 0; i < count; i++)
+    {
+      SubTableSubsetWrapper<TSubTable> wrapper (this+subtables[i], get_type ());
+
+      out_subtables[i].serialize_subset (c, wrapper, out);
+    }
+
+    return_trace (true);
+  }
+
+  /* Older compilers need this to NOT be locally defined in a function. */
+  template <typename TSubTable>
+  struct SubTableSanitizeWrapper : TSubTable
+  {
+    bool sanitize (hb_sanitize_context_t *c, unsigned int lookup_type) const
+    { return this->dispatch (c, lookup_type); }
+  };
+
+  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);
+    if (lookupFlag & LookupFlag::UseMarkFilteringSet)
+    {
+      const HBUINT16 &markFilteringSet = StructAfter<HBUINT16> (subTable);
+      if (!markFilteringSet.sanitize (c)) return_trace (false);
+    }
+
+    if (unlikely (!CastR<OffsetArrayOf<SubTableSanitizeWrapper<TSubTable> > > (subTable)
+                   .sanitize (c, this, get_type ())))
+      return_trace (false);
+
+    if (unlikely (get_type () == TSubTable::Extension))
+    {
+      /* 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! */
+      unsigned int type = get_subtable<TSubTable> (0).u.extension.get_type ();
+      unsigned int count = get_subtable_count ();
+      for (unsigned int i = 1; i < count; i++)
+        if (get_subtable<TSubTable> (i).u.extension.get_type () != type)
+          return_trace (false);
+    }
+    return_trace (true);
+    return_trace (true);
+  }
+
+  private:
+  HBUINT16      lookupType;             /* Different enumerations for GSUB and GPOS */
+  HBUINT16      lookupFlag;             /* Lookup qualifiers */
+  ArrayOf<Offset16>
+                subTable;               /* Array of SubTables */
+/*HBUINT16      markFilteringSetX[VAR];*//* 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);
+};
+
+typedef OffsetListOf<Lookup> LookupList;
+
+
+/*
+ * Coverage Table
+ */
+
+struct CoverageFormat1
+{
+  friend struct Coverage;
+
+  private:
+  unsigned int get_coverage (hb_codepoint_t glyph_id) const
+  {
+    unsigned int i;
+    glyphArray.bfind (glyph_id, &i, HB_BFIND_NOT_FOUND_STORE, NOT_COVERED);
+    return i;
+  }
+
+  bool serialize (hb_serialize_context_t *c,
+                  hb_array_t<const GlyphID> glyphs)
+  {
+    TRACE_SERIALIZE (this);
+    return_trace (glyphArray.serialize (c, glyphs));
+  }
+
+  bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (glyphArray.sanitize (c));
+  }
+
+  bool intersects (const hb_set_t *glyphs) const
+  {
+    /* TODO Speed up, using hb_set_next() and bsearch()? */
+    unsigned int count = glyphArray.len;
+    for (unsigned int i = 0; i < count; i++)
+      if (glyphs->has (glyphArray[i]))
+        return true;
+    return false;
+  }
+  bool intersects_coverage (const hb_set_t *glyphs, unsigned int index) const
+  { return glyphs->has (glyphArray[index]); }
+
+  template <typename set_t>
+  bool add_coverage (set_t *glyphs) const
+  {
+    return glyphs->add_sorted_array (glyphArray.arrayZ, glyphArray.len);
+  }
+
+  public:
+  /* Older compilers need this to be public. */
+  struct Iter {
+    void init (const struct CoverageFormat1 &c_) { c = &c_; i = 0; }
+    void fini () {}
+    bool more () { return i < c->glyphArray.len; }
+    void next () { i++; }
+    hb_codepoint_t get_glyph () { return c->glyphArray[i]; }
+    unsigned int get_coverage () { return i; }
+
+    private:
+    const struct CoverageFormat1 *c;
+    unsigned int i;
+  };
+  private:
+
+  protected:
+  HBUINT16      coverageFormat; /* Format identifier--format = 1 */
+  SortedArrayOf<GlyphID>
+                glyphArray;     /* Array of GlyphIDs--in numerical order */
+  public:
+  DEFINE_SIZE_ARRAY (4, glyphArray);
+};
+
+struct CoverageFormat2
+{
+  friend struct Coverage;
+
+  private:
+  unsigned int get_coverage (hb_codepoint_t glyph_id) const
+  {
+    const RangeRecord &range = rangeRecord.bsearch (glyph_id);
+    return likely (range.start <= range.end) ?
+           (unsigned int) range.value + (glyph_id - range.start) :
+           NOT_COVERED;
+  }
+
+  bool serialize (hb_serialize_context_t *c,
+                  hb_array_t<const GlyphID> glyphs)
+  {
+    TRACE_SERIALIZE (this);
+    if (unlikely (!c->extend_min (*this))) return_trace (false);
+
+    if (unlikely (!glyphs.length))
+    {
+      rangeRecord.len.set (0);
+      return_trace (true);
+    }
+
+    unsigned int num_ranges = 1;
+    for (unsigned int i = 1; i < glyphs.length; i++)
+      if (glyphs[i - 1] + 1 != glyphs[i])
+        num_ranges++;
+    rangeRecord.len.set (num_ranges);
+    if (unlikely (!c->extend (rangeRecord))) return_trace (false);
+
+    unsigned int range = 0;
+    rangeRecord[range].start = glyphs[0];
+    rangeRecord[range].value.set (0);
+    for (unsigned int i = 1; i < glyphs.length; i++)
+    {
+      if (glyphs[i - 1] + 1 != glyphs[i])
+      {
+        range++;
+        rangeRecord[range].start = glyphs[i];
+        rangeRecord[range].value.set (i);
+      }
+      rangeRecord[range].end = glyphs[i];
+    }
+    return_trace (true);
+  }
+
+  bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (rangeRecord.sanitize (c));
+  }
+
+  bool intersects (const hb_set_t *glyphs) const
+  {
+    /* TODO Speed up, using hb_set_next() and bsearch()? */
+    unsigned int count = rangeRecord.len;
+    for (unsigned int i = 0; i < count; i++)
+      if (rangeRecord[i].intersects (glyphs))
+        return true;
+    return false;
+  }
+  bool intersects_coverage (const hb_set_t *glyphs, unsigned int index) const
+  {
+    unsigned int i;
+    unsigned int count = rangeRecord.len;
+    for (i = 0; i < count; i++) {
+      const RangeRecord &range = rangeRecord[i];
+      if (range.value <= index &&
+          index < (unsigned int) range.value + (range.end - range.start) &&
+          range.intersects (glyphs))
+        return true;
+      else if (index < range.value)
+        return false;
+    }
+    return false;
+  }
+
+  template <typename set_t>
+  bool add_coverage (set_t *glyphs) const
+  {
+    unsigned int count = rangeRecord.len;
+    for (unsigned int i = 0; i < count; i++)
+      if (unlikely (!rangeRecord[i].add_coverage (glyphs)))
+        return false;
+    return true;
+  }
+
+  public:
+  /* Older compilers need this to be public. */
+  struct Iter
+  {
+    void init (const CoverageFormat2 &c_)
+    {
+      c = &c_;
+      coverage = 0;
+      i = 0;
+      j = c->rangeRecord.len ? c->rangeRecord[0].start : 0;
+      if (unlikely (c->rangeRecord[0].start > c->rangeRecord[0].end))
+      {
+        /* Broken table. Skip. */
+        i = c->rangeRecord.len;
+      }
+    }
+    void fini () {}
+    bool more () { return i < c->rangeRecord.len; }
+    void next ()
+    {
+      if (j >= c->rangeRecord[i].end)
+      {
+        i++;
+        if (more ())
+        {
+          hb_codepoint_t old = j;
+          j = c->rangeRecord[i].start;
+          if (unlikely (j <= old))
+          {
+            /* Broken table. Skip. Important to avoid DoS. */
+           i = c->rangeRecord.len;
+           return;
+          }
+          coverage = c->rangeRecord[i].value;
+        }
+        return;
+      }
+      coverage++;
+      j++;
+    }
+    hb_codepoint_t get_glyph () { return j; }
+    unsigned int get_coverage () { return coverage; }
+
+    private:
+    const struct CoverageFormat2 *c;
+    unsigned int i, coverage;
+    hb_codepoint_t j;
+  };
+  private:
+
+  protected:
+  HBUINT16      coverageFormat; /* Format identifier--format = 2 */
+  SortedArrayOf<RangeRecord>
+                rangeRecord;    /* Array of glyph ranges--ordered by
+                                 * Start GlyphID. rangeCount entries
+                                 * long */
+  public:
+  DEFINE_SIZE_ARRAY (4, rangeRecord);
+};
+
+struct Coverage
+{
+  unsigned int get_coverage (hb_codepoint_t glyph_id) const
+  {
+    switch (u.format) {
+    case 1: return u.format1.get_coverage (glyph_id);
+    case 2: return u.format2.get_coverage (glyph_id);
+    default:return NOT_COVERED;
+    }
+  }
+
+  bool serialize (hb_serialize_context_t *c,
+                  hb_array_t<const GlyphID> glyphs)
+  {
+    TRACE_SERIALIZE (this);
+    if (unlikely (!c->extend_min (*this))) return_trace (false);
+
+    unsigned int num_ranges = 1;
+    for (unsigned int i = 1; i < glyphs.length; i++)
+      if (glyphs[i - 1] + 1 != glyphs[i])
+        num_ranges++;
+    u.format.set (glyphs.length * 2 < num_ranges * 3 ? 1 : 2);
+
+    switch (u.format)
+    {
+    case 1: return_trace (u.format1.serialize (c, glyphs));
+    case 2: return_trace (u.format2.serialize (c, glyphs));
+    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));
+    default:return_trace (true);
+    }
+  }
+
+  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);
+    default:return false;
+    }
+  }
+  bool intersects_coverage (const hb_set_t *glyphs, unsigned int index) const
+  {
+    switch (u.format)
+    {
+    case 1: return u.format1.intersects_coverage (glyphs, index);
+    case 2: return u.format2.intersects_coverage (glyphs, index);
+    default:return false;
+    }
+  }
+
+  /* Might return false if array looks unsorted.
+   * Used for faster rejection of corrupt data. */
+  template <typename set_t>
+  bool add_coverage (set_t *glyphs) const
+  {
+    switch (u.format)
+    {
+    case 1: return u.format1.add_coverage (glyphs);
+    case 2: return u.format2.add_coverage (glyphs);
+    default:return false;
+    }
+  }
+
+  struct Iter
+  {
+    Iter (const Coverage &c_)
+    {
+      memset (this, 0, sizeof (*this));
+      format = c_.u.format;
+      switch (format)
+      {
+      case 1: u.format1.init (c_.u.format1); return;
+      case 2: u.format2.init (c_.u.format2); return;
+      default:                               return;
+      }
+    }
+    bool more ()
+    {
+      switch (format)
+      {
+      case 1: return u.format1.more ();
+      case 2: return u.format2.more ();
+      default:return false;
+      }
+    }
+    void next ()
+    {
+      switch (format)
+      {
+      case 1: u.format1.next (); break;
+      case 2: u.format2.next (); break;
+      default:                   break;
+      }
+    }
+    hb_codepoint_t get_glyph ()
+    {
+      switch (format)
+      {
+      case 1: return u.format1.get_glyph ();
+      case 2: return u.format2.get_glyph ();
+      default:return 0;
+      }
+    }
+    unsigned int get_coverage ()
+    {
+      switch (format)
+      {
+      case 1: return u.format1.get_coverage ();
+      case 2: return u.format2.get_coverage ();
+      default:return -1;
+      }
+    }
+
+    private:
+    unsigned int format;
+    union {
+    CoverageFormat2::Iter       format2; /* Put this one first since it's larger; helps shut up compiler. */
+    CoverageFormat1::Iter       format1;
+    } u;
+  };
+
+  protected:
+  union {
+  HBUINT16              format;         /* Format identifier */
+  CoverageFormat1       format1;
+  CoverageFormat2       format2;
+  } u;
+  public:
+  DEFINE_SIZE_UNION (2, format);
+};
+
+
+/*
+ * Class Definition Table
+ */
+
+static inline void ClassDef_serialize (hb_serialize_context_t *c,
+                                       hb_array_t<const GlyphID> glyphs,
+                                       hb_array_t<const HBUINT16> klasses);
+
+struct ClassDefFormat1
+{
+  friend struct ClassDef;
+
+  private:
+  unsigned int get_class (hb_codepoint_t glyph_id) const
+  {
+    return classValue[(unsigned int) (glyph_id - startGlyph)];
+  }
+
+  bool serialize (hb_serialize_context_t *c,
+                  hb_array_t<const HBUINT16> glyphs,
+                  hb_array_t<const HBUINT16> klasses)
+  {
+    TRACE_SERIALIZE (this);
+    if (unlikely (!c->extend_min (*this))) return_trace (false);
+
+    if (unlikely (!glyphs.length))
+    {
+      startGlyph.set (0);
+      classValue.len.set (0);
+      return_trace (true);
+    }
+
+    hb_codepoint_t glyph_min = glyphs[0];
+    hb_codepoint_t glyph_max = glyphs[glyphs.length - 1];
+
+    startGlyph.set (glyph_min);
+    classValue.len.set (glyph_max - glyph_min + 1);
+    if (unlikely (!c->extend (classValue))) return_trace (false);
+
+    for (unsigned int i = 0; i < glyphs.length; i++)
+      classValue[glyphs[i] - glyph_min] = klasses[i];
+
+    return_trace (true);
+  }
+
+  bool subset (hb_subset_context_t *c) const
+  {
+    TRACE_SUBSET (this);
+    const hb_set_t &glyphset = *c->plan->glyphset;
+    const hb_map_t &glyph_map = *c->plan->glyph_map;
+    hb_vector_t<GlyphID> glyphs;
+    hb_vector_t<HBUINT16> klasses;
+
+    hb_codepoint_t start = startGlyph;
+    hb_codepoint_t end   = start + classValue.len;
+    for (hb_codepoint_t g = start; g < end; g++)
+    {
+      unsigned int value = classValue[g - start];
+      if (!value) continue;
+      if (!glyphset.has (g)) continue;
+      glyphs.push()->set (glyph_map[g]);
+      klasses.push()->set (value);
+    }
+    c->serializer->propagate_error (glyphs, klasses);
+    ClassDef_serialize (c->serializer, glyphs, klasses);
+    return_trace (glyphs.length);
+  }
+
+  bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (c->check_struct (this) && classValue.sanitize (c));
+  }
+
+  template <typename set_t>
+  bool add_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 add_class (set_t *glyphs, unsigned int 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
+  {
+    /* TODO Speed up, using hb_set_next()? */
+    hb_codepoint_t start = startGlyph;
+    hb_codepoint_t end = startGlyph + classValue.len;
+    for (hb_codepoint_t iter = startGlyph - 1;
+         hb_set_next (glyphs, &iter) && iter < end;)
+      if (classValue[iter - start]) return true;
+    return false;
+  }
+  bool intersects_class (const hb_set_t *glyphs, unsigned int 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 (!hb_set_next (glyphs, &g)) return false;
+      if (g < startGlyph) return true;
+      g = startGlyph + count - 1;
+      if (hb_set_next (glyphs, &g)) return true;
+      /* Fall through. */
+    }
+    for (unsigned int i = 0; i < count; i++)
+      if (classValue[i] == klass && glyphs->has (startGlyph + i))
+        return true;
+    return false;
+  }
+
+  protected:
+  HBUINT16      classFormat;    /* Format identifier--format = 1 */
+  GlyphID       startGlyph;     /* First GlyphID of the classValueArray */
+  ArrayOf<HBUINT16>
+                classValue;     /* Array of Class Values--one per GlyphID */
+  public:
+  DEFINE_SIZE_ARRAY (6, classValue);
+};
+
+struct ClassDefFormat2
+{
+  friend struct ClassDef;
+
+  private:
+  unsigned int get_class (hb_codepoint_t glyph_id) const
+  {
+    return rangeRecord.bsearch (glyph_id).value;
+  }
+
+  bool serialize (hb_serialize_context_t *c,
+                  hb_array_t<const HBUINT16> glyphs,
+                  hb_array_t<const HBUINT16> klasses)
+  {
+    TRACE_SERIALIZE (this);
+    if (unlikely (!c->extend_min (*this))) return_trace (false);
+
+    if (unlikely (!glyphs.length))
+    {
+      rangeRecord.len.set (0);
+      return_trace (true);
+    }
+
+    unsigned int num_ranges = 1;
+    for (unsigned int i = 1; i < glyphs.length; i++)
+      if (glyphs[i - 1] + 1 != glyphs[i] ||
+          klasses[i - 1] != klasses[i])
+        num_ranges++;
+    rangeRecord.len.set (num_ranges);
+    if (unlikely (!c->extend (rangeRecord))) return_trace (false);
+
+    unsigned int range = 0;
+    rangeRecord[range].start = glyphs[0];
+    rangeRecord[range].value.set (klasses[0]);
+    for (unsigned int i = 1; i < glyphs.length; i++)
+    {
+      if (glyphs[i - 1] + 1 != glyphs[i] ||
+          klasses[i - 1] != klasses[i])
+      {
+        range++;
+        rangeRecord[range].start = glyphs[i];
+        rangeRecord[range].value = klasses[i];
+      }
+      rangeRecord[range].end = glyphs[i];
+    }
+    return_trace (true);
+  }
+
+  bool subset (hb_subset_context_t *c) const
+  {
+    TRACE_SUBSET (this);
+    const hb_set_t &glyphset = *c->plan->glyphset;
+    const hb_map_t &glyph_map = *c->plan->glyph_map;
+    hb_vector_t<GlyphID> glyphs;
+    hb_vector_t<HBUINT16> klasses;
+
+    unsigned int count = rangeRecord.len;
+    for (unsigned int i = 0; i < count; i++)
+    {
+      unsigned int value = rangeRecord[i].value;
+      if (!value) continue;
+      hb_codepoint_t start = rangeRecord[i].start;
+      hb_codepoint_t end   = rangeRecord[i].end + 1;
+      for (hb_codepoint_t g = start; g < end; g++)
+      {
+        if (!glyphset.has (g)) continue;
+        glyphs.push ()->set (glyph_map[g]);
+        klasses.push ()->set (value);
+      }
+    }
+    c->serializer->propagate_error (glyphs, klasses);
+    ClassDef_serialize (c->serializer, glyphs, klasses);
+    return_trace (glyphs.length);
+  }
+
+  bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (rangeRecord.sanitize (c));
+  }
+
+  template <typename set_t>
+  bool add_coverage (set_t *glyphs) const
+  {
+    unsigned int count = rangeRecord.len;
+    for (unsigned int i = 0; i < count; i++)
+      if (rangeRecord[i].value)
+        if (unlikely (!rangeRecord[i].add_coverage (glyphs)))
+          return false;
+    return true;
+  }
+
+  template <typename set_t>
+  bool add_class (set_t *glyphs, unsigned int klass) const
+  {
+    unsigned int count = rangeRecord.len;
+    for (unsigned int i = 0; i < count; i++)
+    {
+      if (rangeRecord[i].value == klass)
+        if (unlikely (!rangeRecord[i].add_coverage (glyphs)))
+          return false;
+    }
+    return true;
+  }
+
+  bool intersects (const hb_set_t *glyphs) const
+  {
+    /* TODO Speed up, using hb_set_next() and bsearch()? */
+    unsigned int count = rangeRecord.len;
+    for (unsigned int i = 0; i < count; i++)
+      if (rangeRecord[i].intersects (glyphs))
+        return true;
+    return false;
+  }
+  bool intersects_class (const hb_set_t *glyphs, unsigned int klass) const
+  {
+    unsigned int count = rangeRecord.len;
+    if (klass == 0)
+    {
+      /* Match if there's any glyph that is not listed! */
+      hb_codepoint_t g = HB_SET_VALUE_INVALID;
+      for (unsigned int i = 0; i < count; i++)
+      {
+        if (!hb_set_next (glyphs, &g))
+          break;
+        if (g < rangeRecord[i].start)
+          return true;
+        g = rangeRecord[i].end;
+      }
+      if (g != HB_SET_VALUE_INVALID && hb_set_next (glyphs, &g))
+        return true;
+      /* Fall through. */
+    }
+    for (unsigned int i = 0; i < count; i++)
+      if (rangeRecord[i].value == klass && rangeRecord[i].intersects (glyphs))
+        return true;
+    return false;
+  }
+
+  protected:
+  HBUINT16      classFormat;    /* Format identifier--format = 2 */
+  SortedArrayOf<RangeRecord>
+                rangeRecord;    /* Array of glyph ranges--ordered by
+                                 * Start GlyphID */
+  public:
+  DEFINE_SIZE_ARRAY (4, rangeRecord);
+};
+
+struct ClassDef
+{
+  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);
+    default:return 0;
+    }
+  }
+
+  bool serialize (hb_serialize_context_t *c,
+                  hb_array_t<const GlyphID> glyphs,
+                  hb_array_t<const HBUINT16> klasses)
+  {
+    TRACE_SERIALIZE (this);
+    if (unlikely (!c->extend_min (*this))) return_trace (false);
+
+    unsigned int format = 2;
+    if (glyphs.length)
+    {
+      hb_codepoint_t glyph_min = glyphs[0];
+      hb_codepoint_t glyph_max = glyphs[glyphs.length - 1];
+
+      unsigned int num_ranges = 1;
+      for (unsigned int i = 1; i < glyphs.length; i++)
+        if (glyphs[i - 1] + 1 != glyphs[i] ||
+            klasses[i - 1] != klasses[i])
+          num_ranges++;
+
+      if (1 + (glyph_max - glyph_min + 1) < num_ranges * 3)
+        format = 1;
+    }
+    u.format.set (format);
+
+    switch (u.format)
+    {
+    case 1: return_trace (u.format1.serialize (c, glyphs, klasses));
+    case 2: return_trace (u.format2.serialize (c, glyphs, klasses));
+    default:return_trace (false);
+    }
+  }
+
+  bool subset (hb_subset_context_t *c) const
+  {
+    TRACE_SUBSET (this);
+    switch (u.format) {
+    case 1: return_trace (u.format1.subset (c));
+    case 2: return_trace (u.format2.subset (c));
+    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));
+    default:return_trace (true);
+    }
+  }
+
+  /* Might return false if array looks unsorted.
+   * Used for faster rejection of corrupt data. */
+  template <typename set_t>
+  bool add_coverage (set_t *glyphs) const
+  {
+    switch (u.format) {
+    case 1: return u.format1.add_coverage (glyphs);
+    case 2: return u.format2.add_coverage (glyphs);
+    default:return false;
+    }
+  }
+
+  /* Might return false if array looks unsorted.
+   * Used for faster rejection of corrupt data. */
+  template <typename set_t>
+  bool add_class (set_t *glyphs, unsigned int klass) const
+  {
+    switch (u.format) {
+    case 1: return u.format1.add_class (glyphs, klass);
+    case 2: return u.format2.add_class (glyphs, klass);
+    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);
+    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);
+    default:return false;
+    }
+  }
+
+  protected:
+  union {
+  HBUINT16              format;         /* Format identifier */
+  ClassDefFormat1       format1;
+  ClassDefFormat2       format2;
+  } u;
+  public:
+  DEFINE_SIZE_UNION (2, format);
+};
+
+static inline void ClassDef_serialize (hb_serialize_context_t *c,
+                                       hb_array_t<const GlyphID> glyphs,
+                                       hb_array_t<const HBUINT16> klasses)
+{ c->start_embed<ClassDef> ()->serialize (c, glyphs, klasses); }
+
+
+/*
+ * Item Variation Store
+ */
+
+struct VarRegionAxis
+{
+  float evaluate (int coord) const
+  {
+    int start = startCoord, peak = peakCoord, end = endCoord;
+
+    /* TODO Move these to sanitize(). */
+    if (unlikely (start > peak || peak > end))
+      return 1.;
+    if (unlikely (start < 0 && end > 0 && peak != 0))
+      return 1.;
+
+    if (peak == 0 || coord == peak)
+      return 1.;
+
+    if (coord <= start || end <= coord)
+      return 0.;
+
+    /* 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. */
+  }
+
+  public:
+  F2DOT14       startCoord;
+  F2DOT14       peakCoord;
+  F2DOT14       endCoord;
+  public:
+  DEFINE_SIZE_STATIC (6);
+};
+
+struct VarRegionList
+{
+  float evaluate (unsigned int region_index,
+                         const int *coords, unsigned int coord_len) const
+  {
+    if (unlikely (region_index >= regionCount))
+      return 0.;
+
+    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)
+        return 0.;
+      v *= factor;
+    }
+    return v;
+  }
+
+  bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (c->check_struct (this) &&
+                  axesZ.sanitize (c, (unsigned int) axisCount * (unsigned int) regionCount));
+  }
+
+  unsigned int get_region_count () const { return regionCount; }
+
+  protected:
+  HBUINT16      axisCount;
+  HBUINT16      regionCount;
+  UnsizedArrayOf<VarRegionAxis>
+                axesZ;
+  public:
+  DEFINE_SIZE_ARRAY (4, axesZ);
+};
+
+struct VarData
+{
+  unsigned int get_region_index_count () const
+  { return regionIndices.len; }
+
+  unsigned int get_row_size () const
+  { return shortCount + regionIndices.len; }
+
+  unsigned int get_size () const
+  { return itemCount * get_row_size (); }
+
+  float get_delta (unsigned int inner,
+                          const int *coords, unsigned int coord_count,
+                          const VarRegionList &regions) const
+  {
+    if (unlikely (inner >= itemCount))
+      return 0.;
+
+   unsigned int count = regionIndices.len;
+   unsigned int scount = shortCount;
+
+   const HBUINT8 *bytes = &StructAfter<HBUINT8> (regionIndices);
+   const HBUINT8 *row = bytes + inner * (scount + count);
+
+   float delta = 0.;
+   unsigned int i = 0;
+
+   const HBINT16 *scursor = reinterpret_cast<const HBINT16 *> (row);
+   for (; i < scount; i++)
+   {
+     float scalar = regions.evaluate (regionIndices.arrayZ[i], coords, coord_count);
+     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);
+     delta += scalar * *bcursor++;
+   }
+
+   return delta;
+  }
+
+  void get_scalars (int *coords, unsigned int coord_count,
+                    const VarRegionList &regions,
+                    float *scalars /*OUT */,
+                    unsigned int num_scalars) const
+  {
+    assert (num_scalars == regionIndices.len);
+   for (unsigned int i = 0; i < num_scalars; i++)
+   {
+     scalars[i] = regions.evaluate (regionIndices.arrayZ[i], coords, coord_count);
+   }
+  }
+
+  bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (c->check_struct (this) &&
+                  regionIndices.sanitize (c) &&
+                  shortCount <= regionIndices.len &&
+                  c->check_range (&StructAfter<HBUINT8> (regionIndices),
+                                  itemCount,
+                                  get_row_size ()));
+  }
+
+  protected:
+  HBUINT16              itemCount;
+  HBUINT16              shortCount;
+  ArrayOf<HBUINT16>     regionIndices;
+/*UnsizedArrayOf<HBUINT8>bytesX;*/
+  public:
+  DEFINE_SIZE_ARRAY (6, regionIndices);
+};
+
+struct VariationStore
+{
+  float get_delta (unsigned int outer, unsigned int inner,
+                   const int *coords, unsigned int coord_count) const
+  {
+    if (unlikely (outer >= dataSets.len))
+      return 0.;
+
+    return (this+dataSets[outer]).get_delta (inner,
+                                             coords, coord_count,
+                                             this+regions);
+  }
+
+  float get_delta (unsigned int index,
+                   const int *coords, unsigned int coord_count) const
+  {
+    unsigned int outer = index >> 16;
+    unsigned int inner = index & 0xFFFF;
+    return get_delta (outer, inner, coords, coord_count);
+  }
+
+  bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (c->check_struct (this) &&
+                  format == 1 &&
+                  regions.sanitize (c, this) &&
+                  dataSets.sanitize (c, this));
+  }
+
+  unsigned int get_region_index_count (unsigned int ivs) const
+  { return (this+dataSets[ivs]).get_region_index_count (); }
+
+  void get_scalars (unsigned int ivs,
+                    int *coords, unsigned int coord_count,
+                    float *scalars /*OUT*/,
+                    unsigned int num_scalars) const
+  {
+    (this+dataSets[ivs]).get_scalars (coords, coord_count, this+regions,
+                                      &scalars[0], num_scalars);
+  }
+
+  protected:
+  HBUINT16                              format;
+  LOffsetTo<VarRegionList>              regions;
+  LOffsetArrayOf<VarData>               dataSets;
+  public:
+  DEFINE_SIZE_ARRAY (8, dataSets);
+};
+
+/*
+ * Feature Variations
+ */
+
+struct ConditionFormat1
+{
+  friend struct Condition;
+
+  private:
+  bool evaluate (const int *coords, unsigned int coord_len) const
+  {
+    int coord = axisIndex < coord_len ? coords[axisIndex] : 0;
+    return filterRangeMinValue <= coord && coord <= filterRangeMaxValue;
+  }
+
+  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;
+    }
+  }
+
+  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;
+  }
+
+  bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (conditions.sanitize (c, this));
+  }
+
+  protected:
+  LOffsetArrayOf<Condition>     conditions;
+  public:
+  DEFINE_SIZE_ARRAY (2, conditions);
+};
+
+struct FeatureTableSubstitutionRecord
+{
+  friend struct FeatureTableSubstitution;
+
+  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;
+  LOffsetTo<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;
+  }
+
+  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 */
+  ArrayOf<FeatureTableSubstitutionRecord>
+                        substitutions;
+  public:
+  DEFINE_SIZE_ARRAY (6, substitutions);
+};
+
+struct FeatureVariationRecord
+{
+  friend struct FeatureVariations;
+
+  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:
+  LOffsetTo<ConditionSet>
+                        conditions;
+  LOffsetTo<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);
+  }
+
+  bool subset (hb_subset_context_t *c) const
+  {
+    TRACE_SUBSET (this);
+    return_trace (c->serializer->embed (*this));
+  }
+
+  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 */
+  LArrayOf<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); }
+
+  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 ()));
+  }
+
+  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) const
+  { return font->em_scalef_x (get_delta (font, store)); }
+
+  hb_position_t get_y_delta (hb_font_t *font, const VariationStore &store) const
+  { return font->em_scalef_y (get_delta (font, store)); }
+
+  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) const
+  {
+    return store.get_delta (outerIndex, innerIndex, font->coords, font->num_coords);
+  }
+
+  protected:
+  HBUINT16      outerIndex;
+  HBUINT16      innerIndex;
+  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)) const
+  {
+    switch (u.b.format)
+    {
+    case 1: case 2: case 3:
+      return u.hinting.get_x_delta (font);
+    case 0x8000:
+      return u.variation.get_x_delta (font, store);
+    default:
+      return 0;
+    }
+  }
+  hb_position_t get_y_delta (hb_font_t *font, const VariationStore &store=Null (VariationStore)) const
+  {
+    switch (u.b.format)
+    {
+    case 1: case 2: case 3:
+      return u.hinting.get_y_delta (font);
+    case 0x8000:
+      return u.variation.get_y_delta (font, store);
+    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) {
+    case 1: case 2: case 3:
+      return_trace (u.hinting.sanitize (c));
+    case 0x8000:
+      return_trace (u.variation.sanitize (c));
+    default:
+      return_trace (true);
+    }
+  }
+
+  protected:
+  union {
+  DeviceHeader          b;
+  HintingDevice         hinting;
+  VariationDevice       variation;
+  } u;
+  public:
+  DEFINE_SIZE_UNION (6, b);
+};
+
+
+} /* namespace OT */
+
+
+#endif /* HB_OT_LAYOUT_COMMON_HH */