Add m-esr52 at 52.6.0

1 files changed, 1713 insertions, 0 deletions

diff --git a/gfx/harfbuzz/src/hb-ot-layout-common-private.hh b/gfx/harfbuzz/src/hb-ot-layout-common-private.hh
new file mode 100644
index 000000000..62ca7a348
--- /dev/null
+++ b/gfx/harfbuzz/src/hb-ot-layout-common-private.hh
@@ -0,0 +1,1713 @@
+/*
+ * 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_PRIVATE_HH
+#define HB_OT_LAYOUT_COMMON_PRIVATE_HH
+
+#include "hb-ot-layout-private.hh"
+#include "hb-open-type-private.hh"
+#include "hb-set-private.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
+
+
+namespace OT {
+
+
+#define TRACE_DISPATCH(this, format) \
+	hb_auto_trace_t<context_t::max_debug_depth, typename context_t::return_t> trace \
+	(&c->debug_depth, c->get_name (), this, HB_FUNC, \
+	 "format %d", (int) format);
+
+
+#define NOT_COVERED		((unsigned int) -1)
+
+
+
+/*
+ *
+ * OpenType Layout Common Table Formats
+ *
+ */
+
+
+/*
+ * Script, ScriptList, LangSys, Feature, FeatureList, Lookup, LookupList
+ */
+
+template <typename Type>
+struct Record
+{
+  inline int cmp (hb_tag_t a) const {
+    return tag.cmp (a);
+  }
+
+  struct sanitize_closure_t {
+    hb_tag_t tag;
+    const void *list_base;
+  };
+  inline bool sanitize (hb_sanitize_context_t *c, const void *base) const
+  {
+    TRACE_SANITIZE (this);
+    const 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> > {
+  inline const Tag& get_tag (unsigned int i) const
+  {
+    /* We cheat slightly and don't define separate Null objects
+     * for Record types.  Instead, we return the correct Null(Tag)
+     * here. */
+    if (unlikely (i >= this->len)) return Null(Tag);
+    return (*this)[i].tag;
+  }
+  inline 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;
+  }
+  inline bool find_index (hb_tag_t tag, unsigned int *index) const
+  {
+    /* If we want to allow non-sorted data, we can lsearch(). */
+    int i = this->/*lsearch*/bsearch (tag);
+    if (i != -1) {
+        if (index) *index = i;
+        return true;
+    } else {
+      if (index) *index = Index::NOT_FOUND_INDEX;
+      return false;
+    }
+  }
+};
+
+template <typename Type>
+struct RecordListOf : RecordArrayOf<Type>
+{
+  inline const Type& operator [] (unsigned int i) const
+  { return this+RecordArrayOf<Type>::operator [](i).offset; }
+
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (RecordArrayOf<Type>::sanitize (c, this));
+  }
+};
+
+
+struct RangeRecord
+{
+  inline int cmp (hb_codepoint_t g) const {
+    return g < start ? -1 : g <= end ? 0 : +1 ;
+  }
+
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (c->check_struct (this));
+  }
+
+  inline bool intersects (const hb_set_t *glyphs) const {
+    return glyphs->intersects (start, end);
+  }
+
+  template <typename set_t>
+  inline void add_coverage (set_t *glyphs) const {
+    glyphs->add_range (start, end);
+  }
+
+  GlyphID	start;		/* First GlyphID in the range */
+  GlyphID	end;		/* Last GlyphID in the range */
+  USHORT	value;		/* Value */
+  public:
+  DEFINE_SIZE_STATIC (6);
+};
+DEFINE_NULL_DATA (RangeRecord, "\000\001");
+
+
+struct IndexArray : ArrayOf<Index>
+{
+  inline unsigned int get_indexes (unsigned int start_offset,
+				   unsigned int *_count /* IN/OUT */,
+				   unsigned int *_indexes /* OUT */) const
+  {
+    if (_count) {
+      const USHORT *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;
+  }
+};
+
+
+struct Script;
+struct LangSys;
+struct Feature;
+
+
+struct LangSys
+{
+  inline unsigned int get_feature_count (void) const
+  { return featureIndex.len; }
+  inline hb_tag_t get_feature_index (unsigned int i) const
+  { return featureIndex[i]; }
+  inline 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); }
+
+  inline bool has_required_feature (void) const { return reqFeatureIndex != 0xFFFFu; }
+  inline unsigned int get_required_feature_index (void) const
+  {
+    if (reqFeatureIndex == 0xFFFFu)
+      return Index::NOT_FOUND_INDEX;
+   return reqFeatureIndex;;
+  }
+
+  inline bool sanitize (hb_sanitize_context_t *c,
+			const Record<LangSys>::sanitize_closure_t * = NULL) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (c->check_struct (this) && featureIndex.sanitize (c));
+  }
+
+  Offset<>	lookupOrderZ;	/* = Null (reserved for an offset to a
+				 * reordering table) */
+  USHORT	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 (6, featureIndex);
+};
+DEFINE_NULL_DATA (LangSys, "\0\0\xFF\xFF");
+
+
+struct Script
+{
+  inline unsigned int get_lang_sys_count (void) const
+  { return langSys.len; }
+  inline const Tag& get_lang_sys_tag (unsigned int i) const
+  { return langSys.get_tag (i); }
+  inline 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); }
+  inline 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;
+  }
+  inline bool find_lang_sys_index (hb_tag_t tag, unsigned int *index) const
+  { return langSys.find_index (tag, index); }
+
+  inline bool has_default_lang_sys (void) const { return defaultLangSys != 0; }
+  inline const LangSys& get_default_lang_sys (void) const { return this+defaultLangSys; }
+
+  inline bool sanitize (hb_sanitize_context_t *c,
+			const Record<Script>::sanitize_closure_t * = NULL) 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 (4, langSys);
+};
+
+typedef RecordListOf<Script> ScriptList;
+
+
+/* http://www.microsoft.com/typography/otspec/features_pt.htm#size */
+struct FeatureParamsSize
+{
+  inline 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:
+     * http://partners.adobe.com/public/developer/opentype/index_tag8.html#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 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);
+  }
+
+  USHORT	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. */
+  USHORT	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. */
+  USHORT	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. */
+  USHORT	rangeStart;	/* Large end of the recommended usage range
+				 * (inclusive), stored in 720/inch units
+				 * (decipoints). */
+  USHORT	rangeEnd;	/* Small end of the recommended usage range
+				   (exclusive), stored in 720/inch units
+				 * (decipoints). */
+  public:
+  DEFINE_SIZE_STATIC (10);
+};
+
+/* http://www.microsoft.com/typography/otspec/features_pt.htm#ssxx */
+struct FeatureParamsStylisticSet
+{
+  inline 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));
+  }
+
+  USHORT	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. */
+
+  USHORT	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);
+};
+
+/* http://www.microsoft.com/typography/otspec/features_ae.htm#cv01-cv99 */
+struct FeatureParamsCharacterVariants
+{
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (c->check_struct (this) &&
+		  characters.sanitize (c));
+  }
+
+  USHORT	format;			/* Format number is set to 0. */
+  USHORT	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.) */
+  USHORT	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
+					 * NULL.) */
+  USHORT	sampleTextNameID;	/* The ‘name’ table name ID that
+					 * specifies sample text that
+					 * illustrates the effect of this
+					 * feature. (May be NULL.) */
+  USHORT	numNamedParameters;	/* Number of named parameters. (May
+					 * be zero.) */
+  USHORT	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<UINT24>
+		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
+{
+  inline 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);
+  }
+
+  inline const FeatureParamsSize& get_size_params (hb_tag_t tag) const
+  {
+    if (tag == HB_TAG ('s','i','z','e'))
+      return u.size;
+    return Null(FeatureParamsSize);
+  }
+
+  private:
+  union {
+  FeatureParamsSize			size;
+  FeatureParamsStylisticSet		stylisticSet;
+  FeatureParamsCharacterVariants	characterVariants;
+  } u;
+  DEFINE_SIZE_STATIC (17);
+};
+
+struct Feature
+{
+  inline unsigned int get_lookup_count (void) const
+  { return lookupIndex.len; }
+  inline hb_tag_t get_lookup_index (unsigned int i) const
+  { return lookupIndex[i]; }
+  inline 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); }
+
+  inline const FeatureParams &get_feature_params (void) const
+  { return this+featureParams; }
+
+  inline bool sanitize (hb_sanitize_context_t *c,
+			const Record<Feature>::sanitize_closure_t *closure = NULL) 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);
+
+      if (c->edit_count > 1)
+        c->edit_count--; /* This was a "legitimate" edit; don't contribute to error count. */
+    }
+
+    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 (4, lookupIndex);
+};
+
+typedef RecordListOf<Feature> FeatureList;
+
+
+struct LookupFlag : USHORT
+{
+  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
+{
+  inline unsigned int get_subtable_count (void) const { return subTable.len; }
+
+  template <typename SubTableType>
+  inline const SubTableType& get_subtable (unsigned int i) const
+  { return this+CastR<OffsetArrayOf<SubTableType> > (subTable)[i]; }
+
+  template <typename SubTableType>
+  inline const OffsetArrayOf<SubTableType>& get_subtables (void) const
+  { return CastR<OffsetArrayOf<SubTableType> > (subTable); }
+  template <typename SubTableType>
+  inline OffsetArrayOf<SubTableType>& get_subtables (void)
+  { return CastR<OffsetArrayOf<SubTableType> > (subTable); }
+
+  inline unsigned int get_type (void) 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. */
+  inline uint32_t get_props (void) const
+  {
+    unsigned int flag = lookupFlag;
+    if (unlikely (flag & LookupFlag::UseMarkFilteringSet))
+    {
+      const USHORT &markFilteringSet = StructAfter<USHORT> (subTable);
+      flag += (markFilteringSet << 16);
+    }
+    return flag;
+  }
+
+  template <typename SubTableType, typename context_t>
+  inline 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<SubTableType> (i).dispatch (c, lookup_type);
+      if (c->stop_sublookup_iteration (r))
+        return_trace (r);
+    }
+    return_trace (c->default_return_value ());
+  }
+
+  inline 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)
+    {
+      USHORT &markFilteringSet = StructAfter<USHORT> (subTable);
+      markFilteringSet.set (lookup_props >> 16);
+    }
+    return_trace (true);
+  }
+
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    /* Real sanitize of the subtables is done by GSUB/GPOS/... */
+    if (!(c->check_struct (this) && subTable.sanitize (c))) return_trace (false);
+    if (lookupFlag & LookupFlag::UseMarkFilteringSet)
+    {
+      const USHORT &markFilteringSet = StructAfter<USHORT> (subTable);
+      if (!markFilteringSet.sanitize (c)) return_trace (false);
+    }
+    return_trace (true);
+  }
+
+  private:
+  USHORT	lookupType;		/* Different enumerations for GSUB and GPOS */
+  USHORT	lookupFlag;		/* Lookup qualifiers */
+  ArrayOf<Offset<> >
+		subTable;		/* Array of SubTables */
+  USHORT	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_ARRAY2 (6, subTable, markFilteringSetX);
+};
+
+typedef OffsetListOf<Lookup> LookupList;
+
+
+/*
+ * Coverage Table
+ */
+
+struct CoverageFormat1
+{
+  friend struct Coverage;
+
+  private:
+  inline unsigned int get_coverage (hb_codepoint_t glyph_id) const
+  {
+    int i = glyphArray.bsearch (glyph_id);
+    ASSERT_STATIC (((unsigned int) -1) == NOT_COVERED);
+    return i;
+  }
+
+  inline bool serialize (hb_serialize_context_t *c,
+			 Supplier<GlyphID> &glyphs,
+			 unsigned int num_glyphs)
+  {
+    TRACE_SERIALIZE (this);
+    if (unlikely (!c->extend_min (*this))) return_trace (false);
+    glyphArray.len.set (num_glyphs);
+    if (unlikely (!c->extend (glyphArray))) return_trace (false);
+    for (unsigned int i = 0; i < num_glyphs; i++)
+      glyphArray[i] = glyphs[i];
+    glyphs.advance (num_glyphs);
+    return_trace (true);
+  }
+
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (glyphArray.sanitize (c));
+  }
+
+  inline bool intersects_coverage (const hb_set_t *glyphs, unsigned int index) const {
+    return glyphs->has (glyphArray[index]);
+  }
+
+  template <typename set_t>
+  inline void add_coverage (set_t *glyphs) const {
+    unsigned int count = glyphArray.len;
+    for (unsigned int i = 0; i < count; i++)
+      glyphs->add (glyphArray[i]);
+  }
+
+  public:
+  /* Older compilers need this to be public. */
+  struct Iter {
+    inline void init (const struct CoverageFormat1 &c_) { c = &c_; i = 0; };
+    inline bool more (void) { return i < c->glyphArray.len; }
+    inline void next (void) { i++; }
+    inline hb_codepoint_t get_glyph (void) { return c->glyphArray[i]; }
+    inline unsigned int get_coverage (void) { return i; }
+
+    private:
+    const struct CoverageFormat1 *c;
+    unsigned int i;
+  };
+  private:
+
+  protected:
+  USHORT	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:
+  inline unsigned int get_coverage (hb_codepoint_t glyph_id) const
+  {
+    int i = rangeRecord.bsearch (glyph_id);
+    if (i != -1) {
+      const RangeRecord &range = rangeRecord[i];
+      return (unsigned int) range.value + (glyph_id - range.start);
+    }
+    return NOT_COVERED;
+  }
+
+  inline bool serialize (hb_serialize_context_t *c,
+			 Supplier<GlyphID> &glyphs,
+			 unsigned int num_glyphs)
+  {
+    TRACE_SERIALIZE (this);
+    if (unlikely (!c->extend_min (*this))) return_trace (false);
+
+    if (unlikely (!num_glyphs))
+    {
+      rangeRecord.len.set (0);
+      return_trace (true);
+    }
+
+    unsigned int num_ranges = 1;
+    for (unsigned int i = 1; i < num_glyphs; 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 < num_glyphs; i++)
+      if (glyphs[i - 1] + 1 != glyphs[i]) {
+	range++;
+	rangeRecord[range].start = glyphs[i];
+	rangeRecord[range].value.set (i);
+        rangeRecord[range].end = glyphs[i];
+      } else {
+        rangeRecord[range].end = glyphs[i];
+      }
+    glyphs.advance (num_glyphs);
+    return_trace (true);
+  }
+
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (rangeRecord.sanitize (c));
+  }
+
+  inline 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>
+  inline void add_coverage (set_t *glyphs) const {
+    unsigned int count = rangeRecord.len;
+    for (unsigned int i = 0; i < count; i++)
+      rangeRecord[i].add_coverage (glyphs);
+  }
+
+  public:
+  /* Older compilers need this to be public. */
+  struct Iter
+  {
+    inline void init (const CoverageFormat2 &c_)
+    {
+      c = &c_;
+      coverage = 0;
+      i = 0;
+      j = c->rangeRecord.len ? c_.rangeRecord[0].start : 0;
+    }
+    inline bool more (void) { return i < c->rangeRecord.len; }
+    inline void next (void)
+    {
+      if (j >= c->rangeRecord[i].end)
+      {
+        i++;
+	if (more ())
+	{
+	  j = c->rangeRecord[i].start;
+	  coverage = c->rangeRecord[i].value;
+	}
+	return;
+      }
+      coverage++;
+      j++;
+    }
+    inline hb_codepoint_t get_glyph (void) { return j; }
+    inline unsigned int get_coverage (void) { return coverage; }
+
+    private:
+    const struct CoverageFormat2 *c;
+    unsigned int i, j, coverage;
+  };
+  private:
+
+  protected:
+  USHORT	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
+{
+  inline 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;
+    }
+  }
+
+  inline bool serialize (hb_serialize_context_t *c,
+			 Supplier<GlyphID> &glyphs,
+			 unsigned int num_glyphs)
+  {
+    TRACE_SERIALIZE (this);
+    if (unlikely (!c->extend_min (*this))) return_trace (false);
+    unsigned int num_ranges = 1;
+    for (unsigned int i = 1; i < num_glyphs; i++)
+      if (glyphs[i - 1] + 1 != glyphs[i])
+        num_ranges++;
+    u.format.set (num_glyphs * 2 < num_ranges * 3 ? 1 : 2);
+    switch (u.format) {
+    case 1: return_trace (u.format1.serialize (c, glyphs, num_glyphs));
+    case 2: return_trace (u.format2.serialize (c, glyphs, num_glyphs));
+    default:return_trace (false);
+    }
+  }
+
+  inline 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);
+    }
+  }
+
+  inline bool intersects (const hb_set_t *glyphs) const {
+    /* TODO speed this up */
+    Coverage::Iter iter;
+    for (iter.init (*this); iter.more (); iter.next ()) {
+      if (glyphs->has (iter.get_glyph ()))
+        return true;
+    }
+    return false;
+  }
+
+  inline 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;
+    }
+  }
+
+  template <typename set_t>
+  inline void add_coverage (set_t *glyphs) const {
+    switch (u.format) {
+    case 1: u.format1.add_coverage (glyphs); break;
+    case 2: u.format2.add_coverage (glyphs); break;
+    default:                                 break;
+    }
+  }
+
+  struct Iter {
+    Iter (void) : format (0) {};
+    inline void init (const Coverage &c_) {
+      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;
+      }
+    }
+    inline bool more (void) {
+      switch (format) {
+      case 1: return u.format1.more ();
+      case 2: return u.format2.more ();
+      default:return false;
+      }
+    }
+    inline void next (void) {
+      switch (format) {
+      case 1: u.format1.next (); break;
+      case 2: u.format2.next (); break;
+      default:                   break;
+      }
+    }
+    inline hb_codepoint_t get_glyph (void) {
+      switch (format) {
+      case 1: return u.format1.get_glyph ();
+      case 2: return u.format2.get_glyph ();
+      default:return 0;
+      }
+    }
+    inline unsigned int get_coverage (void) {
+      switch (format) {
+      case 1: return u.format1.get_coverage ();
+      case 2: return u.format2.get_coverage ();
+      default:return -1;
+      }
+    }
+
+    private:
+    unsigned int format;
+    union {
+    CoverageFormat1::Iter	format1;
+    CoverageFormat2::Iter	format2;
+    } u;
+  };
+
+  protected:
+  union {
+  USHORT		format;		/* Format identifier */
+  CoverageFormat1	format1;
+  CoverageFormat2	format2;
+  } u;
+  public:
+  DEFINE_SIZE_UNION (2, format);
+};
+
+
+/*
+ * Class Definition Table
+ */
+
+struct ClassDefFormat1
+{
+  friend struct ClassDef;
+
+  private:
+  inline unsigned int get_class (hb_codepoint_t glyph_id) const
+  {
+    unsigned int i = (unsigned int) (glyph_id - startGlyph);
+    if (unlikely (i < classValue.len))
+      return classValue[i];
+    return 0;
+  }
+
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (c->check_struct (this) && classValue.sanitize (c));
+  }
+
+  template <typename set_t>
+  inline void 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);
+  }
+
+  inline 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 = -1;
+      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:
+  USHORT	classFormat;		/* Format identifier--format = 1 */
+  GlyphID	startGlyph;		/* First GlyphID of the classValueArray */
+  ArrayOf<USHORT>
+		classValue;		/* Array of Class Values--one per GlyphID */
+  public:
+  DEFINE_SIZE_ARRAY (6, classValue);
+};
+
+struct ClassDefFormat2
+{
+  friend struct ClassDef;
+
+  private:
+  inline unsigned int get_class (hb_codepoint_t glyph_id) const
+  {
+    int i = rangeRecord.bsearch (glyph_id);
+    if (unlikely (i != -1))
+      return rangeRecord[i].value;
+    return 0;
+  }
+
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (rangeRecord.sanitize (c));
+  }
+
+  template <typename set_t>
+  inline void 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)
+        rangeRecord[i].add_coverage (glyphs);
+  }
+
+  inline 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_codepoint_t) -1;
+      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_codepoint_t) -1 && 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:
+  USHORT	classFormat;	/* Format identifier--format = 2 */
+  SortedArrayOf<RangeRecord>
+		rangeRecord;	/* Array of glyph ranges--ordered by
+				 * Start GlyphID */
+  public:
+  DEFINE_SIZE_ARRAY (4, rangeRecord);
+};
+
+struct ClassDef
+{
+  inline 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;
+    }
+  }
+
+  inline 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);
+    }
+  }
+
+  inline void add_class (hb_set_t *glyphs, unsigned int klass) const {
+    switch (u.format) {
+    case 1: u.format1.add_class (glyphs, klass); return;
+    case 2: u.format2.add_class (glyphs, klass); return;
+    default:return;
+    }
+  }
+
+  inline 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 {
+  USHORT		format;		/* Format identifier */
+  ClassDefFormat1	format1;
+  ClassDefFormat2	format2;
+  } u;
+  public:
+  DEFINE_SIZE_UNION (2, format);
+};
+
+
+/*
+ * Item Variation Store
+ */
+
+struct VarRegionAxis
+{
+  inline 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);
+  }
+
+  inline 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
+{
+  inline float evaluate (unsigned int region_index,
+			 int *coords, unsigned int coord_len) const
+  {
+    if (unlikely (region_index >= regionCount))
+      return 0.;
+
+    const VarRegionAxis *axes = axesZ + (region_index * axisCount);
+
+    float v = 1.;
+    unsigned int count = MIN (coord_len, (unsigned int) axisCount);
+    for (unsigned int i = 0; i < count; i++)
+    {
+      float factor = axes[i].evaluate (coords[i]);
+      if (factor == 0.)
+        return 0.;
+      v *= factor;
+    }
+    return v;
+  }
+
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (c->check_struct (this) &&
+		  c->check_array (axesZ, axesZ[0].static_size,
+				  (unsigned int) axisCount * (unsigned int) regionCount));
+  }
+
+  protected:
+  USHORT	axisCount;
+  USHORT	regionCount;
+  VarRegionAxis	axesZ[VAR];
+  public:
+  DEFINE_SIZE_ARRAY (4, axesZ);
+};
+
+struct VarData
+{
+  inline unsigned int get_row_size (void) const
+  { return shortCount + regionIndices.len; }
+
+  inline unsigned int get_size (void) const
+  { return itemCount * get_row_size (); }
+
+  inline float get_delta (unsigned int inner,
+			  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 BYTE *bytes = &StructAfter<BYTE> (regionIndices);
+   const BYTE *row = bytes + inner * (scount + count);
+
+   float delta = 0.;
+   unsigned int i = 0;
+
+   const SHORT *scursor = reinterpret_cast<const SHORT *> (row);
+   for (; i < scount; i++)
+   {
+     float scalar = regions.evaluate (regionIndices.array[i], coords, coord_count);
+     delta += scalar * *scursor++;
+   }
+   const INT8 *bcursor = reinterpret_cast<const INT8 *> (scursor);
+   for (; i < count; i++)
+   {
+     float scalar = regions.evaluate (regionIndices.array[i], coords, coord_count);
+     delta += scalar * *bcursor++;
+   }
+
+   return delta;
+  }
+
+  inline 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_array (&StructAfter<BYTE> (regionIndices),
+				  get_row_size (), itemCount));
+  }
+
+  protected:
+  USHORT		itemCount;
+  USHORT		shortCount;
+  ArrayOf<USHORT>	regionIndices;
+  BYTE			bytesX[VAR];
+  public:
+  DEFINE_SIZE_ARRAY2 (6, regionIndices, bytesX);
+};
+
+struct VariationStore
+{
+  inline float get_delta (unsigned int outer, unsigned int inner,
+			  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);
+  }
+
+  inline 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));
+  }
+
+  protected:
+  USHORT				format;
+  OffsetTo<VarRegionList, ULONG>	regions;
+  OffsetArrayOf<VarData, ULONG>		dataSets;
+  public:
+  DEFINE_SIZE_ARRAY (8, dataSets);
+};
+
+/*
+ * Feature Variations
+ */
+
+struct ConditionFormat1
+{
+  friend struct Condition;
+
+  private:
+  inline bool evaluate (const int *coords, unsigned int coord_len) const
+  {
+    int coord = axisIndex < coord_len ? coords[axisIndex] : 0;
+    return filterRangeMinValue <= coord && coord <= filterRangeMaxValue;
+  }
+
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (c->check_struct (this));
+  }
+
+  protected:
+  USHORT	format;		/* Format identifier--format = 1 */
+  USHORT	axisIndex;
+  F2DOT14	filterRangeMinValue;
+  F2DOT14	filterRangeMaxValue;
+  public:
+  DEFINE_SIZE_STATIC (8);
+};
+
+struct Condition
+{
+  inline 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;
+    }
+  }
+
+  inline 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 {
+  USHORT		format;		/* Format identifier */
+  ConditionFormat1	format1;
+  } u;
+  public:
+  DEFINE_SIZE_UNION (2, format);
+};
+
+struct ConditionSet
+{
+  inline 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.array[i]).evaluate (coords, coord_len))
+        return false;
+    return true;
+  }
+
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (conditions.sanitize (c, this));
+  }
+
+  protected:
+  OffsetArrayOf<Condition, ULONG> conditions;
+  public:
+  DEFINE_SIZE_ARRAY (2, conditions);
+};
+
+struct FeatureTableSubstitutionRecord
+{
+  friend struct FeatureTableSubstitution;
+
+  inline 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:
+  USHORT			featureIndex;
+  OffsetTo<Feature, ULONG>	feature;
+  public:
+  DEFINE_SIZE_STATIC (6);
+};
+
+struct FeatureTableSubstitution
+{
+  inline 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.array[i];
+      if (record.featureIndex == feature_index)
+	return &(this+record.feature);
+    }
+    return NULL;
+  }
+
+  inline 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;
+
+  inline 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:
+  OffsetTo<ConditionSet, ULONG>
+			conditions;
+  OffsetTo<FeatureTableSubstitution, ULONG>
+			substitutions;
+  public:
+  DEFINE_SIZE_STATIC (8);
+};
+
+struct FeatureVariations
+{
+  static const unsigned int NOT_FOUND_INDEX = 0xFFFFFFFFu;
+
+  inline 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.array[i];
+      if ((this+record.conditions).evaluate (coords, coord_len))
+      {
+	*index = i;
+	return true;
+      }
+    }
+    *index = NOT_FOUND_INDEX;
+    return false;
+  }
+
+  inline 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);
+  }
+
+  inline 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 */
+  ArrayOf<FeatureVariationRecord, ULONG>
+			varRecords;
+  public:
+  DEFINE_SIZE_ARRAY (8, varRecords);
+};
+
+
+/*
+ * Device Tables
+ */
+
+struct HintingDevice
+{
+  friend struct Device;
+
+  private:
+
+  inline hb_position_t get_x_delta (hb_font_t *font) const
+  { return get_delta (font->x_ppem, font->x_scale); }
+
+  inline hb_position_t get_y_delta (hb_font_t *font) const
+  { return get_delta (font->y_ppem, font->y_scale); }
+
+  inline unsigned int get_size (void) const
+  {
+    unsigned int f = deltaFormat;
+    if (unlikely (f < 1 || f > 3 || startSize > endSize)) return 3 * USHORT::static_size;
+    return USHORT::static_size * (4 + ((endSize - startSize) >> (4 - f)));
+  }
+
+  inline 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:
+
+  inline 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);
+  }
+  inline 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 = deltaValue[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:
+  USHORT	startSize;		/* Smallest size to correct--in ppem */
+  USHORT	endSize;		/* Largest size to correct--in ppem */
+  USHORT	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
+					 */
+  USHORT	deltaValue[VAR];	/* Array of compressed data */
+  public:
+  DEFINE_SIZE_ARRAY (6, deltaValue);
+};
+
+struct VariationDevice
+{
+  friend struct Device;
+
+  private:
+
+  inline hb_position_t get_x_delta (hb_font_t *font, const VariationStore &store) const
+  { return font->em_scalef_x (get_delta (font, store)); }
+
+  inline hb_position_t get_y_delta (hb_font_t *font, const VariationStore &store) const
+  { return font->em_scalef_y (get_delta (font, store)); }
+
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (c->check_struct (this));
+  }
+
+  private:
+
+  inline float get_delta (hb_font_t *font, const VariationStore &store) const
+  {
+    return store.get_delta (outerIndex, innerIndex, font->coords, font->num_coords);
+  }
+
+  protected:
+  USHORT	outerIndex;
+  USHORT	innerIndex;
+  USHORT	deltaFormat;	/* Format identifier for this table: 0x0x8000 */
+  public:
+  DEFINE_SIZE_STATIC (6);
+};
+
+struct DeviceHeader
+{
+  protected:
+  USHORT		reserved1;
+  USHORT		reserved2;
+  public:
+  USHORT		format;		/* Format identifier */
+  public:
+  DEFINE_SIZE_STATIC (6);
+};
+
+struct Device
+{
+  inline 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;
+    }
+  }
+  inline 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;
+    }
+  }
+
+  inline 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_PRIVATE_HH */