Adding upstream version 86.0.1.upstream/86.0.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1157 insertions, 0 deletions

diff --git a/gfx/harfbuzz/src/hb-aat-layout-morx-table.hh b/gfx/harfbuzz/src/hb-aat-layout-morx-table.hh
new file mode 100644
index 0000000000..04027a61be
--- /dev/null
+++ b/gfx/harfbuzz/src/hb-aat-layout-morx-table.hh
@@ -0,0 +1,1157 @@
+/*
+ * Copyright © 2017  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.
+ *
+ * Google Author(s): Behdad Esfahbod
+ */
+
+#ifndef HB_AAT_LAYOUT_MORX_TABLE_HH
+#define HB_AAT_LAYOUT_MORX_TABLE_HH
+
+#include "hb-open-type.hh"
+#include "hb-aat-layout-common.hh"
+#include "hb-ot-layout-common.hh"
+#include "hb-aat-map.hh"
+
+/*
+ * morx -- Extended Glyph Metamorphosis
+ * https://developer.apple.com/fonts/TrueType-Reference-Manual/RM06/Chap6morx.html
+ * https://developer.apple.com/fonts/TrueType-Reference-Manual/RM06/Chap6mort.html
+ */
+#define HB_AAT_TAG_morx HB_TAG('m','o','r','x')
+#define HB_AAT_TAG_mort HB_TAG('m','o','r','t')
+
+
+namespace AAT {
+
+using namespace OT;
+
+template <typename Types>
+struct RearrangementSubtable
+{
+  typedef typename Types::HBUINT HBUINT;
+
+  typedef void EntryData;
+
+  struct driver_context_t
+  {
+    static constexpr bool in_place = true;
+    enum Flags
+    {
+      MarkFirst		= 0x8000,	/* If set, make the current glyph the first
+					 * glyph to be rearranged. */
+      DontAdvance	= 0x4000,	/* If set, don't advance to the next glyph
+					 * before going to the new state. This means
+					 * that the glyph index doesn't change, even
+					 * if the glyph at that index has changed. */
+      MarkLast		= 0x2000,	/* If set, make the current glyph the last
+					 * glyph to be rearranged. */
+      Reserved		= 0x1FF0,	/* These bits are reserved and should be set to 0. */
+      Verb		= 0x000F,	/* The type of rearrangement specified. */
+    };
+
+    driver_context_t (const RearrangementSubtable *table HB_UNUSED) :
+	ret (false),
+	start (0), end (0) {}
+
+    bool is_actionable (StateTableDriver<Types, EntryData> *driver HB_UNUSED,
+			const Entry<EntryData> &entry)
+    {
+      return (entry.flags & Verb) && start < end;
+    }
+    void transition (StateTableDriver<Types, EntryData> *driver,
+		     const Entry<EntryData> &entry)
+    {
+      hb_buffer_t *buffer = driver->buffer;
+      unsigned int flags = entry.flags;
+
+      if (flags & MarkFirst)
+	start = buffer->idx;
+
+      if (flags & MarkLast)
+	end = hb_min (buffer->idx + 1, buffer->len);
+
+      if ((flags & Verb) && start < end)
+      {
+	/* The following map has two nibbles, for start-side
+	 * and end-side. Values of 0,1,2 mean move that many
+	 * to the other side. Value of 3 means move 2 and
+	 * flip them. */
+	const unsigned char map[16] =
+	{
+	  0x00,	/* 0	no change */
+	  0x10,	/* 1	Ax => xA */
+	  0x01,	/* 2	xD => Dx */
+	  0x11,	/* 3	AxD => DxA */
+	  0x20,	/* 4	ABx => xAB */
+	  0x30,	/* 5	ABx => xBA */
+	  0x02,	/* 6	xCD => CDx */
+	  0x03,	/* 7	xCD => DCx */
+	  0x12,	/* 8	AxCD => CDxA */
+	  0x13,	/* 9	AxCD => DCxA */
+	  0x21,	/* 10	ABxD => DxAB */
+	  0x31,	/* 11	ABxD => DxBA */
+	  0x22,	/* 12	ABxCD => CDxAB */
+	  0x32,	/* 13	ABxCD => CDxBA */
+	  0x23,	/* 14	ABxCD => DCxAB */
+	  0x33,	/* 15	ABxCD => DCxBA */
+	};
+
+	unsigned int m = map[flags & Verb];
+	unsigned int l = hb_min (2u, m >> 4);
+	unsigned int r = hb_min (2u, m & 0x0F);
+	bool reverse_l = 3 == (m >> 4);
+	bool reverse_r = 3 == (m & 0x0F);
+
+	if (end - start >= l + r)
+	{
+	  buffer->merge_clusters (start, hb_min (buffer->idx + 1, buffer->len));
+	  buffer->merge_clusters (start, end);
+
+	  hb_glyph_info_t *info = buffer->info;
+	  hb_glyph_info_t buf[4];
+
+	  memcpy (buf, info + start, l * sizeof (buf[0]));
+	  memcpy (buf + 2, info + end - r, r * sizeof (buf[0]));
+
+	  if (l != r)
+	    memmove (info + start + r, info + start + l, (end - start - l - r) * sizeof (buf[0]));
+
+	  memcpy (info + start, buf + 2, r * sizeof (buf[0]));
+	  memcpy (info + end - l, buf, l * sizeof (buf[0]));
+	  if (reverse_l)
+	  {
+	    buf[0] = info[end - 1];
+	    info[end - 1] = info[end - 2];
+	    info[end - 2] = buf[0];
+	  }
+	  if (reverse_r)
+	  {
+	    buf[0] = info[start];
+	    info[start] = info[start + 1];
+	    info[start + 1] = buf[0];
+	  }
+	}
+      }
+    }
+
+    public:
+    bool ret;
+    private:
+    unsigned int start;
+    unsigned int end;
+  };
+
+  bool apply (hb_aat_apply_context_t *c) const
+  {
+    TRACE_APPLY (this);
+
+    driver_context_t dc (this);
+
+    StateTableDriver<Types, EntryData> driver (machine, c->buffer, c->face);
+    driver.drive (&dc);
+
+    return_trace (dc.ret);
+  }
+
+  bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (machine.sanitize (c));
+  }
+
+  protected:
+  StateTable<Types, EntryData>	machine;
+  public:
+  DEFINE_SIZE_STATIC (16);
+};
+
+template <typename Types>
+struct ContextualSubtable
+{
+  typedef typename Types::HBUINT HBUINT;
+
+  struct EntryData
+  {
+    HBUINT16	markIndex;	/* Index of the substitution table for the
+				 * marked glyph (use 0xFFFF for none). */
+    HBUINT16	currentIndex;	/* Index of the substitution table for the
+				 * current glyph (use 0xFFFF for none). */
+    public:
+    DEFINE_SIZE_STATIC (4);
+  };
+
+  struct driver_context_t
+  {
+    static constexpr bool in_place = true;
+    enum Flags
+    {
+      SetMark		= 0x8000,	/* If set, make the current glyph the marked glyph. */
+      DontAdvance	= 0x4000,	/* If set, don't advance to the next glyph before
+					 * going to the new state. */
+      Reserved		= 0x3FFF,	/* These bits are reserved and should be set to 0. */
+    };
+
+    driver_context_t (const ContextualSubtable *table_,
+			     hb_aat_apply_context_t *c_) :
+	ret (false),
+	c (c_),
+	mark_set (false),
+	mark (0),
+	table (table_),
+	subs (table+table->substitutionTables) {}
+
+    bool is_actionable (StateTableDriver<Types, EntryData> *driver,
+			const Entry<EntryData> &entry)
+    {
+      hb_buffer_t *buffer = driver->buffer;
+
+      if (buffer->idx == buffer->len && !mark_set)
+	return false;
+
+      return entry.data.markIndex != 0xFFFF || entry.data.currentIndex != 0xFFFF;
+    }
+    void transition (StateTableDriver<Types, EntryData> *driver,
+		     const Entry<EntryData> &entry)
+    {
+      hb_buffer_t *buffer = driver->buffer;
+
+      /* Looks like CoreText applies neither mark nor current substitution for
+       * end-of-text if mark was not explicitly set. */
+      if (buffer->idx == buffer->len && !mark_set)
+	return;
+
+      const HBGlyphID *replacement;
+
+      replacement = nullptr;
+      if (Types::extended)
+      {
+	if (entry.data.markIndex != 0xFFFF)
+	{
+	  const Lookup<HBGlyphID> &lookup = subs[entry.data.markIndex];
+	  replacement = lookup.get_value (buffer->info[mark].codepoint, driver->num_glyphs);
+	}
+      }
+      else
+      {
+	unsigned int offset = entry.data.markIndex + buffer->info[mark].codepoint;
+	const UnsizedArrayOf<HBGlyphID> &subs_old = (const UnsizedArrayOf<HBGlyphID> &) subs;
+	replacement = &subs_old[Types::wordOffsetToIndex (offset, table, subs_old.arrayZ)];
+	if (!replacement->sanitize (&c->sanitizer) || !*replacement)
+	  replacement = nullptr;
+      }
+      if (replacement)
+      {
+	buffer->unsafe_to_break (mark, hb_min (buffer->idx + 1, buffer->len));
+	buffer->info[mark].codepoint = *replacement;
+	ret = true;
+      }
+
+      replacement = nullptr;
+      unsigned int idx = hb_min (buffer->idx, buffer->len - 1);
+      if (Types::extended)
+      {
+	if (entry.data.currentIndex != 0xFFFF)
+	{
+	  const Lookup<HBGlyphID> &lookup = subs[entry.data.currentIndex];
+	  replacement = lookup.get_value (buffer->info[idx].codepoint, driver->num_glyphs);
+	}
+      }
+      else
+      {
+	unsigned int offset = entry.data.currentIndex + buffer->info[idx].codepoint;
+	const UnsizedArrayOf<HBGlyphID> &subs_old = (const UnsizedArrayOf<HBGlyphID> &) subs;
+	replacement = &subs_old[Types::wordOffsetToIndex (offset, table, subs_old.arrayZ)];
+	if (!replacement->sanitize (&c->sanitizer) || !*replacement)
+	  replacement = nullptr;
+      }
+      if (replacement)
+      {
+	buffer->info[idx].codepoint = *replacement;
+	ret = true;
+      }
+
+      if (entry.flags & SetMark)
+      {
+	mark_set = true;
+	mark = buffer->idx;
+      }
+    }
+
+    public:
+    bool ret;
+    private:
+    hb_aat_apply_context_t *c;
+    bool mark_set;
+    unsigned int mark;
+    const ContextualSubtable *table;
+    const UnsizedOffsetListOf<Lookup<HBGlyphID>, HBUINT, false> &subs;
+  };
+
+  bool apply (hb_aat_apply_context_t *c) const
+  {
+    TRACE_APPLY (this);
+
+    driver_context_t dc (this, c);
+
+    StateTableDriver<Types, EntryData> driver (machine, c->buffer, c->face);
+    driver.drive (&dc);
+
+    return_trace (dc.ret);
+  }
+
+  bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+
+    unsigned int num_entries = 0;
+    if (unlikely (!machine.sanitize (c, &num_entries))) return_trace (false);
+
+    if (!Types::extended)
+      return_trace (substitutionTables.sanitize (c, this, 0));
+
+    unsigned int num_lookups = 0;
+
+    const Entry<EntryData> *entries = machine.get_entries ();
+    for (unsigned int i = 0; i < num_entries; i++)
+    {
+      const EntryData &data = entries[i].data;
+
+      if (data.markIndex != 0xFFFF)
+	num_lookups = hb_max (num_lookups, 1 + data.markIndex);
+      if (data.currentIndex != 0xFFFF)
+	num_lookups = hb_max (num_lookups, 1 + data.currentIndex);
+    }
+
+    return_trace (substitutionTables.sanitize (c, this, num_lookups));
+  }
+
+  protected:
+  StateTable<Types, EntryData>
+		machine;
+  NNOffsetTo<UnsizedOffsetListOf<Lookup<HBGlyphID>, HBUINT, false>, HBUINT>
+		substitutionTables;
+  public:
+  DEFINE_SIZE_STATIC (20);
+};
+
+
+template <bool extended>
+struct LigatureEntry;
+
+template <>
+struct LigatureEntry<true>
+{
+  enum Flags
+  {
+    SetComponent	= 0x8000,	/* Push this glyph onto the component stack for
+					 * eventual processing. */
+    DontAdvance		= 0x4000,	/* Leave the glyph pointer at this glyph for the
+					   next iteration. */
+    PerformAction	= 0x2000,	/* Use the ligActionIndex to process a ligature
+					 * group. */
+    Reserved		= 0x1FFF,	/* These bits are reserved and should be set to 0. */
+  };
+
+  struct EntryData
+  {
+    HBUINT16	ligActionIndex;	/* Index to the first ligActionTable entry
+				 * for processing this group, if indicated
+				 * by the flags. */
+    public:
+    DEFINE_SIZE_STATIC (2);
+  };
+
+  static bool performAction (const Entry<EntryData> &entry)
+  { return entry.flags & PerformAction; }
+
+  static unsigned int ligActionIndex (const Entry<EntryData> &entry)
+  { return entry.data.ligActionIndex; }
+};
+template <>
+struct LigatureEntry<false>
+{
+  enum Flags
+  {
+    SetComponent	= 0x8000,	/* Push this glyph onto the component stack for
+					 * eventual processing. */
+    DontAdvance		= 0x4000,	/* Leave the glyph pointer at this glyph for the
+					   next iteration. */
+    Offset		= 0x3FFF,	/* Byte offset from beginning of subtable to the
+					 * ligature action list. This value must be a
+					 * multiple of 4. */
+  };
+
+  typedef void EntryData;
+
+  static bool performAction (const Entry<EntryData> &entry)
+  { return entry.flags & Offset; }
+
+  static unsigned int ligActionIndex (const Entry<EntryData> &entry)
+  { return entry.flags & Offset; }
+};
+
+
+template <typename Types>
+struct LigatureSubtable
+{
+  typedef typename Types::HBUINT HBUINT;
+
+  typedef LigatureEntry<Types::extended> LigatureEntryT;
+  typedef typename LigatureEntryT::EntryData EntryData;
+
+  struct driver_context_t
+  {
+    static constexpr bool in_place = false;
+    enum
+    {
+      DontAdvance	= LigatureEntryT::DontAdvance,
+    };
+    enum LigActionFlags
+    {
+      LigActionLast	= 0x80000000,	/* This is the last action in the list. This also
+					 * implies storage. */
+      LigActionStore	= 0x40000000,	/* Store the ligature at the current cumulated index
+					 * in the ligature table in place of the marked
+					 * (i.e. currently-popped) glyph. */
+      LigActionOffset	= 0x3FFFFFFF,	/* A 30-bit value which is sign-extended to 32-bits
+					 * and added to the glyph ID, resulting in an index
+					 * into the component table. */
+    };
+
+    driver_context_t (const LigatureSubtable *table_,
+		      hb_aat_apply_context_t *c_) :
+	ret (false),
+	c (c_),
+	table (table_),
+	ligAction (table+table->ligAction),
+	component (table+table->component),
+	ligature (table+table->ligature),
+	match_length (0) {}
+
+    bool is_actionable (StateTableDriver<Types, EntryData> *driver HB_UNUSED,
+			const Entry<EntryData> &entry)
+    {
+      return LigatureEntryT::performAction (entry);
+    }
+    void transition (StateTableDriver<Types, EntryData> *driver,
+		     const Entry<EntryData> &entry)
+    {
+      hb_buffer_t *buffer = driver->buffer;
+
+      DEBUG_MSG (APPLY, nullptr, "Ligature transition at %u", buffer->idx);
+      if (entry.flags & LigatureEntryT::SetComponent)
+      {
+	/* Never mark same index twice, in case DontAdvance was used... */
+	if (match_length && match_positions[(match_length - 1u) % ARRAY_LENGTH (match_positions)] == buffer->out_len)
+	  match_length--;
+
+	match_positions[match_length++ % ARRAY_LENGTH (match_positions)] = buffer->out_len;
+	DEBUG_MSG (APPLY, nullptr, "Set component at %u", buffer->out_len);
+      }
+
+      if (LigatureEntryT::performAction (entry))
+      {
+	DEBUG_MSG (APPLY, nullptr, "Perform action with %u", match_length);
+	unsigned int end = buffer->out_len;
+
+	if (unlikely (!match_length))
+	  return;
+
+	if (buffer->idx >= buffer->len)
+	  return; /* TODO Work on previous instead? */
+
+	unsigned int cursor = match_length;
+
+	unsigned int action_idx = LigatureEntryT::ligActionIndex (entry);
+	action_idx = Types::offsetToIndex (action_idx, table, ligAction.arrayZ);
+	const HBUINT32 *actionData = &ligAction[action_idx];
+
+	unsigned int ligature_idx = 0;
+	unsigned int action;
+	do
+	{
+	  if (unlikely (!cursor))
+	  {
+	    /* Stack underflow.  Clear the stack. */
+	    DEBUG_MSG (APPLY, nullptr, "Stack underflow");
+	    match_length = 0;
+	    break;
+	  }
+
+	  DEBUG_MSG (APPLY, nullptr, "Moving to stack position %u", cursor - 1);
+	  buffer->move_to (match_positions[--cursor % ARRAY_LENGTH (match_positions)]);
+
+	  if (unlikely (!actionData->sanitize (&c->sanitizer))) break;
+	  action = *actionData;
+
+	  uint32_t uoffset = action & LigActionOffset;
+	  if (uoffset & 0x20000000)
+	    uoffset |= 0xC0000000; /* Sign-extend. */
+	  int32_t offset = (int32_t) uoffset;
+	  unsigned int component_idx = buffer->cur().codepoint + offset;
+	  component_idx = Types::wordOffsetToIndex (component_idx, table, component.arrayZ);
+	  const HBUINT16 &componentData = component[component_idx];
+	  if (unlikely (!componentData.sanitize (&c->sanitizer))) break;
+	  ligature_idx += componentData;
+
+	  DEBUG_MSG (APPLY, nullptr, "Action store %u last %u",
+		     bool (action & LigActionStore),
+		     bool (action & LigActionLast));
+	  if (action & (LigActionStore | LigActionLast))
+	  {
+	    ligature_idx = Types::offsetToIndex (ligature_idx, table, ligature.arrayZ);
+	    const HBGlyphID &ligatureData = ligature[ligature_idx];
+	    if (unlikely (!ligatureData.sanitize (&c->sanitizer))) break;
+	    hb_codepoint_t lig = ligatureData;
+
+	    DEBUG_MSG (APPLY, nullptr, "Produced ligature %u", lig);
+	    buffer->replace_glyph (lig);
+
+	    unsigned int lig_end = match_positions[(match_length - 1u) % ARRAY_LENGTH (match_positions)] + 1u;
+	    /* Now go and delete all subsequent components. */
+	    while (match_length - 1u > cursor)
+	    {
+	      DEBUG_MSG (APPLY, nullptr, "Skipping ligature component");
+	      buffer->move_to (match_positions[--match_length % ARRAY_LENGTH (match_positions)]);
+	      buffer->replace_glyph (DELETED_GLYPH);
+	    }
+
+	    buffer->move_to (lig_end);
+	    buffer->merge_out_clusters (match_positions[cursor % ARRAY_LENGTH (match_positions)], buffer->out_len);
+	  }
+
+	  actionData++;
+	}
+	while (!(action & LigActionLast));
+	buffer->move_to (end);
+      }
+    }
+
+    public:
+    bool ret;
+    private:
+    hb_aat_apply_context_t *c;
+    const LigatureSubtable *table;
+    const UnsizedArrayOf<HBUINT32> &ligAction;
+    const UnsizedArrayOf<HBUINT16> &component;
+    const UnsizedArrayOf<HBGlyphID> &ligature;
+    unsigned int match_length;
+    unsigned int match_positions[HB_MAX_CONTEXT_LENGTH];
+  };
+
+  bool apply (hb_aat_apply_context_t *c) const
+  {
+    TRACE_APPLY (this);
+
+    driver_context_t dc (this, c);
+
+    StateTableDriver<Types, EntryData> driver (machine, c->buffer, c->face);
+    driver.drive (&dc);
+
+    return_trace (dc.ret);
+  }
+
+  bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    /* The rest of array sanitizations are done at run-time. */
+    return_trace (c->check_struct (this) && machine.sanitize (c) &&
+		  ligAction && component && ligature);
+  }
+
+  protected:
+  StateTable<Types, EntryData>
+		machine;
+  NNOffsetTo<UnsizedArrayOf<HBUINT32>, HBUINT>
+		ligAction;	/* Offset to the ligature action table. */
+  NNOffsetTo<UnsizedArrayOf<HBUINT16>, HBUINT>
+		component;	/* Offset to the component table. */
+  NNOffsetTo<UnsizedArrayOf<HBGlyphID>, HBUINT>
+		ligature;	/* Offset to the actual ligature lists. */
+  public:
+  DEFINE_SIZE_STATIC (28);
+};
+
+template <typename Types>
+struct NoncontextualSubtable
+{
+  bool apply (hb_aat_apply_context_t *c) const
+  {
+    TRACE_APPLY (this);
+
+    bool ret = false;
+    unsigned int num_glyphs = c->face->get_num_glyphs ();
+
+    hb_glyph_info_t *info = c->buffer->info;
+    unsigned int count = c->buffer->len;
+    for (unsigned int i = 0; i < count; i++)
+    {
+      const HBGlyphID *replacement = substitute.get_value (info[i].codepoint, num_glyphs);
+      if (replacement)
+      {
+	info[i].codepoint = *replacement;
+	ret = true;
+      }
+    }
+
+    return_trace (ret);
+  }
+
+  bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (substitute.sanitize (c));
+  }
+
+  protected:
+  Lookup<HBGlyphID>	substitute;
+  public:
+  DEFINE_SIZE_MIN (2);
+};
+
+template <typename Types>
+struct InsertionSubtable
+{
+  typedef typename Types::HBUINT HBUINT;
+
+  struct EntryData
+  {
+    HBUINT16	currentInsertIndex;	/* Zero-based index into the insertion glyph table.
+					 * The number of glyphs to be inserted is contained
+					 * in the currentInsertCount field in the flags.
+					 * A value of 0xFFFF indicates no insertion is to
+					 * be done. */
+    HBUINT16	markedInsertIndex;	/* Zero-based index into the insertion glyph table.
+					 * The number of glyphs to be inserted is contained
+					 * in the markedInsertCount field in the flags.
+					 * A value of 0xFFFF indicates no insertion is to
+					 * be done. */
+    public:
+    DEFINE_SIZE_STATIC (4);
+  };
+
+  struct driver_context_t
+  {
+    static constexpr bool in_place = false;
+    enum Flags
+    {
+      SetMark		= 0x8000,	/* If set, mark the current glyph. */
+      DontAdvance	= 0x4000,	/* If set, don't advance to the next glyph before
+					 * going to the new state.  This does not mean
+					 * that the glyph pointed to is the same one as
+					 * before. If you've made insertions immediately
+					 * downstream of the current glyph, the next glyph
+					 * processed would in fact be the first one
+					 * inserted. */
+      CurrentIsKashidaLike= 0x2000,	/* If set, and the currentInsertList is nonzero,
+					 * then the specified glyph list will be inserted
+					 * as a kashida-like insertion, either before or
+					 * after the current glyph (depending on the state
+					 * of the currentInsertBefore flag). If clear, and
+					 * the currentInsertList is nonzero, then the
+					 * specified glyph list will be inserted as a
+					 * split-vowel-like insertion, either before or
+					 * after the current glyph (depending on the state
+					 * of the currentInsertBefore flag). */
+      MarkedIsKashidaLike= 0x1000,	/* If set, and the markedInsertList is nonzero,
+					 * then the specified glyph list will be inserted
+					 * as a kashida-like insertion, either before or
+					 * after the marked glyph (depending on the state
+					 * of the markedInsertBefore flag). If clear, and
+					 * the markedInsertList is nonzero, then the
+					 * specified glyph list will be inserted as a
+					 * split-vowel-like insertion, either before or
+					 * after the marked glyph (depending on the state
+					 * of the markedInsertBefore flag). */
+      CurrentInsertBefore= 0x0800,	/* If set, specifies that insertions are to be made
+					 * to the left of the current glyph. If clear,
+					 * they're made to the right of the current glyph. */
+      MarkedInsertBefore= 0x0400,	/* If set, specifies that insertions are to be
+					 * made to the left of the marked glyph. If clear,
+					 * they're made to the right of the marked glyph. */
+      CurrentInsertCount= 0x3E0,	/* This 5-bit field is treated as a count of the
+					 * number of glyphs to insert at the current
+					 * position. Since zero means no insertions, the
+					 * largest number of insertions at any given
+					 * current location is 31 glyphs. */
+      MarkedInsertCount= 0x001F,	/* This 5-bit field is treated as a count of the
+					 * number of glyphs to insert at the marked
+					 * position. Since zero means no insertions, the
+					 * largest number of insertions at any given
+					 * marked location is 31 glyphs. */
+    };
+
+    driver_context_t (const InsertionSubtable *table,
+		      hb_aat_apply_context_t *c_) :
+	ret (false),
+	c (c_),
+	mark (0),
+	insertionAction (table+table->insertionAction) {}
+
+    bool is_actionable (StateTableDriver<Types, EntryData> *driver HB_UNUSED,
+			const Entry<EntryData> &entry)
+    {
+      return (entry.flags & (CurrentInsertCount | MarkedInsertCount)) &&
+	     (entry.data.currentInsertIndex != 0xFFFF ||entry.data.markedInsertIndex != 0xFFFF);
+    }
+    void transition (StateTableDriver<Types, EntryData> *driver,
+		     const Entry<EntryData> &entry)
+    {
+      hb_buffer_t *buffer = driver->buffer;
+      unsigned int flags = entry.flags;
+
+      unsigned mark_loc = buffer->out_len;
+
+      if (entry.data.markedInsertIndex != 0xFFFF)
+      {
+	unsigned int count = (flags & MarkedInsertCount);
+	if (unlikely ((buffer->max_ops -= count) <= 0)) return;
+	unsigned int start = entry.data.markedInsertIndex;
+	const HBGlyphID *glyphs = &insertionAction[start];
+	if (unlikely (!c->sanitizer.check_array (glyphs, count))) count = 0;
+
+	bool before = flags & MarkedInsertBefore;
+
+	unsigned int end = buffer->out_len;
+	buffer->move_to (mark);
+
+	if (buffer->idx < buffer->len && !before)
+	  buffer->copy_glyph ();
+	/* TODO We ignore KashidaLike setting. */
+	for (unsigned int i = 0; i < count; i++)
+	  buffer->output_glyph (glyphs[i]);
+	if (buffer->idx < buffer->len && !before)
+	  buffer->skip_glyph ();
+
+	buffer->move_to (end + count);
+
+	buffer->unsafe_to_break_from_outbuffer (mark, hb_min (buffer->idx + 1, buffer->len));
+      }
+
+      if (flags & SetMark)
+	mark = mark_loc;
+
+      if (entry.data.currentInsertIndex != 0xFFFF)
+      {
+	unsigned int count = (flags & CurrentInsertCount) >> 5;
+	if (unlikely ((buffer->max_ops -= count) <= 0)) return;
+	unsigned int start = entry.data.currentInsertIndex;
+	const HBGlyphID *glyphs = &insertionAction[start];
+	if (unlikely (!c->sanitizer.check_array (glyphs, count))) count = 0;
+
+	bool before = flags & CurrentInsertBefore;
+
+	unsigned int end = buffer->out_len;
+
+	if (buffer->idx < buffer->len && !before)
+	  buffer->copy_glyph ();
+	/* TODO We ignore KashidaLike setting. */
+	for (unsigned int i = 0; i < count; i++)
+	  buffer->output_glyph (glyphs[i]);
+	if (buffer->idx < buffer->len && !before)
+	  buffer->skip_glyph ();
+
+	/* Humm. Not sure where to move to.  There's this wording under
+	 * DontAdvance flag:
+	 *
+	 * "If set, don't update the glyph index before going to the new state.
+	 * This does not mean that the glyph pointed to is the same one as
+	 * before. If you've made insertions immediately downstream of the
+	 * current glyph, the next glyph processed would in fact be the first
+	 * one inserted."
+	 *
+	 * This suggests that if DontAdvance is NOT set, we should move to
+	 * end+count.  If it *was*, then move to end, such that newly inserted
+	 * glyphs are now visible.
+	 *
+	 * https://github.com/harfbuzz/harfbuzz/issues/1224#issuecomment-427691417
+	 */
+	buffer->move_to ((flags & DontAdvance) ? end : end + count);
+      }
+    }
+
+    public:
+    bool ret;
+    private:
+    hb_aat_apply_context_t *c;
+    unsigned int mark;
+    const UnsizedArrayOf<HBGlyphID> &insertionAction;
+  };
+
+  bool apply (hb_aat_apply_context_t *c) const
+  {
+    TRACE_APPLY (this);
+
+    driver_context_t dc (this, c);
+
+    StateTableDriver<Types, EntryData> driver (machine, c->buffer, c->face);
+    driver.drive (&dc);
+
+    return_trace (dc.ret);
+  }
+
+  bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    /* The rest of array sanitizations are done at run-time. */
+    return_trace (c->check_struct (this) && machine.sanitize (c) &&
+		  insertionAction);
+  }
+
+  protected:
+  StateTable<Types, EntryData>
+		machine;
+  NNOffsetTo<UnsizedArrayOf<HBGlyphID>, HBUINT>
+		insertionAction;	/* Byte offset from stateHeader to the start of
+					 * the insertion glyph table. */
+  public:
+  DEFINE_SIZE_STATIC (20);
+};
+
+
+struct Feature
+{
+  bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (c->check_struct (this));
+  }
+
+  public:
+  HBUINT16	featureType;	/* The type of feature. */
+  HBUINT16	featureSetting;	/* The feature's setting (aka selector). */
+  HBUINT32	enableFlags;	/* Flags for the settings that this feature
+				 * and setting enables. */
+  HBUINT32	disableFlags;	/* Complement of flags for the settings that this
+				 * feature and setting disable. */
+
+  public:
+  DEFINE_SIZE_STATIC (12);
+};
+
+template <typename Types>
+struct ChainSubtable
+{
+  typedef typename Types::HBUINT HBUINT;
+
+  template <typename T>
+  friend struct Chain;
+
+  unsigned int get_size () const     { return length; }
+  unsigned int get_type () const     { return coverage & 0xFF; }
+  unsigned int get_coverage () const { return coverage >> (sizeof (HBUINT) * 8 - 8); }
+
+  enum Coverage
+  {
+    Vertical		= 0x80,	/* If set, this subtable will only be applied
+				 * to vertical text. If clear, this subtable
+				 * will only be applied to horizontal text. */
+    Backwards		= 0x40,	/* If set, this subtable will process glyphs
+				 * in descending order. If clear, it will
+				 * process the glyphs in ascending order. */
+    AllDirections	= 0x20,	/* If set, this subtable will be applied to
+				 * both horizontal and vertical text (i.e.
+				 * the state of bit 0x80000000 is ignored). */
+    Logical		= 0x10,	/* If set, this subtable will process glyphs
+				 * in logical order (or reverse logical order,
+				 * depending on the value of bit 0x80000000). */
+  };
+  enum Type
+  {
+    Rearrangement	= 0,
+    Contextual		= 1,
+    Ligature		= 2,
+    Noncontextual	= 4,
+    Insertion		= 5
+  };
+
+  template <typename context_t, typename ...Ts>
+  typename context_t::return_t dispatch (context_t *c, Ts&&... ds) const
+  {
+    unsigned int subtable_type = get_type ();
+    TRACE_DISPATCH (this, subtable_type);
+    switch (subtable_type) {
+    case Rearrangement:		return_trace (c->dispatch (u.rearrangement, hb_forward<Ts> (ds)...));
+    case Contextual:		return_trace (c->dispatch (u.contextual, hb_forward<Ts> (ds)...));
+    case Ligature:		return_trace (c->dispatch (u.ligature, hb_forward<Ts> (ds)...));
+    case Noncontextual:		return_trace (c->dispatch (u.noncontextual, hb_forward<Ts> (ds)...));
+    case Insertion:		return_trace (c->dispatch (u.insertion, hb_forward<Ts> (ds)...));
+    default:			return_trace (c->default_return_value ());
+    }
+  }
+
+  bool apply (hb_aat_apply_context_t *c) const
+  {
+    TRACE_APPLY (this);
+    hb_sanitize_with_object_t with (&c->sanitizer, this);
+    return_trace (dispatch (c));
+  }
+
+  bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    if (!length.sanitize (c) ||
+	length <= min_size ||
+	!c->check_range (this, length))
+      return_trace (false);
+
+    hb_sanitize_with_object_t with (c, this);
+    return_trace (dispatch (c));
+  }
+
+  protected:
+  HBUINT	length;		/* Total subtable length, including this header. */
+  HBUINT	coverage;	/* Coverage flags and subtable type. */
+  HBUINT32	subFeatureFlags;/* The 32-bit mask identifying which subtable this is. */
+  union {
+  RearrangementSubtable<Types>	rearrangement;
+  ContextualSubtable<Types>	contextual;
+  LigatureSubtable<Types>	ligature;
+  NoncontextualSubtable<Types>	noncontextual;
+  InsertionSubtable<Types>	insertion;
+  } u;
+  public:
+  DEFINE_SIZE_MIN (2 * sizeof (HBUINT) + 4);
+};
+
+template <typename Types>
+struct Chain
+{
+  typedef typename Types::HBUINT HBUINT;
+
+  hb_mask_t compile_flags (const hb_aat_map_builder_t *map) const
+  {
+    hb_mask_t flags = defaultFlags;
+    {
+      unsigned int count = featureCount;
+      for (unsigned i = 0; i < count; i++)
+      {
+	const Feature &feature = featureZ[i];
+	hb_aat_layout_feature_type_t type = (hb_aat_layout_feature_type_t) (unsigned int) feature.featureType;
+	hb_aat_layout_feature_selector_t setting = (hb_aat_layout_feature_selector_t) (unsigned int) feature.featureSetting;
+      retry:
+	// Check whether this type/setting pair was requested in the map, and if so, apply its flags.
+	// (The search here only looks at the type and setting fields of feature_info_t.)
+	hb_aat_map_builder_t::feature_info_t info = { type, setting, false, 0 };
+	if (map->features.bsearch (info))
+	{
+	  flags &= feature.disableFlags;
+	  flags |= feature.enableFlags;
+	}
+	else if (type == HB_AAT_LAYOUT_FEATURE_TYPE_LETTER_CASE && setting == HB_AAT_LAYOUT_FEATURE_SELECTOR_SMALL_CAPS)
+	{
+	  /* Deprecated. https://github.com/harfbuzz/harfbuzz/issues/1342 */
+	  type = HB_AAT_LAYOUT_FEATURE_TYPE_LOWER_CASE;
+	  setting = HB_AAT_LAYOUT_FEATURE_SELECTOR_LOWER_CASE_SMALL_CAPS;
+	  goto retry;
+	}
+      }
+    }
+    return flags;
+  }
+
+  void apply (hb_aat_apply_context_t *c,
+	      hb_mask_t flags) const
+  {
+    const ChainSubtable<Types> *subtable = &StructAfter<ChainSubtable<Types>> (featureZ.as_array (featureCount));
+    unsigned int count = subtableCount;
+    for (unsigned int i = 0; i < count; i++)
+    {
+      bool reverse;
+
+      if (!(subtable->subFeatureFlags & flags))
+	goto skip;
+
+      if (!(subtable->get_coverage() & ChainSubtable<Types>::AllDirections) &&
+	  HB_DIRECTION_IS_VERTICAL (c->buffer->props.direction) !=
+	  bool (subtable->get_coverage() & ChainSubtable<Types>::Vertical))
+	goto skip;
+
+      /* Buffer contents is always in logical direction.  Determine if
+       * we need to reverse before applying this subtable.  We reverse
+       * back after if we did reverse indeed.
+       *
+       * Quoting the spac:
+       * """
+       * Bits 28 and 30 of the coverage field control the order in which
+       * glyphs are processed when the subtable is run by the layout engine.
+       * Bit 28 is used to indicate if the glyph processing direction is
+       * the same as logical order or layout order. Bit 30 is used to
+       * indicate whether glyphs are processed forwards or backwards within
+       * that order.
+
+		Bit 30	Bit 28	Interpretation for Horizontal Text
+		0	0	The subtable is processed in layout order
+				(the same order as the glyphs, which is
+				always left-to-right).
+		1	0	The subtable is processed in reverse layout order
+				(the order opposite that of the glyphs, which is
+				always right-to-left).
+		0	1	The subtable is processed in logical order
+				(the same order as the characters, which may be
+				left-to-right or right-to-left).
+		1	1	The subtable is processed in reverse logical order
+				(the order opposite that of the characters, which
+				may be right-to-left or left-to-right).
+       */
+      reverse = subtable->get_coverage () & ChainSubtable<Types>::Logical ?
+		bool (subtable->get_coverage () & ChainSubtable<Types>::Backwards) :
+		bool (subtable->get_coverage () & ChainSubtable<Types>::Backwards) !=
+		HB_DIRECTION_IS_BACKWARD (c->buffer->props.direction);
+
+      if (!c->buffer->message (c->font, "start chainsubtable %d", c->lookup_index))
+	goto skip;
+
+      if (reverse)
+	c->buffer->reverse ();
+
+      subtable->apply (c);
+
+      if (reverse)
+	c->buffer->reverse ();
+
+      (void) c->buffer->message (c->font, "end chainsubtable %d", c->lookup_index);
+
+      if (unlikely (!c->buffer->successful)) return;
+
+    skip:
+      subtable = &StructAfter<ChainSubtable<Types>> (*subtable);
+      c->set_lookup_index (c->lookup_index + 1);
+    }
+  }
+
+  unsigned int get_size () const { return length; }
+
+  bool sanitize (hb_sanitize_context_t *c, unsigned int version HB_UNUSED) const
+  {
+    TRACE_SANITIZE (this);
+    if (!length.sanitize (c) ||
+	length < min_size ||
+	!c->check_range (this, length))
+      return_trace (false);
+
+    if (!c->check_array (featureZ.arrayZ, featureCount))
+      return_trace (false);
+
+    const ChainSubtable<Types> *subtable = &StructAfter<ChainSubtable<Types>> (featureZ.as_array (featureCount));
+    unsigned int count = subtableCount;
+    for (unsigned int i = 0; i < count; i++)
+    {
+      if (!subtable->sanitize (c))
+	return_trace (false);
+      subtable = &StructAfter<ChainSubtable<Types>> (*subtable);
+    }
+
+    return_trace (true);
+  }
+
+  protected:
+  HBUINT32	defaultFlags;	/* The default specification for subtables. */
+  HBUINT32	length;		/* Total byte count, including this header. */
+  HBUINT	featureCount;	/* Number of feature subtable entries. */
+  HBUINT	subtableCount;	/* The number of subtables in the chain. */
+
+  UnsizedArrayOf<Feature>	featureZ;	/* Features. */
+/*ChainSubtable	firstSubtable;*//* Subtables. */
+/*subtableGlyphCoverageArray*/	/* Only if version >= 3. We don't use. */
+
+  public:
+  DEFINE_SIZE_MIN (8 + 2 * sizeof (HBUINT));
+};
+
+
+/*
+ * The 'mort'/'morx' Table
+ */
+
+template <typename Types, hb_tag_t TAG>
+struct mortmorx
+{
+  static constexpr hb_tag_t tableTag = TAG;
+
+  bool has_data () const { return version != 0; }
+
+  void compile_flags (const hb_aat_map_builder_t *mapper,
+		      hb_aat_map_t *map) const
+  {
+    const Chain<Types> *chain = &firstChain;
+    unsigned int count = chainCount;
+    for (unsigned int i = 0; i < count; i++)
+    {
+      map->chain_flags.push (chain->compile_flags (mapper));
+      chain = &StructAfter<Chain<Types>> (*chain);
+    }
+  }
+
+  void apply (hb_aat_apply_context_t *c) const
+  {
+    if (unlikely (!c->buffer->successful)) return;
+    c->set_lookup_index (0);
+    const Chain<Types> *chain = &firstChain;
+    unsigned int count = chainCount;
+    for (unsigned int i = 0; i < count; i++)
+    {
+      chain->apply (c, c->plan->aat_map.chain_flags[i]);
+      if (unlikely (!c->buffer->successful)) return;
+      chain = &StructAfter<Chain<Types>> (*chain);
+    }
+  }
+
+  bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    if (!version.sanitize (c) || !version || !chainCount.sanitize (c))
+      return_trace (false);
+
+    const Chain<Types> *chain = &firstChain;
+    unsigned int count = chainCount;
+    for (unsigned int i = 0; i < count; i++)
+    {
+      if (!chain->sanitize (c, version))
+	return_trace (false);
+      chain = &StructAfter<Chain<Types>> (*chain);
+    }
+
+    return_trace (true);
+  }
+
+  protected:
+  HBUINT16	version;	/* Version number of the glyph metamorphosis table.
+				 * 1, 2, or 3. */
+  HBUINT16	unused;		/* Set to 0. */
+  HBUINT32	chainCount;	/* Number of metamorphosis chains contained in this
+				 * table. */
+  Chain<Types>	firstChain;	/* Chains. */
+
+  public:
+  DEFINE_SIZE_MIN (8);
+};
+
+struct morx : mortmorx<ExtendedTypes, HB_AAT_TAG_morx> {};
+struct mort : mortmorx<ObsoleteTypes, HB_AAT_TAG_mort> {};
+
+
+} /* namespace AAT */
+
+
+#endif /* HB_AAT_LAYOUT_MORX_TABLE_HH */