The Tor Browser: gfx/harfbuzz/src/hb-ot-layout-gsubgpos-private.hh@925c144e1f1f (annotated)

gfx/harfbuzz/src/hb-ot-layout-gsubgpos-private.hh@925c144e1f1f (annotated)

gfx/harfbuzz/src/hb-ot-layout-gsubgpos-private.hh

Fri, 16 Jan 2015 18:13:44 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Fri, 16 Jan 2015 18:13:44 +0100
branch: TOR_BUG_9701
changeset 14: 925c144e1f1f
permissions: -rw-r--r--

Integrate suggestion from review to improve consistency with existing code.

 /*
  * Copyright © 2007,2008,2009,2010  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_GSUBGPOS_PRIVATE_HH
 #define HB_OT_LAYOUT_GSUBGPOS_PRIVATE_HH
 #include "hb-buffer-private.hh"
 #include "hb-ot-layout-gdef-table.hh"
 #include "hb-set-private.hh"
 namespace OT {
 #define TRACE_DISPATCH(this) \
 	hb_auto_trace_t<context_t::max_debug_depth, typename context_t::return_t> trace \
 	(&c->debug_depth, c->get_name (), this, HB_FUNC, \
 	 "");
 #ifndef HB_DEBUG_CLOSURE
 #define HB_DEBUG_CLOSURE (HB_DEBUG+0)
 #endif
 #define TRACE_CLOSURE(this) \
 	hb_auto_trace_t<HB_DEBUG_CLOSURE, hb_void_t> trace \
 	(&c->debug_depth, c->get_name (), this, HB_FUNC, \
 	 "");
 struct hb_closure_context_t
 {
   inline const char *get_name (void) { return "CLOSURE"; }
   static const unsigned int max_debug_depth = HB_DEBUG_CLOSURE;
   typedef hb_void_t return_t;
   typedef return_t (*recurse_func_t) (hb_closure_context_t *c, unsigned int lookup_index);
   template <typename T>
   inline return_t dispatch (const T &obj) { obj.closure (this); return HB_VOID; }
   static return_t default_return_value (void) { return HB_VOID; }
   bool stop_sublookup_iteration (return_t r HB_UNUSED) const { return false; }
   return_t recurse (unsigned int lookup_index)
   {
     if (unlikely (nesting_level_left == 0 || !recurse_func))
       return default_return_value ();
     nesting_level_left--;
     recurse_func (this, lookup_index);
     nesting_level_left++;
     return HB_VOID;
   }
   hb_face_t *face;
   hb_set_t *glyphs;
   recurse_func_t recurse_func;
   unsigned int nesting_level_left;
   unsigned int debug_depth;
   hb_closure_context_t (hb_face_t *face_,
 			hb_set_t *glyphs_,
 		        unsigned int nesting_level_left_ = MAX_NESTING_LEVEL) :
 			  face (face_),
 			  glyphs (glyphs_),
 			  recurse_func (NULL),
 			  nesting_level_left (nesting_level_left_),
 			  debug_depth (0) {}
   void set_recurse_func (recurse_func_t func) { recurse_func = func; }
 };
 #ifndef HB_DEBUG_WOULD_APPLY
 #define HB_DEBUG_WOULD_APPLY (HB_DEBUG+0)
 #endif
 #define TRACE_WOULD_APPLY(this) \
 	hb_auto_trace_t<HB_DEBUG_WOULD_APPLY, bool> trace \
 	(&c->debug_depth, c->get_name (), this, HB_FUNC, \
 	 "%d glyphs", c->len);
 struct hb_would_apply_context_t
 {
   inline const char *get_name (void) { return "WOULD_APPLY"; }
   static const unsigned int max_debug_depth = HB_DEBUG_WOULD_APPLY;
   typedef bool return_t;
   template <typename T>
   inline return_t dispatch (const T &obj) { return obj.would_apply (this); }
   static return_t default_return_value (void) { return false; }
   bool stop_sublookup_iteration (return_t r) const { return r; }
   hb_face_t *face;
   const hb_codepoint_t *glyphs;
   unsigned int len;
   bool zero_context;
   unsigned int debug_depth;
   hb_would_apply_context_t (hb_face_t *face_,
 			    const hb_codepoint_t *glyphs_,
 			    unsigned int len_,
 			    bool zero_context_) :
 			      face (face_),
 			      glyphs (glyphs_),
 			      len (len_),
 			      zero_context (zero_context_),
 			      debug_depth (0) {}
 };
 #ifndef HB_DEBUG_COLLECT_GLYPHS
 #define HB_DEBUG_COLLECT_GLYPHS (HB_DEBUG+0)
 #endif
 #define TRACE_COLLECT_GLYPHS(this) \
 	hb_auto_trace_t<HB_DEBUG_COLLECT_GLYPHS, hb_void_t> trace \
 	(&c->debug_depth, c->get_name (), this, HB_FUNC, \
 	 "");
 struct hb_collect_glyphs_context_t
 {
   inline const char *get_name (void) { return "COLLECT_GLYPHS"; }
   static const unsigned int max_debug_depth = HB_DEBUG_COLLECT_GLYPHS;
   typedef hb_void_t return_t;
   typedef return_t (*recurse_func_t) (hb_collect_glyphs_context_t *c, unsigned int lookup_index);
   template <typename T>
   inline return_t dispatch (const T &obj) { obj.collect_glyphs (this); return HB_VOID; }
   static return_t default_return_value (void) { return HB_VOID; }
   bool stop_sublookup_iteration (return_t r HB_UNUSED) const { return false; }
   return_t recurse (unsigned int lookup_index)
   {
     if (unlikely (nesting_level_left == 0 || !recurse_func))
       return default_return_value ();
     /* Note that GPOS sets recurse_func to NULL already, so it doesn't get
      * past the previous check.  For GSUB, we only want to collect the output
      * glyphs in the recursion.  If output is not requested, we can go home now.
      *
      * Note further, that the above is not exactly correct.  A recursed lookup
      * is allowed to match input that is not matched in the context, but that's
      * not how most fonts are built.  It's possible to relax that and recurse
      * with all sets here if it proves to be an issue.
      */
     if (output == hb_set_get_empty ())
       return HB_VOID;
     hb_set_t *old_before = before;
     hb_set_t *old_input  = input;
     hb_set_t *old_after  = after;
     before = input = after = hb_set_get_empty ();
     nesting_level_left--;
     recurse_func (this, lookup_index);
     nesting_level_left++;
     before = old_before;
     input  = old_input;
     after  = old_after;
     return HB_VOID;
   }
   hb_face_t *face;
   hb_set_t *before;
   hb_set_t *input;
   hb_set_t *after;
   hb_set_t *output;
   recurse_func_t recurse_func;
   unsigned int nesting_level_left;
   unsigned int debug_depth;
   hb_collect_glyphs_context_t (hb_face_t *face_,
 			       hb_set_t  *glyphs_before, /* OUT. May be NULL */
 			       hb_set_t  *glyphs_input,  /* OUT. May be NULL */
 			       hb_set_t  *glyphs_after,  /* OUT. May be NULL */
 			       hb_set_t  *glyphs_output, /* OUT. May be NULL */
 			       unsigned int nesting_level_left_ = MAX_NESTING_LEVEL) :
 			      face (face_),
 			      before (glyphs_before ? glyphs_before : hb_set_get_empty ()),
 			      input  (glyphs_input  ? glyphs_input  : hb_set_get_empty ()),
 			      after  (glyphs_after  ? glyphs_after  : hb_set_get_empty ()),
 			      output (glyphs_output ? glyphs_output : hb_set_get_empty ()),
 			      recurse_func (NULL),
 			      nesting_level_left (nesting_level_left_),
 			      debug_depth (0) {}
   void set_recurse_func (recurse_func_t func) { recurse_func = func; }
 };
 struct hb_get_coverage_context_t
 {
   inline const char *get_name (void) { return "GET_COVERAGE"; }
   static const unsigned int max_debug_depth = 0;
   typedef const Coverage &return_t;
   template <typename T>
   inline return_t dispatch (const T &obj) { return obj.get_coverage (); }
   static return_t default_return_value (void) { return Null(Coverage); }
   hb_get_coverage_context_t (void) :
 			    debug_depth (0) {}
   unsigned int debug_depth;
 };
 #ifndef HB_DEBUG_APPLY
 #define HB_DEBUG_APPLY (HB_DEBUG+0)
 #endif
 #define TRACE_APPLY(this) \
 	hb_auto_trace_t<HB_DEBUG_APPLY, bool> trace \
 	(&c->debug_depth, c->get_name (), this, HB_FUNC, \
 	 "idx %d codepoint %u", c->buffer->idx, c->buffer->cur().codepoint);
 struct hb_apply_context_t
 {
   inline const char *get_name (void) { return "APPLY"; }
   static const unsigned int max_debug_depth = HB_DEBUG_APPLY;
   typedef bool return_t;
   typedef return_t (*recurse_func_t) (hb_apply_context_t *c, unsigned int lookup_index);
   template <typename T>
   inline return_t dispatch (const T &obj) { return obj.apply (this); }
   static return_t default_return_value (void) { return false; }
   bool stop_sublookup_iteration (return_t r) const { return r; }
   return_t recurse (unsigned int lookup_index)
   {
     if (unlikely (nesting_level_left == 0 || !recurse_func))
       return default_return_value ();
     nesting_level_left--;
     bool ret = recurse_func (this, lookup_index);
     nesting_level_left++;
     return ret;
   }
   unsigned int table_index; /* GSUB/GPOS */
   hb_font_t *font;
   hb_face_t *face;
   hb_buffer_t *buffer;
   hb_direction_t direction;
   hb_mask_t lookup_mask;
   bool auto_zwj;
   recurse_func_t recurse_func;
   unsigned int nesting_level_left;
   unsigned int lookup_props;
   const GDEF &gdef;
   bool has_glyph_classes;
   unsigned int debug_depth;
   hb_apply_context_t (unsigned int table_index_,
 		      hb_font_t *font_,
 		      hb_buffer_t *buffer_) :
 			table_index (table_index_),
 			font (font_), face (font->face), buffer (buffer_),
 			direction (buffer_->props.direction),
 			lookup_mask (1),
 			auto_zwj (true),
 			recurse_func (NULL),
 			nesting_level_left (MAX_NESTING_LEVEL),
 			lookup_props (0),
 			gdef (*hb_ot_layout_from_face (face)->gdef),
 			has_glyph_classes (gdef.has_glyph_classes ()),
 			debug_depth (0) {}
   inline void set_lookup_mask (hb_mask_t mask) { lookup_mask = mask; }
   inline void set_auto_zwj (bool auto_zwj_) { auto_zwj = auto_zwj_; }
   inline void set_recurse_func (recurse_func_t func) { recurse_func = func; }
   inline void set_lookup_props (unsigned int lookup_props_) { lookup_props = lookup_props_; }
   inline void set_lookup (const Lookup &l) { lookup_props = l.get_props (); }
   struct matcher_t
   {
     inline matcher_t (void) :
 	     lookup_props (0),
 	     ignore_zwnj (false),
 	     ignore_zwj (false),
 	     mask (-1),
 #define arg1(arg) (arg) /* Remove the macro to see why it's needed! */
 	     syllable arg1(0),
 #undef arg1
 	     match_func (NULL),
 	     match_data (NULL) {};
     typedef bool (*match_func_t) (hb_codepoint_t glyph_id, const USHORT &value, const void *data);
     inline void set_ignore_zwnj (bool ignore_zwnj_) { ignore_zwnj = ignore_zwnj_; }
     inline void set_ignore_zwj (bool ignore_zwj_) { ignore_zwj = ignore_zwj_; }
     inline void set_lookup_props (unsigned int lookup_props_) { lookup_props = lookup_props_; }
     inline void set_mask (hb_mask_t mask_) { mask = mask_; }
     inline void set_syllable (uint8_t syllable_)  { syllable = syllable_; }
     inline void set_match_func (match_func_t match_func_,
 				const void *match_data_)
     { match_func = match_func_; match_data = match_data_; }
     enum may_match_t {
       MATCH_NO,
       MATCH_YES,
       MATCH_MAYBE
     };
     inline may_match_t may_match (const hb_glyph_info_t &info,
 				  const USHORT          *glyph_data) const
     {
       if (!(info.mask & mask) ||
 	  (syllable && syllable != info.syllable ()))
 	return MATCH_NO;
       if (match_func)
         return match_func (info.codepoint, *glyph_data, match_data) ? MATCH_YES : MATCH_NO;
       return MATCH_MAYBE;
     }
     enum may_skip_t {
       SKIP_NO,
       SKIP_YES,
       SKIP_MAYBE
     };
     inline may_skip_t
     may_skip (const hb_apply_context_t *c,
 	      const hb_glyph_info_t    &info) const
     {
       unsigned int property;
       property = _hb_glyph_info_get_glyph_props (&info);
       if (!c->match_properties (info.codepoint, property, lookup_props))
 	return SKIP_YES;
       if (unlikely (_hb_glyph_info_is_default_ignorable (&info) &&
 		    (ignore_zwnj || !_hb_glyph_info_is_zwnj (&info)) &&
 		    (ignore_zwj || !_hb_glyph_info_is_zwj (&info)) &&
 		    !_hb_glyph_info_ligated (&info)))
 	return SKIP_MAYBE;
       return SKIP_NO;
     }
     protected:
     unsigned int lookup_props;
     bool ignore_zwnj;
     bool ignore_zwj;
     hb_mask_t mask;
     uint8_t syllable;
     match_func_t match_func;
     const void *match_data;
   };
   struct skipping_forward_iterator_t
   {
     inline skipping_forward_iterator_t (hb_apply_context_t *c_,
 					unsigned int start_index_,
 					unsigned int num_items_,
 					bool context_match = false) :
 					 idx (start_index_),
 					 c (c_),
 					 match_glyph_data (NULL),
 					 num_items (num_items_),
 					 end (c->buffer->len)
     {
       matcher.set_lookup_props (c->lookup_props);
       /* Ignore ZWNJ if we are matching GSUB context, or matching GPOS. */
       matcher.set_ignore_zwnj (context_match || c->table_index == 1);
       /* Ignore ZWJ if we are matching GSUB context, or matching GPOS, or if asked to. */
       matcher.set_ignore_zwj (context_match || c->table_index == 1 || c->auto_zwj);
       if (!context_match)
 	matcher.set_mask (c->lookup_mask);
       matcher.set_syllable (start_index_ == c->buffer->idx ? c->buffer->cur().syllable () : 0);
     }
     inline void set_lookup_props (unsigned int lookup_props) { matcher.set_lookup_props (lookup_props); }
     inline void set_syllable (unsigned int syllable) { matcher.set_syllable (syllable); }
     inline void set_match_func (matcher_t::match_func_t match_func,
 				const void *match_data,
 				const USHORT glyph_data[])
     {
       matcher.set_match_func (match_func, match_data);
       match_glyph_data = glyph_data;
     }
     inline bool has_no_chance (void) const { return unlikely (num_items && idx + num_items >= end); }
     inline void reject (void) { num_items++; match_glyph_data--; }
     inline bool next (void)
     {
       assert (num_items > 0);
       while (!has_no_chance ())
       {
 	idx++;
 	const hb_glyph_info_t &info = c->buffer->info[idx];
 	matcher_t::may_skip_t skip = matcher.may_skip (c, info);
 	if (unlikely (skip == matcher_t::SKIP_YES))
 	  continue;
 	matcher_t::may_match_t match = matcher.may_match (info, match_glyph_data);
 	if (match == matcher_t::MATCH_YES ||
 	    (match == matcher_t::MATCH_MAYBE &&
 	     skip == matcher_t::SKIP_NO))
 	{
 	  num_items--;
 	  match_glyph_data++;
 	  return true;
 	}
 	if (skip == matcher_t::SKIP_NO)
 	  return false;
       }
       return false;
     }
     unsigned int idx;
     protected:
     hb_apply_context_t *c;
     matcher_t matcher;
     const USHORT *match_glyph_data;
     unsigned int num_items;
     unsigned int end;
   };
   struct skipping_backward_iterator_t
   {
     inline skipping_backward_iterator_t (hb_apply_context_t *c_,
 					 unsigned int start_index_,
 					 unsigned int num_items_,
 					 bool context_match = false) :
 					  idx (start_index_),
 					  c (c_),
 					  match_glyph_data (NULL),
 					  num_items (num_items_)
     {
       matcher.set_lookup_props (c->lookup_props);
       /* Ignore ZWNJ if we are matching GSUB context, or matching GPOS. */
       matcher.set_ignore_zwnj (context_match || c->table_index == 1);
       /* Ignore ZWJ if we are matching GSUB context, or matching GPOS, or if asked to. */
       matcher.set_ignore_zwj (context_match || c->table_index == 1 || c->auto_zwj);
       if (!context_match)
 	matcher.set_mask (c->lookup_mask);
       matcher.set_syllable (start_index_ == c->buffer->idx ? c->buffer->cur().syllable () : 0);
     }
     inline void set_lookup_props (unsigned int lookup_props) { matcher.set_lookup_props (lookup_props); }
     inline void set_syllable (unsigned int syllable) { matcher.set_syllable (syllable); }
     inline void set_match_func (matcher_t::match_func_t match_func,
 				const void *match_data,
 				const USHORT glyph_data[])
     {
       matcher.set_match_func (match_func, match_data);
       match_glyph_data = glyph_data;
     }
     inline bool has_no_chance (void) const { return unlikely (idx < num_items); }
     inline void reject (void) { num_items++; }
     inline bool prev (void)
     {
       assert (num_items > 0);
       while (!has_no_chance ())
       {
 	idx--;
 	const hb_glyph_info_t &info = c->buffer->out_info[idx];
 	matcher_t::may_skip_t skip = matcher.may_skip (c, info);
 	if (unlikely (skip == matcher_t::SKIP_YES))
 	  continue;
 	matcher_t::may_match_t match = matcher.may_match (info, match_glyph_data);
 	if (match == matcher_t::MATCH_YES ||
 	    (match == matcher_t::MATCH_MAYBE &&
 	     skip == matcher_t::SKIP_NO))
 	{
 	  num_items--;
 	  match_glyph_data++;
 	  return true;
 	}
 	if (skip == matcher_t::SKIP_NO)
 	  return false;
       }
       return false;
     }
     unsigned int idx;
     protected:
     hb_apply_context_t *c;
     matcher_t matcher;
     const USHORT *match_glyph_data;
     unsigned int num_items;
   };
   inline bool
   match_properties_mark (hb_codepoint_t  glyph,
 			 unsigned int    glyph_props,
 			 unsigned int    lookup_props) const
   {
     /* If using mark filtering sets, the high short of
      * lookup_props has the set index.
      */
     if (lookup_props & LookupFlag::UseMarkFilteringSet)
       return gdef.mark_set_covers (lookup_props >> 16, glyph);
     /* The second byte of lookup_props has the meaning
      * "ignore marks of attachment type different than
      * the attachment type specified."
      */
     if (lookup_props & LookupFlag::MarkAttachmentType)
       return (lookup_props & LookupFlag::MarkAttachmentType) == (glyph_props & LookupFlag::MarkAttachmentType);
     return true;
   }
   inline bool
   match_properties (hb_codepoint_t  glyph,
 		    unsigned int    glyph_props,
 		    unsigned int    lookup_props) const
   {
     /* Not covered, if, for example, glyph class is ligature and
      * lookup_props includes LookupFlags::IgnoreLigatures
      */
     if (glyph_props & lookup_props & LookupFlag::IgnoreFlags)
       return false;
     if (unlikely (glyph_props & HB_OT_LAYOUT_GLYPH_PROPS_MARK))
       return match_properties_mark (glyph, glyph_props, lookup_props);
     return true;
   }
   inline bool
   check_glyph_property (hb_glyph_info_t *info,
 			unsigned int  lookup_props) const
   {
     unsigned int property;
     property = _hb_glyph_info_get_glyph_props (info);
     return match_properties (info->codepoint, property, lookup_props);
   }
   inline void _set_glyph_props (hb_codepoint_t glyph_index,
 			  unsigned int class_guess = 0,
 			  bool ligature = false) const
   {
     unsigned int add_in = _hb_glyph_info_get_glyph_props (&buffer->cur()) &
 			  HB_OT_LAYOUT_GLYPH_PROPS_PRESERVE;
     add_in |= HB_OT_LAYOUT_GLYPH_PROPS_SUBSTITUTED;
     if (ligature)
       add_in |= HB_OT_LAYOUT_GLYPH_PROPS_LIGATED;
     if (likely (has_glyph_classes))
       _hb_glyph_info_set_glyph_props (&buffer->cur(), add_in | gdef.get_glyph_props (glyph_index));
     else if (class_guess)
       _hb_glyph_info_set_glyph_props (&buffer->cur(), add_in | class_guess);
   }
   inline void replace_glyph (hb_codepoint_t glyph_index) const
   {
     _set_glyph_props (glyph_index);
     buffer->replace_glyph (glyph_index);
   }
   inline void replace_glyph_inplace (hb_codepoint_t glyph_index) const
   {
     _set_glyph_props (glyph_index);
     buffer->cur().codepoint = glyph_index;
   }
   inline void replace_glyph_with_ligature (hb_codepoint_t glyph_index,
 					   unsigned int class_guess) const
   {
     _set_glyph_props (glyph_index, class_guess, true);
     buffer->replace_glyph (glyph_index);
   }
   inline void output_glyph (hb_codepoint_t glyph_index,
 			    unsigned int class_guess) const
   {
     _set_glyph_props (glyph_index, class_guess);
     buffer->output_glyph (glyph_index);
   }
 };
 typedef bool (*intersects_func_t) (hb_set_t *glyphs, const USHORT &value, const void *data);
 typedef void (*collect_glyphs_func_t) (hb_set_t *glyphs, const USHORT &value, const void *data);
 typedef bool (*match_func_t) (hb_codepoint_t glyph_id, const USHORT &value, const void *data);
 struct ContextClosureFuncs
 {
   intersects_func_t intersects;
 };
 struct ContextCollectGlyphsFuncs
 {
   collect_glyphs_func_t collect;
 };
 struct ContextApplyFuncs
 {
   match_func_t match;
 };
 static inline bool intersects_glyph (hb_set_t *glyphs, const USHORT &value, const void *data HB_UNUSED)
 {
   return glyphs->has (value);
 }
 static inline bool intersects_class (hb_set_t *glyphs, const USHORT &value, const void *data)
 {
   const ClassDef &class_def = *reinterpret_cast<const ClassDef *>(data);
   return class_def.intersects_class (glyphs, value);
 }
 static inline bool intersects_coverage (hb_set_t *glyphs, const USHORT &value, const void *data)
 {
   const OffsetTo<Coverage> &coverage = (const OffsetTo<Coverage>&)value;
   return (data+coverage).intersects (glyphs);
 }
 static inline bool intersects_array (hb_closure_context_t *c,
 				     unsigned int count,
 				     const USHORT values[],
 				     intersects_func_t intersects_func,
 				     const void *intersects_data)
 {
   for (unsigned int i = 0; i < count; i++)
     if (likely (!intersects_func (c->glyphs, values[i], intersects_data)))
       return false;
   return true;
 }
 static inline void collect_glyph (hb_set_t *glyphs, const USHORT &value, const void *data HB_UNUSED)
 {
   glyphs->add (value);
 }
 static inline void collect_class (hb_set_t *glyphs, const USHORT &value, const void *data)
 {
   const ClassDef &class_def = *reinterpret_cast<const ClassDef *>(data);
   class_def.add_class (glyphs, value);
 }
 static inline void collect_coverage (hb_set_t *glyphs, const USHORT &value, const void *data)
 {
   const OffsetTo<Coverage> &coverage = (const OffsetTo<Coverage>&)value;
   (data+coverage).add_coverage (glyphs);
 }
 static inline void collect_array (hb_collect_glyphs_context_t *c HB_UNUSED,
 				  hb_set_t *glyphs,
 				  unsigned int count,
 				  const USHORT values[],
 				  collect_glyphs_func_t collect_func,
 				  const void *collect_data)
 {
   for (unsigned int i = 0; i < count; i++)
     collect_func (glyphs, values[i], collect_data);
 }
 static inline bool match_glyph (hb_codepoint_t glyph_id, const USHORT &value, const void *data HB_UNUSED)
 {
   return glyph_id == value;
 }
 static inline bool match_class (hb_codepoint_t glyph_id, const USHORT &value, const void *data)
 {
   const ClassDef &class_def = *reinterpret_cast<const ClassDef *>(data);
   return class_def.get_class (glyph_id) == value;
 }
 static inline bool match_coverage (hb_codepoint_t glyph_id, const USHORT &value, const void *data)
 {
   const OffsetTo<Coverage> &coverage = (const OffsetTo<Coverage>&)value;
   return (data+coverage).get_coverage (glyph_id) != NOT_COVERED;
 }
 static inline bool would_match_input (hb_would_apply_context_t *c,
 				      unsigned int count, /* Including the first glyph (not matched) */
 				      const USHORT input[], /* Array of input values--start with second glyph */
 				      match_func_t match_func,
 				      const void *match_data)
 {
   if (count != c->len)
     return false;
   for (unsigned int i = 1; i < count; i++)
     if (likely (!match_func (c->glyphs[i], input[i - 1], match_data)))
       return false;
   return true;
 }
 static inline bool match_input (hb_apply_context_t *c,
 				unsigned int count, /* Including the first glyph (not matched) */
 				const USHORT input[], /* Array of input values--start with second glyph */
 				match_func_t match_func,
 				const void *match_data,
 				unsigned int *end_offset,
 				unsigned int match_positions[MAX_CONTEXT_LENGTH],
 				bool *p_is_mark_ligature = NULL,
 				unsigned int *p_total_component_count = NULL)
 {
   TRACE_APPLY (NULL);
   if (unlikely (count > MAX_CONTEXT_LENGTH)) TRACE_RETURN (false);
   hb_buffer_t *buffer = c->buffer;
   hb_apply_context_t::skipping_forward_iterator_t skippy_iter (c, buffer->idx, count - 1);
   skippy_iter.set_match_func (match_func, match_data, input);
   if (skippy_iter.has_no_chance ()) return TRACE_RETURN (false);
   /*
    * This is perhaps the trickiest part of OpenType...  Remarks:
    *
    * - If all components of the ligature were marks, we call this a mark ligature.
    *
    * - If there is no GDEF, and the ligature is NOT a mark ligature, we categorize
    *   it as a ligature glyph.
    *
    * - Ligatures cannot be formed across glyphs attached to different components
    *   of previous ligatures.  Eg. the sequence is LAM,SHADDA,LAM,FATHA,HEH, and
    *   LAM,LAM,HEH form a ligature, leaving SHADDA,FATHA next to eachother.
    *   However, it would be wrong to ligate that SHADDA,FATHA sequence.o
    *   There is an exception to this: If a ligature tries ligating with marks that
    *   belong to it itself, go ahead, assuming that the font designer knows what
    *   they are doing (otherwise it can break Indic stuff when a matra wants to
    *   ligate with a conjunct...)
    */
   bool is_mark_ligature = _hb_glyph_info_is_mark (&buffer->cur());
   unsigned int total_component_count = 0;
   total_component_count += _hb_glyph_info_get_lig_num_comps (&buffer->cur());
   unsigned int first_lig_id = _hb_glyph_info_get_lig_id (&buffer->cur());
   unsigned int first_lig_comp = _hb_glyph_info_get_lig_comp (&buffer->cur());
   match_positions[0] = buffer->idx;
   for (unsigned int i = 1; i < count; i++)
   {
     if (!skippy_iter.next ()) return TRACE_RETURN (false);
     match_positions[i] = skippy_iter.idx;
     unsigned int this_lig_id = _hb_glyph_info_get_lig_id (&buffer->info[skippy_iter.idx]);
     unsigned int this_lig_comp = _hb_glyph_info_get_lig_comp (&buffer->info[skippy_iter.idx]);
     if (first_lig_id && first_lig_comp) {
       /* If first component was attached to a previous ligature component,
        * all subsequent components should be attached to the same ligature
        * component, otherwise we shouldn't ligate them. */
       if (first_lig_id != this_lig_id || first_lig_comp != this_lig_comp)
 	return TRACE_RETURN (false);
     } else {
       /* If first component was NOT attached to a previous ligature component,
        * all subsequent components should also NOT be attached to any ligature
        * component, unless they are attached to the first component itself! */
       if (this_lig_id && this_lig_comp && (this_lig_id != first_lig_id))
 	return TRACE_RETURN (false);
     }
     is_mark_ligature = is_mark_ligature && _hb_glyph_info_is_mark (&buffer->info[skippy_iter.idx]);
     total_component_count += _hb_glyph_info_get_lig_num_comps (&buffer->info[skippy_iter.idx]);
   }
   *end_offset = skippy_iter.idx - buffer->idx + 1;
   if (p_is_mark_ligature)
     *p_is_mark_ligature = is_mark_ligature;
   if (p_total_component_count)
     *p_total_component_count = total_component_count;
   return TRACE_RETURN (true);
 }
 static inline void ligate_input (hb_apply_context_t *c,
 				 unsigned int count, /* Including the first glyph */
 				 unsigned int match_positions[MAX_CONTEXT_LENGTH], /* Including the first glyph */
 				 unsigned int match_length,
 				 hb_codepoint_t lig_glyph,
 				 bool is_mark_ligature,
 				 unsigned int total_component_count)
 {
   TRACE_APPLY (NULL);
   hb_buffer_t *buffer = c->buffer;
   buffer->merge_clusters (buffer->idx, buffer->idx + match_length);
   /*
    * - If it *is* a mark ligature, we don't allocate a new ligature id, and leave
    *   the ligature to keep its old ligature id.  This will allow it to attach to
    *   a base ligature in GPOS.  Eg. if the sequence is: LAM,LAM,SHADDA,FATHA,HEH,
    *   and LAM,LAM,HEH for a ligature, they will leave SHADDA and FATHA wit a
    *   ligature id and component value of 2.  Then if SHADDA,FATHA form a ligature
    *   later, we don't want them to lose their ligature id/component, otherwise
    *   GPOS will fail to correctly position the mark ligature on top of the
    *   LAM,LAM,HEH ligature.  See:
    *     https://bugzilla.gnome.org/show_bug.cgi?id=676343
    *
    * - If a ligature is formed of components that some of which are also ligatures
    *   themselves, and those ligature components had marks attached to *their*
    *   components, we have to attach the marks to the new ligature component
    *   positions!  Now *that*'s tricky!  And these marks may be following the
    *   last component of the whole sequence, so we should loop forward looking
    *   for them and update them.
    *
    *   Eg. the sequence is LAM,LAM,SHADDA,FATHA,HEH, and the font first forms a
    *   'calt' ligature of LAM,HEH, leaving the SHADDA and FATHA with a ligature
    *   id and component == 1.  Now, during 'liga', the LAM and the LAM-HEH ligature
    *   form a LAM-LAM-HEH ligature.  We need to reassign the SHADDA and FATHA to
    *   the new ligature with a component value of 2.
    *
    *   This in fact happened to a font...  See:
    *   https://bugzilla.gnome.org/show_bug.cgi?id=437633
    */
   unsigned int klass = is_mark_ligature ? 0 : HB_OT_LAYOUT_GLYPH_PROPS_LIGATURE;
   unsigned int lig_id = is_mark_ligature ? 0 : _hb_allocate_lig_id (buffer);
   unsigned int last_lig_id = _hb_glyph_info_get_lig_id (&buffer->cur());
   unsigned int last_num_components = _hb_glyph_info_get_lig_num_comps (&buffer->cur());
   unsigned int components_so_far = last_num_components;
   if (!is_mark_ligature)
   {
     _hb_glyph_info_set_lig_props_for_ligature (&buffer->cur(), lig_id, total_component_count);
     if (_hb_glyph_info_get_general_category (&buffer->cur()) == HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK)
     {
       _hb_glyph_info_set_general_category (&buffer->cur(), HB_UNICODE_GENERAL_CATEGORY_OTHER_LETTER);
       _hb_glyph_info_set_modified_combining_class (&buffer->cur(), 0);
     }
   }
   c->replace_glyph_with_ligature (lig_glyph, klass);
   for (unsigned int i = 1; i < count; i++)
   {
     while (buffer->idx < match_positions[i])
     {
       if (!is_mark_ligature) {
 	unsigned int new_lig_comp = components_so_far - last_num_components +
 				    MIN (MAX (_hb_glyph_info_get_lig_comp (&buffer->cur()), 1u), last_num_components);
 	_hb_glyph_info_set_lig_props_for_mark (&buffer->cur(), lig_id, new_lig_comp);
       }
       buffer->next_glyph ();
     }
     last_lig_id = _hb_glyph_info_get_lig_id (&buffer->cur());
     last_num_components = _hb_glyph_info_get_lig_num_comps (&buffer->cur());
     components_so_far += last_num_components;
     /* Skip the base glyph */
     buffer->idx++;
   }
   if (!is_mark_ligature && last_lig_id) {
     /* Re-adjust components for any marks following. */
     for (unsigned int i = buffer->idx; i < buffer->len; i++) {
       if (last_lig_id == _hb_glyph_info_get_lig_id (&buffer->info[i])) {
 	unsigned int new_lig_comp = components_so_far - last_num_components +
 				    MIN (MAX (_hb_glyph_info_get_lig_comp (&buffer->info[i]), 1u), last_num_components);
 	_hb_glyph_info_set_lig_props_for_mark (&buffer->info[i], lig_id, new_lig_comp);
       } else
 	break;
     }
   }
 }
 static inline bool match_backtrack (hb_apply_context_t *c,
 				    unsigned int count,
 				    const USHORT backtrack[],
 				    match_func_t match_func,
 				    const void *match_data)
 {
   TRACE_APPLY (NULL);
   hb_apply_context_t::skipping_backward_iterator_t skippy_iter (c, c->buffer->backtrack_len (), count, true);
   skippy_iter.set_match_func (match_func, match_data, backtrack);
   if (skippy_iter.has_no_chance ()) return TRACE_RETURN (false);
   for (unsigned int i = 0; i < count; i++)
     if (!skippy_iter.prev ())
       return TRACE_RETURN (false);
   return TRACE_RETURN (true);
 }
 static inline bool match_lookahead (hb_apply_context_t *c,
 				    unsigned int count,
 				    const USHORT lookahead[],
 				    match_func_t match_func,
 				    const void *match_data,
 				    unsigned int offset)
 {
   TRACE_APPLY (NULL);
   hb_apply_context_t::skipping_forward_iterator_t skippy_iter (c, c->buffer->idx + offset - 1, count, true);
   skippy_iter.set_match_func (match_func, match_data, lookahead);
   if (skippy_iter.has_no_chance ()) return TRACE_RETURN (false);
   for (unsigned int i = 0; i < count; i++)
     if (!skippy_iter.next ())
       return TRACE_RETURN (false);
   return TRACE_RETURN (true);
 }
 struct LookupRecord
 {
   inline bool sanitize (hb_sanitize_context_t *c) {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (c->check_struct (this));
   }
   USHORT	sequenceIndex;		/* Index into current glyph
 					 * sequence--first glyph = 0 */
   USHORT	lookupListIndex;	/* Lookup to apply to that
 					 * position--zero--based */
   public:
   DEFINE_SIZE_STATIC (4);
 };
 template <typename context_t>
 static inline void recurse_lookups (context_t *c,
 				    unsigned int lookupCount,
 				    const LookupRecord lookupRecord[] /* Array of LookupRecords--in design order */)
 {
   for (unsigned int i = 0; i < lookupCount; i++)
     c->recurse (lookupRecord[i].lookupListIndex);
 }
 static inline bool apply_lookup (hb_apply_context_t *c,
 				 unsigned int count, /* Including the first glyph */
 				 unsigned int match_positions[MAX_CONTEXT_LENGTH], /* Including the first glyph */
 				 unsigned int lookupCount,
 				 const LookupRecord lookupRecord[], /* Array of LookupRecords--in design order */
 				 unsigned int match_length)
 {
   TRACE_APPLY (NULL);
   hb_buffer_t *buffer = c->buffer;
   unsigned int end;
   /* All positions are distance from beginning of *output* buffer.
    * Adjust. */
   {
     unsigned int bl = buffer->backtrack_len ();
     end = bl + match_length;
     int delta = bl - buffer->idx;
     /* Convert positions to new indexing. */
     for (unsigned int j = 0; j < count; j++)
       match_positions[j] += delta;
   }
   for (unsigned int i = 0; i < lookupCount; i++)
   {
     unsigned int idx = lookupRecord[i].sequenceIndex;
     if (idx >= count)
       continue;
     buffer->move_to (match_positions[idx]);
     unsigned int orig_len = buffer->backtrack_len () + buffer->lookahead_len ();
     if (!c->recurse (lookupRecord[i].lookupListIndex))
       continue;
     unsigned int new_len = buffer->backtrack_len () + buffer->lookahead_len ();
     int delta = new_len - orig_len;
     if (!delta)
         continue;
     /* Recursed lookup changed buffer len.  Adjust. */
     /* end can't go back past the current match position. */
     end = MAX ((int) match_positions[idx] + 1, int (end) + delta);
     unsigned int next = idx + 1; /* next now is the position after the recursed lookup. */
     if (delta > 0)
     {
       if (unlikely (delta + count > MAX_CONTEXT_LENGTH))
 	break;
     }
     else
     {
       /* NOTE: delta is negative. */
       delta = MAX (delta, (int) next - (int) count);
       next -= delta;
     }
     /* Shift! */
     memmove (match_positions + next + delta, match_positions + next,
 	     (count - next) * sizeof (match_positions[0]));
     next += delta;
     count += delta;
     /* Fill in new entries. */
     for (unsigned int j = idx + 1; j < next; j++)
       match_positions[j] = match_positions[j - 1] + 1;
     /* And fixup the rest. */
     for (; next < count; next++)
       match_positions[next] += delta;
   }
   buffer->move_to (end);
   return TRACE_RETURN (true);
 }
 /* Contextual lookups */
 struct ContextClosureLookupContext
 {
   ContextClosureFuncs funcs;
   const void *intersects_data;
 };
 struct ContextCollectGlyphsLookupContext
 {
   ContextCollectGlyphsFuncs funcs;
   const void *collect_data;
 };
 struct ContextApplyLookupContext
 {
   ContextApplyFuncs funcs;
   const void *match_data;
 };
 static inline void context_closure_lookup (hb_closure_context_t *c,
 					   unsigned int inputCount, /* Including the first glyph (not matched) */
 					   const USHORT input[], /* Array of input values--start with second glyph */
 					   unsigned int lookupCount,
 					   const LookupRecord lookupRecord[],
 					   ContextClosureLookupContext &lookup_context)
 {
   if (intersects_array (c,
 			inputCount ? inputCount - 1 : 0, input,
 			lookup_context.funcs.intersects, lookup_context.intersects_data))
     recurse_lookups (c,
 		     lookupCount, lookupRecord);
 }
 static inline void context_collect_glyphs_lookup (hb_collect_glyphs_context_t *c,
 						  unsigned int inputCount, /* Including the first glyph (not matched) */
 						  const USHORT input[], /* Array of input values--start with second glyph */
 						  unsigned int lookupCount,
 						  const LookupRecord lookupRecord[],
 						  ContextCollectGlyphsLookupContext &lookup_context)
 {
   collect_array (c, c->input,
 		 inputCount ? inputCount - 1 : 0, input,
 		 lookup_context.funcs.collect, lookup_context.collect_data);
   recurse_lookups (c,
 		   lookupCount, lookupRecord);
 }
 static inline bool context_would_apply_lookup (hb_would_apply_context_t *c,
 					       unsigned int inputCount, /* Including the first glyph (not matched) */
 					       const USHORT input[], /* Array of input values--start with second glyph */
 					       unsigned int lookupCount HB_UNUSED,
 					       const LookupRecord lookupRecord[] HB_UNUSED,
 					       ContextApplyLookupContext &lookup_context)
 {
   return would_match_input (c,
 			    inputCount, input,
 			    lookup_context.funcs.match, lookup_context.match_data);
 }
 static inline bool context_apply_lookup (hb_apply_context_t *c,
 					 unsigned int inputCount, /* Including the first glyph (not matched) */
 					 const USHORT input[], /* Array of input values--start with second glyph */
 					 unsigned int lookupCount,
 					 const LookupRecord lookupRecord[],
 					 ContextApplyLookupContext &lookup_context)
 {
   unsigned int match_length = 0;
   unsigned int match_positions[MAX_CONTEXT_LENGTH];
   return match_input (c,
 		      inputCount, input,
 		      lookup_context.funcs.match, lookup_context.match_data,
 		      &match_length, match_positions)
       && apply_lookup (c,
 		       inputCount, match_positions,
 		       lookupCount, lookupRecord,
 		       match_length);
 }
 struct Rule
 {
   inline void closure (hb_closure_context_t *c, ContextClosureLookupContext &lookup_context) const
   {
     TRACE_CLOSURE (this);
     const LookupRecord *lookupRecord = &StructAtOffset<LookupRecord> (input, input[0].static_size * (inputCount ? inputCount - 1 : 0));
     context_closure_lookup (c,
 			    inputCount, input,
 			    lookupCount, lookupRecord,
 			    lookup_context);
   }
   inline void collect_glyphs (hb_collect_glyphs_context_t *c, ContextCollectGlyphsLookupContext &lookup_context) const
   {
     TRACE_COLLECT_GLYPHS (this);
     const LookupRecord *lookupRecord = &StructAtOffset<LookupRecord> (input, input[0].static_size * (inputCount ? inputCount - 1 : 0));
     context_collect_glyphs_lookup (c,
 				   inputCount, input,
 				   lookupCount, lookupRecord,
 				   lookup_context);
   }
   inline bool would_apply (hb_would_apply_context_t *c, ContextApplyLookupContext &lookup_context) const
   {
     TRACE_WOULD_APPLY (this);
     const LookupRecord *lookupRecord = &StructAtOffset<LookupRecord> (input, input[0].static_size * (inputCount ? inputCount - 1 : 0));
     return TRACE_RETURN (context_would_apply_lookup (c, inputCount, input, lookupCount, lookupRecord, lookup_context));
   }
   inline bool apply (hb_apply_context_t *c, ContextApplyLookupContext &lookup_context) const
   {
     TRACE_APPLY (this);
     const LookupRecord *lookupRecord = &StructAtOffset<LookupRecord> (input, input[0].static_size * (inputCount ? inputCount - 1 : 0));
     return TRACE_RETURN (context_apply_lookup (c, inputCount, input, lookupCount, lookupRecord, lookup_context));
   }
   public:
   inline bool sanitize (hb_sanitize_context_t *c) {
     TRACE_SANITIZE (this);
     return inputCount.sanitize (c)
 	&& lookupCount.sanitize (c)
 	&& c->check_range (input,
 			   input[0].static_size * inputCount
 			   + lookupRecordX[0].static_size * lookupCount);
   }
   protected:
   USHORT	inputCount;		/* Total number of glyphs in input
 					 * glyph sequence--includes the first
 					 * glyph */
   USHORT	lookupCount;		/* Number of LookupRecords */
   USHORT	input[VAR];		/* Array of match inputs--start with
 					 * second glyph */
   LookupRecord	lookupRecordX[VAR];	/* Array of LookupRecords--in
 					 * design order */
   public:
   DEFINE_SIZE_ARRAY2 (4, input, lookupRecordX);
 };
 struct RuleSet
 {
   inline void closure (hb_closure_context_t *c, ContextClosureLookupContext &lookup_context) const
   {
     TRACE_CLOSURE (this);
     unsigned int num_rules = rule.len;
     for (unsigned int i = 0; i < num_rules; i++)
       (this+rule[i]).closure (c, lookup_context);
   }
   inline void collect_glyphs (hb_collect_glyphs_context_t *c, ContextCollectGlyphsLookupContext &lookup_context) const
   {
     TRACE_COLLECT_GLYPHS (this);
     unsigned int num_rules = rule.len;
     for (unsigned int i = 0; i < num_rules; i++)
       (this+rule[i]).collect_glyphs (c, lookup_context);
   }
   inline bool would_apply (hb_would_apply_context_t *c, ContextApplyLookupContext &lookup_context) const
   {
     TRACE_WOULD_APPLY (this);
     unsigned int num_rules = rule.len;
     for (unsigned int i = 0; i < num_rules; i++)
     {
       if ((this+rule[i]).would_apply (c, lookup_context))
         return TRACE_RETURN (true);
     }
     return TRACE_RETURN (false);
   }
   inline bool apply (hb_apply_context_t *c, ContextApplyLookupContext &lookup_context) const
   {
     TRACE_APPLY (this);
     unsigned int num_rules = rule.len;
     for (unsigned int i = 0; i < num_rules; i++)
     {
       if ((this+rule[i]).apply (c, lookup_context))
         return TRACE_RETURN (true);
     }
     return TRACE_RETURN (false);
   }
   inline bool sanitize (hb_sanitize_context_t *c) {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (rule.sanitize (c, this));
   }
   protected:
   OffsetArrayOf<Rule>
 		rule;			/* Array of Rule tables
 					 * ordered by preference */
   public:
   DEFINE_SIZE_ARRAY (2, rule);
 };
 struct ContextFormat1
 {
   inline void closure (hb_closure_context_t *c) const
   {
     TRACE_CLOSURE (this);
     const Coverage &cov = (this+coverage);
     struct ContextClosureLookupContext lookup_context = {
       {intersects_glyph},
       NULL
     };
     unsigned int count = ruleSet.len;
     for (unsigned int i = 0; i < count; i++)
       if (cov.intersects_coverage (c->glyphs, i)) {
 	const RuleSet &rule_set = this+ruleSet[i];
 	rule_set.closure (c, lookup_context);
       }
   }
   inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
   {
     TRACE_COLLECT_GLYPHS (this);
     (this+coverage).add_coverage (c->input);
     struct ContextCollectGlyphsLookupContext lookup_context = {
       {collect_glyph},
       NULL
     };
     unsigned int count = ruleSet.len;
     for (unsigned int i = 0; i < count; i++)
       (this+ruleSet[i]).collect_glyphs (c, lookup_context);
   }
   inline bool would_apply (hb_would_apply_context_t *c) const
   {
     TRACE_WOULD_APPLY (this);
     const RuleSet &rule_set = this+ruleSet[(this+coverage).get_coverage (c->glyphs[0])];
     struct ContextApplyLookupContext lookup_context = {
       {match_glyph},
       NULL
     };
     return TRACE_RETURN (rule_set.would_apply (c, lookup_context));
   }
   inline const Coverage &get_coverage (void) const
   {
     return this+coverage;
   }
   inline bool apply (hb_apply_context_t *c) const
   {
     TRACE_APPLY (this);
     unsigned int index = (this+coverage).get_coverage (c->buffer->cur().codepoint);
     if (likely (index == NOT_COVERED))
       return TRACE_RETURN (false);
     const RuleSet &rule_set = this+ruleSet[index];
     struct ContextApplyLookupContext lookup_context = {
       {match_glyph},
       NULL
     };
     return TRACE_RETURN (rule_set.apply (c, lookup_context));
   }
   inline bool sanitize (hb_sanitize_context_t *c) {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (coverage.sanitize (c, this) && ruleSet.sanitize (c, this));
   }
   protected:
   USHORT	format;			/* Format identifier--format = 1 */
   OffsetTo<Coverage>
 		coverage;		/* Offset to Coverage table--from
 					 * beginning of table */
   OffsetArrayOf<RuleSet>
 		ruleSet;		/* Array of RuleSet tables
 					 * ordered by Coverage Index */
   public:
   DEFINE_SIZE_ARRAY (6, ruleSet);
 };
 struct ContextFormat2
 {
   inline void closure (hb_closure_context_t *c) const
   {
     TRACE_CLOSURE (this);
     if (!(this+coverage).intersects (c->glyphs))
       return;
     const ClassDef &class_def = this+classDef;
     struct ContextClosureLookupContext lookup_context = {
       {intersects_class},
       &class_def
     };
     unsigned int count = ruleSet.len;
     for (unsigned int i = 0; i < count; i++)
       if (class_def.intersects_class (c->glyphs, i)) {
 	const RuleSet &rule_set = this+ruleSet[i];
 	rule_set.closure (c, lookup_context);
       }
   }
   inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
   {
     TRACE_COLLECT_GLYPHS (this);
     (this+coverage).add_coverage (c->input);
     const ClassDef &class_def = this+classDef;
     struct ContextCollectGlyphsLookupContext lookup_context = {
       {collect_class},
       &class_def
     };
     unsigned int count = ruleSet.len;
     for (unsigned int i = 0; i < count; i++)
       (this+ruleSet[i]).collect_glyphs (c, lookup_context);
   }
   inline bool would_apply (hb_would_apply_context_t *c) const
   {
     TRACE_WOULD_APPLY (this);
     const ClassDef &class_def = this+classDef;
     unsigned int index = class_def.get_class (c->glyphs[0]);
     const RuleSet &rule_set = this+ruleSet[index];
     struct ContextApplyLookupContext lookup_context = {
       {match_class},
       &class_def
     };
     return TRACE_RETURN (rule_set.would_apply (c, lookup_context));
   }
   inline const Coverage &get_coverage (void) const
   {
     return this+coverage;
   }
   inline bool apply (hb_apply_context_t *c) const
   {
     TRACE_APPLY (this);
     unsigned int index = (this+coverage).get_coverage (c->buffer->cur().codepoint);
     if (likely (index == NOT_COVERED)) return TRACE_RETURN (false);
     const ClassDef &class_def = this+classDef;
     index = class_def.get_class (c->buffer->cur().codepoint);
     const RuleSet &rule_set = this+ruleSet[index];
     struct ContextApplyLookupContext lookup_context = {
       {match_class},
       &class_def
     };
     return TRACE_RETURN (rule_set.apply (c, lookup_context));
   }
   inline bool sanitize (hb_sanitize_context_t *c) {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (coverage.sanitize (c, this) && classDef.sanitize (c, this) && ruleSet.sanitize (c, this));
   }
   protected:
   USHORT	format;			/* Format identifier--format = 2 */
   OffsetTo<Coverage>
 		coverage;		/* Offset to Coverage table--from
 					 * beginning of table */
   OffsetTo<ClassDef>
 		classDef;		/* Offset to glyph ClassDef table--from
 					 * beginning of table */
   OffsetArrayOf<RuleSet>
 		ruleSet;		/* Array of RuleSet tables
 					 * ordered by class */
   public:
   DEFINE_SIZE_ARRAY (8, ruleSet);
 };
 struct ContextFormat3
 {
   inline void closure (hb_closure_context_t *c) const
   {
     TRACE_CLOSURE (this);
     if (!(this+coverage[0]).intersects (c->glyphs))
       return;
     const LookupRecord *lookupRecord = &StructAtOffset<LookupRecord> (coverage, coverage[0].static_size * glyphCount);
     struct ContextClosureLookupContext lookup_context = {
       {intersects_coverage},
       this
     };
     context_closure_lookup (c,
 			    glyphCount, (const USHORT *) (coverage + 1),
 			    lookupCount, lookupRecord,
 			    lookup_context);
   }
   inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
   {
     TRACE_COLLECT_GLYPHS (this);
     (this+coverage[0]).add_coverage (c->input);
     const LookupRecord *lookupRecord = &StructAtOffset<LookupRecord> (coverage, coverage[0].static_size * glyphCount);
     struct ContextCollectGlyphsLookupContext lookup_context = {
       {collect_coverage},
       this
     };
     context_collect_glyphs_lookup (c,
 				   glyphCount, (const USHORT *) (coverage + 1),
 				   lookupCount, lookupRecord,
 				   lookup_context);
   }
   inline bool would_apply (hb_would_apply_context_t *c) const
   {
     TRACE_WOULD_APPLY (this);
     const LookupRecord *lookupRecord = &StructAtOffset<LookupRecord> (coverage, coverage[0].static_size * glyphCount);
     struct ContextApplyLookupContext lookup_context = {
       {match_coverage},
       this
     };
     return TRACE_RETURN (context_would_apply_lookup (c, glyphCount, (const USHORT *) (coverage + 1), lookupCount, lookupRecord, lookup_context));
   }
   inline const Coverage &get_coverage (void) const
   {
     return this+coverage[0];
   }
   inline bool apply (hb_apply_context_t *c) const
   {
     TRACE_APPLY (this);
     unsigned int index = (this+coverage[0]).get_coverage (c->buffer->cur().codepoint);
     if (likely (index == NOT_COVERED)) return TRACE_RETURN (false);
     const LookupRecord *lookupRecord = &StructAtOffset<LookupRecord> (coverage, coverage[0].static_size * glyphCount);
     struct ContextApplyLookupContext lookup_context = {
       {match_coverage},
       this
     };
     return TRACE_RETURN (context_apply_lookup (c, glyphCount, (const USHORT *) (coverage + 1), lookupCount, lookupRecord, lookup_context));
   }
   inline bool sanitize (hb_sanitize_context_t *c) {
     TRACE_SANITIZE (this);
     if (!c->check_struct (this)) return TRACE_RETURN (false);
     unsigned int count = glyphCount;
     if (!c->check_array (coverage, coverage[0].static_size, count)) return TRACE_RETURN (false);
     for (unsigned int i = 0; i < count; i++)
       if (!coverage[i].sanitize (c, this)) return TRACE_RETURN (false);
     LookupRecord *lookupRecord = &StructAtOffset<LookupRecord> (coverage, coverage[0].static_size * count);
     return TRACE_RETURN (c->check_array (lookupRecord, lookupRecord[0].static_size, lookupCount));
   }
   protected:
   USHORT	format;			/* Format identifier--format = 3 */
   USHORT	glyphCount;		/* Number of glyphs in the input glyph
 					 * sequence */
   USHORT	lookupCount;		/* Number of LookupRecords */
   OffsetTo<Coverage>
 		coverage[VAR];		/* Array of offsets to Coverage
 					 * table in glyph sequence order */
   LookupRecord	lookupRecordX[VAR];	/* Array of LookupRecords--in
 					 * design order */
   public:
   DEFINE_SIZE_ARRAY2 (6, coverage, lookupRecordX);
 };
 struct Context
 {
   template <typename context_t>
   inline typename context_t::return_t dispatch (context_t *c) const
   {
     TRACE_DISPATCH (this);
     switch (u.format) {
     case 1: return TRACE_RETURN (c->dispatch (u.format1));
     case 2: return TRACE_RETURN (c->dispatch (u.format2));
     case 3: return TRACE_RETURN (c->dispatch (u.format3));
     default:return TRACE_RETURN (c->default_return_value ());
     }
   }
   inline bool sanitize (hb_sanitize_context_t *c) {
     TRACE_SANITIZE (this);
     if (!u.format.sanitize (c)) return TRACE_RETURN (false);
     switch (u.format) {
     case 1: return TRACE_RETURN (u.format1.sanitize (c));
     case 2: return TRACE_RETURN (u.format2.sanitize (c));
     case 3: return TRACE_RETURN (u.format3.sanitize (c));
     default:return TRACE_RETURN (true);
     }
   }
   protected:
   union {
   USHORT		format;		/* Format identifier */
   ContextFormat1	format1;
   ContextFormat2	format2;
   ContextFormat3	format3;
   } u;
 };
 /* Chaining Contextual lookups */
 struct ChainContextClosureLookupContext
 {
   ContextClosureFuncs funcs;
   const void *intersects_data[3];
 };
 struct ChainContextCollectGlyphsLookupContext
 {
   ContextCollectGlyphsFuncs funcs;
   const void *collect_data[3];
 };
 struct ChainContextApplyLookupContext
 {
   ContextApplyFuncs funcs;
   const void *match_data[3];
 };
 static inline void chain_context_closure_lookup (hb_closure_context_t *c,
 						 unsigned int backtrackCount,
 						 const USHORT backtrack[],
 						 unsigned int inputCount, /* Including the first glyph (not matched) */
 						 const USHORT input[], /* Array of input values--start with second glyph */
 						 unsigned int lookaheadCount,
 						 const USHORT lookahead[],
 						 unsigned int lookupCount,
 						 const LookupRecord lookupRecord[],
 						 ChainContextClosureLookupContext &lookup_context)
 {
   if (intersects_array (c,
 			backtrackCount, backtrack,
 			lookup_context.funcs.intersects, lookup_context.intersects_data[0])
    && intersects_array (c,
 			inputCount ? inputCount - 1 : 0, input,
 			lookup_context.funcs.intersects, lookup_context.intersects_data[1])
    && intersects_array (c,
 		       lookaheadCount, lookahead,
 		       lookup_context.funcs.intersects, lookup_context.intersects_data[2]))
     recurse_lookups (c,
 		     lookupCount, lookupRecord);
 }
 static inline void chain_context_collect_glyphs_lookup (hb_collect_glyphs_context_t *c,
 						        unsigned int backtrackCount,
 						        const USHORT backtrack[],
 						        unsigned int inputCount, /* Including the first glyph (not matched) */
 						        const USHORT input[], /* Array of input values--start with second glyph */
 						        unsigned int lookaheadCount,
 						        const USHORT lookahead[],
 						        unsigned int lookupCount,
 						        const LookupRecord lookupRecord[],
 						        ChainContextCollectGlyphsLookupContext &lookup_context)
 {
   collect_array (c, c->before,
 		 backtrackCount, backtrack,
 		 lookup_context.funcs.collect, lookup_context.collect_data[0]);
   collect_array (c, c->input,
 		 inputCount ? inputCount - 1 : 0, input,
 		 lookup_context.funcs.collect, lookup_context.collect_data[1]);
   collect_array (c, c->after,
 		 lookaheadCount, lookahead,
 		 lookup_context.funcs.collect, lookup_context.collect_data[2]);
   recurse_lookups (c,
 		   lookupCount, lookupRecord);
 }
 static inline bool chain_context_would_apply_lookup (hb_would_apply_context_t *c,
 						     unsigned int backtrackCount,
 						     const USHORT backtrack[] HB_UNUSED,
 						     unsigned int inputCount, /* Including the first glyph (not matched) */
 						     const USHORT input[], /* Array of input values--start with second glyph */
 						     unsigned int lookaheadCount,
 						     const USHORT lookahead[] HB_UNUSED,
 						     unsigned int lookupCount HB_UNUSED,
 						     const LookupRecord lookupRecord[] HB_UNUSED,
 						     ChainContextApplyLookupContext &lookup_context)
 {
   return (c->zero_context ? !backtrackCount && !lookaheadCount : true)
       && would_match_input (c,
 			    inputCount, input,
 			    lookup_context.funcs.match, lookup_context.match_data[1]);
 }
 static inline bool chain_context_apply_lookup (hb_apply_context_t *c,
 					       unsigned int backtrackCount,
 					       const USHORT backtrack[],
 					       unsigned int inputCount, /* Including the first glyph (not matched) */
 					       const USHORT input[], /* Array of input values--start with second glyph */
 					       unsigned int lookaheadCount,
 					       const USHORT lookahead[],
 					       unsigned int lookupCount,
 					       const LookupRecord lookupRecord[],
 					       ChainContextApplyLookupContext &lookup_context)
 {
   unsigned int match_length = 0;
   unsigned int match_positions[MAX_CONTEXT_LENGTH];
   return match_input (c,
 		      inputCount, input,
 		      lookup_context.funcs.match, lookup_context.match_data[1],
 		      &match_length, match_positions)
       && match_backtrack (c,
 			  backtrackCount, backtrack,
 			  lookup_context.funcs.match, lookup_context.match_data[0])
       && match_lookahead (c,
 			  lookaheadCount, lookahead,
 			  lookup_context.funcs.match, lookup_context.match_data[2],
 			  match_length)
       && apply_lookup (c,
 		       inputCount, match_positions,
 		       lookupCount, lookupRecord,
 		       match_length);
 }
 struct ChainRule
 {
   inline void closure (hb_closure_context_t *c, ChainContextClosureLookupContext &lookup_context) const
   {
     TRACE_CLOSURE (this);
     const HeadlessArrayOf<USHORT> &input = StructAfter<HeadlessArrayOf<USHORT> > (backtrack);
     const ArrayOf<USHORT> &lookahead = StructAfter<ArrayOf<USHORT> > (input);
     const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
     chain_context_closure_lookup (c,
 				  backtrack.len, backtrack.array,
 				  input.len, input.array,
 				  lookahead.len, lookahead.array,
 				  lookup.len, lookup.array,
 				  lookup_context);
   }
   inline void collect_glyphs (hb_collect_glyphs_context_t *c, ChainContextCollectGlyphsLookupContext &lookup_context) const
   {
     TRACE_COLLECT_GLYPHS (this);
     const HeadlessArrayOf<USHORT> &input = StructAfter<HeadlessArrayOf<USHORT> > (backtrack);
     const ArrayOf<USHORT> &lookahead = StructAfter<ArrayOf<USHORT> > (input);
     const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
     chain_context_collect_glyphs_lookup (c,
 					 backtrack.len, backtrack.array,
 					 input.len, input.array,
 					 lookahead.len, lookahead.array,
 					 lookup.len, lookup.array,
 					 lookup_context);
   }
   inline bool would_apply (hb_would_apply_context_t *c, ChainContextApplyLookupContext &lookup_context) const
   {
     TRACE_WOULD_APPLY (this);
     const HeadlessArrayOf<USHORT> &input = StructAfter<HeadlessArrayOf<USHORT> > (backtrack);
     const ArrayOf<USHORT> &lookahead = StructAfter<ArrayOf<USHORT> > (input);
     const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
     return TRACE_RETURN (chain_context_would_apply_lookup (c,
 							   backtrack.len, backtrack.array,
 							   input.len, input.array,
 							   lookahead.len, lookahead.array, lookup.len,
 							   lookup.array, lookup_context));
   }
   inline bool apply (hb_apply_context_t *c, ChainContextApplyLookupContext &lookup_context) const
   {
     TRACE_APPLY (this);
     const HeadlessArrayOf<USHORT> &input = StructAfter<HeadlessArrayOf<USHORT> > (backtrack);
     const ArrayOf<USHORT> &lookahead = StructAfter<ArrayOf<USHORT> > (input);
     const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
     return TRACE_RETURN (chain_context_apply_lookup (c,
 						     backtrack.len, backtrack.array,
 						     input.len, input.array,
 						     lookahead.len, lookahead.array, lookup.len,
 						     lookup.array, lookup_context));
   }
   inline bool sanitize (hb_sanitize_context_t *c) {
     TRACE_SANITIZE (this);
     if (!backtrack.sanitize (c)) return TRACE_RETURN (false);
     HeadlessArrayOf<USHORT> &input = StructAfter<HeadlessArrayOf<USHORT> > (backtrack);
     if (!input.sanitize (c)) return TRACE_RETURN (false);
     ArrayOf<USHORT> &lookahead = StructAfter<ArrayOf<USHORT> > (input);
     if (!lookahead.sanitize (c)) return TRACE_RETURN (false);
     ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
     return TRACE_RETURN (lookup.sanitize (c));
   }
   protected:
   ArrayOf<USHORT>
 		backtrack;		/* Array of backtracking values
 					 * (to be matched before the input
 					 * sequence) */
   HeadlessArrayOf<USHORT>
 		inputX;			/* Array of input values (start with
 					 * second glyph) */
   ArrayOf<USHORT>
 		lookaheadX;		/* Array of lookahead values's (to be
 					 * matched after the input sequence) */
   ArrayOf<LookupRecord>
 		lookupX;		/* Array of LookupRecords--in
 					 * design order) */
   public:
   DEFINE_SIZE_MIN (8);
 };
 struct ChainRuleSet
 {
   inline void closure (hb_closure_context_t *c, ChainContextClosureLookupContext &lookup_context) const
   {
     TRACE_CLOSURE (this);
     unsigned int num_rules = rule.len;
     for (unsigned int i = 0; i < num_rules; i++)
       (this+rule[i]).closure (c, lookup_context);
   }
   inline void collect_glyphs (hb_collect_glyphs_context_t *c, ChainContextCollectGlyphsLookupContext &lookup_context) const
   {
     TRACE_COLLECT_GLYPHS (this);
     unsigned int num_rules = rule.len;
     for (unsigned int i = 0; i < num_rules; i++)
       (this+rule[i]).collect_glyphs (c, lookup_context);
   }
   inline bool would_apply (hb_would_apply_context_t *c, ChainContextApplyLookupContext &lookup_context) const
   {
     TRACE_WOULD_APPLY (this);
     unsigned int num_rules = rule.len;
     for (unsigned int i = 0; i < num_rules; i++)
       if ((this+rule[i]).would_apply (c, lookup_context))
         return TRACE_RETURN (true);
     return TRACE_RETURN (false);
   }
   inline bool apply (hb_apply_context_t *c, ChainContextApplyLookupContext &lookup_context) const
   {
     TRACE_APPLY (this);
     unsigned int num_rules = rule.len;
     for (unsigned int i = 0; i < num_rules; i++)
       if ((this+rule[i]).apply (c, lookup_context))
         return TRACE_RETURN (true);
     return TRACE_RETURN (false);
   }
   inline bool sanitize (hb_sanitize_context_t *c) {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (rule.sanitize (c, this));
   }
   protected:
   OffsetArrayOf<ChainRule>
 		rule;			/* Array of ChainRule tables
 					 * ordered by preference */
   public:
   DEFINE_SIZE_ARRAY (2, rule);
 };
 struct ChainContextFormat1
 {
   inline void closure (hb_closure_context_t *c) const
   {
     TRACE_CLOSURE (this);
     const Coverage &cov = (this+coverage);
     struct ChainContextClosureLookupContext lookup_context = {
       {intersects_glyph},
       {NULL, NULL, NULL}
     };
     unsigned int count = ruleSet.len;
     for (unsigned int i = 0; i < count; i++)
       if (cov.intersects_coverage (c->glyphs, i)) {
 	const ChainRuleSet &rule_set = this+ruleSet[i];
 	rule_set.closure (c, lookup_context);
       }
   }
   inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
   {
     TRACE_COLLECT_GLYPHS (this);
     (this+coverage).add_coverage (c->input);
     struct ChainContextCollectGlyphsLookupContext lookup_context = {
       {collect_glyph},
       {NULL, NULL, NULL}
     };
     unsigned int count = ruleSet.len;
     for (unsigned int i = 0; i < count; i++)
       (this+ruleSet[i]).collect_glyphs (c, lookup_context);
   }
   inline bool would_apply (hb_would_apply_context_t *c) const
   {
     TRACE_WOULD_APPLY (this);
     const ChainRuleSet &rule_set = this+ruleSet[(this+coverage).get_coverage (c->glyphs[0])];
     struct ChainContextApplyLookupContext lookup_context = {
       {match_glyph},
       {NULL, NULL, NULL}
     };
     return TRACE_RETURN (rule_set.would_apply (c, lookup_context));
   }
   inline const Coverage &get_coverage (void) const
   {
     return this+coverage;
   }
   inline bool apply (hb_apply_context_t *c) const
   {
     TRACE_APPLY (this);
     unsigned int index = (this+coverage).get_coverage (c->buffer->cur().codepoint);
     if (likely (index == NOT_COVERED)) return TRACE_RETURN (false);
     const ChainRuleSet &rule_set = this+ruleSet[index];
     struct ChainContextApplyLookupContext lookup_context = {
       {match_glyph},
       {NULL, NULL, NULL}
     };
     return TRACE_RETURN (rule_set.apply (c, lookup_context));
   }
   inline bool sanitize (hb_sanitize_context_t *c) {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (coverage.sanitize (c, this) && ruleSet.sanitize (c, this));
   }
   protected:
   USHORT	format;			/* Format identifier--format = 1 */
   OffsetTo<Coverage>
 		coverage;		/* Offset to Coverage table--from
 					 * beginning of table */
   OffsetArrayOf<ChainRuleSet>
 		ruleSet;		/* Array of ChainRuleSet tables
 					 * ordered by Coverage Index */
   public:
   DEFINE_SIZE_ARRAY (6, ruleSet);
 };
 struct ChainContextFormat2
 {
   inline void closure (hb_closure_context_t *c) const
   {
     TRACE_CLOSURE (this);
     if (!(this+coverage).intersects (c->glyphs))
       return;
     const ClassDef &backtrack_class_def = this+backtrackClassDef;
     const ClassDef &input_class_def = this+inputClassDef;
     const ClassDef &lookahead_class_def = this+lookaheadClassDef;
     struct ChainContextClosureLookupContext lookup_context = {
       {intersects_class},
       {&backtrack_class_def,
        &input_class_def,
        &lookahead_class_def}
     };
     unsigned int count = ruleSet.len;
     for (unsigned int i = 0; i < count; i++)
       if (input_class_def.intersects_class (c->glyphs, i)) {
 	const ChainRuleSet &rule_set = this+ruleSet[i];
 	rule_set.closure (c, lookup_context);
       }
   }
   inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
   {
     TRACE_COLLECT_GLYPHS (this);
     (this+coverage).add_coverage (c->input);
     const ClassDef &backtrack_class_def = this+backtrackClassDef;
     const ClassDef &input_class_def = this+inputClassDef;
     const ClassDef &lookahead_class_def = this+lookaheadClassDef;
     struct ChainContextCollectGlyphsLookupContext lookup_context = {
       {collect_class},
       {&backtrack_class_def,
        &input_class_def,
        &lookahead_class_def}
     };
     unsigned int count = ruleSet.len;
     for (unsigned int i = 0; i < count; i++)
       (this+ruleSet[i]).collect_glyphs (c, lookup_context);
   }
   inline bool would_apply (hb_would_apply_context_t *c) const
   {
     TRACE_WOULD_APPLY (this);
     const ClassDef &backtrack_class_def = this+backtrackClassDef;
     const ClassDef &input_class_def = this+inputClassDef;
     const ClassDef &lookahead_class_def = this+lookaheadClassDef;
     unsigned int index = input_class_def.get_class (c->glyphs[0]);
     const ChainRuleSet &rule_set = this+ruleSet[index];
     struct ChainContextApplyLookupContext lookup_context = {
       {match_class},
       {&backtrack_class_def,
        &input_class_def,
        &lookahead_class_def}
     };
     return TRACE_RETURN (rule_set.would_apply (c, lookup_context));
   }
   inline const Coverage &get_coverage (void) const
   {
     return this+coverage;
   }
   inline bool apply (hb_apply_context_t *c) const
   {
     TRACE_APPLY (this);
     unsigned int index = (this+coverage).get_coverage (c->buffer->cur().codepoint);
     if (likely (index == NOT_COVERED)) return TRACE_RETURN (false);
     const ClassDef &backtrack_class_def = this+backtrackClassDef;
     const ClassDef &input_class_def = this+inputClassDef;
     const ClassDef &lookahead_class_def = this+lookaheadClassDef;
     index = input_class_def.get_class (c->buffer->cur().codepoint);
     const ChainRuleSet &rule_set = this+ruleSet[index];
     struct ChainContextApplyLookupContext lookup_context = {
       {match_class},
       {&backtrack_class_def,
        &input_class_def,
        &lookahead_class_def}
     };
     return TRACE_RETURN (rule_set.apply (c, lookup_context));
   }
   inline bool sanitize (hb_sanitize_context_t *c) {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (coverage.sanitize (c, this) && backtrackClassDef.sanitize (c, this) &&
 			 inputClassDef.sanitize (c, this) && lookaheadClassDef.sanitize (c, this) &&
 			 ruleSet.sanitize (c, this));
   }
   protected:
   USHORT	format;			/* Format identifier--format = 2 */
   OffsetTo<Coverage>
 		coverage;		/* Offset to Coverage table--from
 					 * beginning of table */
   OffsetTo<ClassDef>
 		backtrackClassDef;	/* Offset to glyph ClassDef table
 					 * containing backtrack sequence
 					 * data--from beginning of table */
   OffsetTo<ClassDef>
 		inputClassDef;		/* Offset to glyph ClassDef
 					 * table containing input sequence
 					 * data--from beginning of table */
   OffsetTo<ClassDef>
 		lookaheadClassDef;	/* Offset to glyph ClassDef table
 					 * containing lookahead sequence
 					 * data--from beginning of table */
   OffsetArrayOf<ChainRuleSet>
 		ruleSet;		/* Array of ChainRuleSet tables
 					 * ordered by class */
   public:
   DEFINE_SIZE_ARRAY (12, ruleSet);
 };
 struct ChainContextFormat3
 {
   inline void closure (hb_closure_context_t *c) const
   {
     TRACE_CLOSURE (this);
     const OffsetArrayOf<Coverage> &input = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
     if (!(this+input[0]).intersects (c->glyphs))
       return;
     const OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (input);
     const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
     struct ChainContextClosureLookupContext lookup_context = {
       {intersects_coverage},
       {this, this, this}
     };
     chain_context_closure_lookup (c,
 				  backtrack.len, (const USHORT *) backtrack.array,
 				  input.len, (const USHORT *) input.array + 1,
 				  lookahead.len, (const USHORT *) lookahead.array,
 				  lookup.len, lookup.array,
 				  lookup_context);
   }
   inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
   {
     TRACE_COLLECT_GLYPHS (this);
     const OffsetArrayOf<Coverage> &input = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
     (this+input[0]).add_coverage (c->input);
     const OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (input);
     const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
     struct ChainContextCollectGlyphsLookupContext lookup_context = {
       {collect_coverage},
       {this, this, this}
     };
     chain_context_collect_glyphs_lookup (c,
 					 backtrack.len, (const USHORT *) backtrack.array,
 					 input.len, (const USHORT *) input.array + 1,
 					 lookahead.len, (const USHORT *) lookahead.array,
 					 lookup.len, lookup.array,
 					 lookup_context);
   }
   inline bool would_apply (hb_would_apply_context_t *c) const
   {
     TRACE_WOULD_APPLY (this);
     const OffsetArrayOf<Coverage> &input = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
     const OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (input);
     const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
     struct ChainContextApplyLookupContext lookup_context = {
       {match_coverage},
       {this, this, this}
     };
     return TRACE_RETURN (chain_context_would_apply_lookup (c,
 							   backtrack.len, (const USHORT *) backtrack.array,
 							   input.len, (const USHORT *) input.array + 1,
 							   lookahead.len, (const USHORT *) lookahead.array,
 							   lookup.len, lookup.array, lookup_context));
   }
   inline const Coverage &get_coverage (void) const
   {
     const OffsetArrayOf<Coverage> &input = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
     return this+input[0];
   }
   inline bool apply (hb_apply_context_t *c) const
   {
     TRACE_APPLY (this);
     const OffsetArrayOf<Coverage> &input = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
     unsigned int index = (this+input[0]).get_coverage (c->buffer->cur().codepoint);
     if (likely (index == NOT_COVERED)) return TRACE_RETURN (false);
     const OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (input);
     const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
     struct ChainContextApplyLookupContext lookup_context = {
       {match_coverage},
       {this, this, this}
     };
     return TRACE_RETURN (chain_context_apply_lookup (c,
 						     backtrack.len, (const USHORT *) backtrack.array,
 						     input.len, (const USHORT *) input.array + 1,
 						     lookahead.len, (const USHORT *) lookahead.array,
 						     lookup.len, lookup.array, lookup_context));
   }
   inline bool sanitize (hb_sanitize_context_t *c) {
     TRACE_SANITIZE (this);
     if (!backtrack.sanitize (c, this)) return TRACE_RETURN (false);
     OffsetArrayOf<Coverage> &input = StructAfter<OffsetArrayOf<Coverage> > (backtrack);
     if (!input.sanitize (c, this)) return TRACE_RETURN (false);
     OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage> > (input);
     if (!lookahead.sanitize (c, this)) return TRACE_RETURN (false);
     ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord> > (lookahead);
     return TRACE_RETURN (lookup.sanitize (c));
   }
   protected:
   USHORT	format;			/* Format identifier--format = 3 */
   OffsetArrayOf<Coverage>
 		backtrack;		/* Array of coverage tables
 					 * in backtracking sequence, in  glyph
 					 * sequence order */
   OffsetArrayOf<Coverage>
 		inputX		;	/* Array of coverage
 					 * tables in input sequence, in glyph
 					 * sequence order */
   OffsetArrayOf<Coverage>
 		lookaheadX;		/* Array of coverage tables
 					 * in lookahead sequence, in glyph
 					 * sequence order */
   ArrayOf<LookupRecord>
 		lookupX;		/* Array of LookupRecords--in
 					 * design order) */
   public:
   DEFINE_SIZE_MIN (10);
 };
 struct ChainContext
 {
   template <typename context_t>
   inline typename context_t::return_t dispatch (context_t *c) const
   {
     TRACE_DISPATCH (this);
     switch (u.format) {
     case 1: return TRACE_RETURN (c->dispatch (u.format1));
     case 2: return TRACE_RETURN (c->dispatch (u.format2));
     case 3: return TRACE_RETURN (c->dispatch (u.format3));
     default:return TRACE_RETURN (c->default_return_value ());
     }
   }
   inline bool sanitize (hb_sanitize_context_t *c) {
     TRACE_SANITIZE (this);
     if (!u.format.sanitize (c)) return TRACE_RETURN (false);
     switch (u.format) {
     case 1: return TRACE_RETURN (u.format1.sanitize (c));
     case 2: return TRACE_RETURN (u.format2.sanitize (c));
     case 3: return TRACE_RETURN (u.format3.sanitize (c));
     default:return TRACE_RETURN (true);
     }
   }
   protected:
   union {
   USHORT		format;	/* Format identifier */
   ChainContextFormat1	format1;
   ChainContextFormat2	format2;
   ChainContextFormat3	format3;
   } u;
 };
 struct ExtensionFormat1
 {
   inline unsigned int get_type (void) const { return extensionLookupType; }
   inline unsigned int get_offset (void) const { return extensionOffset; }
   inline bool sanitize (hb_sanitize_context_t *c) {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (c->check_struct (this));
   }
   protected:
   USHORT	format;			/* Format identifier. Set to 1. */
   USHORT	extensionLookupType;	/* Lookup type of subtable referenced
 					 * by ExtensionOffset (i.e. the
 					 * extension subtable). */
   ULONG		extensionOffset;	/* Offset to the extension subtable,
 					 * of lookup type subtable. */
   public:
   DEFINE_SIZE_STATIC (8);
 };
 template <typename T>
 struct Extension
 {
   inline unsigned int get_type (void) const
   {
     switch (u.format) {
     case 1: return u.format1.get_type ();
     default:return 0;
     }
   }
   inline unsigned int get_offset (void) const
   {
     switch (u.format) {
     case 1: return u.format1.get_offset ();
     default:return 0;
     }
   }
   template <typename X>
   inline const X& get_subtable (void) const
   {
     unsigned int offset = get_offset ();
     if (unlikely (!offset)) return Null(typename T::LookupSubTable);
     return StructAtOffset<typename T::LookupSubTable> (this, offset);
   }
   template <typename context_t>
   inline typename context_t::return_t dispatch (context_t *c) const
   {
     return get_subtable<typename T::LookupSubTable> ().dispatch (c, get_type ());
   }
   inline bool sanitize_self (hb_sanitize_context_t *c) {
     TRACE_SANITIZE (this);
     if (!u.format.sanitize (c)) return TRACE_RETURN (false);
     switch (u.format) {
     case 1: return TRACE_RETURN (u.format1.sanitize (c));
     default:return TRACE_RETURN (true);
     }
   }
   inline bool sanitize (hb_sanitize_context_t *c) {
     TRACE_SANITIZE (this);
     if (!sanitize_self (c)) return TRACE_RETURN (false);
     unsigned int offset = get_offset ();
     if (unlikely (!offset)) return TRACE_RETURN (true);
     return TRACE_RETURN (StructAtOffset<typename T::LookupSubTable> (this, offset).sanitize (c, get_type ()));
   }
   protected:
   union {
   USHORT		format;		/* Format identifier */
   ExtensionFormat1	format1;
   } u;
 };
 /*
  * GSUB/GPOS Common
  */
 struct GSUBGPOS
 {
   static const hb_tag_t GSUBTag	= HB_OT_TAG_GSUB;
   static const hb_tag_t GPOSTag	= HB_OT_TAG_GPOS;
   inline unsigned int get_script_count (void) const
   { return (this+scriptList).len; }
   inline const Tag& get_script_tag (unsigned int i) const
   { return (this+scriptList).get_tag (i); }
   inline unsigned int get_script_tags (unsigned int start_offset,
 				       unsigned int *script_count /* IN/OUT */,
 				       hb_tag_t     *script_tags /* OUT */) const
   { return (this+scriptList).get_tags (start_offset, script_count, script_tags); }
   inline const Script& get_script (unsigned int i) const
   { return (this+scriptList)[i]; }
   inline bool find_script_index (hb_tag_t tag, unsigned int *index) const
   { return (this+scriptList).find_index (tag, index); }
   inline unsigned int get_feature_count (void) const
   { return (this+featureList).len; }
   inline const Tag& get_feature_tag (unsigned int i) const
   { return (this+featureList).get_tag (i); }
   inline unsigned int get_feature_tags (unsigned int start_offset,
 					unsigned int *feature_count /* IN/OUT */,
 					hb_tag_t     *feature_tags /* OUT */) const
   { return (this+featureList).get_tags (start_offset, feature_count, feature_tags); }
   inline const Feature& get_feature (unsigned int i) const
   { return (this+featureList)[i]; }
   inline bool find_feature_index (hb_tag_t tag, unsigned int *index) const
   { return (this+featureList).find_index (tag, index); }
   inline unsigned int get_lookup_count (void) const
   { return (this+lookupList).len; }
   inline const Lookup& get_lookup (unsigned int i) const
   { return (this+lookupList)[i]; }
   inline bool sanitize (hb_sanitize_context_t *c) {
     TRACE_SANITIZE (this);
     return TRACE_RETURN (version.sanitize (c) && likely (version.major == 1) &&
 			 scriptList.sanitize (c, this) &&
 			 featureList.sanitize (c, this) &&
 			 lookupList.sanitize (c, this));
   }
   protected:
   FixedVersion	version;	/* Version of the GSUB/GPOS table--initially set
 				 * to 0x00010000 */
   OffsetTo<ScriptList>
 		scriptList;  	/* ScriptList table */
   OffsetTo<FeatureList>
 		featureList; 	/* FeatureList table */
   OffsetTo<LookupList>
 		lookupList; 	/* LookupList table */
   public:
   DEFINE_SIZE_STATIC (10);
 };
 } /* namespace OT */
 #endif /* HB_OT_LAYOUT_GSUBGPOS_PRIVATE_HH */

The Tor Browser / annotate

gfx/harfbuzz/src/hb-ot-layout-gsubgpos-private.hh@925c144e1f1f (annotated)

gfx/harfbuzz/src/hb-ot-layout-gsubgpos-private.hh