tor-browser

LigatureSet.hh (5479B)

---

#ifndef OT_LAYOUT_GSUB_LIGATURESET_HH
#define OT_LAYOUT_GSUB_LIGATURESET_HH

#include "Common.hh"
#include "Ligature.hh"

namespace OT {
namespace Layout {
namespace GSUB_impl {

template <typename Types>
struct LigatureSet
{
 public:
 Array16OfOffset16To<Ligature<Types>>
               ligature;               /* Array LigatureSet tables
                                        * ordered by preference */
 
 DEFINE_SIZE_ARRAY (2, ligature);

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

 bool intersects (const hb_set_t *glyphs) const
 {
   return
   + hb_iter (ligature)
   | hb_map (hb_add (this))
   | hb_map ([glyphs] (const Ligature<Types> &_) { return _.intersects (glyphs); })
   | hb_any
   ;
 }

 bool intersects_lig_glyph (const hb_set_t *glyphs) const
 {
   return
   + hb_iter (ligature)
   | hb_map (hb_add (this))
   | hb_map ([glyphs] (const Ligature<Types> &_) { 
     return _.intersects_lig_glyph (glyphs) && _.intersects (glyphs);
   })
   | hb_any
   ;
 }

 void closure (hb_closure_context_t *c) const
 {
   + hb_iter (ligature)
   | hb_map (hb_add (this))
   | hb_apply ([c] (const Ligature<Types> &_) { _.closure (c); })
   ;
 }

 void collect_glyphs (hb_collect_glyphs_context_t *c) const
 {
   + hb_iter (ligature)
   | hb_map (hb_add (this))
   | hb_apply ([c] (const Ligature<Types> &_) { _.collect_glyphs (c); })
   ;
 }

 template <typename set_t>
 void collect_seconds (set_t &s) const
 {
   + hb_iter (ligature)
   | hb_map (hb_add (this))
   | hb_apply ([&s] (const Ligature<Types> &_) { _.collect_second (s); })
   ;
 }

 bool would_apply (hb_would_apply_context_t *c) const
 {
   return
   + hb_iter (ligature)
   | hb_map (hb_add (this))
   | hb_map ([c] (const Ligature<Types> &_) { return _.would_apply (c); })
   | hb_any
   ;
 }

 bool apply (hb_ot_apply_context_t *c, const hb_set_digest_t *seconds = nullptr) const
 {
   TRACE_APPLY (this);

   unsigned int num_ligs = ligature.len;

#ifndef HB_NO_OT_RULESETS_FAST_PATH
   if (HB_OPTIMIZE_SIZE_VAL || num_ligs <= 1)
#endif
   {
   slow:
     for (unsigned int i = 0; i < num_ligs; i++)
     {
const auto &lig = this+ligature.arrayZ[i];
if (lig.apply (c)) return_trace (true);
     }
     return_trace (false);
   }

   /* This version is optimized for speed by matching the second component
    * of the ligature here, instead of calling into the ligation code.
    *
    * This is replicated in ChainRuleSet and RuleSet. */

   auto &skippy_iter = c->iter_context;
   skippy_iter.reset (c->buffer->idx);
   skippy_iter.set_match_func (match_always, nullptr);
   skippy_iter.set_glyph_data ((HBUINT16 *) nullptr);
   unsigned unsafe_to;
   hb_codepoint_t second = (unsigned) -1;
   bool matched = skippy_iter.next (&unsafe_to);
   if (likely (matched))
   {
     second = c->buffer->info[skippy_iter.idx].codepoint;
     unsafe_to = skippy_iter.idx + 1;

     if (skippy_iter.may_skip (c->buffer->info[skippy_iter.idx]))
     {
/* Can't use the fast path if eg. the next char is a default-ignorable
 * or other skippable. */
       goto slow;
     }
   }
   else
     goto slow;

   if (seconds && !seconds->may_have (second))
     return_trace (false);
   bool unsafe_to_concat = false;
   for (unsigned int i = 0; i < num_ligs; i++)
   {
     const auto &lig = this+ligature.arrayZ[i];
     if (unlikely (lig.component.lenP1 <= 1) ||
  lig.component.arrayZ[0] == second)
     {
if (lig.apply (c))
{
  if (unsafe_to_concat)
    c->buffer->unsafe_to_concat (c->buffer->idx, unsafe_to);
  return_trace (true);
}
     }
     else if (likely (lig.component.lenP1 > 1))
       unsafe_to_concat = true;
   }
   if (likely (unsafe_to_concat))
     c->buffer->unsafe_to_concat (c->buffer->idx, unsafe_to);

   return_trace (false);
 }

 bool serialize (hb_serialize_context_t *c,
                 hb_array_t<const HBGlyphID16> ligatures,
                 hb_array_t<const unsigned int> component_count_list,
                 hb_array_t<const HBGlyphID16> &component_list /* Starting from second for each ligature */)
 {
   TRACE_SERIALIZE (this);
   if (unlikely (!c->extend_min (this))) return_trace (false);
   if (unlikely (!ligature.serialize (c, ligatures.length))) return_trace (false);
   for (unsigned int i = 0; i < ligatures.length; i++)
   {
     unsigned int component_count = (unsigned) hb_max ((int) component_count_list[i] - 1, 0);
     if (unlikely (!ligature[i].serialize_serialize (c,
                                                     ligatures[i],
                                                     component_list.sub_array (0, component_count))))
       return_trace (false);
     component_list += component_count;
   }
   return_trace (true);
 }

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

   + hb_iter (ligature)
   | hb_filter (subset_offset_array (c, out->ligature, this, coverage_idx))
   | hb_drain
   ;

   if (bool (out->ligature))
     // Ensure Coverage table is always packed after this.
     c->serializer->add_virtual_link (coverage_idx);

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

}
}
}

#endif  /* OT_LAYOUT_GSUB_LIGATURESET_HH */