tor-browser

The Tor Browser
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Sequence.hh (4263B)

      1 #ifndef OT_LAYOUT_GSUB_SEQUENCE_HH
      2 #define OT_LAYOUT_GSUB_SEQUENCE_HH
      3 
      4 #include "Common.hh"
      5 
      6 namespace OT {
      7 namespace Layout {
      8 namespace GSUB_impl {
      9 
     10 template <typename Types>
     11 struct Sequence
     12 {
     13  protected:
     14  Array16Of<typename Types::HBGlyphID>
     15                substitute;             /* String of GlyphIDs to substitute */
     16  public:
     17  DEFINE_SIZE_ARRAY (2, substitute);
     18 
     19  bool sanitize (hb_sanitize_context_t *c) const
     20  {
     21    TRACE_SANITIZE (this);
     22    return_trace (substitute.sanitize (c));
     23  }
     24 
     25  bool intersects (const hb_set_t *glyphs) const
     26  { return hb_all (substitute, glyphs); }
     27 
     28  void closure (hb_closure_context_t *c) const
     29  { c->output->add_array (substitute.arrayZ, substitute.len); }
     30 
     31  void collect_glyphs (hb_collect_glyphs_context_t *c) const
     32  { c->output->add_array (substitute.arrayZ, substitute.len); }
     33 
     34  bool apply (hb_ot_apply_context_t *c) const
     35  {
     36    TRACE_APPLY (this);
     37    unsigned int count = substitute.len;
     38 
     39    /* Special-case to make it in-place and not consider this
     40     * as a "multiplied" substitution. */
     41    if (unlikely (count == 1))
     42    {
     43      if (HB_BUFFER_MESSAGE_MORE && c->buffer->messaging ())
     44      {
     45 c->buffer->sync_so_far ();
     46 c->buffer->message (c->font,
     47 		    "replacing glyph at %u (multiple substitution)",
     48 		    c->buffer->idx);
     49      }
     50 
     51      c->replace_glyph (substitute.arrayZ[0]);
     52 
     53      if (HB_BUFFER_MESSAGE_MORE && c->buffer->messaging ())
     54      {
     55 c->buffer->message (c->font,
     56 		    "replaced glyph at %u (multiple substitution)",
     57 		    c->buffer->idx - 1u);
     58      }
     59 
     60      return_trace (true);
     61    }
     62    /* Spec disallows this, but Uniscribe allows it.
     63     * https://github.com/harfbuzz/harfbuzz/issues/253 */
     64    else if (unlikely (count == 0))
     65    {
     66      if (HB_BUFFER_MESSAGE_MORE && c->buffer->messaging ())
     67      {
     68 c->buffer->sync_so_far ();
     69 c->buffer->message (c->font,
     70 		    "deleting glyph at %u (multiple substitution)",
     71 		    c->buffer->idx);
     72      }
     73 
     74      c->buffer->delete_glyph ();
     75 
     76      if (HB_BUFFER_MESSAGE_MORE && c->buffer->messaging ())
     77      {
     78 c->buffer->sync_so_far ();
     79 c->buffer->message (c->font,
     80 		    "deleted glyph at %u (multiple substitution)",
     81 		    c->buffer->idx);
     82      }
     83 
     84      return_trace (true);
     85    }
     86 
     87    if (HB_BUFFER_MESSAGE_MORE && c->buffer->messaging ())
     88    {
     89      c->buffer->sync_so_far ();
     90      c->buffer->message (c->font,
     91 		  "multiplying glyph at %u",
     92 		  c->buffer->idx);
     93    }
     94 
     95    unsigned int klass = _hb_glyph_info_is_ligature (&c->buffer->cur()) ?
     96                         HB_OT_LAYOUT_GLYPH_PROPS_BASE_GLYPH : 0;
     97    unsigned lig_id = _hb_glyph_info_get_lig_id (&c->buffer->cur());
     98 
     99    for (unsigned int i = 0; i < count; i++)
    100    {
    101      /* If is attached to a ligature, don't disturb that.
    102       * https://github.com/harfbuzz/harfbuzz/issues/3069 */
    103      if (!lig_id)
    104        _hb_glyph_info_set_lig_props_for_component (&c->buffer->cur(), i);
    105      c->output_glyph_for_component (substitute.arrayZ[i], klass);
    106    }
    107    c->buffer->skip_glyph ();
    108 
    109    if (HB_BUFFER_MESSAGE_MORE && c->buffer->messaging ())
    110    {
    111      c->buffer->sync_so_far ();
    112 
    113      char buf[HB_MAX_CONTEXT_LENGTH * 16] = {0};
    114      char *p = buf;
    115 
    116      for (unsigned i = c->buffer->idx - count; i < c->buffer->idx; i++)
    117      {
    118 if (buf < p && sizeof(buf) - 1u > unsigned (p - buf))
    119   *p++ = ',';
    120 snprintf (p, sizeof(buf) - (p - buf), "%u", i);
    121 p += strlen(p);
    122      }
    123 
    124      c->buffer->message (c->font,
    125 		  "multiplied glyphs at %s",
    126 		  buf);
    127    }
    128 
    129    return_trace (true);
    130  }
    131 
    132  template <typename Iterator,
    133            hb_requires (hb_is_source_of (Iterator, hb_codepoint_t))>
    134  bool serialize (hb_serialize_context_t *c,
    135                  Iterator subst)
    136  {
    137    TRACE_SERIALIZE (this);
    138    return_trace (substitute.serialize (c, subst));
    139  }
    140 
    141  bool subset (hb_subset_context_t *c) const
    142  {
    143    TRACE_SUBSET (this);
    144    const hb_set_t &glyphset = *c->plan->glyphset_gsub ();
    145    const hb_map_t &glyph_map = *c->plan->glyph_map;
    146 
    147    if (!intersects (&glyphset)) return_trace (false);
    148 
    149    auto it =
    150    + hb_iter (substitute)
    151    | hb_map (glyph_map)
    152    ;
    153 
    154    auto *out = c->serializer->start_embed (*this);
    155    return_trace (out->serialize (c->serializer, it));
    156  }
    157 };
    158 
    159 
    160 }
    161 }
    162 }
    163 
    164 
    165 #endif /* OT_LAYOUT_GSUB_SEQUENCE_HH */