tor-browser

The Tor Browser
git clone https://git.dasho.dev/tor-browser.git
Log | Files | Refs | README | LICENSE

hb-ot-meta-table.hh (3956B)

      1 /*
      2 * Copyright © 2019  Ebrahim Byagowi
      3 *
      4 *  This is part of HarfBuzz, a text shaping library.
      5 *
      6 * Permission is hereby granted, without written agreement and without
      7 * license or royalty fees, to use, copy, modify, and distribute this
      8 * software and its documentation for any purpose, provided that the
      9 * above copyright notice and the following two paragraphs appear in
     10 * all copies of this software.
     11 *
     12 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
     13 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
     14 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
     15 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
     16 * DAMAGE.
     17 *
     18 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
     19 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
     20 * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
     21 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
     22 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
     23 */
     24 
     25 #ifndef HB_OT_META_TABLE_HH
     26 #define HB_OT_META_TABLE_HH
     27 
     28 #include "hb-open-type.hh"
     29 
     30 /*
     31 * meta -- Metadata Table
     32 * https://docs.microsoft.com/en-us/typography/opentype/spec/meta
     33 * https://developer.apple.com/fonts/TrueType-Reference-Manual/RM06/Chap6meta.html
     34 */
     35 #define HB_OT_TAG_meta HB_TAG ('m','e','t','a')
     36 
     37 
     38 namespace OT {
     39 
     40 
     41 struct DataMap
     42 {
     43  int cmp (hb_tag_t a) const { return tag.cmp (a); }
     44 
     45  hb_tag_t get_tag () const { return tag; }
     46 
     47  hb_blob_t *reference_entry (hb_blob_t *meta_blob) const
     48  { return hb_blob_create_sub_blob (meta_blob, dataZ, dataLength); }
     49 
     50  bool sanitize (hb_sanitize_context_t *c, const void *base) const
     51  {
     52    TRACE_SANITIZE (this);
     53    return_trace (likely (c->check_struct (this) &&
     54 		  hb_barrier () &&
     55 		  dataZ.sanitize (c, base, dataLength)));
     56  }
     57 
     58  protected:
     59  Tag		tag;		/* A tag indicating the type of metadata. */
     60  NNOffset32To<UnsizedArrayOf<HBUINT8>>
     61 	dataZ;		/* Offset in bytes from the beginning of the
     62 			 * metadata table to the data for this tag. */
     63  HBUINT32	dataLength;	/* Length of the data. The data is not required to
     64 			 * be padded to any byte boundary. */
     65  public:
     66  DEFINE_SIZE_STATIC (12);
     67 };
     68 
     69 struct meta
     70 {
     71  static constexpr hb_tag_t tableTag = HB_OT_TAG_meta;
     72 
     73  struct accelerator_t
     74  {
     75    accelerator_t (hb_face_t *face)
     76    { table = hb_sanitize_context_t ().reference_table<meta> (face); }
     77    ~accelerator_t () { table.destroy (); }
     78 
     79    hb_blob_t *reference_entry (hb_tag_t tag) const
     80    { return table->dataMaps.lsearch (tag).reference_entry (table.get_blob ()); }
     81 
     82    unsigned int get_entries (unsigned int      start_offset,
     83 		      unsigned int     *count,
     84 		      hb_ot_meta_tag_t *entries) const
     85    {
     86      if (count)
     87      {
     88 + table->dataMaps.as_array ().sub_array (start_offset, count)
     89 | hb_map (&DataMap::get_tag)
     90 | hb_map ([](hb_tag_t tag) { return (hb_ot_meta_tag_t) tag; })
     91 | hb_sink (hb_array (entries, *count))
     92 ;
     93      }
     94      return table->dataMaps.len;
     95    }
     96 
     97    private:
     98    hb_blob_ptr_t<meta> table;
     99  };
    100 
    101  bool sanitize (hb_sanitize_context_t *c) const
    102  {
    103    TRACE_SANITIZE (this);
    104    return_trace (likely (c->check_struct (this) &&
    105 		  hb_barrier () &&
    106 		  version == 1 &&
    107 		  dataMaps.sanitize (c, this)));
    108  }
    109 
    110  protected:
    111  HBUINT32	version;	/* Version number of the metadata table — set to 1. */
    112  HBUINT32	flags;		/* Flags — currently unused; set to 0. */
    113  HBUINT32	dataOffset;
    114 			/* Per Apple specification:
    115 			 * Offset from the beginning of the table to the data.
    116 			 * Per OT specification:
    117 			 * Reserved. Not used; should be set to 0. */
    118  Array32Of<DataMap>
    119 	dataMaps;/* Array of data map records. */
    120  public:
    121  DEFINE_SIZE_ARRAY (16, dataMaps);
    122 };
    123 
    124 struct meta_accelerator_t : meta::accelerator_t {
    125  meta_accelerator_t (hb_face_t *face) : meta::accelerator_t (face) {}
    126 };
    127 
    128 } /* namespace OT */
    129 
    130 
    131 #endif /* HB_OT_META_TABLE_HH */