third_party/harfbuzz-ng/src/hb-ot-hmtx-table.hh

   1 /*
   2  * Copyright © 2011,2012  Google, Inc.
   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  * Google Author(s): Behdad Esfahbod
  25  */
  26
  27 #ifndef HB_OT_HMTX_TABLE_HH
  28 #define HB_OT_HMTX_TABLE_HH
  29
  30 #include "hb-open-type-private.hh"
  31
  32
  33 namespace OT {
  34
  35
  36 /*
  37  * hmtx -- The Horizontal Metrics Table
  38  * vmtx -- The Vertical Metrics Table
  39  */
  40
  41 #define HB_OT_TAG_hmtx HB_TAG('h','m','t','x')
  42 #define HB_OT_TAG_vmtx HB_TAG('v','m','t','x')
  43
  44
  45 struct LongMetric
  46 {
  47   USHORT        advance; /* Advance width/height. */
  48   SHORT         lsb; /* Leading (left/top) side bearing. */
  49   public:
  50   DEFINE_SIZE_STATIC (4);
  51 };
  52
  53 struct _mtx
  54 {
  55   static const hb_tag_t tableTag = HB_TAG('_','m','t','x');
  56
  57   static const hb_tag_t hmtxTag = HB_OT_TAG_hmtx;
  58   static const hb_tag_t vmtxTag = HB_OT_TAG_vmtx;
  59
  60   inline bool sanitize (hb_sanitize_context_t *c) const
  61   {
  62     TRACE_SANITIZE (this);
  63     /* We don't check for anything specific here.  The users of the
  64      * struct do all the hard work... */
  65     return TRACE_RETURN (true);
  66   }
  67
  68   public:
  69   LongMetric    longMetric[VAR];        /* Paired advance width and leading
  70                                          * bearing values for each glyph. The
  71                                          * value numOfHMetrics comes from
  72                                          * the 'hhea' table. If the font is
  73                                          * monospaced, only one entry need
  74                                          * be in the array, but that entry is
  75                                          * required. The last entry applies to
  76                                          * all subsequent glyphs. */
  77   SHORT         leadingBearingX[VAR];   /* Here the advance is assumed
  78                                          * to be the same as the advance
  79                                          * for the last entry above. The
  80                                          * number of entries in this array is
  81                                          * derived from numGlyphs (from 'maxp'
  82                                          * table) minus numberOfLongMetrics.
  83                                          * This generally is used with a run
  84                                          * of monospaced glyphs (e.g., Kanji
  85                                          * fonts or Courier fonts). Only one
  86                                          * run is allowed and it must be at
  87                                          * the end. This allows a monospaced
  88                                          * font to vary the side bearing
  89                                          * values for each glyph. */
  90   public:
  91   DEFINE_SIZE_ARRAY2 (0, longMetric, leadingBearingX);
  92 };
  93
  94 struct hmtx : _mtx {
  95   static const hb_tag_t tableTag        = HB_OT_TAG_hmtx;
  96 };
  97 struct vmtx : _mtx {
  98   static const hb_tag_t tableTag        = HB_OT_TAG_vmtx;
  99 };
 100
 101 } /* namespace OT */
 102
 103
 104 #endif /* HB_OT_HMTX_TABLE_HH */