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   UFWORD        advance; /* Advance width/height. */
  48   FWORD         lsb; /* Leading (left/top) side bearing. */
  49   public:
  50   DEFINE_SIZE_STATIC (4);
  51 };
  52 
  53 struct hmtxvmtx
  54 {
  55   static const hb_tag_t hmtxTag = HB_OT_TAG_hmtx;
  56   static const hb_tag_t vmtxTag = HB_OT_TAG_vmtx;
  57 
  58   inline bool sanitize (hb_sanitize_context_t *c) const
  59   {
  60     TRACE_SANITIZE (this);
  61     /* We don't check for anything specific here.  The users of the
  62      * struct do all the hard work... */
  63     return_trace (true);
  64   }
  65 
  66   public:
  67   LongMetric    longMetric[VAR];        /* Paired advance width and leading
  68                                          * bearing values for each glyph. The
  69                                          * value numOfHMetrics comes from
  70                                          * the 'hhea' table. If the font is
  71                                          * monospaced, only one entry need
  72                                          * be in the array, but that entry is
  73                                          * required. The last entry applies to
  74                                          * all subsequent glyphs. */
  75   FWORD         leadingBearingX[VAR];   /* Here the advance is assumed
  76                                          * to be the same as the advance
  77                                          * for the last entry above. The
  78                                          * number of entries in this array is
  79                                          * derived from numGlyphs (from 'maxp'
  80                                          * table) minus numberOfLongMetrics.
  81                                          * This generally is used with a run
  82                                          * of monospaced glyphs (e.g., Kanji
  83                                          * fonts or Courier fonts). Only one
  84                                          * run is allowed and it must be at
  85                                          * the end. This allows a monospaced
  86                                          * font to vary the side bearing
  87                                          * values for each glyph. */
  88   public:
  89   DEFINE_SIZE_ARRAY2 (0, longMetric, leadingBearingX);
  90 };
  91 
  92 struct hmtx : hmtxvmtx {
  93   static const hb_tag_t tableTag        = HB_OT_TAG_hmtx;
  94 };
  95 struct vmtx : hmtxvmtx {
  96   static const hb_tag_t tableTag        = HB_OT_TAG_vmtx;
  97 };
  98 
  99 } /* namespace OT */
 100 
 101 
 102 #endif /* HB_OT_HMTX_TABLE_HH */