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 
sanitizeOT::hmtxvmtx58   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 */
103