1/*
2 * Copyright © 2017 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_VAR_AVAR_TABLE_HH
28#define HB_OT_VAR_AVAR_TABLE_HH
29
30#include "hb-open-type-private.hh"
31
32namespace OT {
33
34
35struct AxisValueMap
36{
37 inline bool sanitize (hb_sanitize_context_t *c) const
38 {
39 TRACE_SANITIZE (this);
40 return_trace (c->check_struct (this));
41 }
42
43 public:
44 F2DOT14 fromCoord; /* A normalized coordinate value obtained using
45 * default normalization. */
46 F2DOT14 toCoord; /* The modified, normalized coordinate value. */
47
48 public:
49 DEFINE_SIZE_STATIC (4);
50};
51
52struct SegmentMaps : ArrayOf<AxisValueMap>
53{
54 inline int map (int value) const
55 {
56 /* The following special-cases are not part of OpenType, which requires
57 * that at least -1, 0, and +1 must be mapped. But we include these as
58 * part of a better error recovery scheme. */
59
60 if (len < 2)
61 {
62 if (!len)
63 return value;
64 else /* len == 1*/
65 return value - array[0].fromCoord + array[0].toCoord;
66 }
67
68 if (value <= array[0].fromCoord)
69 return value - array[0].fromCoord + array[0].toCoord;
70
71 unsigned int i;
72 unsigned int count = len;
73 for (i = 1; i < count && value > array[i].fromCoord; i++)
74 ;
75
76 if (value >= array[i].fromCoord)
77 return value - array[i].fromCoord + array[i].toCoord;
78
79 if (unlikely (array[i-1].fromCoord == array[i].fromCoord))
80 return array[i-1].toCoord;
81
82 int denom = array[i].fromCoord - array[i-1].fromCoord;
83 return array[i-1].toCoord +
84 ((array[i].toCoord - array[i-1].toCoord) *
85 (value - array[i-1].fromCoord) + denom/2) / denom;
86 }
87
88 DEFINE_SIZE_ARRAY (2, array);
89};
90
91/*
92 * avar — Axis Variations Table
93 */
94
95#define HB_OT_TAG_avar HB_TAG('a','v','a','r')
96
97struct avar
98{
99 static const hb_tag_t tableTag = HB_OT_TAG_avar;
100
101 inline bool sanitize (hb_sanitize_context_t *c) const
102 {
103 TRACE_SANITIZE (this);
104 if (unlikely (!(version.sanitize (c) &&
105 version.major == 1 &&
106 c->check_struct (this))))
107 return_trace (false);
108
109 const SegmentMaps *map = &axisSegmentMapsZ;
110 unsigned int count = axisCount;
111 for (unsigned int i = 0; i < count; i++)
112 {
113 if (unlikely (!map->sanitize (c)))
114 return_trace (false);
115 map = &StructAfter<SegmentMaps> (X: *map);
116 }
117
118 return_trace (true);
119 }
120
121 inline void map_coords (int *coords, unsigned int coords_length) const
122 {
123 unsigned int count = MIN<unsigned int> (a: coords_length, b: axisCount);
124
125 const SegmentMaps *map = &axisSegmentMapsZ;
126 for (unsigned int i = 0; i < count; i++)
127 {
128 coords[i] = map->map (value: coords[i]);
129 map = &StructAfter<SegmentMaps> (X: *map);
130 }
131 }
132
133 protected:
134 FixedVersion<>version; /* Version of the avar table
135 * initially set to 0x00010000u */
136 UINT16 reserved; /* This field is permanently reserved. Set to 0. */
137 UINT16 axisCount; /* The number of variation axes in the font. This
138 * must be the same number as axisCount in the
139 * 'fvar' table. */
140 SegmentMaps axisSegmentMapsZ;
141
142 public:
143 DEFINE_SIZE_MIN (8);
144};
145
146} /* namespace OT */
147
148
149#endif /* HB_OT_VAR_AVAR_TABLE_HH */
150

source code of qtbase/src/3rdparty/harfbuzz-ng/src/hb-ot-var-avar-table.hh