1/*
2 * Copyright © 2018 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): Garret Rieger
25 */
26
27#ifndef HB_OT_HDMX_TABLE_HH
28#define HB_OT_HDMX_TABLE_HH
29
30#include "hb-open-type.hh"
31
32/*
33 * hdmx -- Horizontal Device Metrics
34 * https://docs.microsoft.com/en-us/typography/opentype/spec/hdmx
35 */
36#define HB_OT_TAG_hdmx HB_TAG('h','d','m','x')
37
38
39namespace OT {
40
41
42struct DeviceRecord
43{
44 static unsigned int get_size (unsigned count)
45 { return hb_ceil_to_4 (min_size + count * HBUINT8::static_size); }
46
47 template<typename Iterator,
48 hb_requires (hb_is_iterator (Iterator))>
49 bool serialize (hb_serialize_context_t *c,
50 unsigned pixelSize,
51 Iterator it,
52 const hb_vector_t<hb_codepoint_pair_t> new_to_old_gid_list,
53 unsigned num_glyphs)
54 {
55 TRACE_SERIALIZE (this);
56
57 if (unlikely (!c->extend (this, num_glyphs))) return_trace (false);
58
59 this->pixelSize = pixelSize;
60 this->maxWidth =
61 + it
62 | hb_reduce (hb_max, 0u);
63
64 for (auto &_ : new_to_old_gid_list)
65 widthsZ[_.first] = *it++;
66
67 return_trace (true);
68 }
69
70 bool sanitize (hb_sanitize_context_t *c, unsigned sizeDeviceRecord) const
71 {
72 TRACE_SANITIZE (this);
73 return_trace (likely (c->check_struct (this) &&
74 c->check_range (this, sizeDeviceRecord)));
75 }
76
77 HBUINT8 pixelSize; /* Pixel size for following widths (as ppem). */
78 HBUINT8 maxWidth; /* Maximum width. */
79 UnsizedArrayOf<HBUINT8> widthsZ; /* Array of widths (numGlyphs is from the 'maxp' table). */
80 public:
81 DEFINE_SIZE_UNBOUNDED (2);
82};
83
84
85struct hdmx
86{
87 static constexpr hb_tag_t tableTag = HB_OT_TAG_hdmx;
88
89 unsigned int get_size () const
90 { return min_size + numRecords * sizeDeviceRecord; }
91
92 template<typename Iterator,
93 hb_requires (hb_is_iterator (Iterator))>
94 bool serialize (hb_serialize_context_t *c,
95 unsigned version,
96 Iterator it,
97 const hb_vector_t<hb_codepoint_pair_t> &new_to_old_gid_list,
98 unsigned num_glyphs)
99 {
100 TRACE_SERIALIZE (this);
101
102 if (unlikely (!c->extend_min ((*this)))) return_trace (false);
103
104 this->version = version;
105 this->numRecords = it.len ();
106 this->sizeDeviceRecord = DeviceRecord::get_size (num_glyphs);
107
108 for (const hb_item_type<Iterator>& _ : +it)
109 c->start_embed<DeviceRecord> ()->serialize (c, _.first, _.second, new_to_old_gid_list, num_glyphs);
110
111 return_trace (c->successful ());
112 }
113
114
115 bool subset (hb_subset_context_t *c) const
116 {
117 TRACE_SUBSET (this);
118
119 auto *hdmx_prime = c->serializer->start_embed <hdmx> ();
120
121 unsigned num_input_glyphs = get_num_glyphs ();
122 auto it =
123 + hb_range ((unsigned) numRecords)
124 | hb_map ([c, num_input_glyphs, this] (unsigned _)
125 {
126 const DeviceRecord *device_record =
127 &StructAtOffset<DeviceRecord> (&firstDeviceRecord,
128 _ * sizeDeviceRecord);
129 auto row =
130 + hb_iter (c->plan->new_to_old_gid_list)
131 | hb_map ([num_input_glyphs, device_record] (hb_codepoint_pair_t _)
132 {
133 return device_record->widthsZ.as_array (num_input_glyphs) [_.second];
134 })
135 ;
136 return hb_pair ((unsigned) device_record->pixelSize, +row);
137 })
138 ;
139
140 hdmx_prime->serialize (c->serializer, version, it,
141 c->plan->new_to_old_gid_list,
142 c->plan->num_output_glyphs ());
143 return_trace (true);
144 }
145
146 unsigned get_num_glyphs () const
147 {
148 return sizeDeviceRecord - DeviceRecord::min_size;
149 }
150
151 bool sanitize (hb_sanitize_context_t *c) const
152 {
153 TRACE_SANITIZE (this);
154 return_trace (c->check_struct (this) &&
155 !hb_unsigned_mul_overflows (numRecords, sizeDeviceRecord) &&
156 min_size + numRecords * sizeDeviceRecord > numRecords * sizeDeviceRecord &&
157 sizeDeviceRecord >= DeviceRecord::min_size &&
158 c->check_range (this, get_size ()));
159 }
160
161 protected:
162 HBUINT16 version; /* Table version number (0) */
163 HBUINT16 numRecords; /* Number of device records. */
164 HBUINT32 sizeDeviceRecord;
165 /* Size of a device record, 32-bit aligned. */
166 DeviceRecord firstDeviceRecord;
167 /* Array of device records. */
168 public:
169 DEFINE_SIZE_MIN (8);
170};
171
172} /* namespace OT */
173
174
175#endif /* HB_OT_HDMX_TABLE_HH */
176