1/*
2 * Copyright © 2018 Ebrahim Byagowi
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
25#ifndef HB_AAT_LAYOUT_FEAT_TABLE_HH
26#define HB_AAT_LAYOUT_FEAT_TABLE_HH
27
28#include "hb-aat-layout-common.hh"
29
30/*
31 * feat -- Feature Name
32 * https://developer.apple.com/fonts/TrueType-Reference-Manual/RM06/Chap6feat.html
33 */
34#define HB_AAT_TAG_feat HB_TAG('f','e','a','t')
35
36
37namespace AAT {
38
39
40struct SettingName
41{
42 friend struct FeatureName;
43
44 int cmp (hb_aat_layout_feature_selector_t key) const
45 { return (int) key - (int) setting; }
46
47 hb_aat_layout_feature_selector_t get_selector () const
48 { return (hb_aat_layout_feature_selector_t) (unsigned) setting; }
49
50 hb_aat_layout_feature_selector_info_t get_info (hb_aat_layout_feature_selector_t default_selector) const
51 {
52 return {
53 nameIndex,
54 (hb_aat_layout_feature_selector_t) (unsigned int) setting,
55 default_selector == HB_AAT_LAYOUT_FEATURE_SELECTOR_INVALID
56 ? (hb_aat_layout_feature_selector_t) (setting + 1)
57 : default_selector,
58 0
59 };
60 }
61
62 bool sanitize (hb_sanitize_context_t *c) const
63 {
64 TRACE_SANITIZE (this);
65 return_trace (likely (c->check_struct (this)));
66 }
67
68 protected:
69 HBUINT16 setting; /* The setting. */
70 NameID nameIndex; /* The name table index for the setting's name. */
71 public:
72 DEFINE_SIZE_STATIC (4);
73};
74DECLARE_NULL_NAMESPACE_BYTES (AAT, SettingName);
75
76struct feat;
77
78struct FeatureName
79{
80 int cmp (hb_aat_layout_feature_type_t key) const
81 { return (int) key - (int) feature; }
82
83 enum {
84 Exclusive = 0x8000, /* If set, the feature settings are mutually exclusive. */
85 NotDefault = 0x4000, /* If clear, then the setting with an index of 0 in
86 * the setting name array for this feature should
87 * be taken as the default for the feature
88 * (if one is required). If set, then bits 0-15 of this
89 * featureFlags field contain the index of the setting
90 * which is to be taken as the default. */
91 IndexMask = 0x00FF /* If bits 30 and 31 are set, then these sixteen bits
92 * indicate the index of the setting in the setting name
93 * array for this feature which should be taken
94 * as the default. */
95 };
96
97 unsigned int get_selector_infos (unsigned int start_offset,
98 unsigned int *selectors_count, /* IN/OUT. May be NULL. */
99 hb_aat_layout_feature_selector_info_t *selectors, /* OUT. May be NULL. */
100 unsigned int *pdefault_index, /* OUT. May be NULL. */
101 const void *base) const
102 {
103 hb_array_t< const SettingName> settings_table = (base+settingTableZ).as_array (nSettings);
104
105 static_assert (Index::NOT_FOUND_INDEX == HB_AAT_LAYOUT_NO_SELECTOR_INDEX, "");
106
107 hb_aat_layout_feature_selector_t default_selector = HB_AAT_LAYOUT_FEATURE_SELECTOR_INVALID;
108 unsigned int default_index = Index::NOT_FOUND_INDEX;
109 if (featureFlags & Exclusive)
110 {
111 default_index = (featureFlags & NotDefault) ? featureFlags & IndexMask : 0;
112 default_selector = settings_table[default_index].get_selector ();
113 }
114 if (pdefault_index)
115 *pdefault_index = default_index;
116
117 if (selectors_count)
118 {
119 + settings_table.sub_array (start_offset, selectors_count)
120 | hb_map ([=] (const SettingName& setting) { return setting.get_info (default_selector); })
121 | hb_sink (hb_array (selectors, *selectors_count))
122 ;
123 }
124 return settings_table.length;
125 }
126
127 hb_aat_layout_feature_type_t get_feature_type () const
128 { return (hb_aat_layout_feature_type_t) (unsigned int) feature; }
129
130 hb_ot_name_id_t get_feature_name_id () const { return nameIndex; }
131
132 bool sanitize (hb_sanitize_context_t *c, const void *base) const
133 {
134 TRACE_SANITIZE (this);
135 return_trace (likely (c->check_struct (this) &&
136 (base+settingTableZ).sanitize (c, nSettings)));
137 }
138
139 protected:
140 HBUINT16 feature; /* Feature type. */
141 HBUINT16 nSettings; /* The number of records in the setting name array. */
142 LOffsetTo<UnsizedArrayOf<SettingName>, false>
143 settingTableZ; /* Offset in bytes from the beginning of this table to
144 * this feature's setting name array. The actual type of
145 * record this offset refers to will depend on the
146 * exclusivity value, as described below. */
147 HBUINT16 featureFlags; /* Single-bit flags associated with the feature type. */
148 HBINT16 nameIndex; /* The name table index for the feature's name.
149 * This index has values greater than 255 and
150 * less than 32768. */
151 public:
152 DEFINE_SIZE_STATIC (12);
153};
154
155struct feat
156{
157 static constexpr hb_tag_t tableTag = HB_AAT_TAG_feat;
158
159 bool has_data () const { return version.to_int (); }
160
161 unsigned int get_feature_types (unsigned int start_offset,
162 unsigned int *count,
163 hb_aat_layout_feature_type_t *features) const
164 {
165 if (count)
166 {
167 + namesZ.as_array (featureNameCount).sub_array (start_offset, count)
168 | hb_map (&FeatureName::get_feature_type)
169 | hb_sink (hb_array (features, *count))
170 ;
171 }
172 return featureNameCount;
173 }
174
175 const FeatureName& get_feature (hb_aat_layout_feature_type_t feature_type) const
176 { return namesZ.bsearch (featureNameCount, feature_type); }
177
178 hb_ot_name_id_t get_feature_name_id (hb_aat_layout_feature_type_t feature) const
179 { return get_feature (feature).get_feature_name_id (); }
180
181 unsigned int get_selector_infos (hb_aat_layout_feature_type_t feature_type,
182 unsigned int start_offset,
183 unsigned int *selectors_count, /* IN/OUT. May be NULL. */
184 hb_aat_layout_feature_selector_info_t *selectors, /* OUT. May be NULL. */
185 unsigned int *default_index /* OUT. May be NULL. */) const
186 {
187 return get_feature (feature_type).get_selector_infos (start_offset, selectors_count, selectors,
188 default_index, this);
189 }
190
191 bool sanitize (hb_sanitize_context_t *c) const
192 {
193 TRACE_SANITIZE (this);
194 return_trace (likely (c->check_struct (this) &&
195 version.major == 1 &&
196 namesZ.sanitize (c, featureNameCount, this)));
197 }
198
199 protected:
200 FixedVersion<>version; /* Version number of the feature name table
201 * (0x00010000 for the current version). */
202 HBUINT16 featureNameCount;
203 /* The number of entries in the feature name array. */
204 HBUINT16 reserved1; /* Reserved (set to zero). */
205 HBUINT32 reserved2; /* Reserved (set to zero). */
206 SortedUnsizedArrayOf<FeatureName>
207 namesZ; /* The feature name array. */
208 public:
209 DEFINE_SIZE_ARRAY (12, namesZ);
210};
211
212} /* namespace AAT */
213
214#endif /* HB_AAT_LAYOUT_FEAT_TABLE_HH */
215