1/*
2 * Copyright © 2009,2010 Red Hat, Inc.
3 * Copyright © 2010,2011,2012,2013 Google, Inc.
4 *
5 * This is part of HarfBuzz, a text shaping library.
6 *
7 * Permission is hereby granted, without written agreement and without
8 * license or royalty fees, to use, copy, modify, and distribute this
9 * software and its documentation for any purpose, provided that the
10 * above copyright notice and the following two paragraphs appear in
11 * all copies of this software.
12 *
13 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
14 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
15 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
16 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
17 * DAMAGE.
18 *
19 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
20 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
21 * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
22 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
23 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
24 *
25 * Red Hat Author(s): Behdad Esfahbod
26 * Google Author(s): Behdad Esfahbod
27 */
28
29#ifndef HB_OT_MAP_HH
30#define HB_OT_MAP_HH
31
32#include "hb-buffer.hh"
33
34
35struct hb_ot_shape_plan_t;
36
37static const hb_tag_t table_tags[2] = {HB_OT_TAG_GSUB, HB_OT_TAG_GPOS};
38
39struct hb_ot_map_t
40{
41 friend struct hb_ot_map_builder_t;
42
43 public:
44
45 struct feature_map_t {
46 hb_tag_t tag; /* should be first for our bsearch to work */
47 unsigned int index[2]; /* GSUB/GPOS */
48 unsigned int stage[2]; /* GSUB/GPOS */
49 unsigned int shift;
50 hb_mask_t mask;
51 hb_mask_t _1_mask; /* mask for value=1, for quick access */
52 unsigned int needs_fallback : 1;
53 unsigned int auto_zwnj : 1;
54 unsigned int auto_zwj : 1;
55
56 inline int cmp (const hb_tag_t *tag_) const
57 { return *tag_ < tag ? -1 : *tag_ > tag ? 1 : 0; }
58 };
59
60 struct lookup_map_t {
61 unsigned short index;
62 unsigned short auto_zwnj : 1;
63 unsigned short auto_zwj : 1;
64 hb_mask_t mask;
65
66 static int cmp (const void *pa, const void *pb)
67 {
68 const lookup_map_t *a = (const lookup_map_t *) pa;
69 const lookup_map_t *b = (const lookup_map_t *) pb;
70 return a->index < b->index ? -1 : a->index > b->index ? 1 : 0;
71 }
72 };
73
74 typedef void (*pause_func_t) (const struct hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer);
75
76 struct stage_map_t {
77 unsigned int last_lookup; /* Cumulative */
78 pause_func_t pause_func;
79 };
80
81 inline void init (void)
82 {
83 memset (this, 0, sizeof (*this));
84
85 features.init ();
86 for (unsigned int table_index = 0; table_index < 2; table_index++)
87 {
88 lookups[table_index].init ();
89 stages[table_index].init ();
90 }
91 }
92 inline void fini (void)
93 {
94 features.fini ();
95 for (unsigned int table_index = 0; table_index < 2; table_index++)
96 {
97 lookups[table_index].fini ();
98 stages[table_index].fini ();
99 }
100 }
101
102 inline hb_mask_t get_global_mask (void) const { return global_mask; }
103
104 inline hb_mask_t get_mask (hb_tag_t feature_tag, unsigned int *shift = nullptr) const {
105 const feature_map_t *map = features.bsearch (feature_tag);
106 if (shift) *shift = map ? map->shift : 0;
107 return map ? map->mask : 0;
108 }
109
110 inline bool needs_fallback (hb_tag_t feature_tag) const {
111 const feature_map_t *map = features.bsearch (feature_tag);
112 return map ? map->needs_fallback : false;
113 }
114
115 inline hb_mask_t get_1_mask (hb_tag_t feature_tag) const {
116 const feature_map_t *map = features.bsearch (feature_tag);
117 return map ? map->_1_mask : 0;
118 }
119
120 inline unsigned int get_feature_index (unsigned int table_index, hb_tag_t feature_tag) const {
121 const feature_map_t *map = features.bsearch (feature_tag);
122 return map ? map->index[table_index] : HB_OT_LAYOUT_NO_FEATURE_INDEX;
123 }
124
125 inline unsigned int get_feature_stage (unsigned int table_index, hb_tag_t feature_tag) const {
126 const feature_map_t *map = features.bsearch (feature_tag);
127 return map ? map->stage[table_index] : (unsigned int) -1;
128 }
129
130 inline void get_stage_lookups (unsigned int table_index, unsigned int stage,
131 const struct lookup_map_t **plookups, unsigned int *lookup_count) const {
132 if (unlikely (stage == (unsigned int) -1)) {
133 *plookups = nullptr;
134 *lookup_count = 0;
135 return;
136 }
137 assert (stage <= stages[table_index].len);
138 unsigned int start = stage ? stages[table_index][stage - 1].last_lookup : 0;
139 unsigned int end = stage < stages[table_index].len ? stages[table_index][stage].last_lookup : lookups[table_index].len;
140 *plookups = end == start ? nullptr : &lookups[table_index][start];
141 *lookup_count = end - start;
142 }
143
144 HB_INTERNAL void collect_lookups (unsigned int table_index, hb_set_t *lookups) const;
145 template <typename Proxy>
146 HB_INTERNAL inline void apply (const Proxy &proxy,
147 const struct hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) const;
148 HB_INTERNAL void substitute (const struct hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) const;
149 HB_INTERNAL void position (const struct hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) const;
150
151 public:
152 hb_tag_t chosen_script[2];
153 bool found_script[2];
154
155 private:
156
157 hb_mask_t global_mask;
158
159 hb_vector_t<feature_map_t, 8> features;
160 hb_vector_t<lookup_map_t, 32> lookups[2]; /* GSUB/GPOS */
161 hb_vector_t<stage_map_t, 4> stages[2]; /* GSUB/GPOS */
162};
163
164enum hb_ot_map_feature_flags_t {
165 F_NONE = 0x0000u,
166 F_GLOBAL = 0x0001u, /* Feature applies to all characters; results in no mask allocated for it. */
167 F_HAS_FALLBACK = 0x0002u, /* Has fallback implementation, so include mask bit even if feature not found. */
168 F_MANUAL_ZWNJ = 0x0004u, /* Don't skip over ZWNJ when matching **context**. */
169 F_MANUAL_ZWJ = 0x0008u, /* Don't skip over ZWJ when matching **input**. */
170 F_GLOBAL_SEARCH = 0x0010u /* If feature not found in LangSys, look for it in global feature list and pick one. */
171};
172HB_MARK_AS_FLAG_T (hb_ot_map_feature_flags_t);
173/* Macro version for where const is desired. */
174#define F_COMBINE(l,r) (hb_ot_map_feature_flags_t ((unsigned int) (l) | (unsigned int) (r)))
175
176
177struct hb_ot_map_builder_t
178{
179 public:
180
181 HB_INTERNAL hb_ot_map_builder_t (hb_face_t *face_,
182 const hb_segment_properties_t *props_);
183
184 HB_INTERNAL ~hb_ot_map_builder_t (void);
185
186 HB_INTERNAL void add_feature (hb_tag_t tag, unsigned int value,
187 hb_ot_map_feature_flags_t flags);
188
189 inline void add_global_bool_feature (hb_tag_t tag)
190 { add_feature (tag, 1, F_GLOBAL); }
191
192 inline void add_gsub_pause (hb_ot_map_t::pause_func_t pause_func)
193 { add_pause (0, pause_func); }
194 inline void add_gpos_pause (hb_ot_map_t::pause_func_t pause_func)
195 { add_pause (1, pause_func); }
196
197 HB_INTERNAL void compile (hb_ot_map_t &m,
198 const int *coords,
199 unsigned int num_coords);
200
201 private:
202
203 HB_INTERNAL void add_lookups (hb_ot_map_t &m,
204 unsigned int table_index,
205 unsigned int feature_index,
206 unsigned int variations_index,
207 hb_mask_t mask,
208 bool auto_zwnj = true,
209 bool auto_zwj = true);
210
211 struct feature_info_t {
212 hb_tag_t tag;
213 unsigned int seq; /* sequence#, used for stable sorting only */
214 unsigned int max_value;
215 hb_ot_map_feature_flags_t flags;
216 unsigned int default_value; /* for non-global features, what should the unset glyphs take */
217 unsigned int stage[2]; /* GSUB/GPOS */
218
219 static int cmp (const void *pa, const void *pb)
220 {
221 const feature_info_t *a = (const feature_info_t *) pa;
222 const feature_info_t *b = (const feature_info_t *) pb;
223 return (a->tag != b->tag) ? (a->tag < b->tag ? -1 : 1) :
224 (a->seq < b->seq ? -1 : a->seq > b->seq ? 1 : 0);
225 }
226 };
227
228 struct stage_info_t {
229 unsigned int index;
230 hb_ot_map_t::pause_func_t pause_func;
231 };
232
233 HB_INTERNAL void add_pause (unsigned int table_index, hb_ot_map_t::pause_func_t pause_func);
234
235 public:
236
237 hb_face_t *face;
238 hb_segment_properties_t props;
239
240 hb_tag_t chosen_script[2];
241 bool found_script[2];
242 unsigned int script_index[2], language_index[2];
243
244 private:
245
246 unsigned int current_stage[2]; /* GSUB/GPOS */
247 hb_vector_t<feature_info_t, 32> feature_infos;
248 hb_vector_t<stage_info_t, 8> stages[2]; /* GSUB/GPOS */
249};
250
251
252
253#endif /* HB_OT_MAP_HH */
254