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_PRIVATE_HH
30 #define HB_OT_MAP_PRIVATE_HH
31
32 #include "hb-buffer-private.hh"
33
34
35 struct hb_ot_shape_plan_t;
36
37 static const hb_tag_t table_tags[2] = {HB_OT_TAG_GSUB, HB_OT_TAG_GPOS};
38
39 struct 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
82 hb_ot_map_t (void) { memset (this, 0, sizeof (*this)); }
83
84 inline hb_mask_t get_global_mask (void) const { return global_mask; }
85
86 inline hb_mask_t get_mask (hb_tag_t feature_tag, unsigned int *shift = nullptr) const {
87 const feature_map_t *map = features.bsearch (&feature_tag);
88 if (shift) *shift = map ? map->shift : 0;
89 return map ? map->mask : 0;
90 }
91
92 inline bool needs_fallback (hb_tag_t feature_tag) const {
93 const feature_map_t *map = features.bsearch (&feature_tag);
94 return map ? map->needs_fallback : false;
95 }
96
97 inline hb_mask_t get_1_mask (hb_tag_t feature_tag) const {
98 const feature_map_t *map = features.bsearch (&feature_tag);
99 return map ? map->_1_mask : 0;
100 }
101
102 inline unsigned int get_feature_index (unsigned int table_index, hb_tag_t feature_tag) const {
103 const feature_map_t *map = features.bsearch (&feature_tag);
104 return map ? map->index[table_index] : HB_OT_LAYOUT_NO_FEATURE_INDEX;
105 }
106
107 inline unsigned int get_feature_stage (unsigned int table_index, hb_tag_t feature_tag) const {
108 const feature_map_t *map = features.bsearch (&feature_tag);
109 return map ? map->stage[table_index] : (unsigned int) -1;
110 }
111
112 inline void get_stage_lookups (unsigned int table_index, unsigned int stage,
113 const struct lookup_map_t **plookups, unsigned int *lookup_count) const {
114 if (unlikely (stage == (unsigned int) -1)) {
115 *plookups = nullptr;
116 *lookup_count = 0;
117 return;
118 }
119 assert (stage <= stages[table_index].len);
120 unsigned int start = stage ? stages[table_index][stage - 1].last_lookup : 0;
121 unsigned int end = stage < stages[table_index].len ? stages[table_index][stage].last_lookup : lookups[table_index].len;
122 *plookups = end == start ? nullptr : &lookups[table_index][start];
123 *lookup_count = end - start;
124 }
125
126 HB_INTERNAL void collect_lookups (unsigned int table_index, hb_set_t *lookups) const;
127 template <typename Proxy>
128 HB_INTERNAL inline void apply (const Proxy &proxy,
129 const struct hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) const;
130 HB_INTERNAL void substitute (const struct hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) const;
131 HB_INTERNAL void position (const struct hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) const;
132
133 inline void finish (void) {
134 features.finish ();
135 for (unsigned int table_index = 0; table_index < 2; table_index++)
136 {
137 lookups[table_index].finish ();
138 stages[table_index].finish ();
139 }
140 }
141
142 public:
143 hb_tag_t chosen_script[2];
144 bool found_script[2];
145
146 private:
147
148 hb_mask_t global_mask;
149
150 hb_prealloced_array_t<feature_map_t, 8> features;
151 hb_prealloced_array_t<lookup_map_t, 32> lookups[2]; /* GSUB/GPOS */
152 hb_prealloced_array_t<stage_map_t, 4> stages[2]; /* GSUB/GPOS */
153 };
154
155 enum hb_ot_map_feature_flags_t {
156 F_NONE = 0x0000u,
157 F_GLOBAL = 0x0001u, /* Feature applies to all characters; results in no mask allocated for it. */
158 F_HAS_FALLBACK = 0x0002u, /* Has fallback implementation, so include mask bit even if feature not found. */
159 F_MANUAL_ZWNJ = 0x0004u, /* Don't skip over ZWNJ when matching **context**. */
160 F_MANUAL_ZWJ = 0x0008u, /* Don't skip over ZWJ when matching **input**. */
161 F_GLOBAL_SEARCH = 0x0010u /* If feature not found in LangSys, look for it in global feature list and pick one. */
162 };
163 HB_MARK_AS_FLAG_T (hb_ot_map_feature_flags_t);
164 /* Macro version for where const is desired. */
165 #define F_COMBINE(l,r) (hb_ot_map_feature_flags_t ((unsigned int) (l) | (unsigned int) (r)))
166
167
168 struct hb_ot_map_builder_t
169 {
170 public:
171
172 HB_INTERNAL hb_ot_map_builder_t (hb_face_t *face_,
173 const hb_segment_properties_t *props_);
174
175 HB_INTERNAL void add_feature (hb_tag_t tag, unsigned int value,
176 hb_ot_map_feature_flags_t flags);
177
178 inline void add_global_bool_feature (hb_tag_t tag)
179 { add_feature (tag, 1, F_GLOBAL); }
180
181 inline void add_gsub_pause (hb_ot_map_t::pause_func_t pause_func)
182 { add_pause (0, pause_func); }
183 inline void add_gpos_pause (hb_ot_map_t::pause_func_t pause_func)
184 { add_pause (1, pause_func); }
185
186 HB_INTERNAL void compile (hb_ot_map_t &m,
187 const int *coords,
188 unsigned int num_coords);
189
190 inline void finish (void) {
191 feature_infos.finish ();
192 for (unsigned int table_index = 0; table_index < 2; table_index++)
193 {
194 stages[table_index].finish ();
195 }
196 }
197
198 private:
199
200 HB_INTERNAL void add_lookups (hb_ot_map_t &m,
201 hb_face_t *face,
202 unsigned int table_index,
203 unsigned int feature_index,
204 unsigned int variations_index,
205 hb_mask_t mask,
206 bool auto_zwnj = true,
207 bool auto_zwj = true);
208
209 struct feature_info_t {
210 hb_tag_t tag;
211 unsigned int seq; /* sequence#, used for stable sorting only */
212 unsigned int max_value;
213 hb_ot_map_feature_flags_t flags;
214 unsigned int default_value; /* for non-global features, what should the unset glyphs take */
215 unsigned int stage[2]; /* GSUB/GPOS */
216
217 static int cmp (const void *pa, const void *pb)
218 {
219 const feature_info_t *a = (const feature_info_t *) pa;
220 const feature_info_t *b = (const feature_info_t *) pb;
221 return (a->tag != b->tag) ? (a->tag < b->tag ? -1 : 1) :
222 (a->seq < b->seq ? -1 : a->seq > b->seq ? 1 : 0);
223 }
224 };
225
226 struct stage_info_t {
227 unsigned int index;
228 hb_ot_map_t::pause_func_t pause_func;
229 };
230
231 HB_INTERNAL void add_pause (unsigned int table_index, hb_ot_map_t::pause_func_t pause_func);
232
233 public:
234
235 hb_face_t *face;
236 hb_segment_properties_t props;
237
238 hb_tag_t chosen_script[2];
239 bool found_script[2];
240 unsigned int script_index[2], language_index[2];
241
242 private:
243
244 unsigned int current_stage[2]; /* GSUB/GPOS */
245 hb_prealloced_array_t<feature_info_t, 32> feature_infos;
246 hb_prealloced_array_t<stage_info_t, 8> stages[2]; /* GSUB/GPOS */
247 };
248
249
250
251 #endif /* HB_OT_MAP_PRIVATE_HH */