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
35#define HB_OT_MAP_MAX_BITS 8u
36#define HB_OT_MAP_MAX_VALUE ((1u << HB_OT_MAP_MAX_BITS) - 1u)
37
38struct hb_ot_shape_plan_t;
39
40static const hb_tag_t table_tags[2] = {HB_OT_TAG_GSUB, HB_OT_TAG_GPOS};
41
42struct hb_ot_map_t
43{
44 friend struct hb_ot_map_builder_t;
45
46 public:
47
48 struct feature_map_t {
49 hb_tag_t tag; /* should be first for our bsearch to work */
50 unsigned int index[2]; /* GSUB/GPOS */
51 unsigned int stage[2]; /* GSUB/GPOS */
52 unsigned int shift;
53 hb_mask_t mask;
54 hb_mask_t _1_mask; /* mask for value=1, for quick access */
55 unsigned int needs_fallback : 1;
56 unsigned int auto_zwnj : 1;
57 unsigned int auto_zwj : 1;
58 unsigned int random : 1;
59 unsigned int per_syllable : 1;
60
61 int cmp (const hb_tag_t tag_) const
62 { return tag_ < tag ? -1 : tag_ > tag ? 1 : 0; }
63
64 HB_INTERNAL static int cmp (const void *pa, const void *pb)
65 {
66 const feature_map_t *a = (const feature_map_t *) pa;
67 const feature_map_t *b = (const feature_map_t *) pb;
68 return a->tag < b->tag ? -1 : a->tag > b->tag ? 1 : 0;
69 }
70 };
71
72 struct lookup_map_t {
73 unsigned short index;
74 unsigned short auto_zwnj : 1;
75 unsigned short auto_zwj : 1;
76 unsigned short random : 1;
77 unsigned short per_syllable : 1;
78 hb_mask_t mask;
79 hb_tag_t feature_tag;
80
81 HB_INTERNAL static int cmp (const void *pa, const void *pb)
82 {
83 const lookup_map_t *a = (const lookup_map_t *) pa;
84 const lookup_map_t *b = (const lookup_map_t *) pb;
85 return a->index < b->index ? -1 : a->index > b->index ? 1 : 0;
86 }
87 };
88
89 /* Pause functions return true if new glyph indices might have been
90 * added to the buffer. This is used to update buffer digest. */
91 typedef bool (*pause_func_t) (const struct hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer);
92
93 struct stage_map_t {
94 unsigned int last_lookup; /* Cumulative */
95 pause_func_t pause_func;
96 };
97
98 void init ()
99 {
100 hb_memset (this, 0, sizeof (*this));
101
102 features.init0 ();
103 for (unsigned int table_index = 0; table_index < 2; table_index++)
104 {
105 lookups[table_index].init0 ();
106 stages[table_index].init0 ();
107 }
108 }
109 void fini ()
110 {
111 features.fini ();
112 for (unsigned int table_index = 0; table_index < 2; table_index++)
113 {
114 lookups[table_index].fini ();
115 stages[table_index].fini ();
116 }
117 }
118
119 hb_mask_t get_global_mask () const { return global_mask; }
120
121 hb_mask_t get_mask (hb_tag_t feature_tag, unsigned int *shift = nullptr) const
122 {
123 const feature_map_t *map = features.bsearch (feature_tag);
124 if (shift) *shift = map ? map->shift : 0;
125 return map ? map->mask : 0;
126 }
127
128 bool needs_fallback (hb_tag_t feature_tag) const
129 {
130 const feature_map_t *map = features.bsearch (feature_tag);
131 return map ? map->needs_fallback : false;
132 }
133
134 hb_mask_t get_1_mask (hb_tag_t feature_tag) const
135 {
136 const feature_map_t *map = features.bsearch (feature_tag);
137 return map ? map->_1_mask : 0;
138 }
139
140 unsigned int get_feature_index (unsigned int table_index, hb_tag_t feature_tag) const
141 {
142 const feature_map_t *map = features.bsearch (feature_tag);
143 return map ? map->index[table_index] : HB_OT_LAYOUT_NO_FEATURE_INDEX;
144 }
145
146 unsigned int get_feature_stage (unsigned int table_index, hb_tag_t feature_tag) const
147 {
148 const feature_map_t *map = features.bsearch (feature_tag);
149 return map ? map->stage[table_index] : UINT_MAX;
150 }
151
152 hb_array_t<const hb_ot_map_t::lookup_map_t>
153 get_stage_lookups (unsigned int table_index, unsigned int stage) const
154 {
155 if (unlikely (stage > stages[table_index].length))
156 return hb_array<const hb_ot_map_t::lookup_map_t> (nullptr, 0);
157
158 unsigned int start = stage ? stages[table_index][stage - 1].last_lookup : 0;
159 unsigned int end = stage < stages[table_index].length ? stages[table_index][stage].last_lookup : lookups[table_index].length;
160 return lookups[table_index].as_array ().sub_array (start, end - start);
161 }
162
163 HB_INTERNAL void collect_lookups (unsigned int table_index, hb_set_t *lookups) const;
164 template <typename Proxy>
165 HB_INTERNAL void apply (const Proxy &proxy,
166 const struct hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) const;
167 HB_INTERNAL void substitute (const struct hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) const;
168 HB_INTERNAL void position (const struct hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) const;
169
170 public:
171 hb_tag_t chosen_script[2];
172 bool found_script[2];
173
174 private:
175
176 hb_mask_t global_mask = 0;
177
178 hb_sorted_vector_t<feature_map_t> features;
179 hb_vector_t<lookup_map_t> lookups[2]; /* GSUB/GPOS */
180 hb_vector_t<stage_map_t> stages[2]; /* GSUB/GPOS */
181};
182
183enum hb_ot_map_feature_flags_t
184{
185 F_NONE = 0x0000u,
186 F_GLOBAL = 0x0001u, /* Feature applies to all characters; results in no mask allocated for it. */
187 F_HAS_FALLBACK = 0x0002u, /* Has fallback implementation, so include mask bit even if feature not found. */
188 F_MANUAL_ZWNJ = 0x0004u, /* Don't skip over ZWNJ when matching **context**. */
189 F_MANUAL_ZWJ = 0x0008u, /* Don't skip over ZWJ when matching **input**. */
190 F_MANUAL_JOINERS = F_MANUAL_ZWNJ | F_MANUAL_ZWJ,
191 F_GLOBAL_MANUAL_JOINERS= F_GLOBAL | F_MANUAL_JOINERS,
192 F_GLOBAL_HAS_FALLBACK = F_GLOBAL | F_HAS_FALLBACK,
193 F_GLOBAL_SEARCH = 0x0010u, /* If feature not found in LangSys, look for it in global feature list and pick one. */
194 F_RANDOM = 0x0020u, /* Randomly select a glyph from an AlternateSubstFormat1 subtable. */
195 F_PER_SYLLABLE = 0x0040u /* Contain lookup application to within syllable. */
196};
197HB_MARK_AS_FLAG_T (hb_ot_map_feature_flags_t);
198
199
200struct hb_ot_map_feature_t
201{
202 hb_tag_t tag;
203 hb_ot_map_feature_flags_t flags;
204};
205
206struct hb_ot_shape_plan_key_t;
207
208struct hb_ot_map_builder_t
209{
210 public:
211
212 HB_INTERNAL hb_ot_map_builder_t (hb_face_t *face_,
213 const hb_segment_properties_t &props_);
214
215 HB_INTERNAL ~hb_ot_map_builder_t ();
216
217 HB_INTERNAL void add_feature (hb_tag_t tag,
218 hb_ot_map_feature_flags_t flags=F_NONE,
219 unsigned int value=1);
220
221 HB_INTERNAL bool has_feature (hb_tag_t tag);
222
223 void add_feature (const hb_ot_map_feature_t &feat)
224 { add_feature (feat.tag, feat.flags); }
225
226 void enable_feature (hb_tag_t tag,
227 hb_ot_map_feature_flags_t flags=F_NONE,
228 unsigned int value=1)
229 { add_feature (tag, F_GLOBAL | flags, value); }
230
231 void disable_feature (hb_tag_t tag)
232 { add_feature (tag, F_GLOBAL, 0); }
233
234 void add_gsub_pause (hb_ot_map_t::pause_func_t pause_func)
235 { add_pause (0, pause_func); }
236 void add_gpos_pause (hb_ot_map_t::pause_func_t pause_func)
237 { add_pause (1, pause_func); }
238
239 HB_INTERNAL void compile (hb_ot_map_t &m,
240 const hb_ot_shape_plan_key_t &key);
241
242 private:
243
244 HB_INTERNAL void add_lookups (hb_ot_map_t &m,
245 unsigned int table_index,
246 unsigned int feature_index,
247 unsigned int variations_index,
248 hb_mask_t mask,
249 bool auto_zwnj = true,
250 bool auto_zwj = true,
251 bool random = false,
252 bool per_syllable = false,
253 hb_tag_t feature_tag = HB_TAG(' ',' ',' ',' '));
254
255 struct feature_info_t {
256 hb_tag_t tag;
257 unsigned int seq; /* sequence#, used for stable sorting only */
258 unsigned int max_value;
259 hb_ot_map_feature_flags_t flags;
260 unsigned int default_value; /* for non-global features, what should the unset glyphs take */
261 unsigned int stage[2]; /* GSUB/GPOS */
262
263 HB_INTERNAL static int cmp (const void *pa, const void *pb)
264 {
265 const feature_info_t *a = (const feature_info_t *) pa;
266 const feature_info_t *b = (const feature_info_t *) pb;
267 return (a->tag != b->tag) ? (a->tag < b->tag ? -1 : 1) :
268 (a->seq < b->seq ? -1 : a->seq > b->seq ? 1 : 0);
269 }
270 };
271
272 struct stage_info_t {
273 unsigned int index;
274 hb_ot_map_t::pause_func_t pause_func;
275 };
276
277 HB_INTERNAL void add_pause (unsigned int table_index, hb_ot_map_t::pause_func_t pause_func);
278
279 public:
280
281 hb_face_t *face;
282 hb_segment_properties_t props;
283 bool is_simple;
284
285 hb_tag_t chosen_script[2];
286 bool found_script[2];
287 unsigned int script_index[2], language_index[2];
288
289 private:
290
291 unsigned int current_stage[2]; /* GSUB/GPOS */
292 hb_vector_t<feature_info_t> feature_infos;
293 hb_vector_t<stage_info_t> stages[2]; /* GSUB/GPOS */
294};
295
296
297
298#endif /* HB_OT_MAP_HH */
299