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