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_zwj : 1;
54
55 static int cmp (const feature_map_t *a, const feature_map_t *b)
56 { return a->tag < b->tag ? -1 : a->tag > b->tag ? 1 : 0; }
57 };
58
59 struct lookup_map_t {
60 unsigned short index;
61 unsigned short auto_zwj : 1;
62 hb_mask_t mask;
63
64 static int cmp (const lookup_map_t *a, const lookup_map_t *b)
65 { return a->index < b->index ? -1 : a->index > b->index ? 1 : 0; }
66 };
67
68 typedef void (*pause_func_t) (const struct hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer);
69
70 struct stage_map_t {
71 unsigned int last_lookup; /* Cumulative */
72 pause_func_t pause_func;
73 };
74
75
76 hb_ot_map_t (void) { memset (this, 0, sizeof (*this)); }
77
78 inline hb_mask_t get_global_mask (void) const { return global_mask; }
79
80 inline hb_mask_t get_mask (hb_tag_t feature_tag, unsigned int *shift = NULL) const {
81 const feature_map_t *map = features.bsearch (&feature_tag);
82 if (shift) *shift = map ? map->shift : 0;
83 return map ? map->mask : 0;
84 }
85
86 inline bool needs_fallback (hb_tag_t feature_tag) const {
87 const feature_map_t *map = features.bsearch (&feature_tag);
88 return map ? map->needs_fallback : false;
89 }
90
91 inline hb_mask_t get_1_mask (hb_tag_t feature_tag) const {
92 const feature_map_t *map = features.bsearch (&feature_tag);
93 return map ? map->_1_mask : 0;
94 }
95
96 inline unsigned int get_feature_index (unsigned int table_index, hb_tag_t feature_tag) const {
97 const feature_map_t *map = features.bsearch (&feature_tag);
98 return map ? map->index[table_index] : HB_OT_LAYOUT_NO_FEATURE_INDEX;
99 }
100
101 inline unsigned int get_feature_stage (unsigned int table_index, hb_tag_t feature_tag) const {
102 const feature_map_t *map = features.bsearch (&feature_tag);
103 return map ? map->stage[table_index] : (unsigned int) -1;
104 }
105
106 inline void get_stage_lookups (unsigned int table_index, unsigned int stage,
107 const struct lookup_map_t **plookups, unsigned int *lookup_count) const {
108 if (unlikely (stage == (unsigned int) -1)) {
109 *plookups = NULL;
110 *lookup_count = 0;
111 return;
112 }
113 assert (stage <= stages[table_index].len);
114 unsigned int start = stage ? stages[table_index][stage - 1].last_lookup : 0;
115 unsigned int end = stage < stages[table_index].len ? stages[table_index][stage].last_lookup : lookups[table_index].len;
116 *plookups = &lookups[table_index][start];
117 *lookup_count = end - start;
118 }
119
120 HB_INTERNAL void collect_lookups (unsigned int table_index, hb_set_t *lookups) const;
121 template <typename Proxy>
122 HB_INTERNAL inline void apply (const Proxy &proxy,
123 const struct hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) const;
124 HB_INTERNAL void substitute (const struct hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) const;
125 HB_INTERNAL void position (const struct hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) const;
126
127 inline void finish (void) {
128 features.finish ();
129 for (unsigned int table_index = 0; table_index < 2; table_index++)
130 {
131 lookups[table_index].finish ();
132 stages[table_index].finish ();
133 }
134 }
135
136 public:
137 hb_tag_t chosen_script[2];
138 bool found_script[2];
139
140 private:
141
142 HB_INTERNAL void add_lookups (hb_face_t *face,
143 unsigned int table_index,
144 unsigned int feature_index,
145 hb_mask_t mask,
146 bool auto_zwj);
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_ZWJ = 0x0004u, /* Don't skip over ZWJ when matching. */
160 F_GLOBAL_SEARCH = 0x0008u /* If feature not found in LangSys, look for it in global feature list and pick one. */
161 };
162 HB_MARK_AS_FLAG_T (hb_ot_map_feature_flags_t);
163 /* Macro version for where const is desired. */
164 #define F_COMBINE(l,r) (hb_ot_map_feature_flags_t ((unsigned int) (l) | (unsigned int) (r)))
165
166
167 struct hb_ot_map_builder_t
168 {
169 public:
170
171 HB_INTERNAL hb_ot_map_builder_t (hb_face_t *face_,
172 const hb_segment_properties_t *props_);
173
174 HB_INTERNAL void add_feature (hb_tag_t tag, unsigned int value,
175 hb_ot_map_feature_flags_t flags);
176
177 inline void add_global_bool_feature (hb_tag_t tag)
178 { add_feature (tag, 1, F_GLOBAL); }
179
180 inline void add_gsub_pause (hb_ot_map_t::pause_func_t pause_func)
181 { add_pause (0, pause_func); }
182 inline void add_gpos_pause (hb_ot_map_t::pause_func_t pause_func)
183 { add_pause (1, pause_func); }
184
185 HB_INTERNAL void compile (struct hb_ot_map_t &m);
186
187 inline void finish (void) {
188 feature_infos.finish ();
189 for (unsigned int table_index = 0; table_index < 2; table_index++)
190 {
191 stages[table_index].finish ();
192 }
193 }
194
195 private:
196
197 struct feature_info_t {
198 hb_tag_t tag;
199 unsigned int seq; /* sequence#, used for stable sorting only */
200 unsigned int max_value;
201 hb_ot_map_feature_flags_t flags;
202 unsigned int default_value; /* for non-global features, what should the unset glyphs take */
203 unsigned int stage[2]; /* GSUB/GPOS */
204
205 static int cmp (const feature_info_t *a, const feature_info_t *b)
206 { return (a->tag != b->tag) ? (a->tag < b->tag ? -1 : 1) :
207 (a->seq < b->seq ? -1 : a->seq > b->seq ? 1 : 0); }
208 };
209
210 struct stage_info_t {
211 unsigned int index;
212 hb_ot_map_t::pause_func_t pause_func;
213 };
214
215 HB_INTERNAL void add_pause (unsigned int table_index, hb_ot_map_t::pause_func_t pause_func);
216
217 public:
218
219 hb_face_t *face;
220 hb_segment_properties_t props;
221
222 hb_tag_t chosen_script[2];
223 bool found_script[2];
224 unsigned int script_index[2], language_index[2];
225
226 private:
227
228 unsigned int current_stage[2]; /* GSUB/GPOS */
229 hb_prealloced_array_t<feature_info_t, 32> feature_infos;
230 hb_prealloced_array_t<stage_info_t, 8> stages[2]; /* GSUB/GPOS */
231 };
232
233
234
235 #endif /* HB_OT_MAP_PRIVATE_HH */