hb-ot-map-private.hh revision 2265be0a620bc76ab65f12fedde67791beb51314 
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
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_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  HB_INTERNAL void substitute (const struct hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) const;
122  HB_INTERNAL void position (const struct hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) const;
123
124  inline void finish (void) {
125    features.finish ();
126    for (unsigned int table_index = 0; table_index < 2; table_index++)
127    {
128      lookups[table_index].finish ();
129      stages[table_index].finish ();
130    }
131  }
132
133  public:
134  hb_tag_t chosen_script[2];
135  bool found_script[2];
136
137  private:
138
139  HB_INTERNAL void add_lookups (hb_face_t    *face,
140				unsigned int  table_index,
141				unsigned int  feature_index,
142				hb_mask_t     mask,
143				bool          auto_zwj);
144
145  hb_mask_t global_mask;
146
147  hb_prealloced_array_t<feature_map_t, 8> features;
148  hb_prealloced_array_t<lookup_map_t, 32> lookups[2]; /* GSUB/GPOS */
149  hb_prealloced_array_t<stage_map_t, 1> stages[2]; /* GSUB/GPOS */
150};
151
152enum hb_ot_map_feature_flags_t {
153  F_NONE		= 0x0000,
154  F_GLOBAL		= 0x0001,
155  F_HAS_FALLBACK	= 0x0002,
156  F_MANUAL_ZWJ		= 0x0004
157};
158/* Macro version for where const is desired. */
159#define F_COMBINE(l,r) (hb_ot_map_feature_flags_t ((unsigned int) (l) | (unsigned int) (r)))
160inline hb_ot_map_feature_flags_t
161operator | (hb_ot_map_feature_flags_t l, hb_ot_map_feature_flags_t r)
162{ return hb_ot_map_feature_flags_t ((unsigned int) l | (unsigned int) r); }
163inline hb_ot_map_feature_flags_t
164operator & (hb_ot_map_feature_flags_t l, hb_ot_map_feature_flags_t r)
165{ return hb_ot_map_feature_flags_t ((unsigned int) l & (unsigned int) r); }
166inline hb_ot_map_feature_flags_t
167operator ~ (hb_ot_map_feature_flags_t r)
168{ return hb_ot_map_feature_flags_t (~(unsigned int) r); }
169inline hb_ot_map_feature_flags_t&
170operator |= (hb_ot_map_feature_flags_t &l, hb_ot_map_feature_flags_t r)
171{ l = l | r; return l; }
172inline hb_ot_map_feature_flags_t&
173operator &= (hb_ot_map_feature_flags_t& l, hb_ot_map_feature_flags_t r)
174{ l = l & r; return l; }
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 void add_feature (hb_tag_t tag, unsigned int value,
185				hb_ot_map_feature_flags_t flags);
186
187  inline void add_global_bool_feature (hb_tag_t tag)
188  { add_feature (tag, 1, F_GLOBAL); }
189
190  inline void add_gsub_pause (hb_ot_map_t::pause_func_t pause_func)
191  { add_pause (0, pause_func); }
192  inline void add_gpos_pause (hb_ot_map_t::pause_func_t pause_func)
193  { add_pause (1, pause_func); }
194
195  HB_INTERNAL void compile (struct hb_ot_map_t &m);
196
197  inline void finish (void) {
198    feature_infos.finish ();
199    for (unsigned int table_index = 0; table_index < 2; table_index++)
200    {
201      stages[table_index].finish ();
202    }
203  }
204
205  private:
206
207  struct feature_info_t {
208    hb_tag_t tag;
209    unsigned int seq; /* sequence#, used for stable sorting only */
210    unsigned int max_value;
211    hb_ot_map_feature_flags_t flags;
212    unsigned int default_value; /* for non-global features, what should the unset glyphs take */
213    unsigned int stage[2]; /* GSUB/GPOS */
214
215    static int cmp (const feature_info_t *a, const feature_info_t *b)
216    { return (a->tag != b->tag) ?  (a->tag < b->tag ? -1 : 1) : (a->seq < b->seq ? -1 : 1); }
217  };
218
219  struct stage_info_t {
220    unsigned int index;
221    hb_ot_map_t::pause_func_t pause_func;
222  };
223
224  HB_INTERNAL void add_pause (unsigned int table_index, hb_ot_map_t::pause_func_t pause_func);
225
226  public:
227
228  hb_face_t *face;
229  hb_segment_properties_t props;
230
231  hb_tag_t chosen_script[2];
232  bool found_script[2];
233  unsigned int script_index[2], language_index[2];
234
235  private:
236
237  unsigned int current_stage[2]; /* GSUB/GPOS */
238  hb_prealloced_array_t<feature_info_t,16> feature_infos;
239  hb_prealloced_array_t<stage_info_t, 1> stages[2]; /* GSUB/GPOS */
240};
241
242
243
244#endif /* HB_OT_MAP_PRIVATE_HH */
245