1/*
2 * Copyright © 2009,2010  Red Hat, Inc.
3 * Copyright © 2010,2011,2012  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#include "hb-ot-layout-private.hh"
35
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 pause_map_t {
71    unsigned int num_lookups; /* Cumulative */
72    pause_func_t callback;
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 <= pauses[table_index].len);
114    unsigned int start = stage ? pauses[table_index][stage - 1].num_lookups : 0;
115    unsigned int end   = stage < pauses[table_index].len ? pauses[table_index][stage].num_lookups : 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    lookups[0].finish ();
127    lookups[1].finish ();
128    pauses[0].finish ();
129    pauses[1].finish ();
130  }
131
132  public:
133  hb_tag_t chosen_script[2];
134  bool found_script[2];
135
136  private:
137
138  HB_INTERNAL void add_lookups (hb_face_t    *face,
139				unsigned int  table_index,
140				unsigned int  feature_index,
141				hb_mask_t     mask,
142				bool          auto_zwj);
143
144  hb_mask_t global_mask;
145
146  hb_prealloced_array_t<feature_map_t, 8> features;
147  hb_prealloced_array_t<lookup_map_t, 32> lookups[2]; /* GSUB/GPOS */
148  hb_prealloced_array_t<pause_map_t, 1> pauses[2]; /* GSUB/GPOS */
149};
150
151enum hb_ot_map_feature_flags_t {
152  F_NONE		= 0x0000,
153  F_GLOBAL		= 0x0001,
154  F_HAS_FALLBACK	= 0x0002,
155  F_MANUAL_ZWJ		= 0x0004
156};
157/* Macro version for where const is desired. */
158#define F_COMBINE(l,r) (hb_ot_map_feature_flags_t ((unsigned int) (l) | (unsigned int) (r)))
159inline hb_ot_map_feature_flags_t
160operator | (hb_ot_map_feature_flags_t l, hb_ot_map_feature_flags_t r)
161{ return hb_ot_map_feature_flags_t ((unsigned int) l | (unsigned int) r); }
162inline hb_ot_map_feature_flags_t
163operator & (hb_ot_map_feature_flags_t l, hb_ot_map_feature_flags_t r)
164{ return hb_ot_map_feature_flags_t ((unsigned int) l & (unsigned int) r); }
165inline hb_ot_map_feature_flags_t
166operator ~ (hb_ot_map_feature_flags_t r)
167{ return hb_ot_map_feature_flags_t (~(unsigned int) r); }
168inline hb_ot_map_feature_flags_t&
169operator |= (hb_ot_map_feature_flags_t &l, hb_ot_map_feature_flags_t r)
170{ l = l | r; return l; }
171inline hb_ot_map_feature_flags_t&
172operator &= (hb_ot_map_feature_flags_t& l, hb_ot_map_feature_flags_t r)
173{ l = l & r; return l; }
174
175
176struct hb_ot_map_builder_t
177{
178  public:
179
180  HB_INTERNAL hb_ot_map_builder_t (hb_face_t *face_,
181				   const hb_segment_properties_t *props_);
182
183  HB_INTERNAL void add_feature (hb_tag_t tag, unsigned int value,
184				hb_ot_map_feature_flags_t flags);
185
186  inline void add_global_bool_feature (hb_tag_t tag)
187  { add_feature (tag, 1, F_GLOBAL); }
188
189  inline void add_gsub_pause (hb_ot_map_t::pause_func_t pause_func)
190  { add_pause (0, pause_func); }
191  inline void add_gpos_pause (hb_ot_map_t::pause_func_t pause_func)
192  { add_pause (1, pause_func); }
193
194  HB_INTERNAL void compile (struct hb_ot_map_t &m);
195
196  inline void finish (void) {
197    feature_infos.finish ();
198    pauses[0].finish ();
199    pauses[1].finish ();
200  }
201
202  private:
203
204  struct feature_info_t {
205    hb_tag_t tag;
206    unsigned int seq; /* sequence#, used for stable sorting only */
207    unsigned int max_value;
208    hb_ot_map_feature_flags_t flags;
209    unsigned int default_value; /* for non-global features, what should the unset glyphs take */
210    unsigned int stage[2]; /* GSUB/GPOS */
211
212    static int cmp (const feature_info_t *a, const feature_info_t *b)
213    { return (a->tag != b->tag) ?  (a->tag < b->tag ? -1 : 1) : (a->seq < b->seq ? -1 : 1); }
214  };
215
216  struct pause_info_t {
217    unsigned int stage;
218    hb_ot_map_t::pause_func_t callback;
219  };
220
221  HB_INTERNAL void add_pause (unsigned int table_index, hb_ot_map_t::pause_func_t pause_func);
222
223  public:
224
225  hb_face_t *face;
226  hb_segment_properties_t props;
227
228  hb_tag_t chosen_script[2];
229  bool found_script[2];
230  unsigned int script_index[2], language_index[2];
231
232  private:
233
234  unsigned int current_stage[2]; /* GSUB/GPOS */
235  hb_prealloced_array_t<feature_info_t,16> feature_infos;
236  hb_prealloced_array_t<pause_info_t, 1> pauses[2]; /* GSUB/GPOS */
237};
238
239
240
241#endif /* HB_OT_MAP_PRIVATE_HH */
242