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  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_mask_t global_mask;
143
144  hb_prealloced_array_t<feature_map_t, 8> features;
145  hb_prealloced_array_t<lookup_map_t, 32> lookups[2]; /* GSUB/GPOS */
146  hb_prealloced_array_t<stage_map_t, 4> stages[2]; /* GSUB/GPOS */
147};
148
149enum hb_ot_map_feature_flags_t {
150  F_NONE                = 0x0000u,
151  F_GLOBAL              = 0x0001u, /* Feature applies to all characters; results in no mask allocated for it. */
152  F_HAS_FALLBACK        = 0x0002u, /* Has fallback implementation, so include mask bit even if feature not found. */
153  F_MANUAL_ZWJ          = 0x0004u, /* Don't skip over ZWJ when matching. */
154  F_GLOBAL_SEARCH       = 0x0008u  /* If feature not found in LangSys, look for it in global feature list and pick one. */
155};
156HB_MARK_AS_FLAG_T (hb_ot_map_feature_flags_t);
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)))
159
160
161struct hb_ot_map_builder_t
162{
163  public:
164
165  HB_INTERNAL hb_ot_map_builder_t (hb_face_t *face_,
166                                   const hb_segment_properties_t *props_);
167
168  HB_INTERNAL void add_feature (hb_tag_t tag, unsigned int value,
169                                hb_ot_map_feature_flags_t flags);
170
171  inline void add_global_bool_feature (hb_tag_t tag)
172  { add_feature (tag, 1, F_GLOBAL); }
173
174  inline void add_gsub_pause (hb_ot_map_t::pause_func_t pause_func)
175  { add_pause (0, pause_func); }
176  inline void add_gpos_pause (hb_ot_map_t::pause_func_t pause_func)
177  { add_pause (1, pause_func); }
178
179  HB_INTERNAL void compile (hb_ot_map_t  &m,
180                            const int    *coords,
181                            unsigned int  num_coords);
182
183  inline void finish (void) {
184    feature_infos.finish ();
185    for (unsigned int table_index = 0; table_index < 2; table_index++)
186    {
187      stages[table_index].finish ();
188    }
189  }
190
191  private:
192
193  HB_INTERNAL void add_lookups (hb_ot_map_t  &m,
194                                hb_face_t    *face,
195                                unsigned int  table_index,
196                                unsigned int  feature_index,
197                                unsigned int  variations_index,
198                                hb_mask_t     mask,
199                                bool          auto_zwj);
200
201  struct feature_info_t {
202    hb_tag_t tag;
203    unsigned int seq; /* sequence#, used for stable sorting only */
204    unsigned int max_value;
205    hb_ot_map_feature_flags_t flags;
206    unsigned int default_value; /* for non-global features, what should the unset glyphs take */
207    unsigned int stage[2]; /* GSUB/GPOS */
208
209    static int cmp (const feature_info_t *a, const feature_info_t *b)
210    { return (a->tag != b->tag) ?  (a->tag < b->tag ? -1 : 1) :
211             (a->seq < b->seq ? -1 : a->seq > b->seq ? 1 : 0); }
212  };
213
214  struct stage_info_t {
215    unsigned int index;
216    hb_ot_map_t::pause_func_t pause_func;
217  };
218
219  HB_INTERNAL void add_pause (unsigned int table_index, hb_ot_map_t::pause_func_t pause_func);
220
221  public:
222
223  hb_face_t *face;
224  hb_segment_properties_t props;
225
226  hb_tag_t chosen_script[2];
227  bool found_script[2];
228  unsigned int script_index[2], language_index[2];
229
230  private:
231
232  unsigned int current_stage[2]; /* GSUB/GPOS */
233  hb_prealloced_array_t<feature_info_t, 32> feature_infos;
234  hb_prealloced_array_t<stage_info_t, 8> stages[2]; /* GSUB/GPOS */
235};
236
237
238
239#endif /* HB_OT_MAP_PRIVATE_HH */
240