hb-ot-map-private.hh revision c47a31fb4793b825f4be57e9cb1b10db352b9512 
1/*
2 * Copyright © 2009,2010  Red Hat, Inc.
3 * Copyright © 2010,2011  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.h"
35
36HB_BEGIN_DECLS
37
38
39static const hb_tag_t table_tags[2] = {HB_OT_TAG_GSUB, HB_OT_TAG_GPOS};
40
41struct hb_ot_map_t
42{
43  friend struct hb_ot_map_builder_t;
44
45  public:
46
47  typedef void (*gsub_pause_func_t) (const hb_ot_map_t *map, hb_face_t *face, hb_buffer_t *buffer, void *user_data);
48  typedef void (*gpos_pause_func_t) (const hb_ot_map_t *map, hb_font_t *font, hb_buffer_t *buffer, void *user_data);
49
50  inline hb_mask_t get_global_mask (void) const { return global_mask; }
51
52  inline hb_mask_t get_mask (hb_tag_t tag, unsigned int *shift = NULL) const {
53    const feature_map_t *map = features.bsearch (&tag);
54    if (shift) *shift = map ? map->shift : 0;
55    return map ? map->mask : 0;
56  }
57
58  inline hb_mask_t get_1_mask (hb_tag_t tag) const {
59    const feature_map_t *map = features.bsearch (&tag);
60    return map ? map->_1_mask : 0;
61  }
62
63  inline void substitute (hb_face_t *face, hb_buffer_t *buffer) const
64  { apply (0, (hb_ot_map_t::apply_lookup_func_t) hb_ot_layout_substitute_lookup, face, buffer); }
65  inline void position (hb_font_t *font, hb_buffer_t *buffer) const
66  { apply (1, (hb_ot_map_t::apply_lookup_func_t) hb_ot_layout_position_lookup, font, buffer); }
67
68  inline void finish (void) {
69    features.finish ();
70    lookups[0].finish ();
71    lookups[1].finish ();
72    pauses[0].finish ();
73    pauses[1].finish ();
74  }
75
76  private:
77
78  struct feature_map_t {
79    hb_tag_t tag; /* should be first for our bsearch to work */
80    unsigned int index[2]; /* GSUB/GPOS */
81    unsigned int stage[2]; /* GSUB/GPOS */
82    unsigned int shift;
83    hb_mask_t mask;
84    hb_mask_t _1_mask; /* mask for value=1, for quick access */
85
86    static int cmp (const feature_map_t *a, const feature_map_t *b)
87    { return a->tag < b->tag ? -1 : a->tag > b->tag ? 1 : 0; }
88  };
89
90  struct lookup_map_t {
91    unsigned int index;
92    hb_mask_t mask;
93
94    static int cmp (const lookup_map_t *a, const lookup_map_t *b)
95    { return a->index < b->index ? -1 : a->index > b->index ? 1 : 0; }
96  };
97
98  typedef void (*pause_func_t) (const hb_ot_map_t *map, void *face_or_font, hb_buffer_t *buffer, void *user_data);
99  typedef struct {
100    pause_func_t func;
101    void *user_data;
102  } pause_callback_t;
103
104  struct pause_map_t {
105    unsigned int num_lookups; /* Cumulative */
106    pause_callback_t callback;
107  };
108
109  typedef hb_bool_t (*apply_lookup_func_t) (void *face_or_font,
110					    hb_buffer_t  *buffer,
111					    unsigned int  lookup_index,
112					    hb_mask_t     mask);
113
114  HB_INTERNAL void add_lookups (hb_face_t    *face,
115				unsigned int  table_index,
116				unsigned int  feature_index,
117				hb_mask_t     mask);
118
119  HB_INTERNAL void apply (unsigned int table_index,
120			  hb_ot_map_t::apply_lookup_func_t apply_lookup_func,
121			  void *face_or_font,
122			  hb_buffer_t *buffer) const;
123
124  hb_mask_t global_mask;
125
126  hb_tag_t chosen_script[2];
127  hb_prealloced_array_t<feature_map_t, 8> features;
128  hb_prealloced_array_t<lookup_map_t, 32> lookups[2]; /* GSUB/GPOS */
129  hb_prealloced_array_t<pause_map_t, 1> pauses[2]; /* GSUB/GPOS */
130};
131
132
133struct hb_ot_map_builder_t
134{
135  public:
136
137  HB_INTERNAL void add_feature (hb_tag_t tag, unsigned int value, bool global);
138
139  inline void add_bool_feature (hb_tag_t tag, bool global = true)
140  { add_feature (tag, 1, global); }
141
142  inline void add_gsub_pause (hb_ot_map_t::gsub_pause_func_t pause_func, void *user_data)
143  { add_pause (0, (hb_ot_map_t::pause_func_t) pause_func, user_data); }
144  inline void add_gpos_pause (hb_ot_map_t::gpos_pause_func_t pause_func, void *user_data)
145  { add_pause (1, (hb_ot_map_t::pause_func_t) pause_func, user_data); }
146
147  HB_INTERNAL void compile (hb_face_t *face,
148			    const hb_segment_properties_t *props,
149			    struct hb_ot_map_t &m);
150
151  inline void finish (void) {
152    feature_infos.finish ();
153    pauses[0].finish ();
154    pauses[1].finish ();
155  }
156
157  private:
158
159  struct feature_info_t {
160    hb_tag_t tag;
161    unsigned int seq; /* sequence#, used for stable sorting only */
162    unsigned int max_value;
163    bool global; /* whether the feature applies value to every glyph in the buffer */
164    unsigned int default_value; /* for non-global features, what should the unset glyphs take */
165    unsigned int stage[2]; /* GSUB/GPOS */
166
167    static int cmp (const feature_info_t *a, const feature_info_t *b)
168    { return (a->tag != b->tag) ?  (a->tag < b->tag ? -1 : 1) : (a->seq < b->seq ? -1 : 1); }
169  };
170
171  struct pause_info_t {
172    unsigned int stage;
173    hb_ot_map_t::pause_callback_t callback;
174  };
175
176  HB_INTERNAL void add_pause (unsigned int table_index, hb_ot_map_t::pause_func_t pause_func, void *user_data);
177
178  unsigned int current_stage[2]; /* GSUB/GPOS */
179  hb_prealloced_array_t<feature_info_t,16> feature_infos;
180  hb_prealloced_array_t<pause_info_t, 1> pauses[2]; /* GSUB/GPOS */
181};
182
183
184HB_END_DECLS
185
186#endif /* HB_OT_MAP_PRIVATE_HH */
187