hb-ot-map-private.hh revision f5bc2725cb892264ba223e0a49f7fd2c622a0730 
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 hb_tag_t get_chosen_script (unsigned int table_index) const
64  { return chosen_script[table_index]; }
65
66  inline void substitute (hb_face_t *face, hb_buffer_t *buffer) const
67  { apply (0, (hb_ot_map_t::apply_lookup_func_t) hb_ot_layout_substitute_lookup, face, buffer); }
68  inline void position (hb_font_t *font, hb_buffer_t *buffer) const
69  { apply (1, (hb_ot_map_t::apply_lookup_func_t) hb_ot_layout_position_lookup, font, buffer); }
70
71  inline void finish (void) {
72    features.finish ();
73    lookups[0].finish ();
74    lookups[1].finish ();
75    pauses[0].finish ();
76    pauses[1].finish ();
77  }
78
79  private:
80
81  struct feature_map_t {
82    hb_tag_t tag; /* should be first for our bsearch to work */
83    unsigned int index[2]; /* GSUB/GPOS */
84    unsigned int stage[2]; /* GSUB/GPOS */
85    unsigned int shift;
86    hb_mask_t mask;
87    hb_mask_t _1_mask; /* mask for value=1, for quick access */
88
89    static int cmp (const feature_map_t *a, const feature_map_t *b)
90    { return a->tag < b->tag ? -1 : a->tag > b->tag ? 1 : 0; }
91  };
92
93  struct lookup_map_t {
94    unsigned int index;
95    hb_mask_t mask;
96
97    static int cmp (const lookup_map_t *a, const lookup_map_t *b)
98    { return a->index < b->index ? -1 : a->index > b->index ? 1 : 0; }
99  };
100
101  typedef void (*pause_func_t) (const hb_ot_map_t *map, void *face_or_font, hb_buffer_t *buffer, void *user_data);
102  typedef struct {
103    pause_func_t func;
104    void *user_data;
105  } pause_callback_t;
106
107  struct pause_map_t {
108    unsigned int num_lookups; /* Cumulative */
109    pause_callback_t callback;
110  };
111
112  typedef hb_bool_t (*apply_lookup_func_t) (void *face_or_font,
113					    hb_buffer_t  *buffer,
114					    unsigned int  lookup_index,
115					    hb_mask_t     mask);
116
117  HB_INTERNAL void add_lookups (hb_face_t    *face,
118				unsigned int  table_index,
119				unsigned int  feature_index,
120				hb_mask_t     mask);
121
122  HB_INTERNAL void apply (unsigned int table_index,
123			  hb_ot_map_t::apply_lookup_func_t apply_lookup_func,
124			  void *face_or_font,
125			  hb_buffer_t *buffer) const;
126
127  hb_mask_t global_mask;
128
129  hb_tag_t chosen_script[2];
130  hb_prealloced_array_t<feature_map_t, 8> features;
131  hb_prealloced_array_t<lookup_map_t, 32> lookups[2]; /* GSUB/GPOS */
132  hb_prealloced_array_t<pause_map_t, 1> pauses[2]; /* GSUB/GPOS */
133};
134
135
136struct hb_ot_map_builder_t
137{
138  public:
139
140  HB_INTERNAL void add_feature (hb_tag_t tag, unsigned int value, bool global);
141
142  inline void add_bool_feature (hb_tag_t tag, bool global = true)
143  { add_feature (tag, 1, global); }
144
145  inline void add_gsub_pause (hb_ot_map_t::gsub_pause_func_t pause_func, void *user_data)
146  { add_pause (0, (hb_ot_map_t::pause_func_t) pause_func, user_data); }
147  inline void add_gpos_pause (hb_ot_map_t::gpos_pause_func_t pause_func, void *user_data)
148  { add_pause (1, (hb_ot_map_t::pause_func_t) pause_func, user_data); }
149
150  HB_INTERNAL void compile (hb_face_t *face,
151			    const hb_segment_properties_t *props,
152			    struct hb_ot_map_t &m);
153
154  inline void finish (void) {
155    feature_infos.finish ();
156    pauses[0].finish ();
157    pauses[1].finish ();
158  }
159
160  private:
161
162  struct feature_info_t {
163    hb_tag_t tag;
164    unsigned int seq; /* sequence#, used for stable sorting only */
165    unsigned int max_value;
166    bool global; /* whether the feature applies value to every glyph in the buffer */
167    unsigned int default_value; /* for non-global features, what should the unset glyphs take */
168    unsigned int stage[2]; /* GSUB/GPOS */
169
170    static int cmp (const feature_info_t *a, const feature_info_t *b)
171    { return (a->tag != b->tag) ?  (a->tag < b->tag ? -1 : 1) : (a->seq < b->seq ? -1 : 1); }
172  };
173
174  struct pause_info_t {
175    unsigned int stage;
176    hb_ot_map_t::pause_callback_t callback;
177  };
178
179  HB_INTERNAL void add_pause (unsigned int table_index, hb_ot_map_t::pause_func_t pause_func, void *user_data);
180
181  unsigned int current_stage[2]; /* GSUB/GPOS */
182  hb_prealloced_array_t<feature_info_t,16> feature_infos;
183  hb_prealloced_array_t<pause_info_t, 1> pauses[2]; /* GSUB/GPOS */
184};
185
186
187HB_END_DECLS
188
189#endif /* HB_OT_MAP_PRIVATE_HH */
190