hb-ot-map-private.hh revision b70c96dbe41d6512b80fe3d966a1942e1ef64a4b 
1/*
2 * Copyright © 2009,2010  Red Hat, Inc.
3 * Copyright © 2010  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  HB_INTERNAL void substitute (hb_face_t *face, hb_buffer_t *buffer) const;
64  HB_INTERNAL void position (hb_font_t *font, hb_buffer_t *buffer) const;
65
66  inline void finish (void) {
67    features.finish ();
68    lookups[0].finish ();
69    lookups[1].finish ();
70    pauses[0].finish ();
71    pauses[1].finish ();
72  }
73
74  private:
75
76  struct feature_map_t {
77    hb_tag_t tag; /* should be first for our bsearch to work */
78    unsigned int index[2]; /* GSUB/GPOS */
79    unsigned int stage[2]; /* GSUB/GPOS */
80    unsigned int shift;
81    hb_mask_t mask;
82    hb_mask_t _1_mask; /* mask for value=1, for quick access */
83
84    static int cmp (const feature_map_t *a, const feature_map_t *b)
85    { return a->tag < b->tag ? -1 : a->tag > b->tag ? 1 : 0; }
86  };
87
88  struct lookup_map_t {
89    unsigned int index;
90    hb_mask_t mask;
91
92    static int cmp (const lookup_map_t *a, const lookup_map_t *b)
93    { return a->index < b->index ? -1 : a->index > b->index ? 1 : 0; }
94  };
95
96  typedef union {
97    void *p;
98    gsub_pause_func_t gsub;
99    gpos_pause_func_t gpos;
100  } pause_func_t;
101  typedef struct {
102    pause_func_t func;
103    void *user_data;
104  } pause_callback_t;
105
106  struct pause_map_t {
107    unsigned int num_lookups; /* Cumulative */
108    pause_callback_t callback;
109  };
110
111  HB_INTERNAL void add_lookups (hb_face_t    *face,
112				unsigned int  table_index,
113				unsigned int  feature_index,
114				hb_mask_t     mask);
115
116
117  hb_mask_t global_mask;
118
119  hb_prealloced_array_t<feature_map_t, 8> features;
120  hb_prealloced_array_t<lookup_map_t, 32> lookups[2]; /* GSUB/GPOS */
121  hb_prealloced_array_t<pause_map_t, 1> pauses[2]; /* GSUB/GPOS */
122};
123
124
125struct hb_ot_map_builder_t
126{
127  public:
128
129  HB_INTERNAL void add_feature (hb_tag_t tag, unsigned int value, bool global);
130
131  inline void add_bool_feature (hb_tag_t tag, bool global = true)
132  { add_feature (tag, 1, global); }
133
134  HB_INTERNAL void add_gsub_pause (hb_ot_map_t::gsub_pause_func_t pause_func, void *user_data);
135  HB_INTERNAL void add_gpos_pause (hb_ot_map_t::gpos_pause_func_t pause_func, void *user_data);
136
137  HB_INTERNAL void compile (hb_face_t *face,
138			    const hb_segment_properties_t *props,
139			    struct hb_ot_map_t &m);
140
141  inline void finish (void) {
142    feature_infos.finish ();
143    pauses[0].finish ();
144    pauses[1].finish ();
145  }
146
147  private:
148
149  struct feature_info_t {
150    hb_tag_t tag;
151    unsigned int seq; /* sequence#, used for stable sorting only */
152    unsigned int max_value;
153    bool global; /* whether the feature applies value to every glyph in the buffer */
154    unsigned int default_value; /* for non-global features, what should the unset glyphs take */
155    unsigned int stage[2]; /* GSUB/GPOS */
156
157    static int cmp (const feature_info_t *a, const feature_info_t *b)
158    { return (a->tag != b->tag) ?  (a->tag < b->tag ? -1 : 1) : (a->seq < b->seq ? -1 : 1); }
159  };
160
161  struct pause_info_t {
162    unsigned int stage;
163    hb_ot_map_t::pause_callback_t callback;
164  };
165
166  unsigned int current_stage[2]; /* GSUB/GPOS */
167  hb_prealloced_array_t<feature_info_t,16> feature_infos;
168  hb_prealloced_array_t<pause_info_t, 1> pauses[2]; /* GSUB/GPOS */
169};
170
171
172HB_END_DECLS
173
174#endif /* HB_OT_MAP_PRIVATE_HH */
175