hb-ot-map-private.hh revision 6a9be5bd3524dc3eb1e88d1063bde2e4d8b57011
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
36
37
38static const hb_tag_t table_tags[2] = {HB_OT_TAG_GSUB, HB_OT_TAG_GPOS};
39
40struct hb_ot_map_t
41{
42  friend struct hb_ot_map_builder_t;
43
44  public:
45
46  hb_ot_map_t (void) { memset (this, 0, sizeof (*this)); }
47
48  typedef void (*gsub_pause_func_t) (const hb_ot_map_t *map, hb_face_t *face, hb_buffer_t *buffer, void *user_data);
49  typedef void (*gpos_pause_func_t) (const hb_ot_map_t *map, hb_font_t *font, hb_buffer_t *buffer, void *user_data);
50
51  inline hb_mask_t get_global_mask (void) const { return global_mask; }
52
53  inline hb_mask_t get_mask (hb_tag_t tag, unsigned int *shift = NULL) const {
54    const feature_map_t *map = features.bsearch (&tag);
55    if (shift) *shift = map ? map->shift : 0;
56    return map ? map->mask : 0;
57  }
58
59  inline hb_mask_t get_1_mask (hb_tag_t tag) const {
60    const feature_map_t *map = features.bsearch (&tag);
61    return map ? map->_1_mask : 0;
62  }
63
64  inline hb_tag_t get_chosen_script (unsigned int table_index) const
65  { return chosen_script[table_index]; }
66
67  inline void substitute (hb_face_t *face, hb_buffer_t *buffer) const
68  { apply (0, (hb_ot_map_t::apply_lookup_func_t) hb_ot_layout_substitute_lookup, face, buffer); }
69  inline void position (hb_font_t *font, hb_buffer_t *buffer) const
70  { apply (1, (hb_ot_map_t::apply_lookup_func_t) hb_ot_layout_position_lookup, font, buffer); }
71
72  inline void finish (void) {
73    features.finish ();
74    lookups[0].finish ();
75    lookups[1].finish ();
76    pauses[0].finish ();
77    pauses[1].finish ();
78  }
79
80  private:
81
82  struct feature_map_t {
83    hb_tag_t tag; /* should be first for our bsearch to work */
84    unsigned int index[2]; /* GSUB/GPOS */
85    unsigned int stage[2]; /* GSUB/GPOS */
86    unsigned int shift;
87    hb_mask_t mask;
88    hb_mask_t _1_mask; /* mask for value=1, for quick access */
89
90    static int cmp (const feature_map_t *a, const feature_map_t *b)
91    { return a->tag < b->tag ? -1 : a->tag > b->tag ? 1 : 0; }
92  };
93
94  struct lookup_map_t {
95    unsigned int index;
96    hb_mask_t mask;
97
98    static int cmp (const lookup_map_t *a, const lookup_map_t *b)
99    { return a->index < b->index ? -1 : a->index > b->index ? 1 : 0; }
100  };
101
102  typedef void (*pause_func_t) (const hb_ot_map_t *map, void *face_or_font, hb_buffer_t *buffer, void *user_data);
103  typedef struct {
104    pause_func_t func;
105    void *user_data;
106  } pause_callback_t;
107
108  struct pause_map_t {
109    unsigned int num_lookups; /* Cumulative */
110    pause_callback_t callback;
111  };
112
113  typedef hb_bool_t (*apply_lookup_func_t) (void *face_or_font,
114					    hb_buffer_t  *buffer,
115					    unsigned int  lookup_index,
116					    hb_mask_t     mask);
117
118  HB_INTERNAL void add_lookups (hb_face_t    *face,
119				unsigned int  table_index,
120				unsigned int  feature_index,
121				hb_mask_t     mask);
122
123  HB_INTERNAL void apply (unsigned int table_index,
124			  hb_ot_map_t::apply_lookup_func_t apply_lookup_func,
125			  void *face_or_font,
126			  hb_buffer_t *buffer) const;
127
128  HB_INTERNAL void substitute_closure (hb_face_t *face,
129				       hb_set_t *glyphs) const;
130
131  hb_mask_t global_mask;
132
133  hb_tag_t chosen_script[2];
134  hb_prealloced_array_t<feature_map_t, 8> features;
135  hb_prealloced_array_t<lookup_map_t, 32> lookups[2]; /* GSUB/GPOS */
136  hb_prealloced_array_t<pause_map_t, 1> pauses[2]; /* GSUB/GPOS */
137};
138
139
140struct hb_ot_map_builder_t
141{
142  public:
143
144  hb_ot_map_builder_t (void) { memset (this, 0, sizeof (*this)); }
145
146  HB_INTERNAL void add_feature (hb_tag_t tag, unsigned int value, bool global);
147
148  inline void add_bool_feature (hb_tag_t tag, bool global = true)
149  { add_feature (tag, 1, global); }
150
151  inline void add_gsub_pause (hb_ot_map_t::gsub_pause_func_t pause_func, void *user_data)
152  { add_pause (0, (hb_ot_map_t::pause_func_t) pause_func, user_data); }
153  inline void add_gpos_pause (hb_ot_map_t::gpos_pause_func_t pause_func, void *user_data)
154  { add_pause (1, (hb_ot_map_t::pause_func_t) pause_func, user_data); }
155
156  HB_INTERNAL void compile (hb_face_t *face,
157			    const hb_segment_properties_t *props,
158			    struct hb_ot_map_t &m);
159
160  inline void finish (void) {
161    feature_infos.finish ();
162    pauses[0].finish ();
163    pauses[1].finish ();
164  }
165
166  private:
167
168  struct feature_info_t {
169    hb_tag_t tag;
170    unsigned int seq; /* sequence#, used for stable sorting only */
171    unsigned int max_value;
172    bool global; /* whether the feature applies value to every glyph in the buffer */
173    unsigned int default_value; /* for non-global features, what should the unset glyphs take */
174    unsigned int stage[2]; /* GSUB/GPOS */
175
176    static int cmp (const feature_info_t *a, const feature_info_t *b)
177    { return (a->tag != b->tag) ?  (a->tag < b->tag ? -1 : 1) : (a->seq < b->seq ? -1 : 1); }
178  };
179
180  struct pause_info_t {
181    unsigned int stage;
182    hb_ot_map_t::pause_callback_t callback;
183  };
184
185  HB_INTERNAL void add_pause (unsigned int table_index, hb_ot_map_t::pause_func_t pause_func, void *user_data);
186
187  unsigned int current_stage[2]; /* GSUB/GPOS */
188  hb_prealloced_array_t<feature_info_t,16> feature_infos;
189  hb_prealloced_array_t<pause_info_t, 1> pauses[2]; /* GSUB/GPOS */
190};
191
192
193
194#endif /* HB_OT_MAP_PRIVATE_HH */
195