hb-ot-map-private.hh revision 44b0a4d2fc62689fc56ef57f412b4bb1e439a614 
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
39#define MAX_LOOKUPS 1000 /* FIXME */
40
41static const hb_tag_t table_tags[2] = {HB_OT_TAG_GSUB, HB_OT_TAG_GPOS};
42
43struct hb_ot_map_t {
44
45  private:
46
47  struct feature_info_t {
48    hb_tag_t tag;
49    unsigned int seq; /* sequence#, used for stable sorting only */
50    unsigned int max_value;
51    bool global; /* whether the feature applies value to every glyph in the buffer */
52    unsigned int default_value; /* for non-global features, what should the unset glyphs take */
53
54    static int cmp (const feature_info_t *a, const feature_info_t *b)
55    { return (a->tag != b->tag) ?  (a->tag < b->tag ? -1 : 1) : (a->seq < b->seq ? -1 : 1); }
56  };
57
58  struct feature_map_t {
59    hb_tag_t tag; /* should be first for our bsearch to work */
60    unsigned int index[2]; /* GSUB, GPOS */
61    unsigned int shift;
62    hb_mask_t mask;
63    hb_mask_t _1_mask; /* mask for value=1, for quick access */
64
65    static int cmp (const feature_map_t *a, const feature_map_t *b)
66    { return a->tag < b->tag ? -1 : a->tag > b->tag ? 1 : 0; }
67  };
68
69  struct lookup_map_t {
70    unsigned int index;
71    hb_mask_t mask;
72
73    static int cmp (const lookup_map_t *a, const lookup_map_t *b)
74    { return a->index < b->index ? -1 : a->index > b->index ? 1 : 0; }
75  };
76
77  HB_INTERNAL void add_lookups (hb_face_t    *face,
78				unsigned int  table_index,
79				unsigned int  feature_index,
80				hb_mask_t     mask);
81
82
83  public:
84
85  hb_ot_map_t (void) : feature_count (0) {}
86
87  void add_feature (hb_tag_t tag, unsigned int value, bool global)
88  {
89    feature_info_t *info = feature_infos.push();
90    if (unlikely (!info)) return;
91    info->tag = tag;
92    info->seq = feature_infos.len;
93    info->max_value = value;
94    info->global = global;
95    info->default_value = global ? value : 0;
96  }
97
98  inline void add_bool_feature (hb_tag_t tag, bool global = true)
99  { add_feature (tag, 1, global); }
100
101  HB_INTERNAL void compile (hb_face_t *face,
102			    const hb_segment_properties_t *props);
103
104  inline hb_mask_t get_global_mask (void) const { return global_mask; }
105
106  inline hb_mask_t get_mask (hb_tag_t tag, unsigned int *shift = NULL) const {
107    const feature_map_t *map = (const feature_map_t *) bsearch (&tag, feature_maps, feature_count, sizeof (feature_maps[0]), (hb_compare_func_t) feature_map_t::cmp);
108    if (shift) *shift = map ? map->shift : 0;
109    return map ? map->mask : 0;
110  }
111
112  inline hb_mask_t get_1_mask (hb_tag_t tag) const {
113    const feature_map_t *map = (const feature_map_t *) bsearch (&tag, feature_maps, feature_count, sizeof (feature_maps[0]), (hb_compare_func_t) feature_map_t::cmp);
114    return map ? map->_1_mask : 0;
115  }
116
117  inline void substitute (hb_face_t *face, hb_buffer_t *buffer) const {
118    for (unsigned int i = 0; i < lookup_count[0]; i++)
119      hb_ot_layout_substitute_lookup (face, buffer, lookup_maps[0][i].index, lookup_maps[0][i].mask);
120  }
121
122  inline void position (hb_font_t *font, hb_face_t *face, hb_buffer_t *buffer) const {
123    for (unsigned int i = 0; i < lookup_count[1]; i++)
124      hb_ot_layout_position_lookup (font, buffer, lookup_maps[1][i].index, lookup_maps[1][i].mask);
125  }
126
127  private:
128
129  hb_mask_t global_mask;
130
131  unsigned int feature_count;
132  hb_prealloced_array_t<feature_info_t,16> feature_infos; /* used before compile() only */
133#define MAX_FEATURES 100
134  feature_map_t feature_maps[MAX_FEATURES];
135
136  lookup_map_t lookup_maps[2][MAX_LOOKUPS]; /* GSUB/GPOS */
137  unsigned int lookup_count[2];
138};
139
140
141
142HB_END_DECLS
143
144#endif /* HB_OT_MAP_PRIVATE_HH */
145