hb-ot-layout.h revision e72b360ac6381b549249b8836fa3e70b909d3437 
1/*
2 * Copyright © 2007,2008,2009  Red Hat, Inc.
3 *
4 *  This is part of HarfBuzz, a text shaping library.
5 *
6 * Permission is hereby granted, without written agreement and without
7 * license or royalty fees, to use, copy, modify, and distribute this
8 * software and its documentation for any purpose, provided that the
9 * above copyright notice and the following two paragraphs appear in
10 * all copies of this software.
11 *
12 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
13 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
14 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
15 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
16 * DAMAGE.
17 *
18 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
19 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
20 * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
21 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
22 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
23 *
24 * Red Hat Author(s): Behdad Esfahbod
25 */
26
27#ifndef HB_OT_H_IN
28#error "Include <hb-ot.h> instead."
29#endif
30
31#ifndef HB_OT_LAYOUT_H
32#define HB_OT_LAYOUT_H
33
34#include "hb.h"
35
36#include "hb-ot-tag.h"
37
38HB_BEGIN_DECLS
39
40
41#define HB_OT_TAG_GDEF HB_TAG('G','D','E','F')
42#define HB_OT_TAG_GSUB HB_TAG('G','S','U','B')
43#define HB_OT_TAG_GPOS HB_TAG('G','P','O','S')
44
45/*
46 * GDEF
47 */
48
49hb_bool_t
50hb_ot_layout_has_glyph_classes (hb_face_t *face);
51
52/* Not that useful.  Provides list of attach points for a glyph that a
53 * client may want to cache */
54unsigned int
55hb_ot_layout_get_attach_points (hb_face_t      *face,
56				hb_codepoint_t  glyph,
57				unsigned int    start_offset,
58				unsigned int   *point_count /* IN/OUT */,
59				unsigned int   *point_array /* OUT */);
60
61/* Ligature caret positions */
62unsigned int
63hb_ot_layout_get_ligature_carets (hb_font_t      *font,
64				  hb_direction_t  direction,
65				  hb_codepoint_t  glyph,
66				  unsigned int    start_offset,
67				  unsigned int   *caret_count /* IN/OUT */,
68				  hb_position_t  *caret_array /* OUT */);
69
70
71/*
72 * GSUB/GPOS feature query and enumeration interface
73 */
74
75#define HB_OT_LAYOUT_NO_SCRIPT_INDEX		((unsigned int) 0xFFFF)
76#define HB_OT_LAYOUT_NO_FEATURE_INDEX		((unsigned int) 0xFFFF)
77#define HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX	((unsigned int) 0xFFFF)
78
79unsigned int
80hb_ot_layout_table_get_script_tags (hb_face_t    *face,
81				    hb_tag_t      table_tag,
82				    unsigned int  start_offset,
83				    unsigned int *script_count /* IN/OUT */,
84				    hb_tag_t     *script_tags /* OUT */);
85
86hb_bool_t
87hb_ot_layout_table_find_script (hb_face_t    *face,
88				hb_tag_t      table_tag,
89				hb_tag_t      script_tag,
90				unsigned int *script_index);
91
92/* Like find_script, but takes zero-terminated array of scripts to test */
93hb_bool_t
94hb_ot_layout_table_choose_script (hb_face_t      *face,
95				  hb_tag_t        table_tag,
96				  const hb_tag_t *script_tags,
97				  unsigned int   *script_index,
98				  hb_tag_t       *chosen_script);
99
100unsigned int
101hb_ot_layout_table_get_feature_tags (hb_face_t    *face,
102				     hb_tag_t      table_tag,
103				     unsigned int  start_offset,
104				     unsigned int *feature_count /* IN/OUT */,
105				     hb_tag_t     *feature_tags /* OUT */);
106
107unsigned int
108hb_ot_layout_script_get_language_tags (hb_face_t    *face,
109				       hb_tag_t      table_tag,
110				       unsigned int  script_index,
111				       unsigned int  start_offset,
112				       unsigned int *language_count /* IN/OUT */,
113				       hb_tag_t     *language_tags /* OUT */);
114
115hb_bool_t
116hb_ot_layout_script_find_language (hb_face_t    *face,
117				   hb_tag_t      table_tag,
118				   unsigned int  script_index,
119				   hb_tag_t      language_tag,
120				   unsigned int *language_index);
121
122hb_bool_t
123hb_ot_layout_language_get_required_feature_index (hb_face_t    *face,
124						  hb_tag_t      table_tag,
125						  unsigned int  script_index,
126						  unsigned int  language_index,
127						  unsigned int *feature_index);
128
129unsigned int
130hb_ot_layout_language_get_feature_indexes (hb_face_t    *face,
131					   hb_tag_t      table_tag,
132					   unsigned int  script_index,
133					   unsigned int  language_index,
134					   unsigned int  start_offset,
135					   unsigned int *feature_count /* IN/OUT */,
136					   unsigned int *feature_indexes /* OUT */);
137
138unsigned int
139hb_ot_layout_language_get_feature_tags (hb_face_t    *face,
140					hb_tag_t      table_tag,
141					unsigned int  script_index,
142					unsigned int  language_index,
143					unsigned int  start_offset,
144					unsigned int *feature_count /* IN/OUT */,
145					hb_tag_t     *feature_tags /* OUT */);
146
147hb_bool_t
148hb_ot_layout_language_find_feature (hb_face_t    *face,
149				    hb_tag_t      table_tag,
150				    unsigned int  script_index,
151				    unsigned int  language_index,
152				    hb_tag_t      feature_tag,
153				    unsigned int *feature_index);
154
155unsigned int
156hb_ot_layout_feature_get_lookup_indexes (hb_face_t    *face,
157					 hb_tag_t      table_tag,
158					 unsigned int  feature_index,
159					 unsigned int  start_offset,
160					 unsigned int *lookup_count /* IN/OUT */,
161					 unsigned int *lookup_indexes /* OUT */);
162
163
164/*
165 * GSUB
166 */
167
168hb_bool_t
169hb_ot_layout_has_substitution (hb_face_t *face);
170
171/* Supports length 1 or 2 right now. */
172hb_bool_t
173hb_ot_layout_would_substitute_lookup (hb_face_t            *face,
174				      const hb_codepoint_t *glyphs,
175				      unsigned int          glyphs_length,
176				      unsigned int          lookup_index);
177
178/* Should be called before all the substitute_lookup's are done. */
179void
180hb_ot_layout_substitute_start (hb_buffer_t  *buffer);
181
182hb_bool_t
183hb_ot_layout_substitute_lookup (hb_face_t    *face,
184				hb_buffer_t  *buffer,
185				unsigned int  lookup_index,
186				hb_mask_t     mask);
187
188/* Should be called after all the substitute_lookup's are done */
189void
190hb_ot_layout_substitute_finish (hb_buffer_t  *buffer);
191
192
193void
194hb_ot_layout_substitute_closure_lookup (hb_face_t    *face,
195				        hb_set_t     *glyphs,
196				        unsigned int  lookup_index);
197
198/*
199 * GPOS
200 */
201
202hb_bool_t
203hb_ot_layout_has_positioning (hb_face_t *face);
204
205/* Should be called before all the position_lookup's are done.  Resets positions to zero. */
206void
207hb_ot_layout_position_start (hb_buffer_t  *buffer);
208
209hb_bool_t
210hb_ot_layout_position_lookup (hb_font_t    *font,
211			      hb_buffer_t  *buffer,
212			      unsigned int  lookup_index,
213			      hb_mask_t     mask);
214
215/* Should be called after all the position_lookup's are done */
216void
217hb_ot_layout_position_finish (hb_buffer_t  *buffer);
218
219
220HB_END_DECLS
221
222#endif /* HB_OT_LAYOUT_H */
223