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 
38 HB_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 #define HB_OT_TAG_JSTF HB_TAG('J','S','T','F')
45 
46 
47 /*
48  * GDEF
49  */
50 
51 HB_EXTERN hb_bool_t
52 hb_ot_layout_has_glyph_classes (hb_face_t *face);
53 
54 typedef enum {
55   HB_OT_LAYOUT_GLYPH_CLASS_UNCLASSIFIED	= 0,
56   HB_OT_LAYOUT_GLYPH_CLASS_BASE_GLYPH	= 1,
57   HB_OT_LAYOUT_GLYPH_CLASS_LIGATURE	= 2,
58   HB_OT_LAYOUT_GLYPH_CLASS_MARK		= 3,
59   HB_OT_LAYOUT_GLYPH_CLASS_COMPONENT	= 4
60 } hb_ot_layout_glyph_class_t;
61 
62 HB_EXTERN hb_ot_layout_glyph_class_t
63 hb_ot_layout_get_glyph_class (hb_face_t      *face,
64 			      hb_codepoint_t  glyph);
65 
66 HB_EXTERN void
67 hb_ot_layout_get_glyphs_in_class (hb_face_t                  *face,
68 				  hb_ot_layout_glyph_class_t  klass,
69 				  hb_set_t                   *glyphs /* OUT */);
70 
71 
72 /* Not that useful.  Provides list of attach points for a glyph that a
73  * client may want to cache */
74 HB_EXTERN unsigned int
75 hb_ot_layout_get_attach_points (hb_face_t      *face,
76 				hb_codepoint_t  glyph,
77 				unsigned int    start_offset,
78 				unsigned int   *point_count /* IN/OUT */,
79 				unsigned int   *point_array /* OUT */);
80 
81 /* Ligature caret positions */
82 HB_EXTERN unsigned int
83 hb_ot_layout_get_ligature_carets (hb_font_t      *font,
84 				  hb_direction_t  direction,
85 				  hb_codepoint_t  glyph,
86 				  unsigned int    start_offset,
87 				  unsigned int   *caret_count /* IN/OUT */,
88 				  hb_position_t  *caret_array /* OUT */);
89 
90 
91 /*
92  * GSUB/GPOS feature query and enumeration interface
93  */
94 
95 #define HB_OT_LAYOUT_NO_SCRIPT_INDEX		0xFFFFu
96 #define HB_OT_LAYOUT_NO_FEATURE_INDEX		0xFFFFu
97 #define HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX	0xFFFFu
98 
99 HB_EXTERN unsigned int
100 hb_ot_layout_table_get_script_tags (hb_face_t    *face,
101 				    hb_tag_t      table_tag,
102 				    unsigned int  start_offset,
103 				    unsigned int *script_count /* IN/OUT */,
104 				    hb_tag_t     *script_tags /* OUT */);
105 
106 HB_EXTERN hb_bool_t
107 hb_ot_layout_table_find_script (hb_face_t    *face,
108 				hb_tag_t      table_tag,
109 				hb_tag_t      script_tag,
110 				unsigned int *script_index);
111 
112 /* Like find_script, but takes zero-terminated array of scripts to test */
113 HB_EXTERN hb_bool_t
114 hb_ot_layout_table_choose_script (hb_face_t      *face,
115 				  hb_tag_t        table_tag,
116 				  const hb_tag_t *script_tags,
117 				  unsigned int   *script_index,
118 				  hb_tag_t       *chosen_script);
119 
120 HB_EXTERN unsigned int
121 hb_ot_layout_table_get_feature_tags (hb_face_t    *face,
122 				     hb_tag_t      table_tag,
123 				     unsigned int  start_offset,
124 				     unsigned int *feature_count /* IN/OUT */,
125 				     hb_tag_t     *feature_tags /* OUT */);
126 
127 HB_EXTERN unsigned int
128 hb_ot_layout_script_get_language_tags (hb_face_t    *face,
129 				       hb_tag_t      table_tag,
130 				       unsigned int  script_index,
131 				       unsigned int  start_offset,
132 				       unsigned int *language_count /* IN/OUT */,
133 				       hb_tag_t     *language_tags /* OUT */);
134 
135 HB_EXTERN hb_bool_t
136 hb_ot_layout_script_find_language (hb_face_t    *face,
137 				   hb_tag_t      table_tag,
138 				   unsigned int  script_index,
139 				   hb_tag_t      language_tag,
140 				   unsigned int *language_index);
141 
142 HB_EXTERN hb_bool_t
143 hb_ot_layout_language_get_required_feature_index (hb_face_t    *face,
144 						  hb_tag_t      table_tag,
145 						  unsigned int  script_index,
146 						  unsigned int  language_index,
147 						  unsigned int *feature_index);
148 
149 HB_EXTERN hb_bool_t
150 hb_ot_layout_language_get_required_feature (hb_face_t    *face,
151 					    hb_tag_t      table_tag,
152 					    unsigned int  script_index,
153 					    unsigned int  language_index,
154 					    unsigned int *feature_index,
155 					    hb_tag_t     *feature_tag);
156 
157 HB_EXTERN unsigned int
158 hb_ot_layout_language_get_feature_indexes (hb_face_t    *face,
159 					   hb_tag_t      table_tag,
160 					   unsigned int  script_index,
161 					   unsigned int  language_index,
162 					   unsigned int  start_offset,
163 					   unsigned int *feature_count /* IN/OUT */,
164 					   unsigned int *feature_indexes /* OUT */);
165 
166 HB_EXTERN unsigned int
167 hb_ot_layout_language_get_feature_tags (hb_face_t    *face,
168 					hb_tag_t      table_tag,
169 					unsigned int  script_index,
170 					unsigned int  language_index,
171 					unsigned int  start_offset,
172 					unsigned int *feature_count /* IN/OUT */,
173 					hb_tag_t     *feature_tags /* OUT */);
174 
175 HB_EXTERN hb_bool_t
176 hb_ot_layout_language_find_feature (hb_face_t    *face,
177 				    hb_tag_t      table_tag,
178 				    unsigned int  script_index,
179 				    unsigned int  language_index,
180 				    hb_tag_t      feature_tag,
181 				    unsigned int *feature_index);
182 
183 HB_EXTERN unsigned int
184 hb_ot_layout_feature_get_lookups (hb_face_t    *face,
185 				  hb_tag_t      table_tag,
186 				  unsigned int  feature_index,
187 				  unsigned int  start_offset,
188 				  unsigned int *lookup_count /* IN/OUT */,
189 				  unsigned int *lookup_indexes /* OUT */);
190 
191 HB_EXTERN unsigned int
192 hb_ot_layout_table_get_lookup_count (hb_face_t    *face,
193 				     hb_tag_t      table_tag);
194 
195 
196 HB_EXTERN void
197 hb_ot_layout_collect_lookups (hb_face_t      *face,
198 			      hb_tag_t        table_tag,
199 			      const hb_tag_t *scripts,
200 			      const hb_tag_t *languages,
201 			      const hb_tag_t *features,
202 			      hb_set_t       *lookup_indexes /* OUT */);
203 
204 HB_EXTERN void
205 hb_ot_layout_lookup_collect_glyphs (hb_face_t    *face,
206 				    hb_tag_t      table_tag,
207 				    unsigned int  lookup_index,
208 				    hb_set_t     *glyphs_before, /* OUT. May be NULL */
209 				    hb_set_t     *glyphs_input,  /* OUT. May be NULL */
210 				    hb_set_t     *glyphs_after,  /* OUT. May be NULL */
211 				    hb_set_t     *glyphs_output  /* OUT. May be NULL */);
212 
213 #ifdef HB_NOT_IMPLEMENTED
214 typedef struct
215 {
216   const hb_codepoint_t *before,
217   unsigned int          before_length,
218   const hb_codepoint_t *input,
219   unsigned int          input_length,
220   const hb_codepoint_t *after,
221   unsigned int          after_length,
222 } hb_ot_layout_glyph_sequence_t;
223 
224 typedef hb_bool_t
225 (*hb_ot_layout_glyph_sequence_func_t) (hb_font_t    *font,
226 				       hb_tag_t      table_tag,
227 				       unsigned int  lookup_index,
228 				       const hb_ot_layout_glyph_sequence_t *sequence,
229 				       void         *user_data);
230 
231 HB_EXTERN void
232 Xhb_ot_layout_lookup_enumerate_sequences (hb_face_t    *face,
233 					 hb_tag_t      table_tag,
234 					 unsigned int  lookup_index,
235 					 hb_ot_layout_glyph_sequence_func_t callback,
236 					 void         *user_data);
237 #endif
238 
239 
240 /*
241  * GSUB
242  */
243 
244 HB_EXTERN hb_bool_t
245 hb_ot_layout_has_substitution (hb_face_t *face);
246 
247 HB_EXTERN hb_bool_t
248 hb_ot_layout_lookup_would_substitute (hb_face_t            *face,
249 				      unsigned int          lookup_index,
250 				      const hb_codepoint_t *glyphs,
251 				      unsigned int          glyphs_length,
252 				      hb_bool_t             zero_context);
253 
254 HB_EXTERN void
255 hb_ot_layout_lookup_substitute_closure (hb_face_t    *face,
256 				        unsigned int  lookup_index,
257 				        hb_set_t     *glyphs
258 					/*TODO , hb_bool_t  inclusive */);
259 
260 #ifdef HB_NOT_IMPLEMENTED
261 /* Note: You better have GDEF when using this API, or marks won't do much. */
262 HB_EXTERN hb_bool_t
263 Xhb_ot_layout_lookup_substitute (hb_font_t            *font,
264 				unsigned int          lookup_index,
265 				const hb_ot_layout_glyph_sequence_t *sequence,
266 				unsigned int          out_size,
267 				hb_codepoint_t       *glyphs_out,   /* OUT */
268 				unsigned int         *clusters_out, /* OUT */
269 				unsigned int         *out_length    /* OUT */);
270 #endif
271 
272 
273 /*
274  * GPOS
275  */
276 
277 HB_EXTERN hb_bool_t
278 hb_ot_layout_has_positioning (hb_face_t *face);
279 
280 #ifdef HB_NOT_IMPLEMENTED
281 /* Note: You better have GDEF when using this API, or marks won't do much. */
282 HB_EXTERN hb_bool_t
283 Xhb_ot_layout_lookup_position (hb_font_t            *font,
284 			      unsigned int          lookup_index,
285 			      const hb_ot_layout_glyph_sequence_t *sequence,
286 			      hb_glyph_position_t  *positions /* IN / OUT */);
287 #endif
288 
289 /* Optical 'size' feature info.  Returns true if found.
290  * http://www.microsoft.com/typography/otspec/features_pt.htm#size */
291 HB_EXTERN hb_bool_t
292 hb_ot_layout_get_size_params (hb_face_t    *face,
293 			      unsigned int *design_size,       /* OUT.  May be NULL */
294 			      unsigned int *subfamily_id,      /* OUT.  May be NULL */
295 			      unsigned int *subfamily_name_id, /* OUT.  May be NULL */
296 			      unsigned int *range_start,       /* OUT.  May be NULL */
297 			      unsigned int *range_end          /* OUT.  May be NULL */);
298 
299 
300 HB_END_DECLS
301 
302 #endif /* HB_OT_LAYOUT_H */
303