1 /*
2  * Copyright © 2007,2008,2009  Red Hat, Inc.
3  * Copyright © 2010,2011,2012  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_LAYOUT_GDEF_TABLE_HH
30 #define HB_OT_LAYOUT_GDEF_TABLE_HH
31 
32 #include "hb-ot-layout-common-private.hh"
33 
34 #include "hb-font-private.hh"
35 
36 
37 namespace OT {
38 
39 
40 /*
41  * Attachment List Table
42  */
43 
44 typedef ArrayOf<USHORT> AttachPoint;	/* Array of contour point indices--in
45 					 * increasing numerical order */
46 
47 struct AttachList
48 {
get_attach_pointsOT::AttachList49   inline unsigned int get_attach_points (hb_codepoint_t glyph_id,
50 					 unsigned int start_offset,
51 					 unsigned int *point_count /* IN/OUT */,
52 					 unsigned int *point_array /* OUT */) const
53   {
54     unsigned int index = (this+coverage).get_coverage (glyph_id);
55     if (index == NOT_COVERED)
56     {
57       if (point_count)
58 	*point_count = 0;
59       return 0;
60     }
61 
62     const AttachPoint &points = this+attachPoint[index];
63 
64     if (point_count) {
65       const USHORT *array = points.sub_array (start_offset, point_count);
66       unsigned int count = *point_count;
67       for (unsigned int i = 0; i < count; i++)
68 	point_array[i] = array[i];
69     }
70 
71     return points.len;
72   }
73 
sanitizeOT::AttachList74   inline bool sanitize (hb_sanitize_context_t *c) const
75   {
76     TRACE_SANITIZE (this);
77     return_trace (coverage.sanitize (c, this) && attachPoint.sanitize (c, this));
78   }
79 
80   protected:
81   OffsetTo<Coverage>
82 		coverage;		/* Offset to Coverage table -- from
83 					 * beginning of AttachList table */
84   OffsetArrayOf<AttachPoint>
85 		attachPoint;		/* Array of AttachPoint tables
86 					 * in Coverage Index order */
87   public:
88   DEFINE_SIZE_ARRAY (4, attachPoint);
89 };
90 
91 /*
92  * Ligature Caret Table
93  */
94 
95 struct CaretValueFormat1
96 {
97   friend struct CaretValue;
98 
99   private:
get_caret_valueOT::CaretValueFormat1100   inline hb_position_t get_caret_value (hb_font_t *font, hb_direction_t direction, hb_codepoint_t glyph_id HB_UNUSED) const
101   {
102     return HB_DIRECTION_IS_HORIZONTAL (direction) ? font->em_scale_x (coordinate) : font->em_scale_y (coordinate);
103   }
104 
sanitizeOT::CaretValueFormat1105   inline bool sanitize (hb_sanitize_context_t *c) const
106   {
107     TRACE_SANITIZE (this);
108     return_trace (c->check_struct (this));
109   }
110 
111   protected:
112   USHORT	caretValueFormat;	/* Format identifier--format = 1 */
113   SHORT		coordinate;		/* X or Y value, in design units */
114   public:
115   DEFINE_SIZE_STATIC (4);
116 };
117 
118 struct CaretValueFormat2
119 {
120   friend struct CaretValue;
121 
122   private:
get_caret_valueOT::CaretValueFormat2123   inline hb_position_t get_caret_value (hb_font_t *font, hb_direction_t direction, hb_codepoint_t glyph_id) const
124   {
125     hb_position_t x, y;
126     if (font->get_glyph_contour_point_for_origin (glyph_id, caretValuePoint, direction, &x, &y))
127       return HB_DIRECTION_IS_HORIZONTAL (direction) ? x : y;
128     else
129       return 0;
130   }
131 
sanitizeOT::CaretValueFormat2132   inline bool sanitize (hb_sanitize_context_t *c) const
133   {
134     TRACE_SANITIZE (this);
135     return_trace (c->check_struct (this));
136   }
137 
138   protected:
139   USHORT	caretValueFormat;	/* Format identifier--format = 2 */
140   USHORT	caretValuePoint;	/* Contour point index on glyph */
141   public:
142   DEFINE_SIZE_STATIC (4);
143 };
144 
145 struct CaretValueFormat3
146 {
147   friend struct CaretValue;
148 
get_caret_valueOT::CaretValueFormat3149   inline hb_position_t get_caret_value (hb_font_t *font, hb_direction_t direction, hb_codepoint_t glyph_id HB_UNUSED) const
150   {
151     return HB_DIRECTION_IS_HORIZONTAL (direction) ?
152            font->em_scale_x (coordinate) + (this+deviceTable).get_x_delta (font) :
153            font->em_scale_y (coordinate) + (this+deviceTable).get_y_delta (font);
154   }
155 
sanitizeOT::CaretValueFormat3156   inline bool sanitize (hb_sanitize_context_t *c) const
157   {
158     TRACE_SANITIZE (this);
159     return_trace (c->check_struct (this) && deviceTable.sanitize (c, this));
160   }
161 
162   protected:
163   USHORT	caretValueFormat;	/* Format identifier--format = 3 */
164   SHORT		coordinate;		/* X or Y value, in design units */
165   OffsetTo<Device>
166 		deviceTable;		/* Offset to Device table for X or Y
167 					 * value--from beginning of CaretValue
168 					 * table */
169   public:
170   DEFINE_SIZE_STATIC (6);
171 };
172 
173 struct CaretValue
174 {
get_caret_valueOT::CaretValue175   inline hb_position_t get_caret_value (hb_font_t *font, hb_direction_t direction, hb_codepoint_t glyph_id) const
176   {
177     switch (u.format) {
178     case 1: return u.format1.get_caret_value (font, direction, glyph_id);
179     case 2: return u.format2.get_caret_value (font, direction, glyph_id);
180     case 3: return u.format3.get_caret_value (font, direction, glyph_id);
181     default:return 0;
182     }
183   }
184 
sanitizeOT::CaretValue185   inline bool sanitize (hb_sanitize_context_t *c) const
186   {
187     TRACE_SANITIZE (this);
188     if (!u.format.sanitize (c)) return_trace (false);
189     switch (u.format) {
190     case 1: return_trace (u.format1.sanitize (c));
191     case 2: return_trace (u.format2.sanitize (c));
192     case 3: return_trace (u.format3.sanitize (c));
193     default:return_trace (true);
194     }
195   }
196 
197   protected:
198   union {
199   USHORT		format;		/* Format identifier */
200   CaretValueFormat1	format1;
201   CaretValueFormat2	format2;
202   CaretValueFormat3	format3;
203   } u;
204   public:
205   DEFINE_SIZE_UNION (2, format);
206 };
207 
208 struct LigGlyph
209 {
get_lig_caretsOT::LigGlyph210   inline unsigned int get_lig_carets (hb_font_t *font,
211 				      hb_direction_t direction,
212 				      hb_codepoint_t glyph_id,
213 				      unsigned int start_offset,
214 				      unsigned int *caret_count /* IN/OUT */,
215 				      hb_position_t *caret_array /* OUT */) const
216   {
217     if (caret_count) {
218       const OffsetTo<CaretValue> *array = carets.sub_array (start_offset, caret_count);
219       unsigned int count = *caret_count;
220       for (unsigned int i = 0; i < count; i++)
221 	caret_array[i] = (this+array[i]).get_caret_value (font, direction, glyph_id);
222     }
223 
224     return carets.len;
225   }
226 
sanitizeOT::LigGlyph227   inline bool sanitize (hb_sanitize_context_t *c) const
228   {
229     TRACE_SANITIZE (this);
230     return_trace (carets.sanitize (c, this));
231   }
232 
233   protected:
234   OffsetArrayOf<CaretValue>
235 		carets;			/* Offset array of CaretValue tables
236 					 * --from beginning of LigGlyph table
237 					 * --in increasing coordinate order */
238   public:
239   DEFINE_SIZE_ARRAY (2, carets);
240 };
241 
242 struct LigCaretList
243 {
get_lig_caretsOT::LigCaretList244   inline unsigned int get_lig_carets (hb_font_t *font,
245 				      hb_direction_t direction,
246 				      hb_codepoint_t glyph_id,
247 				      unsigned int start_offset,
248 				      unsigned int *caret_count /* IN/OUT */,
249 				      hb_position_t *caret_array /* OUT */) const
250   {
251     unsigned int index = (this+coverage).get_coverage (glyph_id);
252     if (index == NOT_COVERED)
253     {
254       if (caret_count)
255 	*caret_count = 0;
256       return 0;
257     }
258     const LigGlyph &lig_glyph = this+ligGlyph[index];
259     return lig_glyph.get_lig_carets (font, direction, glyph_id, start_offset, caret_count, caret_array);
260   }
261 
sanitizeOT::LigCaretList262   inline bool sanitize (hb_sanitize_context_t *c) const
263   {
264     TRACE_SANITIZE (this);
265     return_trace (coverage.sanitize (c, this) && ligGlyph.sanitize (c, this));
266   }
267 
268   protected:
269   OffsetTo<Coverage>
270 		coverage;		/* Offset to Coverage table--from
271 					 * beginning of LigCaretList table */
272   OffsetArrayOf<LigGlyph>
273 		ligGlyph;		/* Array of LigGlyph tables
274 					 * in Coverage Index order */
275   public:
276   DEFINE_SIZE_ARRAY (4, ligGlyph);
277 };
278 
279 
280 struct MarkGlyphSetsFormat1
281 {
coversOT::MarkGlyphSetsFormat1282   inline bool covers (unsigned int set_index, hb_codepoint_t glyph_id) const
283   { return (this+coverage[set_index]).get_coverage (glyph_id) != NOT_COVERED; }
284 
sanitizeOT::MarkGlyphSetsFormat1285   inline bool sanitize (hb_sanitize_context_t *c) const
286   {
287     TRACE_SANITIZE (this);
288     return_trace (coverage.sanitize (c, this));
289   }
290 
291   protected:
292   USHORT	format;			/* Format identifier--format = 1 */
293   ArrayOf<OffsetTo<Coverage, ULONG> >
294 		coverage;		/* Array of long offsets to mark set
295 					 * coverage tables */
296   public:
297   DEFINE_SIZE_ARRAY (4, coverage);
298 };
299 
300 struct MarkGlyphSets
301 {
coversOT::MarkGlyphSets302   inline bool covers (unsigned int set_index, hb_codepoint_t glyph_id) const
303   {
304     switch (u.format) {
305     case 1: return u.format1.covers (set_index, glyph_id);
306     default:return false;
307     }
308   }
309 
sanitizeOT::MarkGlyphSets310   inline bool sanitize (hb_sanitize_context_t *c) const
311   {
312     TRACE_SANITIZE (this);
313     if (!u.format.sanitize (c)) return_trace (false);
314     switch (u.format) {
315     case 1: return_trace (u.format1.sanitize (c));
316     default:return_trace (true);
317     }
318   }
319 
320   protected:
321   union {
322   USHORT		format;		/* Format identifier */
323   MarkGlyphSetsFormat1	format1;
324   } u;
325   public:
326   DEFINE_SIZE_UNION (2, format);
327 };
328 
329 
330 /*
331  * GDEF -- The Glyph Definition Table
332  */
333 
334 struct GDEF
335 {
336   static const hb_tag_t tableTag	= HB_OT_TAG_GDEF;
337 
338   enum GlyphClasses {
339     UnclassifiedGlyph	= 0,
340     BaseGlyph		= 1,
341     LigatureGlyph	= 2,
342     MarkGlyph		= 3,
343     ComponentGlyph	= 4
344   };
345 
has_glyph_classesOT::GDEF346   inline bool has_glyph_classes (void) const { return glyphClassDef != 0; }
get_glyph_classOT::GDEF347   inline unsigned int get_glyph_class (hb_codepoint_t glyph) const
348   { return (this+glyphClassDef).get_class (glyph); }
get_glyphs_in_classOT::GDEF349   inline void get_glyphs_in_class (unsigned int klass, hb_set_t *glyphs) const
350   { (this+glyphClassDef).add_class (glyphs, klass); }
351 
has_mark_attachment_typesOT::GDEF352   inline bool has_mark_attachment_types (void) const { return markAttachClassDef != 0; }
get_mark_attachment_typeOT::GDEF353   inline unsigned int get_mark_attachment_type (hb_codepoint_t glyph) const
354   { return (this+markAttachClassDef).get_class (glyph); }
355 
has_attach_pointsOT::GDEF356   inline bool has_attach_points (void) const { return attachList != 0; }
get_attach_pointsOT::GDEF357   inline unsigned int get_attach_points (hb_codepoint_t glyph_id,
358 					 unsigned int start_offset,
359 					 unsigned int *point_count /* IN/OUT */,
360 					 unsigned int *point_array /* OUT */) const
361   { return (this+attachList).get_attach_points (glyph_id, start_offset, point_count, point_array); }
362 
has_lig_caretsOT::GDEF363   inline bool has_lig_carets (void) const { return ligCaretList != 0; }
get_lig_caretsOT::GDEF364   inline unsigned int get_lig_carets (hb_font_t *font,
365 				      hb_direction_t direction,
366 				      hb_codepoint_t glyph_id,
367 				      unsigned int start_offset,
368 				      unsigned int *caret_count /* IN/OUT */,
369 				      hb_position_t *caret_array /* OUT */) const
370   { return (this+ligCaretList).get_lig_carets (font, direction, glyph_id, start_offset, caret_count, caret_array); }
371 
has_mark_setsOT::GDEF372   inline bool has_mark_sets (void) const { return version.to_int () >= 0x00010002u && markGlyphSetsDef[0] != 0; }
mark_set_coversOT::GDEF373   inline bool mark_set_covers (unsigned int set_index, hb_codepoint_t glyph_id) const
374   { return version.to_int () >= 0x00010002u && (this+markGlyphSetsDef[0]).covers (set_index, glyph_id); }
375 
sanitizeOT::GDEF376   inline bool sanitize (hb_sanitize_context_t *c) const
377   {
378     TRACE_SANITIZE (this);
379     return_trace (version.sanitize (c) &&
380 		  likely (version.major == 1) &&
381 		  glyphClassDef.sanitize (c, this) &&
382 		  attachList.sanitize (c, this) &&
383 		  ligCaretList.sanitize (c, this) &&
384 		  markAttachClassDef.sanitize (c, this) &&
385 		  (version.to_int () < 0x00010002u || markGlyphSetsDef[0].sanitize (c, this)));
386   }
387 
388 
389   /* glyph_props is a 16-bit integer where the lower 8-bit have bits representing
390    * glyph class and other bits, and high 8-bit gthe mark attachment type (if any).
391    * Not to be confused with lookup_props which is very similar. */
get_glyph_propsOT::GDEF392   inline unsigned int get_glyph_props (hb_codepoint_t glyph) const
393   {
394     unsigned int klass = get_glyph_class (glyph);
395 
396     ASSERT_STATIC ((unsigned int) HB_OT_LAYOUT_GLYPH_PROPS_BASE_GLYPH == (unsigned int) LookupFlag::IgnoreBaseGlyphs);
397     ASSERT_STATIC ((unsigned int) HB_OT_LAYOUT_GLYPH_PROPS_LIGATURE == (unsigned int) LookupFlag::IgnoreLigatures);
398     ASSERT_STATIC ((unsigned int) HB_OT_LAYOUT_GLYPH_PROPS_MARK == (unsigned int) LookupFlag::IgnoreMarks);
399 
400     switch (klass) {
401     default:			return 0;
402     case BaseGlyph:		return HB_OT_LAYOUT_GLYPH_PROPS_BASE_GLYPH;
403     case LigatureGlyph:		return HB_OT_LAYOUT_GLYPH_PROPS_LIGATURE;
404     case MarkGlyph:
405 	  klass = get_mark_attachment_type (glyph);
406 	  return HB_OT_LAYOUT_GLYPH_PROPS_MARK | (klass << 8);
407     }
408   }
409 
410 
411   protected:
412   FixedVersion<>version;		/* Version of the GDEF table--currently
413 					 * 0x00010002u */
414   OffsetTo<ClassDef>
415 		glyphClassDef;		/* Offset to class definition table
416 					 * for glyph type--from beginning of
417 					 * GDEF header (may be Null) */
418   OffsetTo<AttachList>
419 		attachList;		/* Offset to list of glyphs with
420 					 * attachment points--from beginning
421 					 * of GDEF header (may be Null) */
422   OffsetTo<LigCaretList>
423 		ligCaretList;		/* Offset to list of positioning points
424 					 * for ligature carets--from beginning
425 					 * of GDEF header (may be Null) */
426   OffsetTo<ClassDef>
427 		markAttachClassDef;	/* Offset to class definition table for
428 					 * mark attachment type--from beginning
429 					 * of GDEF header (may be Null) */
430   OffsetTo<MarkGlyphSets>
431 		markGlyphSetsDef[VAR];	/* Offset to the table of mark set
432 					 * definitions--from beginning of GDEF
433 					 * header (may be NULL).  Introduced
434 					 * in version 00010002. */
435   public:
436   DEFINE_SIZE_ARRAY (12, markGlyphSetsDef);
437 };
438 
439 
440 } /* namespace OT */
441 
442 
443 #endif /* HB_OT_LAYOUT_GDEF_TABLE_HH */
444