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) {
75     TRACE_SANITIZE (this);
76     return TRACE_RETURN (coverage.sanitize (c, this) && attachPoint.sanitize (c, this));
77   }
78 
79   protected:
80   OffsetTo<Coverage>
81 		coverage;		/* Offset to Coverage table -- from
82 					 * beginning of AttachList table */
83   OffsetArrayOf<AttachPoint>
84 		attachPoint;		/* Array of AttachPoint tables
85 					 * in Coverage Index order */
86   public:
87   DEFINE_SIZE_ARRAY (4, attachPoint);
88 };
89 
90 /*
91  * Ligature Caret Table
92  */
93 
94 struct CaretValueFormat1
95 {
96   friend struct CaretValue;
97 
98   private:
get_caret_valueOT::CaretValueFormat199   inline hb_position_t get_caret_value (hb_font_t *font, hb_direction_t direction, hb_codepoint_t glyph_id HB_UNUSED) const
100   {
101     return HB_DIRECTION_IS_HORIZONTAL (direction) ? font->em_scale_x (coordinate) : font->em_scale_y (coordinate);
102   }
103 
sanitizeOT::CaretValueFormat1104   inline bool sanitize (hb_sanitize_context_t *c) {
105     TRACE_SANITIZE (this);
106     return TRACE_RETURN (c->check_struct (this));
107   }
108 
109   protected:
110   USHORT	caretValueFormat;	/* Format identifier--format = 1 */
111   SHORT		coordinate;		/* X or Y value, in design units */
112   public:
113   DEFINE_SIZE_STATIC (4);
114 };
115 
116 struct CaretValueFormat2
117 {
118   friend struct CaretValue;
119 
120   private:
get_caret_valueOT::CaretValueFormat2121   inline hb_position_t get_caret_value (hb_font_t *font, hb_direction_t direction, hb_codepoint_t glyph_id) const
122   {
123     hb_position_t x, y;
124     if (font->get_glyph_contour_point_for_origin (glyph_id, caretValuePoint, direction, &x, &y))
125       return HB_DIRECTION_IS_HORIZONTAL (direction) ? x : y;
126     else
127       return 0;
128   }
129 
sanitizeOT::CaretValueFormat2130   inline bool sanitize (hb_sanitize_context_t *c) {
131     TRACE_SANITIZE (this);
132     return TRACE_RETURN (c->check_struct (this));
133   }
134 
135   protected:
136   USHORT	caretValueFormat;	/* Format identifier--format = 2 */
137   USHORT	caretValuePoint;	/* Contour point index on glyph */
138   public:
139   DEFINE_SIZE_STATIC (4);
140 };
141 
142 struct CaretValueFormat3
143 {
144   friend struct CaretValue;
145 
get_caret_valueOT::CaretValueFormat3146   inline hb_position_t get_caret_value (hb_font_t *font, hb_direction_t direction, hb_codepoint_t glyph_id HB_UNUSED) const
147   {
148     return HB_DIRECTION_IS_HORIZONTAL (direction) ?
149            font->em_scale_x (coordinate) + (this+deviceTable).get_x_delta (font) :
150            font->em_scale_y (coordinate) + (this+deviceTable).get_y_delta (font);
151   }
152 
sanitizeOT::CaretValueFormat3153   inline bool sanitize (hb_sanitize_context_t *c) {
154     TRACE_SANITIZE (this);
155     return TRACE_RETURN (c->check_struct (this) && deviceTable.sanitize (c, this));
156   }
157 
158   protected:
159   USHORT	caretValueFormat;	/* Format identifier--format = 3 */
160   SHORT		coordinate;		/* X or Y value, in design units */
161   OffsetTo<Device>
162 		deviceTable;		/* Offset to Device table for X or Y
163 					 * value--from beginning of CaretValue
164 					 * table */
165   public:
166   DEFINE_SIZE_STATIC (6);
167 };
168 
169 struct CaretValue
170 {
get_caret_valueOT::CaretValue171   inline hb_position_t get_caret_value (hb_font_t *font, hb_direction_t direction, hb_codepoint_t glyph_id) const
172   {
173     switch (u.format) {
174     case 1: return u.format1.get_caret_value (font, direction, glyph_id);
175     case 2: return u.format2.get_caret_value (font, direction, glyph_id);
176     case 3: return u.format3.get_caret_value (font, direction, glyph_id);
177     default:return 0;
178     }
179   }
180 
sanitizeOT::CaretValue181   inline bool sanitize (hb_sanitize_context_t *c) {
182     TRACE_SANITIZE (this);
183     if (!u.format.sanitize (c)) return TRACE_RETURN (false);
184     switch (u.format) {
185     case 1: return TRACE_RETURN (u.format1.sanitize (c));
186     case 2: return TRACE_RETURN (u.format2.sanitize (c));
187     case 3: return TRACE_RETURN (u.format3.sanitize (c));
188     default:return TRACE_RETURN (true);
189     }
190   }
191 
192   protected:
193   union {
194   USHORT		format;		/* Format identifier */
195   CaretValueFormat1	format1;
196   CaretValueFormat2	format2;
197   CaretValueFormat3	format3;
198   } u;
199   public:
200   DEFINE_SIZE_UNION (2, format);
201 };
202 
203 struct LigGlyph
204 {
get_lig_caretsOT::LigGlyph205   inline unsigned int get_lig_carets (hb_font_t *font,
206 				      hb_direction_t direction,
207 				      hb_codepoint_t glyph_id,
208 				      unsigned int start_offset,
209 				      unsigned int *caret_count /* IN/OUT */,
210 				      hb_position_t *caret_array /* OUT */) const
211   {
212     if (caret_count) {
213       const OffsetTo<CaretValue> *array = carets.sub_array (start_offset, caret_count);
214       unsigned int count = *caret_count;
215       for (unsigned int i = 0; i < count; i++)
216 	caret_array[i] = (this+array[i]).get_caret_value (font, direction, glyph_id);
217     }
218 
219     return carets.len;
220   }
221 
sanitizeOT::LigGlyph222   inline bool sanitize (hb_sanitize_context_t *c) {
223     TRACE_SANITIZE (this);
224     return TRACE_RETURN (carets.sanitize (c, this));
225   }
226 
227   protected:
228   OffsetArrayOf<CaretValue>
229 		carets;			/* Offset array of CaretValue tables
230 					 * --from beginning of LigGlyph table
231 					 * --in increasing coordinate order */
232   public:
233   DEFINE_SIZE_ARRAY (2, carets);
234 };
235 
236 struct LigCaretList
237 {
get_lig_caretsOT::LigCaretList238   inline unsigned int get_lig_carets (hb_font_t *font,
239 				      hb_direction_t direction,
240 				      hb_codepoint_t glyph_id,
241 				      unsigned int start_offset,
242 				      unsigned int *caret_count /* IN/OUT */,
243 				      hb_position_t *caret_array /* OUT */) const
244   {
245     unsigned int index = (this+coverage).get_coverage (glyph_id);
246     if (index == NOT_COVERED)
247     {
248       if (caret_count)
249 	*caret_count = 0;
250       return 0;
251     }
252     const LigGlyph &lig_glyph = this+ligGlyph[index];
253     return lig_glyph.get_lig_carets (font, direction, glyph_id, start_offset, caret_count, caret_array);
254   }
255 
sanitizeOT::LigCaretList256   inline bool sanitize (hb_sanitize_context_t *c) {
257     TRACE_SANITIZE (this);
258     return TRACE_RETURN (coverage.sanitize (c, this) && ligGlyph.sanitize (c, this));
259   }
260 
261   protected:
262   OffsetTo<Coverage>
263 		coverage;		/* Offset to Coverage table--from
264 					 * beginning of LigCaretList table */
265   OffsetArrayOf<LigGlyph>
266 		ligGlyph;		/* Array of LigGlyph tables
267 					 * in Coverage Index order */
268   public:
269   DEFINE_SIZE_ARRAY (4, ligGlyph);
270 };
271 
272 
273 struct MarkGlyphSetsFormat1
274 {
coversOT::MarkGlyphSetsFormat1275   inline bool covers (unsigned int set_index, hb_codepoint_t glyph_id) const
276   { return (this+coverage[set_index]).get_coverage (glyph_id) != NOT_COVERED; }
277 
sanitizeOT::MarkGlyphSetsFormat1278   inline bool sanitize (hb_sanitize_context_t *c) {
279     TRACE_SANITIZE (this);
280     return TRACE_RETURN (coverage.sanitize (c, this));
281   }
282 
283   protected:
284   USHORT	format;			/* Format identifier--format = 1 */
285   ArrayOf<OffsetTo<Coverage, ULONG> >
286 		coverage;		/* Array of long offsets to mark set
287 					 * coverage tables */
288   public:
289   DEFINE_SIZE_ARRAY (4, coverage);
290 };
291 
292 struct MarkGlyphSets
293 {
coversOT::MarkGlyphSets294   inline bool covers (unsigned int set_index, hb_codepoint_t glyph_id) const
295   {
296     switch (u.format) {
297     case 1: return u.format1.covers (set_index, glyph_id);
298     default:return false;
299     }
300   }
301 
sanitizeOT::MarkGlyphSets302   inline bool sanitize (hb_sanitize_context_t *c) {
303     TRACE_SANITIZE (this);
304     if (!u.format.sanitize (c)) return TRACE_RETURN (false);
305     switch (u.format) {
306     case 1: return TRACE_RETURN (u.format1.sanitize (c));
307     default:return TRACE_RETURN (true);
308     }
309   }
310 
311   protected:
312   union {
313   USHORT		format;		/* Format identifier */
314   MarkGlyphSetsFormat1	format1;
315   } u;
316   public:
317   DEFINE_SIZE_UNION (2, format);
318 };
319 
320 
321 /*
322  * GDEF -- The Glyph Definition Table
323  */
324 
325 struct GDEF
326 {
327   static const hb_tag_t tableTag	= HB_OT_TAG_GDEF;
328 
329   enum GlyphClasses {
330     UnclassifiedGlyph	= 0,
331     BaseGlyph		= 1,
332     LigatureGlyph	= 2,
333     MarkGlyph		= 3,
334     ComponentGlyph	= 4
335   };
336 
has_glyph_classesOT::GDEF337   inline bool has_glyph_classes (void) const { return glyphClassDef != 0; }
get_glyph_classOT::GDEF338   inline unsigned int get_glyph_class (hb_codepoint_t glyph) const
339   { return (this+glyphClassDef).get_class (glyph); }
get_glyphs_in_classOT::GDEF340   inline void get_glyphs_in_class (unsigned int klass, hb_set_t *glyphs) const
341   { (this+glyphClassDef).add_class (glyphs, klass); }
342 
has_mark_attachment_typesOT::GDEF343   inline bool has_mark_attachment_types (void) const { return markAttachClassDef != 0; }
get_mark_attachment_typeOT::GDEF344   inline unsigned int get_mark_attachment_type (hb_codepoint_t glyph) const
345   { return (this+markAttachClassDef).get_class (glyph); }
346 
has_attach_pointsOT::GDEF347   inline bool has_attach_points (void) const { return attachList != 0; }
get_attach_pointsOT::GDEF348   inline unsigned int get_attach_points (hb_codepoint_t glyph_id,
349 					 unsigned int start_offset,
350 					 unsigned int *point_count /* IN/OUT */,
351 					 unsigned int *point_array /* OUT */) const
352   { return (this+attachList).get_attach_points (glyph_id, start_offset, point_count, point_array); }
353 
has_lig_caretsOT::GDEF354   inline bool has_lig_carets (void) const { return ligCaretList != 0; }
get_lig_caretsOT::GDEF355   inline unsigned int get_lig_carets (hb_font_t *font,
356 				      hb_direction_t direction,
357 				      hb_codepoint_t glyph_id,
358 				      unsigned int start_offset,
359 				      unsigned int *caret_count /* IN/OUT */,
360 				      hb_position_t *caret_array /* OUT */) const
361   { return (this+ligCaretList).get_lig_carets (font, direction, glyph_id, start_offset, caret_count, caret_array); }
362 
has_mark_setsOT::GDEF363   inline bool has_mark_sets (void) const { return version.to_int () >= 0x00010002u && markGlyphSetsDef[0] != 0; }
mark_set_coversOT::GDEF364   inline bool mark_set_covers (unsigned int set_index, hb_codepoint_t glyph_id) const
365   { return version.to_int () >= 0x00010002u && (this+markGlyphSetsDef[0]).covers (set_index, glyph_id); }
366 
sanitizeOT::GDEF367   inline bool sanitize (hb_sanitize_context_t *c) {
368     TRACE_SANITIZE (this);
369     return TRACE_RETURN (version.sanitize (c) &&
370 			 likely (version.major == 1) &&
371 			 glyphClassDef.sanitize (c, this) &&
372 			 attachList.sanitize (c, this) &&
373 			 ligCaretList.sanitize (c, this) &&
374 			 markAttachClassDef.sanitize (c, this) &&
375 			 (version.to_int () < 0x00010002u || markGlyphSetsDef[0].sanitize (c, this)));
376   }
377 
378 
379   /* glyph_props is a 16-bit integer where the lower 8-bit have bits representing
380    * glyph class and other bits, and high 8-bit gthe mark attachment type (if any).
381    * Not to be confused with lookup_props which is very similar. */
get_glyph_propsOT::GDEF382   inline unsigned int get_glyph_props (hb_codepoint_t glyph) const
383   {
384     unsigned int klass = get_glyph_class (glyph);
385 
386     ASSERT_STATIC ((unsigned int) HB_OT_LAYOUT_GLYPH_PROPS_BASE_GLYPH == (unsigned int) LookupFlag::IgnoreBaseGlyphs);
387     ASSERT_STATIC ((unsigned int) HB_OT_LAYOUT_GLYPH_PROPS_LIGATURE == (unsigned int) LookupFlag::IgnoreLigatures);
388     ASSERT_STATIC ((unsigned int) HB_OT_LAYOUT_GLYPH_PROPS_MARK == (unsigned int) LookupFlag::IgnoreMarks);
389 
390     switch (klass) {
391     default:			return 0;
392     case BaseGlyph:		return HB_OT_LAYOUT_GLYPH_PROPS_BASE_GLYPH;
393     case LigatureGlyph:		return HB_OT_LAYOUT_GLYPH_PROPS_LIGATURE;
394     case MarkGlyph:
395 	  klass = get_mark_attachment_type (glyph);
396 	  return HB_OT_LAYOUT_GLYPH_PROPS_MARK | (klass << 8);
397     }
398   }
399 
400 
401   protected:
402   FixedVersion	version;		/* Version of the GDEF table--currently
403 					 * 0x00010002u */
404   OffsetTo<ClassDef>
405 		glyphClassDef;		/* Offset to class definition table
406 					 * for glyph type--from beginning of
407 					 * GDEF header (may be Null) */
408   OffsetTo<AttachList>
409 		attachList;		/* Offset to list of glyphs with
410 					 * attachment points--from beginning
411 					 * of GDEF header (may be Null) */
412   OffsetTo<LigCaretList>
413 		ligCaretList;		/* Offset to list of positioning points
414 					 * for ligature carets--from beginning
415 					 * of GDEF header (may be Null) */
416   OffsetTo<ClassDef>
417 		markAttachClassDef;	/* Offset to class definition table for
418 					 * mark attachment type--from beginning
419 					 * of GDEF header (may be Null) */
420   OffsetTo<MarkGlyphSets>
421 		markGlyphSetsDef[VAR];	/* Offset to the table of mark set
422 					 * definitions--from beginning of GDEF
423 					 * header (may be NULL).  Introduced
424 					 * in version 00010002. */
425   public:
426   DEFINE_SIZE_ARRAY (12, markGlyphSetsDef);
427 };
428 
429 
430 } /* namespace OT */
431 
432 
433 #endif /* HB_OT_LAYOUT_GDEF_TABLE_HH */
434