third_party/harfbuzz-ng/src/hb-ot-layout-gdef-table.hh

   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 {
  49   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
  74   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:
  99   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
 104   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:
 121   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
 130   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
 146   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
 153   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 {
 171   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
 181   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 {
 205   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
 222   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 {
 238   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
 256   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 {
 275   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
 278   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   LongOffsetArrayOf<Coverage>
 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 {
 294   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
 302   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 Tag     = 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
 337   inline bool has_glyph_classes (void) const { return glyphClassDef != 0; }
 338   inline unsigned int get_glyph_class (hb_codepoint_t glyph) const
 339   { return (this+glyphClassDef).get_class (glyph); }
 340   inline void get_glyphs_in_class (unsigned int klass, hb_set_t *glyphs) const
 341   { (this+glyphClassDef).add_class (glyphs, klass); }
 342
 343   inline bool has_mark_attachment_types (void) const { return markAttachClassDef != 0; }
 344   inline unsigned int get_mark_attachment_type (hb_codepoint_t glyph) const
 345   { return (this+markAttachClassDef).get_class (glyph); }
 346
 347   inline bool has_attach_points (void) const { return attachList != 0; }
 348   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
 354   inline bool has_lig_carets (void) const { return ligCaretList != 0; }
 355   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
 363   inline bool has_mark_sets (void) const { return version.to_int () >= 0x00010002 && markGlyphSetsDef[0] != 0; }
 364   inline bool mark_set_covers (unsigned int set_index, hb_codepoint_t glyph_id) const
 365   { return version.to_int () >= 0x00010002 && (this+markGlyphSetsDef[0]).covers (set_index, glyph_id); }
 366
 367   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 () < 0x00010002 || 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. */
 382   inline unsigned int get_glyph_props (hb_codepoint_t glyph) const
 383   {
 384     unsigned int klass = get_glyph_class (glyph);
 385
 386     switch (klass) {
 387     default:
 388     case UnclassifiedGlyph:     return HB_OT_LAYOUT_GLYPH_PROPS_UNCLASSIFIED;
 389     case BaseGlyph:             return HB_OT_LAYOUT_GLYPH_PROPS_BASE_GLYPH;
 390     case LigatureGlyph:         return HB_OT_LAYOUT_GLYPH_PROPS_LIGATURE;
 391     case ComponentGlyph:        return HB_OT_LAYOUT_GLYPH_PROPS_COMPONENT;
 392     case MarkGlyph:
 393           klass = get_mark_attachment_type (glyph);
 394           return HB_OT_LAYOUT_GLYPH_PROPS_MARK | (klass << 8);
 395     }
 396   }
 397
 398
 399   protected:
 400   FixedVersion  version;                /* Version of the GDEF table--currently
 401                                          * 0x00010002 */
 402   OffsetTo<ClassDef>
 403                 glyphClassDef;          /* Offset to class definition table
 404                                          * for glyph type--from beginning of
 405                                          * GDEF header (may be Null) */
 406   OffsetTo<AttachList>
 407                 attachList;             /* Offset to list of glyphs with
 408                                          * attachment points--from beginning
 409                                          * of GDEF header (may be Null) */
 410   OffsetTo<LigCaretList>
 411                 ligCaretList;           /* Offset to list of positioning points
 412                                          * for ligature carets--from beginning
 413                                          * of GDEF header (may be Null) */
 414   OffsetTo<ClassDef>
 415                 markAttachClassDef;     /* Offset to class definition table for
 416                                          * mark attachment type--from beginning
 417                                          * of GDEF header (may be Null) */
 418   OffsetTo<MarkGlyphSets>
 419                 markGlyphSetsDef[VAR];  /* Offset to the table of mark set
 420                                          * definitions--from beginning of GDEF
 421                                          * header (may be NULL).  Introduced
 422                                          * in version 00010002. */
 423   public:
 424   DEFINE_SIZE_ARRAY (12, markGlyphSetsDef);
 425 };
 426
 427
 428 } /* namespace OT */
 429
 430
 431 #endif /* HB_OT_LAYOUT_GDEF_TABLE_HH */