1 /* 2 * Copyright 2007,2008,2009 Red Hat, Inc. 3 * Copyright 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_OPEN_FILE_PRIVATE_HH 30 #define HB_OPEN_FILE_PRIVATE_HH 31 32 #include "hb-open-type-private.hh" 33 34 35 namespace OT { 36 37 38 /* 39 * 40 * The OpenType Font File 41 * 42 */ 43 44 45 /* 46 * Organization of an OpenType Font 47 */ 48 49 struct OpenTypeFontFile; 50 struct OffsetTable; 51 struct TTCHeader; 52 53 54 typedef struct TableRecord 55 { 56 inline bool sanitize (hb_sanitize_context_t *c) const 57 { 58 TRACE_SANITIZE (this); 59 return_trace (c->check_struct (this)); 60 } 61 62 Tag tag; /* 4-byte identifier. */ 63 CheckSum checkSum; /* CheckSum for this table. */ 64 ULONG offset; /* Offset from beginning of TrueType font 65 * file. */ 66 ULONG length; /* Length of this table. */ 67 public: 68 DEFINE_SIZE_STATIC (16); 69 } OpenTypeTable; 70 71 typedef struct OffsetTable 72 { 73 friend struct OpenTypeFontFile; 74 75 inline unsigned int get_table_count (void) const 76 { return numTables; } 77 inline const TableRecord& get_table (unsigned int i) const 78 { 79 if (unlikely (i >= numTables)) return Null(TableRecord); 80 return tables[i]; 81 } 82 inline bool find_table_index (hb_tag_t tag, unsigned int *table_index) const 83 { 84 Tag t; 85 t.set (tag); 86 unsigned int count = numTables; 87 for (unsigned int i = 0; i < count; i++) 88 { 89 if (t == tables[i].tag) 90 { 91 if (table_index) *table_index = i; 92 return true; 93 } 94 } 95 if (table_index) *table_index = Index::NOT_FOUND_INDEX; 96 return false; 97 } 98 inline const TableRecord& get_table_by_tag (hb_tag_t tag) const 99 { 100 unsigned int table_index; 101 find_table_index (tag, &table_index); 102 return get_table (table_index); 103 } 104 105 public: 106 inline bool sanitize (hb_sanitize_context_t *c) const 107 { 108 TRACE_SANITIZE (this); 109 return_trace (c->check_struct (this) && c->check_array (tables, TableRecord::static_size, numTables)); 110 } 111 112 protected: 113 Tag sfnt_version; /* '\0\001\0\00' if TrueType / 'OTTO' if CFF */ 114 USHORT numTables; /* Number of tables. */ 115 USHORT searchRangeZ; /* (Maximum power of 2 <= numTables) x 16 */ 116 USHORT entrySelectorZ; /* Log2(maximum power of 2 <= numTables). */ 117 USHORT rangeShiftZ; /* NumTables x 16-searchRange. */ 118 TableRecord tables[VAR]; /* TableRecord entries. numTables items */ 119 public: 120 DEFINE_SIZE_ARRAY (12, tables); 121 } OpenTypeFontFace; 122 123 124 /* 125 * TrueType Collections 126 */ 127 128 struct TTCHeaderVersion1 129 { 130 friend struct TTCHeader; 131 132 inline unsigned int get_face_count (void) const { return table.len; } 133 inline const OpenTypeFontFace& get_face (unsigned int i) const { return this+table[i]; } 134 135 inline bool sanitize (hb_sanitize_context_t *c) const 136 { 137 TRACE_SANITIZE (this); 138 return_trace (table.sanitize (c, this)); 139 } 140 141 protected: 142 Tag ttcTag; /* TrueType Collection ID string: 'ttcf' */ 143 FixedVersion<>version; /* Version of the TTC Header (1.0), 144 * 0x00010000u */ 145 ArrayOf<LOffsetTo<OffsetTable>, ULONG> 146 table; /* Array of offsets to the OffsetTable for each font 147 * from the beginning of the file */ 148 public: 149 DEFINE_SIZE_ARRAY (12, table); 150 }; 151 152 struct TTCHeader 153 { 154 friend struct OpenTypeFontFile; 155 156 private: 157 158 inline unsigned int get_face_count (void) const 159 { 160 switch (u.header.version.major) { 161 case 2: /* version 2 is compatible with version 1 */ 162 case 1: return u.version1.get_face_count (); 163 default:return 0; 164 } 165 } 166 inline const OpenTypeFontFace& get_face (unsigned int i) const 167 { 168 switch (u.header.version.major) { 169 case 2: /* version 2 is compatible with version 1 */ 170 case 1: return u.version1.get_face (i); 171 default:return Null(OpenTypeFontFace); 172 } 173 } 174 175 inline bool sanitize (hb_sanitize_context_t *c) const 176 { 177 TRACE_SANITIZE (this); 178 if (unlikely (!u.header.version.sanitize (c))) return_trace (false); 179 switch (u.header.version.major) { 180 case 2: /* version 2 is compatible with version 1 */ 181 case 1: return_trace (u.version1.sanitize (c)); 182 default:return_trace (true); 183 } 184 } 185 186 protected: 187 union { 188 struct { 189 Tag ttcTag; /* TrueType Collection ID string: 'ttcf' */ 190 FixedVersion<>version; /* Version of the TTC Header (1.0 or 2.0), 191 * 0x00010000u or 0x00020000u */ 192 } header; 193 TTCHeaderVersion1 version1; 194 } u; 195 }; 196 197 198 /* 199 * OpenType Font File 200 */ 201 202 struct OpenTypeFontFile 203 { 204 static const hb_tag_t tableTag = HB_TAG ('_','_','_','_'); /* Sanitizer needs this. */ 205 206 static const hb_tag_t CFFTag = HB_TAG ('O','T','T','O'); /* OpenType with Postscript outlines */ 207 static const hb_tag_t TrueTypeTag = HB_TAG ( 0 , 1 , 0 , 0 ); /* OpenType with TrueType outlines */ 208 static const hb_tag_t TTCTag = HB_TAG ('t','t','c','f'); /* TrueType Collection */ 209 static const hb_tag_t TrueTag = HB_TAG ('t','r','u','e'); /* Obsolete Apple TrueType */ 210 static const hb_tag_t Typ1Tag = HB_TAG ('t','y','p','1'); /* Obsolete Apple Type1 font in SFNT container */ 211 212 inline hb_tag_t get_tag (void) const { return u.tag; } 213 214 inline unsigned int get_face_count (void) const 215 { 216 switch (u.tag) { 217 case CFFTag: /* All the non-collection tags */ 218 case TrueTag: 219 case Typ1Tag: 220 case TrueTypeTag: return 1; 221 case TTCTag: return u.ttcHeader.get_face_count (); 222 default: return 0; 223 } 224 } 225 inline const OpenTypeFontFace& get_face (unsigned int i) const 226 { 227 switch (u.tag) { 228 /* Note: for non-collection SFNT data we ignore index. This is because 229 * Apple dfont container is a container of SFNT's. So each SFNT is a 230 * non-TTC, but the index is more than zero. */ 231 case CFFTag: /* All the non-collection tags */ 232 case TrueTag: 233 case Typ1Tag: 234 case TrueTypeTag: return u.fontFace; 235 case TTCTag: return u.ttcHeader.get_face (i); 236 default: return Null(OpenTypeFontFace); 237 } 238 } 239 240 inline bool sanitize (hb_sanitize_context_t *c) const 241 { 242 TRACE_SANITIZE (this); 243 if (unlikely (!u.tag.sanitize (c))) return_trace (false); 244 switch (u.tag) { 245 case CFFTag: /* All the non-collection tags */ 246 case TrueTag: 247 case Typ1Tag: 248 case TrueTypeTag: return_trace (u.fontFace.sanitize (c)); 249 case TTCTag: return_trace (u.ttcHeader.sanitize (c)); 250 default: return_trace (true); 251 } 252 } 253 254 protected: 255 union { 256 Tag tag; /* 4-byte identifier. */ 257 OpenTypeFontFace fontFace; 258 TTCHeader ttcHeader; 259 } u; 260 public: 261 DEFINE_SIZE_UNION (4, tag); 262 }; 263 264 265 } /* namespace OT */ 266 267 268 #endif /* HB_OPEN_FILE_PRIVATE_HH */ 269
