1 /* 2 * Copyright © 2011,2012 Google, Inc. 3 * Copyright © 2018 Ebrahim Byagowi 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 * Google Author(s): Behdad Esfahbod 26 */ 27 28 #ifndef HB_OT_OS2_TABLE_HH 29 #define HB_OT_OS2_TABLE_HH 30 31 #include "hb-open-type.hh" 32 #include "hb-ot-os2-unicode-ranges.hh" 33 34 #include "hb-set.hh" 35 36 /* 37 * OS/2 and Windows Metrics 38 * https://docs.microsoft.com/en-us/typography/opentype/spec/os2 39 */ 40 #define HB_OT_TAG_OS2 HB_TAG('O','S','/','2') 41 42 43 namespace OT { 44 45 struct OS2V1Tail 46 { sanitizeOT::OS2V1Tail47 bool sanitize (hb_sanitize_context_t *c) const 48 { 49 TRACE_SANITIZE (this); 50 return_trace (c->check_struct (this)); 51 } 52 53 public: 54 HBUINT32 ulCodePageRange1; 55 HBUINT32 ulCodePageRange2; 56 public: 57 DEFINE_SIZE_STATIC (8); 58 }; 59 60 struct OS2V2Tail 61 { has_dataOT::OS2V2Tail62 bool has_data () const { return sxHeight || sCapHeight; } 63 operator ->OT::OS2V2Tail64 const OS2V2Tail * operator -> () const { return this; } 65 sanitizeOT::OS2V2Tail66 bool sanitize (hb_sanitize_context_t *c) const 67 { 68 TRACE_SANITIZE (this); 69 return_trace (c->check_struct (this)); 70 } 71 72 public: 73 HBINT16 sxHeight; 74 HBINT16 sCapHeight; 75 HBUINT16 usDefaultChar; 76 HBUINT16 usBreakChar; 77 HBUINT16 usMaxContext; 78 public: 79 DEFINE_SIZE_STATIC (10); 80 }; 81 82 struct OS2V5Tail 83 { get_optical_sizeOT::OS2V5Tail84 inline bool get_optical_size (unsigned int *lower, unsigned int *upper) const 85 { 86 unsigned int lower_optical_size = usLowerOpticalPointSize; 87 unsigned int upper_optical_size = usUpperOpticalPointSize; 88 89 /* Per https://docs.microsoft.com/en-us/typography/opentype/spec/os2#lps */ 90 if (lower_optical_size < upper_optical_size && 91 lower_optical_size >= 1 && lower_optical_size <= 0xFFFE && 92 upper_optical_size >= 2 && upper_optical_size <= 0xFFFF) 93 { 94 *lower = lower_optical_size; 95 *upper = upper_optical_size; 96 return true; 97 } 98 return false; 99 } 100 sanitizeOT::OS2V5Tail101 bool sanitize (hb_sanitize_context_t *c) const 102 { 103 TRACE_SANITIZE (this); 104 return_trace (c->check_struct (this)); 105 } 106 107 public: 108 HBUINT16 usLowerOpticalPointSize; 109 HBUINT16 usUpperOpticalPointSize; 110 public: 111 DEFINE_SIZE_STATIC (4); 112 }; 113 114 struct OS2 115 { 116 static constexpr hb_tag_t tableTag = HB_OT_TAG_OS2; 117 has_dataOT::OS2118 bool has_data () const { return usWeightClass || usWidthClass || usFirstCharIndex || usLastCharIndex; } 119 v1OT::OS2120 const OS2V1Tail &v1 () const { return version >= 1 ? v1X : Null (OS2V1Tail); } v2OT::OS2121 const OS2V2Tail &v2 () const { return version >= 2 ? v2X : Null (OS2V2Tail); } v5OT::OS2122 const OS2V5Tail &v5 () const { return version >= 5 ? v5X : Null (OS2V5Tail); } 123 124 enum selection_flag_t { 125 ITALIC = 1u<<0, 126 UNDERSCORE = 1u<<1, 127 NEGATIVE = 1u<<2, 128 OUTLINED = 1u<<3, 129 STRIKEOUT = 1u<<4, 130 BOLD = 1u<<5, 131 REGULAR = 1u<<6, 132 USE_TYPO_METRICS = 1u<<7, 133 WWS = 1u<<8, 134 OBLIQUE = 1u<<9 135 }; 136 is_italicOT::OS2137 bool is_italic () const { return fsSelection & ITALIC; } is_obliqueOT::OS2138 bool is_oblique () const { return fsSelection & OBLIQUE; } use_typo_metricsOT::OS2139 bool use_typo_metrics () const { return fsSelection & USE_TYPO_METRICS; } 140 141 enum width_class_t { 142 FWIDTH_ULTRA_CONDENSED = 1, /* 50% */ 143 FWIDTH_EXTRA_CONDENSED = 2, /* 62.5% */ 144 FWIDTH_CONDENSED = 3, /* 75% */ 145 FWIDTH_SEMI_CONDENSED = 4, /* 87.5% */ 146 FWIDTH_NORMAL = 5, /* 100% */ 147 FWIDTH_SEMI_EXPANDED = 6, /* 112.5% */ 148 FWIDTH_EXPANDED = 7, /* 125% */ 149 FWIDTH_EXTRA_EXPANDED = 8, /* 150% */ 150 FWIDTH_ULTRA_EXPANDED = 9 /* 200% */ 151 }; 152 get_widthOT::OS2153 float get_width () const 154 { 155 switch (usWidthClass) { 156 case FWIDTH_ULTRA_CONDENSED:return 50.f; 157 case FWIDTH_EXTRA_CONDENSED:return 62.5f; 158 case FWIDTH_CONDENSED: return 75.f; 159 case FWIDTH_SEMI_CONDENSED: return 87.5f; 160 default: 161 case FWIDTH_NORMAL: return 100.f; 162 case FWIDTH_SEMI_EXPANDED: return 112.5f; 163 case FWIDTH_EXPANDED: return 125.f; 164 case FWIDTH_EXTRA_EXPANDED: return 150.f; 165 case FWIDTH_ULTRA_EXPANDED: return 200.f; 166 } 167 } 168 map_wdth_to_widthclassOT::OS2169 float map_wdth_to_widthclass(float width) const 170 { 171 if (width < 50) return 1.0f; 172 if (width > 200) return 9.0f; 173 174 float ratio = (width - 50) / 12.5f; 175 int a = (int) floorf (ratio); 176 int b = (int) ceilf (ratio); 177 178 /* follow this maping: 179 * https://docs.microsoft.com/en-us/typography/opentype/spec/os2#uswidthclass 180 */ 181 if (b <= 6) // 50-125 182 { 183 if (a == b) return a + 1.0f; 184 } 185 else if (b == 7) // no mapping for 137.5 186 { 187 a = 6; 188 b = 8; 189 } 190 else if (b == 8) 191 { 192 if (a == b) return 8.0f; // 150 193 a = 6; 194 } 195 else 196 { 197 if (a == b && a == 12) return 9.0f; //200 198 b = 12; 199 a = 8; 200 } 201 202 float va = 50 + a * 12.5f; 203 float vb = 50 + b * 12.5f; 204 205 float ret = a + (width - va) / (vb - va); 206 if (a <= 6) ret += 1.0f; 207 return ret; 208 } 209 subsetOT::OS2210 bool subset (hb_subset_context_t *c) const 211 { 212 TRACE_SUBSET (this); 213 OS2 *os2_prime = c->serializer->embed (this); 214 if (unlikely (!os2_prime)) return_trace (false); 215 216 if (c->plan->user_axes_location->has (HB_TAG ('w','g','h','t')) && 217 !c->plan->pinned_at_default) 218 { 219 float weight_class = c->plan->user_axes_location->get (HB_TAG ('w','g','h','t')); 220 if (!c->serializer->check_assign (os2_prime->usWeightClass, 221 roundf (hb_clamp (weight_class, 1.0f, 1000.0f)), 222 HB_SERIALIZE_ERROR_INT_OVERFLOW)) 223 return_trace (false); 224 } 225 226 if (c->plan->user_axes_location->has (HB_TAG ('w','d','t','h')) && 227 !c->plan->pinned_at_default) 228 { 229 float width = c->plan->user_axes_location->get (HB_TAG ('w','d','t','h')); 230 if (!c->serializer->check_assign (os2_prime->usWidthClass, 231 roundf (map_wdth_to_widthclass (width)), 232 HB_SERIALIZE_ERROR_INT_OVERFLOW)) 233 return_trace (false); 234 } 235 236 if (c->plan->flags & HB_SUBSET_FLAGS_NO_PRUNE_UNICODE_RANGES) 237 return_trace (true); 238 239 /* when --gids option is not used, no need to do collect_mapping that is 240 * iterating all codepoints in each subtable, which is not efficient */ 241 uint16_t min_cp, max_cp; 242 find_min_and_max_codepoint (c->plan->unicodes, &min_cp, &max_cp); 243 os2_prime->usFirstCharIndex = min_cp; 244 os2_prime->usLastCharIndex = max_cp; 245 246 _update_unicode_ranges (c->plan->unicodes, os2_prime->ulUnicodeRange); 247 248 return_trace (true); 249 } 250 _update_unicode_rangesOT::OS2251 void _update_unicode_ranges (const hb_set_t *codepoints, 252 HBUINT32 ulUnicodeRange[4]) const 253 { 254 HBUINT32 newBits[4]; 255 for (unsigned int i = 0; i < 4; i++) 256 newBits[i] = 0; 257 258 hb_codepoint_t cp = HB_SET_VALUE_INVALID; 259 while (codepoints->next (&cp)) { 260 unsigned int bit = _hb_ot_os2_get_unicode_range_bit (cp); 261 if (bit < 128) 262 { 263 unsigned int block = bit / 32; 264 unsigned int bit_in_block = bit % 32; 265 unsigned int mask = 1 << bit_in_block; 266 newBits[block] = newBits[block] | mask; 267 } 268 if (cp >= 0x10000 && cp <= 0x110000) 269 { 270 /* the spec says that bit 57 ("Non Plane 0") implies that there's 271 at least one codepoint beyond the BMP; so I also include all 272 the non-BMP codepoints here */ 273 newBits[1] = newBits[1] | (1 << 25); 274 } 275 } 276 277 for (unsigned int i = 0; i < 4; i++) 278 ulUnicodeRange[i] = ulUnicodeRange[i] & newBits[i]; // set bits only if set in the original 279 } 280 find_min_and_max_codepointOT::OS2281 static void find_min_and_max_codepoint (const hb_set_t *codepoints, 282 uint16_t *min_cp, /* OUT */ 283 uint16_t *max_cp /* OUT */) 284 { 285 *min_cp = hb_min (0xFFFFu, codepoints->get_min ()); 286 *max_cp = hb_min (0xFFFFu, codepoints->get_max ()); 287 } 288 289 /* https://github.com/Microsoft/Font-Validator/blob/520aaae/OTFontFileVal/val_OS2.cs#L644-L681 290 * https://docs.microsoft.com/en-us/typography/legacy/legacy_arabic_fonts */ 291 enum font_page_t 292 { 293 FONT_PAGE_NONE = 0, 294 FONT_PAGE_HEBREW = 0xB100, /* Hebrew Windows 3.1 font page */ 295 FONT_PAGE_SIMP_ARABIC = 0xB200, /* Simplified Arabic Windows 3.1 font page */ 296 FONT_PAGE_TRAD_ARABIC = 0xB300, /* Traditional Arabic Windows 3.1 font page */ 297 FONT_PAGE_OEM_ARABIC = 0xB400, /* OEM Arabic Windows 3.1 font page */ 298 FONT_PAGE_SIMP_FARSI = 0xBA00, /* Simplified Farsi Windows 3.1 font page */ 299 FONT_PAGE_TRAD_FARSI = 0xBB00, /* Traditional Farsi Windows 3.1 font page */ 300 FONT_PAGE_THAI = 0xDE00 /* Thai Windows 3.1 font page */ 301 }; get_font_pageOT::OS2302 font_page_t get_font_page () const 303 { return (font_page_t) (version == 0 ? fsSelection & 0xFF00 : 0); } 304 get_sizeOT::OS2305 unsigned get_size () const 306 { 307 unsigned result = min_size; 308 if (version >= 1) result += v1X.get_size (); 309 if (version >= 2) result += v2X.get_size (); 310 if (version >= 5) result += v5X.get_size (); 311 return result; 312 } 313 sanitizeOT::OS2314 bool sanitize (hb_sanitize_context_t *c) const 315 { 316 TRACE_SANITIZE (this); 317 if (unlikely (!c->check_struct (this))) return_trace (false); 318 if (unlikely (version >= 1 && !v1X.sanitize (c))) return_trace (false); 319 if (unlikely (version >= 2 && !v2X.sanitize (c))) return_trace (false); 320 if (unlikely (version >= 5 && !v5X.sanitize (c))) return_trace (false); 321 return_trace (true); 322 } 323 324 public: 325 HBUINT16 version; 326 HBINT16 xAvgCharWidth; 327 HBUINT16 usWeightClass; 328 HBUINT16 usWidthClass; 329 HBUINT16 fsType; 330 HBINT16 ySubscriptXSize; 331 HBINT16 ySubscriptYSize; 332 HBINT16 ySubscriptXOffset; 333 HBINT16 ySubscriptYOffset; 334 HBINT16 ySuperscriptXSize; 335 HBINT16 ySuperscriptYSize; 336 HBINT16 ySuperscriptXOffset; 337 HBINT16 ySuperscriptYOffset; 338 HBINT16 yStrikeoutSize; 339 HBINT16 yStrikeoutPosition; 340 HBINT16 sFamilyClass; 341 HBUINT8 panose[10]; 342 HBUINT32 ulUnicodeRange[4]; 343 Tag achVendID; 344 HBUINT16 fsSelection; 345 HBUINT16 usFirstCharIndex; 346 HBUINT16 usLastCharIndex; 347 HBINT16 sTypoAscender; 348 HBINT16 sTypoDescender; 349 HBINT16 sTypoLineGap; 350 HBUINT16 usWinAscent; 351 HBUINT16 usWinDescent; 352 OS2V1Tail v1X; 353 OS2V2Tail v2X; 354 OS2V5Tail v5X; 355 public: 356 DEFINE_SIZE_MIN (78); 357 }; 358 359 } /* namespace OT */ 360 361 362 #endif /* HB_OT_OS2_TABLE_HH */ 363