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 subsetOT::OS2169 bool subset (hb_subset_context_t *c) const 170 { 171 TRACE_SUBSET (this); 172 OS2 *os2_prime = c->serializer->embed (this); 173 if (unlikely (!os2_prime)) return_trace (false); 174 175 uint16_t min_cp, max_cp; 176 find_min_and_max_codepoint (c->plan->unicodes, &min_cp, &max_cp); 177 os2_prime->usFirstCharIndex = min_cp; 178 os2_prime->usLastCharIndex = max_cp; 179 180 _update_unicode_ranges (c->plan->unicodes, os2_prime->ulUnicodeRange); 181 182 return_trace (true); 183 } 184 _update_unicode_rangesOT::OS2185 void _update_unicode_ranges (const hb_set_t *codepoints, 186 HBUINT32 ulUnicodeRange[4]) const 187 { 188 HBUINT32 newBits[4]; 189 for (unsigned int i = 0; i < 4; i++) 190 newBits[i] = 0; 191 192 hb_codepoint_t cp = HB_SET_VALUE_INVALID; 193 while (codepoints->next (&cp)) { 194 unsigned int bit = _hb_ot_os2_get_unicode_range_bit (cp); 195 if (bit < 128) 196 { 197 unsigned int block = bit / 32; 198 unsigned int bit_in_block = bit % 32; 199 unsigned int mask = 1 << bit_in_block; 200 newBits[block] = newBits[block] | mask; 201 } 202 if (cp >= 0x10000 && cp <= 0x110000) 203 { 204 /* the spec says that bit 57 ("Non Plane 0") implies that there's 205 at least one codepoint beyond the BMP; so I also include all 206 the non-BMP codepoints here */ 207 newBits[1] = newBits[1] | (1 << 25); 208 } 209 } 210 211 for (unsigned int i = 0; i < 4; i++) 212 ulUnicodeRange[i] = ulUnicodeRange[i] & newBits[i]; // set bits only if set in the original 213 } 214 find_min_and_max_codepointOT::OS2215 static void find_min_and_max_codepoint (const hb_set_t *codepoints, 216 uint16_t *min_cp, /* OUT */ 217 uint16_t *max_cp /* OUT */) 218 { 219 *min_cp = codepoints->get_min (); 220 *max_cp = codepoints->get_max (); 221 } 222 223 /* https://github.com/Microsoft/Font-Validator/blob/520aaae/OTFontFileVal/val_OS2.cs#L644-L681 */ 224 enum font_page_t { 225 HEBREW_FONT_PAGE = 0xB100, // Hebrew Windows 3.1 font page 226 SIMP_ARABIC_FONT_PAGE = 0xB200, // Simplified Arabic Windows 3.1 font page 227 TRAD_ARABIC_FONT_PAGE = 0xB300, // Traditional Arabic Windows 3.1 font page 228 OEM_ARABIC_FONT_PAGE = 0xB400, // OEM Arabic Windows 3.1 font page 229 SIMP_FARSI_FONT_PAGE = 0xBA00, // Simplified Farsi Windows 3.1 font page 230 TRAD_FARSI_FONT_PAGE = 0xBB00, // Traditional Farsi Windows 3.1 font page 231 THAI_FONT_PAGE = 0xDE00 // Thai Windows 3.1 font page 232 }; get_font_pageOT::OS2233 font_page_t get_font_page () const 234 { return (font_page_t) (version == 0 ? fsSelection & 0xFF00 : 0); } 235 get_sizeOT::OS2236 unsigned get_size () const 237 { 238 unsigned result = min_size; 239 if (version >= 1) result += v1X.get_size (); 240 if (version >= 2) result += v2X.get_size (); 241 if (version >= 5) result += v5X.get_size (); 242 return result; 243 } 244 sanitizeOT::OS2245 bool sanitize (hb_sanitize_context_t *c) const 246 { 247 TRACE_SANITIZE (this); 248 if (unlikely (!c->check_struct (this))) return_trace (false); 249 if (unlikely (version >= 1 && !v1X.sanitize (c))) return_trace (false); 250 if (unlikely (version >= 2 && !v2X.sanitize (c))) return_trace (false); 251 if (unlikely (version >= 5 && !v5X.sanitize (c))) return_trace (false); 252 return_trace (true); 253 } 254 255 public: 256 HBUINT16 version; 257 HBINT16 xAvgCharWidth; 258 HBUINT16 usWeightClass; 259 HBUINT16 usWidthClass; 260 HBUINT16 fsType; 261 HBINT16 ySubscriptXSize; 262 HBINT16 ySubscriptYSize; 263 HBINT16 ySubscriptXOffset; 264 HBINT16 ySubscriptYOffset; 265 HBINT16 ySuperscriptXSize; 266 HBINT16 ySuperscriptYSize; 267 HBINT16 ySuperscriptXOffset; 268 HBINT16 ySuperscriptYOffset; 269 HBINT16 yStrikeoutSize; 270 HBINT16 yStrikeoutPosition; 271 HBINT16 sFamilyClass; 272 HBUINT8 panose[10]; 273 HBUINT32 ulUnicodeRange[4]; 274 Tag achVendID; 275 HBUINT16 fsSelection; 276 HBUINT16 usFirstCharIndex; 277 HBUINT16 usLastCharIndex; 278 HBINT16 sTypoAscender; 279 HBINT16 sTypoDescender; 280 HBINT16 sTypoLineGap; 281 HBUINT16 usWinAscent; 282 HBUINT16 usWinDescent; 283 OS2V1Tail v1X; 284 OS2V2Tail v2X; 285 OS2V5Tail v5X; 286 public: 287 DEFINE_SIZE_MIN (78); 288 }; 289 290 } /* namespace OT */ 291 292 293 #endif /* HB_OT_OS2_TABLE_HH */ 294