lib/tablue.dat

   1 //  tablue.dat
   2 //
   3 //    Auto-fitter data for blue strings.
   4 //
   5 // Copyright (C) 2013-2015 by Werner Lemberg.
   6 //
   7 // This file is part of the ttfautohint library, and may only be used,
   8 // modified, and distributed under the terms given in `COPYING'.  By
   9 // continuing to use, modify, or distribute this file you indicate that you
  10 // have read `COPYING' and understand and accept it fully.
  11 //
  12 // The file `COPYING' mentioned in the previous paragraph is distributed
  13 // with the ttfautohint library.
  14
  15 // originally file `afblue.dat' (2013-Sep-22) from FreeType */
  16
  17
  18 // This file contains data specific to blue zones.  It gets processed by
  19 // a script to simulate `jagged arrays', with enumeration values holding
  20 // offsets into the arrays.
  21 //
  22 // The format of the file is rather simple:  A section starts with three
  23 // labels separated by whitespace and followed by a colon (everything in a
  24 // single line); the first label gives the name of the enumeration template,
  25 // the second the name of the array template, and the third the name of the
  26 // `maximum' template, holding the size of the largest array element.  The
  27 // script then fills the corresponding templates (indicated by `@'
  28 // characters around the name).
  29 //
  30 // A section contains one or more data records.  Each data record consists
  31 // of two or more lines.  The first line holds the enumeration name, and the
  32 // remaining lines the corresponding array data.
  33 //
  34 // There are two possible representations for array data.
  35 //
  36 // - A string of characters in UTF-8 encoding enclosed in double quotes,
  37 //   using C syntax.  There can be only one string per line, thus the
  38 //   starting and ending double quote must be the first and last character
  39 //   in the line, respectively, ignoring whitespace before and after the
  40 //   string.  Space characters within the string are ignored too.  If there
  41 //   are multiple strings (in multiple lines), they are concatenated to a
  42 //   single string.  In the output, a string gets represented as a series of
  43 //   singles bytes, followed by a zero byte.  The enumeration values simply
  44 //   hold byte offsets to the start of the corresponding strings.
  45 //
  46 // - Data blocks enclosed in balanced braces, which get copied verbatim and
  47 //   which can span multiple lines.  The opening brace of a block must be
  48 //   the first character of a line (ignoring whitespace), and the closing
  49 //   brace the last (ignoring whitespace also).  The script appends a comma
  50 //   character after each block and counts the number of blocks to set the
  51 //   enumeration values.
  52 //
  53 // A section can contain either strings only or data blocks only.
  54 //
  55 // A comment line starts with `//'; it gets removed.  A preprocessor
  56 // directive line (using the standard syntax of `cpp') starts with `#' and
  57 // gets copied verbatim to both the enumeration and the array.  Whitespace
  58 // outside of a string is insignificant.
  59 //
  60 // Preprocessor directives are ignored while the script computes maximum
  61 // values; this essentially means that the maximum values can easily be too
  62 // large.  Given that the purpose of those values is to create local
  63 // fixed-size arrays at compile time for further processing of the blue zone
  64 // data, this isn't a problem.  Note the the final zero byte of a string is
  65 // not counted.  Note also that the count holds the number of UTF-8 encoded
  66 // characters, not bytes.
  67
  68
  69 // The blue zone string data, to be used in the blue stringsets below.
  70
  71 TA_BLUE_STRING_ENUM TA_BLUE_STRINGS_ARRAY TA_BLUE_STRING_MAX_LEN:
  72
  73   TA_BLUE_STRING_CYRILLIC_CAPITAL_TOP
  74     "БВЕПЗОСЭ"
  75   TA_BLUE_STRING_CYRILLIC_CAPITAL_BOTTOM
  76     "БВЕШЗОСЭ"
  77   TA_BLUE_STRING_CYRILLIC_SMALL
  78     "хпншезос"
  79   TA_BLUE_STRING_CYRILLIC_SMALL_DESCENDER
  80     "руф"
  81
  82   // we separate the letters with spaces to avoid ligatures;
  83   // this is just for convenience to simplify reading
  84   TA_BLUE_STRING_DEVANAGARI_BASE
  85     "क न म उ छ ट ठ ड"
  86   TA_BLUE_STRING_DEVANAGARI_TOP
  87     "ई ऐ ओ औ ि ी ो ौ"
  88   // note that some fonts have extreme variation in the height of the
  89   // round head elements; for this reason we also define the `base'
  90   // blue zone, which must be always present
  91   TA_BLUE_STRING_DEVANAGARI_HEAD
  92     "क म अ आ थ ध भ श"
  93   TA_BLUE_STRING_DEVANAGARI_BOTTOM
  94     "ु ृ"
  95
  96   TA_BLUE_STRING_GREEK_CAPITAL_TOP
  97     "ΓΒΕΖΘΟΩ"
  98   TA_BLUE_STRING_GREEK_CAPITAL_BOTTOM
  99     "ΒΔΖΞΘΟ"
 100   TA_BLUE_STRING_GREEK_SMALL_BETA_TOP
 101     "βθδζλξ"
 102   TA_BLUE_STRING_GREEK_SMALL
 103     "αειοπστω"
 104   TA_BLUE_STRING_GREEK_SMALL_DESCENDER
 105     "βγημρφχψ"
 106
 107   TA_BLUE_STRING_HEBREW_TOP
 108     "בדהחךכםס"
 109   TA_BLUE_STRING_HEBREW_BOTTOM
 110     "בטכםסצ"
 111   TA_BLUE_STRING_HEBREW_DESCENDER
 112     "קךןףץ"
 113
 114   TA_BLUE_STRING_LATIN_CAPITAL_TOP
 115     "THEZOCQS"
 116   TA_BLUE_STRING_LATIN_CAPITAL_BOTTOM
 117     "HEZLOCUS"
 118   TA_BLUE_STRING_LATIN_SMALL_F_TOP
 119     "fijkdbh"
 120   TA_BLUE_STRING_LATIN_SMALL
 121     "xzroesc"
 122   TA_BLUE_STRING_LATIN_SMALL_DESCENDER
 123     "pqgjy"
 124
 125   // we separate the letters with spaces to avoid ligatures;
 126   // this is just for convenience to simplify reading
 127   TA_BLUE_STRING_TELUGU_TOP
 128     "ఇ ఌ ఙ ఞ ణ ఱ ౯"
 129   TA_BLUE_STRING_TELUGU_BOTTOM
 130     "అ క చ ర ఽ ౨ ౬"
 131
 132   TA_BLUE_STRING_THAI_TOP
 133     "บ เ แ อ ก า"
 134   TA_BLUE_STRING_THAI_BOTTOM
 135     "บ ป ษ ฯ อ ย ฮ"
 136   TA_BLUE_STRING_THAI_ASCENDER
 137     "ป ฝ ฟ"
 138   TA_BLUE_STRING_THAI_LARGE_ASCENDER
 139     "โ ใ ไ"
 140   TA_BLUE_STRING_THAI_DESCENDER
 141     "ฎ ฏ ฤ ฦ"
 142   TA_BLUE_STRING_THAI_LARGE_DESCENDER
 143     "ญ ฐ"
 144   TA_BLUE_STRING_THAI_DIGIT_TOP
 145     "๐ ๑ ๓"
 146
 147 // The blue zone stringsets, as used in the script styles, cf. `tastyles.h'.
 148 //
 149 // The TA_BLUE_PROPERTY_XXX flags are defined in `tablue.h'; here some
 150 // explanations.
 151 //
 152 // A blue zone in general is defined by a reference and an overshoot line.
 153 // During the hinting process, all coordinate values between those two lines
 154 // are set equal to the reference value, provided that the blue zone is not
 155 // wider than 0.75 pixels (otherwise the blue zone gets ignored).  All
 156 // entries must have `TA_BLUE_STRING_MAX' as the final line.
 157 //
 158 // During the glyph analysis, edges are sorted from bottom to top, and then
 159 // sequentially checked, edge by edge, against the blue zones in the order
 160 // given below.
 161 //
 162 //
 163 // latin auto-hinter
 164 // -----------------
 165 //
 166 // Characters in a blue string are automatically classified as having a flat
 167 // (reference) or a round (overshoot) extremum.  The blue zone is then set
 168 // up by the mean values of all flat extrema and all round extrema,
 169 // respectively.  Only horizontal blue zones (i.e., adjusting vertical
 170 // coordinate values) are supported.
 171 //
 172 // For the latin auto-hinter, the overshoot should be larger than the
 173 // reference for top zones, and vice versa for bottom zones.
 174 //
 175 //   LATIN_TOP
 176 //     Take the maximum flat and round coordinate values of the blue string
 177 //     characters for computing the blue zone's reference and overshoot
 178 //     values.
 179 //
 180 //     If not set, take the minimum values.
 181 //
 182 //   LATIN_NEUTRAL
 183 //     Ignore round extrema and define the blue zone with flat values only.
 184 //     Both top and bottom of contours can match.  This is useful for
 185 //     scripts like Devanagari where vowel signs attach to the base
 186 //     character and are implemented as components of composite glyphs.
 187 //
 188 //     If not set, both round and flat extrema are taken into account.
 189 //     Additionally, only the top or the bottom of a contour can match,
 190 //     depending on the LATIN_TOP flag.
 191 //
 192 //     Neutral blue zones should always follow non-neutral blue zones.
 193 //
 194 //   LATIN_X_HEIGHT
 195 //     Scale all glyphs vertically from the corresponding script to make the
 196 //     reference line of this blue zone align on the grid.  The scaling
 197 //     takes place before all other blue zones get aligned to the grid.
 198 //     Only one blue character string of a script style can have this flag.
 199 //
 200 //   LATIN_LONG
 201 //     Apply an additional constraint for blue zone values: Don't
 202 //     necessarily use the extremum as-is but a segment of the topmost (or
 203 //     bottommost) contour that is longer than a heuristic threshold, and
 204 //     which is not too far away vertically from the real extremum.  This
 205 //     ensures that small bumps in the outline are ignored (for example, the
 206 //     `vertical serifs' found in many Hebrew glyph designs).
 207 //
 208 //     The segment must be at least EM/25 font units long, and the distance
 209 //     to the extremum must be smaller than EM/4.
 210
 211
 212 TA_BLUE_STRINGSET_ENUM TA_BLUE_STRINGSETS_ARRAY TA_BLUE_STRINGSET_MAX_LEN:
 213
 214   TA_BLUE_STRINGSET_CYRL
 215     { TA_BLUE_STRING_CYRILLIC_CAPITAL_TOP,     TA_BLUE_PROPERTY_LATIN_TOP        }
 216     { TA_BLUE_STRING_CYRILLIC_CAPITAL_BOTTOM,  0                                 }
 217     { TA_BLUE_STRING_CYRILLIC_SMALL,           TA_BLUE_PROPERTY_LATIN_TOP      |
 218                                                TA_BLUE_PROPERTY_LATIN_X_HEIGHT   }
 219     { TA_BLUE_STRING_CYRILLIC_SMALL,           0                                 }
 220     { TA_BLUE_STRING_CYRILLIC_SMALL_DESCENDER, 0                                 }
 221     { TA_BLUE_STRING_MAX,                      0                                 }
 222
 223   TA_BLUE_STRINGSET_DEVA
 224     { TA_BLUE_STRING_DEVANAGARI_TOP,    TA_BLUE_PROPERTY_LATIN_TOP        }
 225     { TA_BLUE_STRING_DEVANAGARI_HEAD,   TA_BLUE_PROPERTY_LATIN_TOP        }
 226     { TA_BLUE_STRING_DEVANAGARI_BASE,   TA_BLUE_PROPERTY_LATIN_TOP      |
 227                                         TA_BLUE_PROPERTY_LATIN_NEUTRAL  |
 228                                         TA_BLUE_PROPERTY_LATIN_X_HEIGHT   }
 229     { TA_BLUE_STRING_DEVANAGARI_BASE,   0                                 }
 230     { TA_BLUE_STRING_DEVANAGARI_BOTTOM, 0                                 }
 231     { TA_BLUE_STRING_MAX,               0                                 }
 232
 233   TA_BLUE_STRINGSET_GREK
 234     { TA_BLUE_STRING_GREEK_CAPITAL_TOP,     TA_BLUE_PROPERTY_LATIN_TOP        }
 235     { TA_BLUE_STRING_GREEK_CAPITAL_BOTTOM,  0                                 }
 236     { TA_BLUE_STRING_GREEK_SMALL_BETA_TOP,  TA_BLUE_PROPERTY_LATIN_TOP        }
 237     { TA_BLUE_STRING_GREEK_SMALL,           TA_BLUE_PROPERTY_LATIN_TOP      |
 238                                             TA_BLUE_PROPERTY_LATIN_X_HEIGHT   }
 239     { TA_BLUE_STRING_GREEK_SMALL,           0                                 }
 240     { TA_BLUE_STRING_GREEK_SMALL_DESCENDER, 0                                 }
 241     { TA_BLUE_STRING_MAX,                   0                                 }
 242
 243   TA_BLUE_STRINGSET_HEBR
 244     { TA_BLUE_STRING_HEBREW_TOP,       TA_BLUE_PROPERTY_LATIN_TOP  |
 245                                        TA_BLUE_PROPERTY_LATIN_LONG   }
 246     { TA_BLUE_STRING_HEBREW_BOTTOM,    0                             }
 247     { TA_BLUE_STRING_HEBREW_DESCENDER, 0                             }
 248     { TA_BLUE_STRING_MAX,              0                             }
 249
 250   TA_BLUE_STRINGSET_LATN
 251     { TA_BLUE_STRING_LATIN_CAPITAL_TOP,     TA_BLUE_PROPERTY_LATIN_TOP        }
 252     { TA_BLUE_STRING_LATIN_CAPITAL_BOTTOM,  0                                 }
 253     { TA_BLUE_STRING_LATIN_SMALL_F_TOP,     TA_BLUE_PROPERTY_LATIN_TOP        }
 254     { TA_BLUE_STRING_LATIN_SMALL,           TA_BLUE_PROPERTY_LATIN_TOP      |
 255                                             TA_BLUE_PROPERTY_LATIN_X_HEIGHT   }
 256     { TA_BLUE_STRING_LATIN_SMALL,           0                                 }
 257     { TA_BLUE_STRING_LATIN_SMALL_DESCENDER, 0                                 }
 258     { TA_BLUE_STRING_MAX,                   0                                 }
 259
 260   TA_BLUE_STRINGSET_TELU
 261     { TA_BLUE_STRING_TELUGU_TOP,    TA_BLUE_PROPERTY_LATIN_TOP }
 262     { TA_BLUE_STRING_TELUGU_BOTTOM, 0                          }
 263     { TA_BLUE_STRING_MAX,           0                          }
 264
 265   TA_BLUE_STRINGSET_THAI
 266     { TA_BLUE_STRING_THAI_TOP,             TA_BLUE_PROPERTY_LATIN_TOP      |
 267                                            TA_BLUE_PROPERTY_LATIN_X_HEIGHT   }
 268     { TA_BLUE_STRING_THAI_BOTTOM,          0                                 }
 269     { TA_BLUE_STRING_THAI_ASCENDER,        TA_BLUE_PROPERTY_LATIN_TOP        }
 270     { TA_BLUE_STRING_THAI_LARGE_ASCENDER,  TA_BLUE_PROPERTY_LATIN_TOP        }
 271     { TA_BLUE_STRING_THAI_DESCENDER,       0                                 }
 272     { TA_BLUE_STRING_THAI_LARGE_DESCENDER, 0                                 }
 273     { TA_BLUE_STRING_THAI_DIGIT_TOP,       0                                 }
 274     { TA_BLUE_STRING_MAX,                  0                                 }
 275
 276 // END