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_ARABIC_TOP
  74     "ا إ ل ك ط ظ"
  75   TA_BLUE_STRING_ARABIC_JOIN
  76     "ت ث ط ظ ك"
  77
  78   TA_BLUE_STRING_CYRILLIC_CAPITAL_TOP
  79     "БВЕПЗОСЭ"
  80   TA_BLUE_STRING_CYRILLIC_CAPITAL_BOTTOM
  81     "БВЕШЗОСЭ"
  82   TA_BLUE_STRING_CYRILLIC_SMALL
  83     "хпншезос"
  84   TA_BLUE_STRING_CYRILLIC_SMALL_DESCENDER
  85     "руф"
  86
  87   // we separate the letters with spaces to avoid ligatures;
  88   // this is just for convenience to simplify reading
  89   TA_BLUE_STRING_DEVANAGARI_BASE
  90     "क न म उ छ ट ठ ड"
  91   TA_BLUE_STRING_DEVANAGARI_TOP
  92     "ई ऐ ओ औ ि ी ो ौ"
  93   // note that some fonts have extreme variation in the height of the
  94   // round head elements; for this reason we also define the `base'
  95   // blue zone, which must be always present
  96   TA_BLUE_STRING_DEVANAGARI_HEAD
  97     "क म अ आ थ ध भ श"
  98   TA_BLUE_STRING_DEVANAGARI_BOTTOM
  99     "ु ृ"
 100
 101   TA_BLUE_STRING_GREEK_CAPITAL_TOP
 102     "ΓΒΕΖΘΟΩ"
 103   TA_BLUE_STRING_GREEK_CAPITAL_BOTTOM
 104     "ΒΔΖΞΘΟ"
 105   TA_BLUE_STRING_GREEK_SMALL_BETA_TOP
 106     "βθδζλξ"
 107   TA_BLUE_STRING_GREEK_SMALL
 108     "αειοπστω"
 109   TA_BLUE_STRING_GREEK_SMALL_DESCENDER
 110     "βγημρφχψ"
 111
 112   TA_BLUE_STRING_HEBREW_TOP
 113     "בדהחךכםס"
 114   TA_BLUE_STRING_HEBREW_BOTTOM
 115     "בטכםסצ"
 116   TA_BLUE_STRING_HEBREW_DESCENDER
 117     "קךןףץ"
 118
 119   TA_BLUE_STRING_LATIN_CAPITAL_TOP
 120     "THEZOCQS"
 121   TA_BLUE_STRING_LATIN_CAPITAL_BOTTOM
 122     "HEZLOCUS"
 123   TA_BLUE_STRING_LATIN_SMALL_F_TOP
 124     "fijkdbh"
 125   TA_BLUE_STRING_LATIN_SMALL
 126     "xzroesc"
 127   TA_BLUE_STRING_LATIN_SMALL_DESCENDER
 128     "pqgjy"
 129
 130   // we separate the letters with spaces to avoid ligatures;
 131   // this is just for convenience to simplify reading
 132   TA_BLUE_STRING_TELUGU_TOP
 133     "ఇ ఌ ఙ ఞ ణ ఱ ౯"
 134   TA_BLUE_STRING_TELUGU_BOTTOM
 135     "అ క చ ర ఽ ౨ ౬"
 136
 137   TA_BLUE_STRING_THAI_TOP
 138     "บ เ แ อ ก า"
 139   TA_BLUE_STRING_THAI_BOTTOM
 140     "บ ป ษ ฯ อ ย ฮ"
 141   TA_BLUE_STRING_THAI_ASCENDER
 142     "ป ฝ ฟ"
 143   TA_BLUE_STRING_THAI_LARGE_ASCENDER
 144     "โ ใ ไ"
 145   TA_BLUE_STRING_THAI_DESCENDER
 146     "ฎ ฏ ฤ ฦ"
 147   TA_BLUE_STRING_THAI_LARGE_DESCENDER
 148     "ญ ฐ"
 149   TA_BLUE_STRING_THAI_DIGIT_TOP
 150     "๐ ๑ ๓"
 151
 152 // The blue zone stringsets, as used in the script styles, cf. `tastyles.h'.
 153 //
 154 // The TA_BLUE_PROPERTY_XXX flags are defined in `tablue.h'; here some
 155 // explanations.
 156 //
 157 // A blue zone in general is defined by a reference and an overshoot line.
 158 // During the hinting process, all coordinate values between those two lines
 159 // are set equal to the reference value, provided that the blue zone is not
 160 // wider than 0.75 pixels (otherwise the blue zone gets ignored).  All
 161 // entries must have `TA_BLUE_STRING_MAX' as the final line.
 162 //
 163 // During the glyph analysis, edges are sorted from bottom to top, and then
 164 // sequentially checked, edge by edge, against the blue zones in the order
 165 // given below.
 166 //
 167 //
 168 // latin auto-hinter
 169 // -----------------
 170 //
 171 // Characters in a blue string are automatically classified as having a flat
 172 // (reference) or a round (overshoot) extremum.  The blue zone is then set
 173 // up by the mean values of all flat extrema and all round extrema,
 174 // respectively.  Only horizontal blue zones (i.e., adjusting vertical
 175 // coordinate values) are supported.
 176 //
 177 // For the latin auto-hinter, the overshoot should be larger than the
 178 // reference for top zones, and vice versa for bottom zones.
 179 //
 180 //   LATIN_TOP
 181 //     Take the maximum flat and round coordinate values of the blue string
 182 //     characters for computing the blue zone's reference and overshoot
 183 //     values.
 184 //
 185 //     If not set, take the minimum values.
 186 //
 187 //   LATIN_NEUTRAL
 188 //     Ignore round extrema and define the blue zone with flat values only.
 189 //     Both top and bottom of contours can match.  This is useful for
 190 //     scripts like Devanagari where vowel signs attach to the base
 191 //     character and are implemented as components of composite glyphs.
 192 //
 193 //     If not set, both round and flat extrema are taken into account.
 194 //     Additionally, only the top or the bottom of a contour can match,
 195 //     depending on the LATIN_TOP flag.
 196 //
 197 //     Neutral blue zones should always follow non-neutral blue zones.
 198 //
 199 //   LATIN_X_HEIGHT
 200 //     Scale all glyphs vertically from the corresponding script to make the
 201 //     reference line of this blue zone align on the grid.  The scaling
 202 //     takes place before all other blue zones get aligned to the grid.
 203 //     Only one blue character string of a script style can have this flag.
 204 //
 205 //   LATIN_LONG
 206 //     Apply an additional constraint for blue zone values: Don't
 207 //     necessarily use the extremum as-is but a segment of the topmost (or
 208 //     bottommost) contour that is longer than a heuristic threshold, and
 209 //     which is not too far away vertically from the real extremum.  This
 210 //     ensures that small bumps in the outline are ignored (for example, the
 211 //     `vertical serifs' found in many Hebrew glyph designs).
 212 //
 213 //     The segment must be at least EM/25 font units long, and the distance
 214 //     to the extremum must be smaller than EM/4.
 215
 216
 217 TA_BLUE_STRINGSET_ENUM TA_BLUE_STRINGSETS_ARRAY TA_BLUE_STRINGSET_MAX_LEN:
 218
 219   TA_BLUE_STRINGSET_ARAB
 220     { TA_BLUE_STRING_ARABIC_TOP,   TA_BLUE_PROPERTY_LATIN_TOP }
 221     { TA_BLUE_STRING_ARABIC_JOIN,  0                          }
 222     { TA_BLUE_STRING_MAX,          0                          }
 223
 224   TA_BLUE_STRINGSET_CYRL
 225     { TA_BLUE_STRING_CYRILLIC_CAPITAL_TOP,     TA_BLUE_PROPERTY_LATIN_TOP        }
 226     { TA_BLUE_STRING_CYRILLIC_CAPITAL_BOTTOM,  0                                 }
 227     { TA_BLUE_STRING_CYRILLIC_SMALL,           TA_BLUE_PROPERTY_LATIN_TOP      |
 228                                                TA_BLUE_PROPERTY_LATIN_X_HEIGHT   }
 229     { TA_BLUE_STRING_CYRILLIC_SMALL,           0                                 }
 230     { TA_BLUE_STRING_CYRILLIC_SMALL_DESCENDER, 0                                 }
 231     { TA_BLUE_STRING_MAX,                      0                                 }
 232
 233   TA_BLUE_STRINGSET_DEVA
 234     { TA_BLUE_STRING_DEVANAGARI_TOP,    TA_BLUE_PROPERTY_LATIN_TOP        }
 235     { TA_BLUE_STRING_DEVANAGARI_HEAD,   TA_BLUE_PROPERTY_LATIN_TOP        }
 236     { TA_BLUE_STRING_DEVANAGARI_BASE,   TA_BLUE_PROPERTY_LATIN_TOP      |
 237                                         TA_BLUE_PROPERTY_LATIN_NEUTRAL  |
 238                                         TA_BLUE_PROPERTY_LATIN_X_HEIGHT   }
 239     { TA_BLUE_STRING_DEVANAGARI_BASE,   0                                 }
 240     { TA_BLUE_STRING_DEVANAGARI_BOTTOM, 0                                 }
 241     { TA_BLUE_STRING_MAX,               0                                 }
 242
 243   TA_BLUE_STRINGSET_GREK
 244     { TA_BLUE_STRING_GREEK_CAPITAL_TOP,     TA_BLUE_PROPERTY_LATIN_TOP        }
 245     { TA_BLUE_STRING_GREEK_CAPITAL_BOTTOM,  0                                 }
 246     { TA_BLUE_STRING_GREEK_SMALL_BETA_TOP,  TA_BLUE_PROPERTY_LATIN_TOP        }
 247     { TA_BLUE_STRING_GREEK_SMALL,           TA_BLUE_PROPERTY_LATIN_TOP      |
 248                                             TA_BLUE_PROPERTY_LATIN_X_HEIGHT   }
 249     { TA_BLUE_STRING_GREEK_SMALL,           0                                 }
 250     { TA_BLUE_STRING_GREEK_SMALL_DESCENDER, 0                                 }
 251     { TA_BLUE_STRING_MAX,                   0                                 }
 252
 253   TA_BLUE_STRINGSET_HEBR
 254     { TA_BLUE_STRING_HEBREW_TOP,       TA_BLUE_PROPERTY_LATIN_TOP  |
 255                                        TA_BLUE_PROPERTY_LATIN_LONG   }
 256     { TA_BLUE_STRING_HEBREW_BOTTOM,    0                             }
 257     { TA_BLUE_STRING_HEBREW_DESCENDER, 0                             }
 258     { TA_BLUE_STRING_MAX,              0                             }
 259
 260   TA_BLUE_STRINGSET_LATN
 261     { TA_BLUE_STRING_LATIN_CAPITAL_TOP,     TA_BLUE_PROPERTY_LATIN_TOP        }
 262     { TA_BLUE_STRING_LATIN_CAPITAL_BOTTOM,  0                                 }
 263     { TA_BLUE_STRING_LATIN_SMALL_F_TOP,     TA_BLUE_PROPERTY_LATIN_TOP        }
 264     { TA_BLUE_STRING_LATIN_SMALL,           TA_BLUE_PROPERTY_LATIN_TOP      |
 265                                             TA_BLUE_PROPERTY_LATIN_X_HEIGHT   }
 266     { TA_BLUE_STRING_LATIN_SMALL,           0                                 }
 267     { TA_BLUE_STRING_LATIN_SMALL_DESCENDER, 0                                 }
 268     { TA_BLUE_STRING_MAX,                   0                                 }
 269
 270   TA_BLUE_STRINGSET_TELU
 271     { TA_BLUE_STRING_TELUGU_TOP,    TA_BLUE_PROPERTY_LATIN_TOP }
 272     { TA_BLUE_STRING_TELUGU_BOTTOM, 0                          }
 273     { TA_BLUE_STRING_MAX,           0                          }
 274
 275   TA_BLUE_STRINGSET_THAI
 276     { TA_BLUE_STRING_THAI_TOP,             TA_BLUE_PROPERTY_LATIN_TOP      |
 277                                            TA_BLUE_PROPERTY_LATIN_X_HEIGHT   }
 278     { TA_BLUE_STRING_THAI_BOTTOM,          0                                 }
 279     { TA_BLUE_STRING_THAI_ASCENDER,        TA_BLUE_PROPERTY_LATIN_TOP        }
 280     { TA_BLUE_STRING_THAI_LARGE_ASCENDER,  TA_BLUE_PROPERTY_LATIN_TOP        }
 281     { TA_BLUE_STRING_THAI_DESCENDER,       0                                 }
 282     { TA_BLUE_STRING_THAI_LARGE_DESCENDER, 0                                 }
 283     { TA_BLUE_STRING_THAI_DIGIT_TOP,       0                                 }
 284     { TA_BLUE_STRING_MAX,                  0                                 }
 285
 286 // END