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      1 /*
      2  * Copyright  2009  Red Hat, Inc.
      3  * Copyright  2011  Codethink Limited
      4  * Copyright  2010,2011,2012  Google, Inc.
      5  *
      6  *  This is part of HarfBuzz, a text shaping library.
      7  *
      8  * Permission is hereby granted, without written agreement and without
      9  * license or royalty fees, to use, copy, modify, and distribute this
     10  * software and its documentation for any purpose, provided that the
     11  * above copyright notice and the following two paragraphs appear in
     12  * all copies of this software.
     13  *
     14  * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
     15  * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
     16  * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
     17  * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
     18  * DAMAGE.
     19  *
     20  * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
     21  * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
     22  * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
     23  * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
     24  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
     25  *
     26  * Red Hat Author(s): Behdad Esfahbod
     27  * Codethink Author(s): Ryan Lortie
     28  * Google Author(s): Behdad Esfahbod
     29  */
     30 
     31 #ifndef HB_UNICODE_PRIVATE_HH
     32 #define HB_UNICODE_PRIVATE_HH
     33 
     34 #include "hb-private.hh"
     35 #include "hb-object-private.hh"
     36 
     37 
     38 extern HB_INTERNAL const uint8_t _hb_modified_combining_class[256];
     39 
     40 /*
     41  * hb_unicode_funcs_t
     42  */
     43 
     44 #define HB_UNICODE_FUNCS_IMPLEMENT_CALLBACKS \
     45   HB_UNICODE_FUNC_IMPLEMENT (combining_class) \
     46   HB_UNICODE_FUNC_IMPLEMENT (eastasian_width) \
     47   HB_UNICODE_FUNC_IMPLEMENT (general_category) \
     48   HB_UNICODE_FUNC_IMPLEMENT (mirroring) \
     49   HB_UNICODE_FUNC_IMPLEMENT (script) \
     50   HB_UNICODE_FUNC_IMPLEMENT (compose) \
     51   HB_UNICODE_FUNC_IMPLEMENT (decompose) \
     52   HB_UNICODE_FUNC_IMPLEMENT (decompose_compatibility) \
     53   /* ^--- Add new callbacks here */
     54 
     55 /* Simple callbacks are those taking a hb_codepoint_t and returning a hb_codepoint_t */
     56 #define HB_UNICODE_FUNCS_IMPLEMENT_CALLBACKS_SIMPLE \
     57   HB_UNICODE_FUNC_IMPLEMENT (hb_unicode_combining_class_t, combining_class) \
     58   HB_UNICODE_FUNC_IMPLEMENT (unsigned int, eastasian_width) \
     59   HB_UNICODE_FUNC_IMPLEMENT (hb_unicode_general_category_t, general_category) \
     60   HB_UNICODE_FUNC_IMPLEMENT (hb_codepoint_t, mirroring) \
     61   HB_UNICODE_FUNC_IMPLEMENT (hb_script_t, script) \
     62   /* ^--- Add new simple callbacks here */
     63 
     64 struct hb_unicode_funcs_t {
     65   hb_object_header_t header;
     66   ASSERT_POD ();
     67 
     68   hb_unicode_funcs_t *parent;
     69 
     70   bool immutable;
     71 
     72 #define HB_UNICODE_FUNC_IMPLEMENT(return_type, name) \
     73   inline return_type name (hb_codepoint_t unicode) { return func.name (this, unicode, user_data.name); }
     74 HB_UNICODE_FUNCS_IMPLEMENT_CALLBACKS_SIMPLE
     75 #undef HB_UNICODE_FUNC_IMPLEMENT
     76 
     77   inline hb_bool_t compose (hb_codepoint_t a, hb_codepoint_t b,
     78 			    hb_codepoint_t *ab)
     79   {
     80     *ab = 0;
     81     if (unlikely (!a || !b)) return false;
     82     return func.compose (this, a, b, ab, user_data.compose);
     83   }
     84 
     85   inline hb_bool_t decompose (hb_codepoint_t ab,
     86 			      hb_codepoint_t *a, hb_codepoint_t *b)
     87   {
     88     *a = ab; *b = 0;
     89     return func.decompose (this, ab, a, b, user_data.decompose);
     90   }
     91 
     92   inline unsigned int decompose_compatibility (hb_codepoint_t  u,
     93 					       hb_codepoint_t *decomposed)
     94   {
     95     unsigned int ret = func.decompose_compatibility (this, u, decomposed, user_data.decompose_compatibility);
     96     if (ret == 1 && u == decomposed[0]) {
     97       decomposed[0] = 0;
     98       return 0;
     99     }
    100     decomposed[ret] = 0;
    101     return ret;
    102   }
    103 
    104 
    105   inline unsigned int
    106   modified_combining_class (hb_codepoint_t unicode)
    107   {
    108     /* XXX This hack belongs to the Myanmar shaper. */
    109     if (unlikely (unicode == 0x1037u)) unicode = 0x103Au;
    110 
    111     /* XXX This hack belongs to the SEA shaper (for Tai Tham):
    112      * Reorder SAKOT to ensure it comes after any tone marks. */
    113     if (unlikely (unicode == 0x1A60u)) return 254;
    114 
    115     /* XXX This hack belongs to the Tibetan shaper:
    116      * Reorder PADMA to ensure it comes after any vowel marks. */
    117     if (unlikely (unicode == 0x0FC6u)) return 254;
    118 
    119     return _hb_modified_combining_class[combining_class (unicode)];
    120   }
    121 
    122   static inline hb_bool_t
    123   is_variation_selector (hb_codepoint_t unicode)
    124   {
    125     /* U+180B..180D MONGOLIAN FREE VARIATION SELECTORs are handled in the
    126      * Arabic shaper.  No need to match them here. */
    127     return unlikely (hb_in_ranges (unicode,
    128 				   0xFE00u, 0xFE0Fu, /* VARIATION SELECTOR-1..16 */
    129 				   0xE0100u, 0xE01EFu));  /* VARIATION SELECTOR-17..256 */
    130   }
    131 
    132   /* Default_Ignorable codepoints:
    133    *
    134    * Note: While U+115F, U+1160, U+3164 and U+FFA0 are Default_Ignorable,
    135    * we do NOT want to hide them, as the way Uniscribe has implemented them
    136    * is with regular spacing glyphs, and that's the way fonts are made to work.
    137    * As such, we make exceptions for those four.
    138    *
    139    * Unicode 7.0:
    140    * $ grep '; Default_Ignorable_Code_Point ' DerivedCoreProperties.txt | sed 's/;.*#/#/'
    141    * 00AD          # Cf       SOFT HYPHEN
    142    * 034F          # Mn       COMBINING GRAPHEME JOINER
    143    * 061C          # Cf       ARABIC LETTER MARK
    144    * 115F..1160    # Lo   [2] HANGUL CHOSEONG FILLER..HANGUL JUNGSEONG FILLER
    145    * 17B4..17B5    # Mn   [2] KHMER VOWEL INHERENT AQ..KHMER VOWEL INHERENT AA
    146    * 180B..180D    # Mn   [3] MONGOLIAN FREE VARIATION SELECTOR ONE..MONGOLIAN FREE VARIATION SELECTOR THREE
    147    * 180E          # Cf       MONGOLIAN VOWEL SEPARATOR
    148    * 200B..200F    # Cf   [5] ZERO WIDTH SPACE..RIGHT-TO-LEFT MARK
    149    * 202A..202E    # Cf   [5] LEFT-TO-RIGHT EMBEDDING..RIGHT-TO-LEFT OVERRIDE
    150    * 2060..2064    # Cf   [5] WORD JOINER..INVISIBLE PLUS
    151    * 2065          # Cn       <reserved-2065>
    152    * 2066..206F    # Cf  [10] LEFT-TO-RIGHT ISOLATE..NOMINAL DIGIT SHAPES
    153    * 3164          # Lo       HANGUL FILLER
    154    * FE00..FE0F    # Mn  [16] VARIATION SELECTOR-1..VARIATION SELECTOR-16
    155    * FEFF          # Cf       ZERO WIDTH NO-BREAK SPACE
    156    * FFA0          # Lo       HALFWIDTH HANGUL FILLER
    157    * FFF0..FFF8    # Cn   [9] <reserved-FFF0>..<reserved-FFF8>
    158    * 1BCA0..1BCA3  # Cf   [4] SHORTHAND FORMAT LETTER OVERLAP..SHORTHAND FORMAT UP STEP
    159    * 1D173..1D17A  # Cf   [8] MUSICAL SYMBOL BEGIN BEAM..MUSICAL SYMBOL END PHRASE
    160    * E0000         # Cn       <reserved-E0000>
    161    * E0001         # Cf       LANGUAGE TAG
    162    * E0002..E001F  # Cn  [30] <reserved-E0002>..<reserved-E001F>
    163    * E0020..E007F  # Cf  [96] TAG SPACE..CANCEL TAG
    164    * E0080..E00FF  # Cn [128] <reserved-E0080>..<reserved-E00FF>
    165    * E0100..E01EF  # Mn [240] VARIATION SELECTOR-17..VARIATION SELECTOR-256
    166    * E01F0..E0FFF  # Cn [3600] <reserved-E01F0>..<reserved-E0FFF>
    167    */
    168   static inline hb_bool_t
    169   is_default_ignorable (hb_codepoint_t ch)
    170   {
    171     hb_codepoint_t plane = ch >> 16;
    172     if (likely (plane == 0))
    173     {
    174       /* BMP */
    175       hb_codepoint_t page = ch >> 8;
    176       switch (page) {
    177 	case 0x00: return unlikely (ch == 0x00ADu);
    178 	case 0x03: return unlikely (ch == 0x034Fu);
    179 	case 0x06: return unlikely (ch == 0x061Cu);
    180 	case 0x17: return hb_in_range (ch, 0x17B4u, 0x17B5u);
    181 	case 0x18: return hb_in_range (ch, 0x180Bu, 0x180Eu);
    182 	case 0x20: return hb_in_ranges (ch, 0x200Bu, 0x200Fu,
    183 							    0x202Au, 0x202Eu,
    184 							    0x2060u, 0x206Fu);
    185 	case 0xFE: return hb_in_range (ch, 0xFE00u, 0xFE0Fu) || ch == 0xFEFFu;
    186 	case 0xFF: return hb_in_range (ch, 0xFFF0u, 0xFFF8u);
    187 	default: return false;
    188       }
    189     }
    190     else
    191     {
    192       /* Other planes */
    193       switch (plane) {
    194 	case 0x01: return hb_in_ranges (ch, 0x1BCA0u, 0x1BCA3u,
    195 					    0x1D173u, 0x1D17Au);
    196 	case 0x0E: return hb_in_range (ch, 0xE0000u, 0xE0FFFu);
    197 	default: return false;
    198       }
    199     }
    200   }
    201 
    202   /* Space estimates based on:
    203    * http://www.unicode.org/charts/PDF/U2000.pdf
    204    * https://www.microsoft.com/typography/developers/fdsspec/spaces.aspx
    205    */
    206   enum space_t {
    207     NOT_SPACE = 0,
    208     SPACE_EM   = 1,
    209     SPACE_EM_2 = 2,
    210     SPACE_EM_3 = 3,
    211     SPACE_EM_4 = 4,
    212     SPACE_EM_5 = 5,
    213     SPACE_EM_6 = 6,
    214     SPACE_EM_16 = 16,
    215     SPACE_4_EM_18,	/* 4/18th of an EM! */
    216     SPACE,
    217     SPACE_FIGURE,
    218     SPACE_PUNCTUATION,
    219     SPACE_NARROW,
    220   };
    221   static inline space_t
    222   space_fallback_type (hb_codepoint_t u)
    223   {
    224     switch (u)
    225     {
    226       /* All GC=Zs chars that can use a fallback. */
    227       default:	    return NOT_SPACE;	/* U+1680 OGHAM SPACE MARK */
    228       case 0x0020u: return SPACE;	/* U+0020 SPACE */
    229       case 0x00A0u: return SPACE;	/* U+00A0 NO-BREAK SPACE */
    230       case 0x2000u: return SPACE_EM_2;	/* U+2000 EN QUAD */
    231       case 0x2001u: return SPACE_EM;	/* U+2001 EM QUAD */
    232       case 0x2002u: return SPACE_EM_2;	/* U+2002 EN SPACE */
    233       case 0x2003u: return SPACE_EM;	/* U+2003 EM SPACE */
    234       case 0x2004u: return SPACE_EM_3;	/* U+2004 THREE-PER-EM SPACE */
    235       case 0x2005u: return SPACE_EM_4;	/* U+2005 FOUR-PER-EM SPACE */
    236       case 0x2006u: return SPACE_EM_6;	/* U+2006 SIX-PER-EM SPACE */
    237       case 0x2007u: return SPACE_FIGURE;	/* U+2007 FIGURE SPACE */
    238       case 0x2008u: return SPACE_PUNCTUATION;	/* U+2008 PUNCTUATION SPACE */
    239       case 0x2009u: return SPACE_EM_5;		/* U+2009 THIN SPACE */
    240       case 0x200Au: return SPACE_EM_16;		/* U+200A HAIR SPACE */
    241       case 0x202Fu: return SPACE_NARROW;	/* U+202F NARROW NO-BREAK SPACE */
    242       case 0x205Fu: return SPACE_4_EM_18;	/* U+205F MEDIUM MATHEMATICAL SPACE */
    243       case 0x3000u: return SPACE_EM;		/* U+3000 IDEOGRAPHIC SPACE */
    244     }
    245   }
    246 
    247   struct {
    248 #define HB_UNICODE_FUNC_IMPLEMENT(name) hb_unicode_##name##_func_t name;
    249     HB_UNICODE_FUNCS_IMPLEMENT_CALLBACKS
    250 #undef HB_UNICODE_FUNC_IMPLEMENT
    251   } func;
    252 
    253   struct {
    254 #define HB_UNICODE_FUNC_IMPLEMENT(name) void *name;
    255     HB_UNICODE_FUNCS_IMPLEMENT_CALLBACKS
    256 #undef HB_UNICODE_FUNC_IMPLEMENT
    257   } user_data;
    258 
    259   struct {
    260 #define HB_UNICODE_FUNC_IMPLEMENT(name) hb_destroy_func_t name;
    261     HB_UNICODE_FUNCS_IMPLEMENT_CALLBACKS
    262 #undef HB_UNICODE_FUNC_IMPLEMENT
    263   } destroy;
    264 };
    265 
    266 
    267 extern HB_INTERNAL const hb_unicode_funcs_t _hb_unicode_funcs_nil;
    268 
    269 
    270 /* Modified combining marks */
    271 
    272 /* Hebrew
    273  *
    274  * We permute the "fixed-position" classes 10-26 into the order
    275  * described in the SBL Hebrew manual:
    276  *
    277  * http://www.sbl-site.org/Fonts/SBLHebrewUserManual1.5x.pdf
    278  *
    279  * (as recommended by:
    280  *  http://forum.fontlab.com/archive-old-microsoft-volt-group/vista-and-diacritic-ordering-t6751.0.html)
    281  *
    282  * More details here:
    283  * https://bugzilla.mozilla.org/show_bug.cgi?id=662055
    284  */
    285 #define HB_MODIFIED_COMBINING_CLASS_CCC10 22 /* sheva */
    286 #define HB_MODIFIED_COMBINING_CLASS_CCC11 15 /* hataf segol */
    287 #define HB_MODIFIED_COMBINING_CLASS_CCC12 16 /* hataf patah */
    288 #define HB_MODIFIED_COMBINING_CLASS_CCC13 17 /* hataf qamats */
    289 #define HB_MODIFIED_COMBINING_CLASS_CCC14 23 /* hiriq */
    290 #define HB_MODIFIED_COMBINING_CLASS_CCC15 18 /* tsere */
    291 #define HB_MODIFIED_COMBINING_CLASS_CCC16 19 /* segol */
    292 #define HB_MODIFIED_COMBINING_CLASS_CCC17 20 /* patah */
    293 #define HB_MODIFIED_COMBINING_CLASS_CCC18 21 /* qamats */
    294 #define HB_MODIFIED_COMBINING_CLASS_CCC19 14 /* holam */
    295 #define HB_MODIFIED_COMBINING_CLASS_CCC20 24 /* qubuts */
    296 #define HB_MODIFIED_COMBINING_CLASS_CCC21 12 /* dagesh */
    297 #define HB_MODIFIED_COMBINING_CLASS_CCC22 25 /* meteg */
    298 #define HB_MODIFIED_COMBINING_CLASS_CCC23 13 /* rafe */
    299 #define HB_MODIFIED_COMBINING_CLASS_CCC24 10 /* shin dot */
    300 #define HB_MODIFIED_COMBINING_CLASS_CCC25 11 /* sin dot */
    301 #define HB_MODIFIED_COMBINING_CLASS_CCC26 26 /* point varika */
    302 
    303 /*
    304  * Arabic
    305  *
    306  * Modify to move Shadda (ccc=33) before other marks.  See:
    307  * http://unicode.org/faq/normalization.html#8
    308  * http://unicode.org/faq/normalization.html#9
    309  */
    310 #define HB_MODIFIED_COMBINING_CLASS_CCC27 28 /* fathatan */
    311 #define HB_MODIFIED_COMBINING_CLASS_CCC28 29 /* dammatan */
    312 #define HB_MODIFIED_COMBINING_CLASS_CCC29 30 /* kasratan */
    313 #define HB_MODIFIED_COMBINING_CLASS_CCC30 31 /* fatha */
    314 #define HB_MODIFIED_COMBINING_CLASS_CCC31 32 /* damma */
    315 #define HB_MODIFIED_COMBINING_CLASS_CCC32 33 /* kasra */
    316 #define HB_MODIFIED_COMBINING_CLASS_CCC33 27 /* shadda */
    317 #define HB_MODIFIED_COMBINING_CLASS_CCC34 34 /* sukun */
    318 #define HB_MODIFIED_COMBINING_CLASS_CCC35 35 /* superscript alef */
    319 
    320 /* Syriac */
    321 #define HB_MODIFIED_COMBINING_CLASS_CCC36 36 /* superscript alaph */
    322 
    323 /* Telugu
    324  *
    325  * Modify Telugu length marks (ccc=84, ccc=91).
    326  * These are the only matras in the main Indic scripts range that have
    327  * a non-zero ccc.  That makes them reorder with the Halant that is
    328  * ccc=9.  Just zero them, we don't need them in our Indic shaper.
    329  */
    330 #define HB_MODIFIED_COMBINING_CLASS_CCC84 0 /* length mark */
    331 #define HB_MODIFIED_COMBINING_CLASS_CCC91 0 /* ai length mark */
    332 
    333 /* Thai
    334  *
    335  * Modify U+0E38 and U+0E39 (ccc=103) to be reordered before U+0E3A (ccc=9).
    336  * Assign 3, which is unassigned otherwise.
    337  * Uniscribe does this reordering too.
    338  */
    339 #define HB_MODIFIED_COMBINING_CLASS_CCC103 3 /* sara u / sara uu */
    340 #define HB_MODIFIED_COMBINING_CLASS_CCC107 107 /* mai * */
    341 
    342 /* Lao */
    343 #define HB_MODIFIED_COMBINING_CLASS_CCC118 118 /* sign u / sign uu */
    344 #define HB_MODIFIED_COMBINING_CLASS_CCC122 122 /* mai * */
    345 
    346 /* Tibetan */
    347 #define HB_MODIFIED_COMBINING_CLASS_CCC129 129 /* sign aa */
    348 #define HB_MODIFIED_COMBINING_CLASS_CCC130 130 /* sign i */
    349 #define HB_MODIFIED_COMBINING_CLASS_CCC132 132 /* sign u */
    350 
    351 
    352 /* Misc */
    353 
    354 #define HB_UNICODE_GENERAL_CATEGORY_IS_MARK(gen_cat) \
    355 	(FLAG_SAFE (gen_cat) & \
    356 	 (FLAG (HB_UNICODE_GENERAL_CATEGORY_SPACING_MARK) | \
    357 	  FLAG (HB_UNICODE_GENERAL_CATEGORY_ENCLOSING_MARK) | \
    358 	  FLAG (HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK)))
    359 
    360 #define HB_UNICODE_GENERAL_CATEGORY_IS_NON_ENCLOSING_MARK_OR_MODIFIER_SYMBOL(gen_cat) \
    361 	(FLAG_SAFE (gen_cat) & \
    362 	 (FLAG (HB_UNICODE_GENERAL_CATEGORY_SPACING_MARK) | \
    363 	  FLAG (HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK) | \
    364 	  FLAG (HB_UNICODE_GENERAL_CATEGORY_MODIFIER_SYMBOL)))
    365 
    366 #endif /* HB_UNICODE_PRIVATE_HH */
    367