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      1 /*
      2  * Copyright  2012  Google, Inc.
      3  *
      4  *  This is part of HarfBuzz, a text shaping library.
      5  *
      6  * Permission is hereby granted, without written agreement and without
      7  * license or royalty fees, to use, copy, modify, and distribute this
      8  * software and its documentation for any purpose, provided that the
      9  * above copyright notice and the following two paragraphs appear in
     10  * all copies of this software.
     11  *
     12  * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
     13  * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
     14  * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
     15  * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
     16  * DAMAGE.
     17  *
     18  * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
     19  * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
     20  * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
     21  * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
     22  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
     23  *
     24  * Google Author(s): Behdad Esfahbod
     25  */
     26 
     27 #ifndef HB_OT_SHAPE_COMPLEX_INDIC_PRIVATE_HH
     28 #define HB_OT_SHAPE_COMPLEX_INDIC_PRIVATE_HH
     29 
     30 #include "hb-private.hh"
     31 
     32 
     33 #include "hb-ot-shape-complex-private.hh"
     34 #include "hb-ot-shape-private.hh" /* XXX Remove */
     35 
     36 
     37 #define INDIC_TABLE_ELEMENT_TYPE uint16_t
     38 
     39 /* Cateories used in the OpenType spec:
     40  * https://www.microsoft.com/typography/otfntdev/devanot/shaping.aspx
     41  */
     42 /* Note: This enum is duplicated in the -machine.rl source file.
     43  * Not sure how to avoid duplication. */
     44 enum indic_category_t {
     45   OT_X = 0,
     46   OT_C = 1,
     47   OT_V = 2,
     48   OT_N = 3,
     49   OT_H = 4,
     50   OT_ZWNJ = 5,
     51   OT_ZWJ = 6,
     52   OT_M = 7,
     53   OT_SM = 8,
     54   OT_VD = 9,
     55   OT_A = 10,
     56   OT_PLACEHOLDER = 11,
     57   OT_DOTTEDCIRCLE = 12,
     58   OT_RS = 13, /* Register Shifter, used in Khmer OT spec. */
     59   OT_Coeng = 14, /* Khmer-style Virama. */
     60   OT_Repha = 15, /* Atomically-encoded logical or visual repha. */
     61   OT_Ra = 16,
     62   OT_CM = 17,  /* Consonant-Medial. */
     63   OT_Symbol = 18, /* Avagraha, etc that take marks (SM,A,VD). */
     64   OT_CM2 = 31 /* Consonant-Medial, second slot. */
     65 };
     66 
     67 #define MEDIAL_FLAGS (FLAG (OT_CM) | FLAG (OT_CM2))
     68 
     69 /* Note:
     70  *
     71  * We treat Vowels and placeholders as if they were consonants.  This is safe because Vowels
     72  * cannot happen in a consonant syllable.  The plus side however is, we can call the
     73  * consonant syllable logic from the vowel syllable function and get it all right! */
     74 #define CONSONANT_FLAGS (FLAG (OT_C) | FLAG (OT_Ra) | MEDIAL_FLAGS | FLAG (OT_V) | FLAG (OT_PLACEHOLDER) | FLAG (OT_DOTTEDCIRCLE))
     75 #define JOINER_FLAGS (FLAG (OT_ZWJ) | FLAG (OT_ZWNJ))
     76 #define HALANT_OR_COENG_FLAGS (FLAG (OT_H) | FLAG (OT_Coeng))
     77 
     78 
     79 /* Visual positions in a syllable from left to right. */
     80 enum indic_position_t {
     81   POS_START,
     82 
     83   POS_RA_TO_BECOME_REPH,
     84   POS_PRE_M,
     85   POS_PRE_C,
     86 
     87   POS_BASE_C,
     88   POS_AFTER_MAIN,
     89 
     90   POS_ABOVE_C,
     91 
     92   POS_BEFORE_SUB,
     93   POS_BELOW_C,
     94   POS_AFTER_SUB,
     95 
     96   POS_BEFORE_POST,
     97   POS_POST_C,
     98   POS_AFTER_POST,
     99 
    100   POS_FINAL_C,
    101   POS_SMVD,
    102 
    103   POS_END
    104 };
    105 
    106 /* Categories used in IndicSyllabicCategory.txt from UCD. */
    107 enum indic_syllabic_category_t {
    108   INDIC_SYLLABIC_CATEGORY_OTHER				= OT_X,
    109 
    110   INDIC_SYLLABIC_CATEGORY_AVAGRAHA			= OT_Symbol,
    111   INDIC_SYLLABIC_CATEGORY_BINDU				= OT_SM,
    112   INDIC_SYLLABIC_CATEGORY_BRAHMI_JOINING_NUMBER		= OT_PLACEHOLDER, /* TODO */
    113   INDIC_SYLLABIC_CATEGORY_CANTILLATION_MARK		= OT_A,
    114   INDIC_SYLLABIC_CATEGORY_CONSONANT			= OT_C,
    115   INDIC_SYLLABIC_CATEGORY_CONSONANT_DEAD		= OT_C,
    116   INDIC_SYLLABIC_CATEGORY_CONSONANT_FINAL		= OT_CM,
    117   INDIC_SYLLABIC_CATEGORY_CONSONANT_HEAD_LETTER		= OT_C,
    118   INDIC_SYLLABIC_CATEGORY_CONSONANT_MEDIAL		= OT_CM,
    119   INDIC_SYLLABIC_CATEGORY_CONSONANT_PLACEHOLDER		= OT_PLACEHOLDER,
    120   INDIC_SYLLABIC_CATEGORY_CONSONANT_PRECEDING_REPHA	= OT_Repha,
    121   INDIC_SYLLABIC_CATEGORY_CONSONANT_SUBJOINED		= OT_CM,
    122   INDIC_SYLLABIC_CATEGORY_CONSONANT_SUCCEEDING_REPHA	= OT_N,
    123   INDIC_SYLLABIC_CATEGORY_GEMINATION_MARK		= OT_SM,
    124   INDIC_SYLLABIC_CATEGORY_INVISIBLE_STACKER		= OT_H, /* TODO */
    125   INDIC_SYLLABIC_CATEGORY_JOINER			= OT_ZWJ,
    126   INDIC_SYLLABIC_CATEGORY_MODIFYING_LETTER		= OT_X,
    127   INDIC_SYLLABIC_CATEGORY_NON_JOINER			= OT_ZWNJ,
    128   INDIC_SYLLABIC_CATEGORY_NUKTA				= OT_N,
    129   INDIC_SYLLABIC_CATEGORY_NUMBER			= OT_PLACEHOLDER,
    130   INDIC_SYLLABIC_CATEGORY_NUMBER_JOINER			= OT_PLACEHOLDER, /* TODO */
    131   INDIC_SYLLABIC_CATEGORY_PURE_KILLER			= OT_H, /* TODO */
    132   INDIC_SYLLABIC_CATEGORY_REGISTER_SHIFTER		= OT_RS,
    133   INDIC_SYLLABIC_CATEGORY_TONE_LETTER			= OT_X,
    134   INDIC_SYLLABIC_CATEGORY_TONE_MARK			= OT_N,
    135   INDIC_SYLLABIC_CATEGORY_VIRAMA			= OT_H,
    136   INDIC_SYLLABIC_CATEGORY_VISARGA			= OT_SM,
    137   INDIC_SYLLABIC_CATEGORY_VOWEL				= OT_V,
    138   INDIC_SYLLABIC_CATEGORY_VOWEL_DEPENDENT		= OT_M,
    139   INDIC_SYLLABIC_CATEGORY_VOWEL_INDEPENDENT		= OT_V
    140 };
    141 
    142 /* Categories used in IndicSMatraCategory.txt from UCD */
    143 enum indic_matra_category_t {
    144   INDIC_MATRA_CATEGORY_NOT_APPLICABLE			= POS_END,
    145 
    146   INDIC_MATRA_CATEGORY_LEFT				= POS_PRE_C,
    147   INDIC_MATRA_CATEGORY_TOP				= POS_ABOVE_C,
    148   INDIC_MATRA_CATEGORY_BOTTOM				= POS_BELOW_C,
    149   INDIC_MATRA_CATEGORY_RIGHT				= POS_POST_C,
    150 
    151   /* These should resolve to the position of the last part of the split sequence. */
    152   INDIC_MATRA_CATEGORY_BOTTOM_AND_RIGHT			= INDIC_MATRA_CATEGORY_RIGHT,
    153   INDIC_MATRA_CATEGORY_LEFT_AND_RIGHT			= INDIC_MATRA_CATEGORY_RIGHT,
    154   INDIC_MATRA_CATEGORY_TOP_AND_BOTTOM			= INDIC_MATRA_CATEGORY_BOTTOM,
    155   INDIC_MATRA_CATEGORY_TOP_AND_BOTTOM_AND_RIGHT		= INDIC_MATRA_CATEGORY_RIGHT,
    156   INDIC_MATRA_CATEGORY_TOP_AND_LEFT			= INDIC_MATRA_CATEGORY_TOP,
    157   INDIC_MATRA_CATEGORY_TOP_AND_LEFT_AND_RIGHT		= INDIC_MATRA_CATEGORY_RIGHT,
    158   INDIC_MATRA_CATEGORY_TOP_AND_RIGHT			= INDIC_MATRA_CATEGORY_RIGHT,
    159 
    160   INDIC_MATRA_CATEGORY_OVERSTRUCK			= POS_AFTER_MAIN,
    161   INDIC_MATRA_CATEGORY_VISUAL_ORDER_LEFT		= POS_PRE_M
    162 };
    163 
    164 /* Note: We use ASSERT_STATIC_EXPR_ZERO() instead of ASSERT_STATIC_EXPR() and the comma operation
    165  * because gcc fails to optimize the latter and fills the table in at runtime. */
    166 #define INDIC_COMBINE_CATEGORIES(S,M) \
    167   (ASSERT_STATIC_EXPR_ZERO (M == INDIC_MATRA_CATEGORY_NOT_APPLICABLE || \
    168 			    ( \
    169 			     S == INDIC_SYLLABIC_CATEGORY_CONSONANT_MEDIAL || \
    170 			     S == INDIC_SYLLABIC_CATEGORY_GEMINATION_MARK || \
    171 			     S == INDIC_SYLLABIC_CATEGORY_REGISTER_SHIFTER || \
    172 			     S == INDIC_SYLLABIC_CATEGORY_CONSONANT_SUCCEEDING_REPHA || \
    173 			     S == INDIC_SYLLABIC_CATEGORY_VIRAMA || \
    174 			     S == INDIC_SYLLABIC_CATEGORY_VOWEL_DEPENDENT || \
    175 			     false)) + \
    176    ASSERT_STATIC_EXPR_ZERO (S < 255 && M < 255) + \
    177    ((M << 8) | S))
    178 
    179 HB_INTERNAL INDIC_TABLE_ELEMENT_TYPE
    180 hb_indic_get_categories (hb_codepoint_t u);
    181 
    182 #endif /* HB_OT_SHAPE_COMPLEX_INDIC_PRIVATE_HH */
    183