src/hb-ot-shape-complex-indic.cc

   1 /*
   2  * Copyright © 2011  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 #include "hb-ot-shape-complex-private.hh"
  28
  29 HB_BEGIN_DECLS
  30
  31
  32 /* buffer var allocations */
  33 #define indic_category() var2.u8[0] /* indic_category_t */
  34 #define indic_position() var2.u8[1] /* indic_matra_category_t */
  35
  36 #define INDIC_TABLE_ELEMENT_TYPE uint8_t
  37
  38 /* Cateories used in the OpenType spec:
  39  * https://www.microsoft.com/typography/otfntdev/devanot/shaping.aspx
  40  */
  41 /* Note: This enum is duplicated in the -machine.rl source file.
  42  * Not sure how to avoid duplication. */
  43 enum indic_category_t {
  44   OT_X = 0,
  45   OT_C,
  46   OT_Ra, /* Not explicitly listed in the OT spec, but used in the grammar. */
  47   OT_V,
  48   OT_N,
  49   OT_H,
  50   OT_ZWNJ,
  51   OT_ZWJ,
  52   OT_M,
  53   OT_SM,
  54   OT_VD,
  55   OT_A,
  56   OT_NBSP
  57 };
  58
  59 /* Categories used in IndicSyllabicCategory.txt from UCD */
  60 /* The assignments are guesswork */
  61 enum indic_syllabic_category_t {
  62   INDIC_SYLLABIC_CATEGORY_OTHER                 = OT_X,
  63
  64   INDIC_SYLLABIC_CATEGORY_AVAGRAHA              = OT_X,
  65   INDIC_SYLLABIC_CATEGORY_BINDU                 = OT_SM,
  66   INDIC_SYLLABIC_CATEGORY_CONSONANT             = OT_C,
  67   INDIC_SYLLABIC_CATEGORY_CONSONANT_DEAD        = OT_C,
  68   INDIC_SYLLABIC_CATEGORY_CONSONANT_FINAL       = OT_C,
  69   INDIC_SYLLABIC_CATEGORY_CONSONANT_HEAD_LETTER = OT_C,
  70   INDIC_SYLLABIC_CATEGORY_CONSONANT_MEDIAL      = OT_C,
  71   INDIC_SYLLABIC_CATEGORY_CONSONANT_PLACEHOLDER = OT_NBSP,
  72   INDIC_SYLLABIC_CATEGORY_CONSONANT_SUBJOINED   = OT_C,
  73   INDIC_SYLLABIC_CATEGORY_CONSONANT_REPHA       = OT_C,
  74   INDIC_SYLLABIC_CATEGORY_MODIFYING_LETTER      = OT_X,
  75   INDIC_SYLLABIC_CATEGORY_NUKTA                 = OT_N,
  76   INDIC_SYLLABIC_CATEGORY_REGISTER_SHIFTER      = OT_X,
  77   INDIC_SYLLABIC_CATEGORY_TONE_LETTER           = OT_X,
  78   INDIC_SYLLABIC_CATEGORY_TONE_MARK             = OT_X,
  79   INDIC_SYLLABIC_CATEGORY_VIRAMA                = OT_H,
  80   INDIC_SYLLABIC_CATEGORY_VISARGA               = OT_SM,
  81   INDIC_SYLLABIC_CATEGORY_VOWEL                 = OT_V,
  82   INDIC_SYLLABIC_CATEGORY_VOWEL_DEPENDENT       = OT_M,
  83   INDIC_SYLLABIC_CATEGORY_VOWEL_INDEPENDENT     = OT_V
  84 };
  85
  86 /* Categories used in IndicSMatraCategory.txt from UCD */
  87 enum indic_matra_category_t {
  88   INDIC_MATRA_CATEGORY_NOT_APPLICABLE           = 0,
  89
  90   INDIC_MATRA_CATEGORY_LEFT                     = 0x01,
  91   INDIC_MATRA_CATEGORY_TOP                      = 0x02,
  92   INDIC_MATRA_CATEGORY_BOTTOM                   = 0x04,
  93   INDIC_MATRA_CATEGORY_RIGHT                    = 0x08,
  94
  95   /* We don't really care much about these since we decompose them
  96    * in the generic pre-shaping layer. */
  97   INDIC_MATRA_CATEGORY_BOTTOM_AND_RIGHT         = INDIC_MATRA_CATEGORY_BOTTOM +
  98                                                   INDIC_MATRA_CATEGORY_RIGHT,
  99   INDIC_MATRA_CATEGORY_LEFT_AND_RIGHT           = INDIC_MATRA_CATEGORY_LEFT +
 100                                                   INDIC_MATRA_CATEGORY_RIGHT,
 101   INDIC_MATRA_CATEGORY_TOP_AND_BOTTOM           = INDIC_MATRA_CATEGORY_TOP +
 102                                                   INDIC_MATRA_CATEGORY_BOTTOM,
 103   INDIC_MATRA_CATEGORY_TOP_AND_BOTTOM_AND_RIGHT = INDIC_MATRA_CATEGORY_TOP +
 104                                                   INDIC_MATRA_CATEGORY_BOTTOM +
 105                                                   INDIC_MATRA_CATEGORY_RIGHT,
 106   INDIC_MATRA_CATEGORY_TOP_AND_LEFT             = INDIC_MATRA_CATEGORY_TOP +
 107                                                   INDIC_MATRA_CATEGORY_LEFT,
 108   INDIC_MATRA_CATEGORY_TOP_AND_LEFT_AND_RIGHT   = INDIC_MATRA_CATEGORY_TOP +
 109                                                   INDIC_MATRA_CATEGORY_LEFT +
 110                                                   INDIC_MATRA_CATEGORY_RIGHT,
 111   INDIC_MATRA_CATEGORY_TOP_AND_RIGHT            = INDIC_MATRA_CATEGORY_TOP +
 112                                                   INDIC_MATRA_CATEGORY_RIGHT,
 113
 114   INDIC_MATRA_CATEGORY_INVISIBLE                = INDIC_MATRA_CATEGORY_NOT_APPLICABLE,
 115   INDIC_MATRA_CATEGORY_OVERSTRUCK               = INDIC_MATRA_CATEGORY_NOT_APPLICABLE,
 116   INDIC_MATRA_CATEGORY_VISUAL_ORDER_LEFT        = INDIC_MATRA_CATEGORY_NOT_APPLICABLE
 117 };
 118
 119 #define INDIC_COMBINE_CATEGORIES(S,M) \
 120   (ASSERT_STATIC_EXPR (M == INDIC_MATRA_CATEGORY_NOT_APPLICABLE || (S == INDIC_SYLLABIC_CATEGORY_VIRAMA || S == INDIC_SYLLABIC_CATEGORY_VOWEL_DEPENDENT)), \
 121    ASSERT_STATIC_EXPR (S < 16 && M < 16), \
 122    (M << 4) | S)
 123
 124 #include "hb-ot-shape-complex-indic-table.hh"
 125
 126
 127 static const struct {
 128   hb_tag_t tag;
 129   hb_bool_t is_global;
 130 } indic_basic_features[] =
 131 {
 132   {HB_TAG('n','u','k','t'), true},
 133   {HB_TAG('a','k','h','n'), false},
 134   {HB_TAG('r','p','h','f'), false},
 135   {HB_TAG('r','k','r','f'), false},
 136   {HB_TAG('p','r','e','f'), false},
 137   {HB_TAG('b','l','w','f'), false},
 138   {HB_TAG('h','a','l','f'), false},
 139   {HB_TAG('v','a','t','u'), true},
 140   {HB_TAG('p','s','t','f'), false},
 141   {HB_TAG('c','j','c','t'), true},
 142 };
 143
 144 /* Same order as the indic_basic_features array */
 145 enum {
 146   _NUKT,
 147   AKHN,
 148   RPHF,
 149   RKRF,
 150   PREF,
 151   BLWF,
 152   HALF,
 153   _VATU,
 154   PSTF,
 155   _CJCT,
 156 };
 157
 158 static const hb_tag_t indic_other_features[] =
 159 {
 160   HB_TAG('p','r','e','s'),
 161   HB_TAG('a','b','v','s'),
 162   HB_TAG('b','l','w','s'),
 163   HB_TAG('p','s','t','s'),
 164   HB_TAG('h','a','l','n'),
 165
 166   HB_TAG('d','i','s','t'),
 167   HB_TAG('a','b','v','m'),
 168   HB_TAG('b','l','w','m'),
 169 };
 170
 171
 172 void
 173 _hb_ot_shape_complex_collect_features_indic (hb_ot_shape_planner_t *planner, const hb_segment_properties_t *props HB_UNUSED)
 174 {
 175   for (unsigned int i = 0; i < ARRAY_LENGTH (indic_basic_features); i++)
 176     planner->map.add_bool_feature (indic_basic_features[i].tag, indic_basic_features[i].is_global);
 177
 178   for (unsigned int i = 0; i < ARRAY_LENGTH (indic_other_features); i++)
 179     planner->map.add_bool_feature (indic_other_features[i], true);
 180 }
 181
 182
 183
 184 #include "hb-ot-shape-complex-indic-machine.hh"
 185
 186
 187 void
 188 _hb_ot_shape_complex_setup_masks_indic  (hb_ot_shape_context_t *c)
 189 {
 190   unsigned int count = c->buffer->len;
 191
 192   for (unsigned int i = 0; i < count; i++)
 193   {
 194     unsigned int type = get_indic_categories (c->buffer->info[i].codepoint);
 195
 196     c->buffer->info[i].indic_category() = type & 0x0F;
 197     c->buffer->info[i].indic_position() = type >> 4;
 198   }
 199
 200   find_syllables (c);
 201
 202   hb_mask_t mask_array[ARRAY_LENGTH (indic_basic_features)] = {0};
 203   unsigned int num_masks = ARRAY_LENGTH (indic_basic_features);
 204   for (unsigned int i = 0; i < num_masks; i++)
 205     mask_array[i] = c->plan->map.get_1_mask (indic_basic_features[i].tag);
 206 }
 207
 208
 209 HB_END_DECLS