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_categories() var2.u32 /* indic shaping action */
  34
  35 #define INDIC_TABLE_ELEMENT_TYPE uint8_t
  36
  37 /* Cateories used in the OpenType spec:
  38  * https://www.microsoft.com/typography/otfntdev/devanot/shaping.aspx
  39  */
  40 enum {
  41   OT_X = 0,
  42   OT_C,
  43   OT_V,
  44   OT_N,
  45   OT_H,
  46   OT_ZWNJ,
  47   OT_ZWJ,
  48   OT_M,
  49   OT_SM,
  50   OT_VD,
  51   OT_A,
  52   OT_NBSP
  53 };
  54
  55 /* Categories used in IndicSyllabicCategory.txt from UCD */
  56 /* The assignments are guesswork */
  57 enum indic_syllabic_category_t {
  58   INDIC_SYLLABIC_CATEGORY_OTHER                 = OT_X,
  59
  60   INDIC_SYLLABIC_CATEGORY_AVAGRAHA              = OT_X,
  61   INDIC_SYLLABIC_CATEGORY_BINDU                 = OT_SM,
  62   INDIC_SYLLABIC_CATEGORY_CONSONANT             = OT_C,
  63   INDIC_SYLLABIC_CATEGORY_CONSONANT_DEAD        = OT_C,
  64   INDIC_SYLLABIC_CATEGORY_CONSONANT_FINAL       = OT_C,
  65   INDIC_SYLLABIC_CATEGORY_CONSONANT_HEAD_LETTER = OT_C,
  66   INDIC_SYLLABIC_CATEGORY_CONSONANT_MEDIAL      = OT_C,
  67   INDIC_SYLLABIC_CATEGORY_CONSONANT_PLACEHOLDER = OT_NBSP,
  68   INDIC_SYLLABIC_CATEGORY_CONSONANT_SUBJOINED   = OT_C,
  69   INDIC_SYLLABIC_CATEGORY_CONSONANT_REPHA       = OT_C,
  70   INDIC_SYLLABIC_CATEGORY_MODIFYING_LETTER      = OT_X,
  71   INDIC_SYLLABIC_CATEGORY_NUKTA                 = OT_N,
  72   INDIC_SYLLABIC_CATEGORY_REGISTER_SHIFTER      = OT_X,
  73   INDIC_SYLLABIC_CATEGORY_TONE_LETTER           = OT_X,
  74   INDIC_SYLLABIC_CATEGORY_TONE_MARK             = OT_X,
  75   INDIC_SYLLABIC_CATEGORY_VIRAMA                = OT_H,
  76   INDIC_SYLLABIC_CATEGORY_VISARGA               = OT_SM,
  77   INDIC_SYLLABIC_CATEGORY_VOWEL                 = OT_V,
  78   INDIC_SYLLABIC_CATEGORY_VOWEL_DEPENDENT       = OT_M,
  79   INDIC_SYLLABIC_CATEGORY_VOWEL_INDEPENDENT     = OT_V
  80 };
  81
  82 /* Categories used in IndicSMatraCategory.txt from UCD */
  83 enum indic_matra_category_t {
  84   INDIC_MATRA_CATEGORY_NOT_APPLICABLE           = 0,
  85
  86   INDIC_MATRA_CATEGORY_LEFT                     = 0x01,
  87   INDIC_MATRA_CATEGORY_TOP                      = 0x02,
  88   INDIC_MATRA_CATEGORY_BOTTOM                   = 0x04,
  89   INDIC_MATRA_CATEGORY_RIGHT                    = 0x08,
  90
  91   /* We don't really care much about these since we decompose them
  92    * in the generic pre-shaping layer. */
  93   INDIC_MATRA_CATEGORY_BOTTOM_AND_RIGHT         = INDIC_MATRA_CATEGORY_BOTTOM +
  94                                                   INDIC_MATRA_CATEGORY_RIGHT,
  95   INDIC_MATRA_CATEGORY_LEFT_AND_RIGHT           = INDIC_MATRA_CATEGORY_LEFT +
  96                                                   INDIC_MATRA_CATEGORY_RIGHT,
  97   INDIC_MATRA_CATEGORY_TOP_AND_BOTTOM           = INDIC_MATRA_CATEGORY_TOP +
  98                                                   INDIC_MATRA_CATEGORY_BOTTOM,
  99   INDIC_MATRA_CATEGORY_TOP_AND_BOTTOM_AND_RIGHT = INDIC_MATRA_CATEGORY_TOP +
 100                                                   INDIC_MATRA_CATEGORY_BOTTOM +
 101                                                   INDIC_MATRA_CATEGORY_RIGHT,
 102   INDIC_MATRA_CATEGORY_TOP_AND_LEFT             = INDIC_MATRA_CATEGORY_TOP +
 103                                                   INDIC_MATRA_CATEGORY_LEFT,
 104   INDIC_MATRA_CATEGORY_TOP_AND_LEFT_AND_RIGHT   = INDIC_MATRA_CATEGORY_TOP +
 105                                                   INDIC_MATRA_CATEGORY_LEFT +
 106                                                   INDIC_MATRA_CATEGORY_RIGHT,
 107   INDIC_MATRA_CATEGORY_TOP_AND_RIGHT            = INDIC_MATRA_CATEGORY_TOP +
 108                                                   INDIC_MATRA_CATEGORY_RIGHT,
 109
 110   INDIC_MATRA_CATEGORY_INVISIBLE                = INDIC_MATRA_CATEGORY_NOT_APPLICABLE,
 111   INDIC_MATRA_CATEGORY_OVERSTRUCK               = INDIC_MATRA_CATEGORY_NOT_APPLICABLE,
 112   INDIC_MATRA_CATEGORY_VISUAL_ORDER_LEFT        = INDIC_MATRA_CATEGORY_NOT_APPLICABLE
 113 };
 114
 115 #define INDIC_COMBINE_CATEGORIES(S,M) \
 116   (ASSERT_STATIC_EXPR (M == INDIC_MATRA_CATEGORY_NOT_APPLICABLE || (S == INDIC_SYLLABIC_CATEGORY_VIRAMA || S == INDIC_SYLLABIC_CATEGORY_VOWEL_DEPENDENT)), \
 117    ASSERT_STATIC_EXPR (S < 16 && M < 16), \
 118    (M << 4) | S)
 119
 120 #include "hb-ot-shape-complex-indic-table.hh"
 121
 122 static const hb_tag_t indic_basic_features[] =
 123 {
 124   HB_TAG('n','u','k','t'),
 125   HB_TAG('a','k','h','n'),
 126   HB_TAG('r','p','h','f'),
 127   HB_TAG('r','k','r','f'),
 128   HB_TAG('p','r','e','f'),
 129   HB_TAG('b','l','w','f'),
 130   HB_TAG('h','a','l','f'),
 131   HB_TAG('v','a','t','u'),
 132   HB_TAG('p','s','t','f'),
 133   HB_TAG('c','j','c','t'),
 134 };
 135
 136 static const hb_tag_t indic_other_features[] =
 137 {
 138   HB_TAG('p','r','e','s'),
 139   HB_TAG('a','b','v','s'),
 140   HB_TAG('b','l','w','s'),
 141   HB_TAG('p','s','t','s'),
 142   HB_TAG('h','a','l','n'),
 143
 144   HB_TAG('d','i','s','t'),
 145   HB_TAG('a','b','v','m'),
 146   HB_TAG('b','l','w','m'),
 147 };
 148
 149
 150
 151 void
 152 _hb_ot_shape_complex_collect_features_indic     (hb_ot_shape_planner_t *planner, const hb_segment_properties_t  *props HB_UNUSED)
 153 {
 154   for (unsigned int i = 0; i < ARRAY_LENGTH (indic_basic_features); i++)
 155     planner->map.add_bool_feature (indic_basic_features[i], false);
 156
 157   for (unsigned int i = 0; i < ARRAY_LENGTH (indic_other_features); i++)
 158     planner->map.add_bool_feature (indic_other_features[i], true);
 159 }
 160
 161 void
 162 _hb_ot_shape_complex_setup_masks_indic  (hb_ot_shape_context_t *c)
 163 {
 164   unsigned int count = c->buffer->len;
 165
 166   for (unsigned int i = 0; i < count; i++)
 167   {
 168     unsigned int this_type = get_indic_categories (c->buffer->info[i].codepoint);
 169
 170     c->buffer->info[i].indic_categories() = this_type;
 171   }
 172
 173   hb_mask_t mask_array[ARRAY_LENGTH (indic_basic_features)] = {0};
 174   unsigned int num_masks = ARRAY_LENGTH (indic_basic_features);
 175   for (unsigned int i = 0; i < num_masks; i++)
 176     mask_array[i] = c->plan->map.get_1_mask (indic_basic_features[i]);
 177 }
 178
 179
 180 HB_END_DECLS