third_party/harfbuzz-ng/src/hb-ot-map-private.hh

   1 /*
   2  * Copyright © 2009,2010  Red Hat, Inc.
   3  * Copyright © 2010,2011,2012,2013  Google, Inc.
   4  *
   5  *  This is part of HarfBuzz, a text shaping library.
   6  *
   7  * Permission is hereby granted, without written agreement and without
   8  * license or royalty fees, to use, copy, modify, and distribute this
   9  * software and its documentation for any purpose, provided that the
  10  * above copyright notice and the following two paragraphs appear in
  11  * all copies of this software.
  12  *
  13  * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
  14  * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
  15  * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
  16  * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
  17  * DAMAGE.
  18  *
  19  * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
  20  * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
  21  * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
  22  * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
  23  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
  24  *
  25  * Red Hat Author(s): Behdad Esfahbod
  26  * Google Author(s): Behdad Esfahbod
  27  */
  28
  29 #ifndef HB_OT_MAP_PRIVATE_HH
  30 #define HB_OT_MAP_PRIVATE_HH
  31
  32 #include "hb-buffer-private.hh"
  33
  34
  35 struct hb_ot_shape_plan_t;
  36
  37 static const hb_tag_t table_tags[2] = {HB_OT_TAG_GSUB, HB_OT_TAG_GPOS};
  38
  39 struct hb_ot_map_t
  40 {
  41   friend struct hb_ot_map_builder_t;
  42
  43   public:
  44
  45   struct feature_map_t {
  46     hb_tag_t tag; /* should be first for our bsearch to work */
  47     unsigned int index[2]; /* GSUB/GPOS */
  48     unsigned int stage[2]; /* GSUB/GPOS */
  49     unsigned int shift;
  50     hb_mask_t mask;
  51     hb_mask_t _1_mask; /* mask for value=1, for quick access */
  52     unsigned int needs_fallback : 1;
  53     unsigned int auto_zwj : 1;
  54
  55     static int cmp (const feature_map_t *a, const feature_map_t *b)
  56     { return a->tag < b->tag ? -1 : a->tag > b->tag ? 1 : 0; }
  57   };
  58
  59   struct lookup_map_t {
  60     unsigned short index;
  61     unsigned short auto_zwj : 1;
  62     hb_mask_t mask;
  63
  64     static int cmp (const lookup_map_t *a, const lookup_map_t *b)
  65     { return a->index < b->index ? -1 : a->index > b->index ? 1 : 0; }
  66   };
  67
  68   typedef void (*pause_func_t) (const struct hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer);
  69
  70   struct stage_map_t {
  71     unsigned int last_lookup; /* Cumulative */
  72     pause_func_t pause_func;
  73   };
  74
  75
  76   hb_ot_map_t (void) { memset (this, 0, sizeof (*this)); }
  77
  78   inline hb_mask_t get_global_mask (void) const { return global_mask; }
  79
  80   inline hb_mask_t get_mask (hb_tag_t feature_tag, unsigned int *shift = NULL) const {
  81     const feature_map_t *map = features.bsearch (&feature_tag);
  82     if (shift) *shift = map ? map->shift : 0;
  83     return map ? map->mask : 0;
  84   }
  85
  86   inline bool needs_fallback (hb_tag_t feature_tag) const {
  87     const feature_map_t *map = features.bsearch (&feature_tag);
  88     return map ? map->needs_fallback : false;
  89   }
  90
  91   inline hb_mask_t get_1_mask (hb_tag_t feature_tag) const {
  92     const feature_map_t *map = features.bsearch (&feature_tag);
  93     return map ? map->_1_mask : 0;
  94   }
  95
  96   inline unsigned int get_feature_index (unsigned int table_index, hb_tag_t feature_tag) const {
  97     const feature_map_t *map = features.bsearch (&feature_tag);
  98     return map ? map->index[table_index] : HB_OT_LAYOUT_NO_FEATURE_INDEX;
  99   }
 100
 101   inline unsigned int get_feature_stage (unsigned int table_index, hb_tag_t feature_tag) const {
 102     const feature_map_t *map = features.bsearch (&feature_tag);
 103     return map ? map->stage[table_index] : (unsigned int) -1;
 104   }
 105
 106   inline void get_stage_lookups (unsigned int table_index, unsigned int stage,
 107                                  const struct lookup_map_t **plookups, unsigned int *lookup_count) const {
 108     if (unlikely (stage == (unsigned int) -1)) {
 109       *plookups = NULL;
 110       *lookup_count = 0;
 111       return;
 112     }
 113     assert (stage <= stages[table_index].len);
 114     unsigned int start = stage ? stages[table_index][stage - 1].last_lookup : 0;
 115     unsigned int end   = stage < stages[table_index].len ? stages[table_index][stage].last_lookup : lookups[table_index].len;
 116     *plookups = &lookups[table_index][start];
 117     *lookup_count = end - start;
 118   }
 119
 120   HB_INTERNAL void collect_lookups (unsigned int table_index, hb_set_t *lookups) const;
 121   template <typename Proxy>
 122   HB_INTERNAL inline void apply (const Proxy &proxy,
 123                                  const struct hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) const;
 124   HB_INTERNAL void substitute (const struct hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) const;
 125   HB_INTERNAL void position (const struct hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) const;
 126
 127   inline void finish (void) {
 128     features.finish ();
 129     for (unsigned int table_index = 0; table_index < 2; table_index++)
 130     {
 131       lookups[table_index].finish ();
 132       stages[table_index].finish ();
 133     }
 134   }
 135
 136   public:
 137   hb_tag_t chosen_script[2];
 138   bool found_script[2];
 139
 140   private:
 141
 142   HB_INTERNAL void add_lookups (hb_face_t    *face,
 143                                 unsigned int  table_index,
 144                                 unsigned int  feature_index,
 145                                 hb_mask_t     mask,
 146                                 bool          auto_zwj);
 147
 148   hb_mask_t global_mask;
 149
 150   hb_prealloced_array_t<feature_map_t, 8> features;
 151   hb_prealloced_array_t<lookup_map_t, 32> lookups[2]; /* GSUB/GPOS */
 152   hb_prealloced_array_t<stage_map_t, 4> stages[2]; /* GSUB/GPOS */
 153 };
 154
 155 enum hb_ot_map_feature_flags_t {
 156   F_NONE                = 0x0000u,
 157   F_GLOBAL              = 0x0001u,
 158   F_HAS_FALLBACK        = 0x0002u,
 159   F_MANUAL_ZWJ          = 0x0004u
 160 };
 161 /* Macro version for where const is desired. */
 162 #define F_COMBINE(l,r) (hb_ot_map_feature_flags_t ((unsigned int) (l) | (unsigned int) (r)))
 163 static inline hb_ot_map_feature_flags_t
 164 operator | (hb_ot_map_feature_flags_t l, hb_ot_map_feature_flags_t r)
 165 { return hb_ot_map_feature_flags_t ((unsigned int) l | (unsigned int) r); }
 166 static inline hb_ot_map_feature_flags_t
 167 operator & (hb_ot_map_feature_flags_t l, hb_ot_map_feature_flags_t r)
 168 { return hb_ot_map_feature_flags_t ((unsigned int) l & (unsigned int) r); }
 169 static inline hb_ot_map_feature_flags_t
 170 operator ~ (hb_ot_map_feature_flags_t r)
 171 { return hb_ot_map_feature_flags_t (~(unsigned int) r); }
 172 static inline hb_ot_map_feature_flags_t&
 173 operator |= (hb_ot_map_feature_flags_t &l, hb_ot_map_feature_flags_t r)
 174 { l = l | r; return l; }
 175 static inline hb_ot_map_feature_flags_t&
 176 operator &= (hb_ot_map_feature_flags_t& l, hb_ot_map_feature_flags_t r)
 177 { l = l & r; return l; }
 178
 179
 180 struct hb_ot_map_builder_t
 181 {
 182   public:
 183
 184   HB_INTERNAL hb_ot_map_builder_t (hb_face_t *face_,
 185                                    const hb_segment_properties_t *props_);
 186
 187   HB_INTERNAL void add_feature (hb_tag_t tag, unsigned int value,
 188                                 hb_ot_map_feature_flags_t flags);
 189
 190   inline void add_global_bool_feature (hb_tag_t tag)
 191   { add_feature (tag, 1, F_GLOBAL); }
 192
 193   inline void add_gsub_pause (hb_ot_map_t::pause_func_t pause_func)
 194   { add_pause (0, pause_func); }
 195   inline void add_gpos_pause (hb_ot_map_t::pause_func_t pause_func)
 196   { add_pause (1, pause_func); }
 197
 198   HB_INTERNAL void compile (struct hb_ot_map_t &m);
 199
 200   inline void finish (void) {
 201     feature_infos.finish ();
 202     for (unsigned int table_index = 0; table_index < 2; table_index++)
 203     {
 204       stages[table_index].finish ();
 205     }
 206   }
 207
 208   private:
 209
 210   struct feature_info_t {
 211     hb_tag_t tag;
 212     unsigned int seq; /* sequence#, used for stable sorting only */
 213     unsigned int max_value;
 214     hb_ot_map_feature_flags_t flags;
 215     unsigned int default_value; /* for non-global features, what should the unset glyphs take */
 216     unsigned int stage[2]; /* GSUB/GPOS */
 217
 218     static int cmp (const feature_info_t *a, const feature_info_t *b)
 219     { return (a->tag != b->tag) ?  (a->tag < b->tag ? -1 : 1) : (a->seq < b->seq ? -1 : 1); }
 220   };
 221
 222   struct stage_info_t {
 223     unsigned int index;
 224     hb_ot_map_t::pause_func_t pause_func;
 225   };
 226
 227   HB_INTERNAL void add_pause (unsigned int table_index, hb_ot_map_t::pause_func_t pause_func);
 228
 229   public:
 230
 231   hb_face_t *face;
 232   hb_segment_properties_t props;
 233
 234   hb_tag_t chosen_script[2];
 235   bool found_script[2];
 236   unsigned int script_index[2], language_index[2];
 237
 238   private:
 239
 240   unsigned int current_stage[2]; /* GSUB/GPOS */
 241   hb_prealloced_array_t<feature_info_t, 32> feature_infos;
 242   hb_prealloced_array_t<stage_info_t, 8> stages[2]; /* GSUB/GPOS */
 243 };
 244
 245
 246
 247 #endif /* HB_OT_MAP_PRIVATE_HH */