michael@0: /*
michael@0:  * Copyright © 2009,2010  Red Hat, Inc.
michael@0:  * Copyright © 2010,2011,2012,2013  Google, Inc.
michael@0:  *
michael@0:  *  This is part of HarfBuzz, a text shaping library.
michael@0:  *
michael@0:  * Permission is hereby granted, without written agreement and without
michael@0:  * license or royalty fees, to use, copy, modify, and distribute this
michael@0:  * software and its documentation for any purpose, provided that the
michael@0:  * above copyright notice and the following two paragraphs appear in
michael@0:  * all copies of this software.
michael@0:  *
michael@0:  * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
michael@0:  * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
michael@0:  * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
michael@0:  * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
michael@0:  * DAMAGE.
michael@0:  *
michael@0:  * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
michael@0:  * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
michael@0:  * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
michael@0:  * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
michael@0:  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
michael@0:  *
michael@0:  * Red Hat Author(s): Behdad Esfahbod
michael@0:  * Google Author(s): Behdad Esfahbod
michael@0:  */
michael@0: 
michael@0: #ifndef HB_OT_MAP_PRIVATE_HH
michael@0: #define HB_OT_MAP_PRIVATE_HH
michael@0: 
michael@0: #include "hb-buffer-private.hh"
michael@0: 
michael@0: 
michael@0: struct hb_ot_shape_plan_t;
michael@0: 
michael@0: static const hb_tag_t table_tags[2] = {HB_OT_TAG_GSUB, HB_OT_TAG_GPOS};
michael@0: 
michael@0: struct hb_ot_map_t
michael@0: {
michael@0:   friend struct hb_ot_map_builder_t;
michael@0: 
michael@0:   public:
michael@0: 
michael@0:   struct feature_map_t {
michael@0:     hb_tag_t tag; /* should be first for our bsearch to work */
michael@0:     unsigned int index[2]; /* GSUB/GPOS */
michael@0:     unsigned int stage[2]; /* GSUB/GPOS */
michael@0:     unsigned int shift;
michael@0:     hb_mask_t mask;
michael@0:     hb_mask_t _1_mask; /* mask for value=1, for quick access */
michael@0:     unsigned int needs_fallback : 1;
michael@0:     unsigned int auto_zwj : 1;
michael@0: 
michael@0:     static int cmp (const feature_map_t *a, const feature_map_t *b)
michael@0:     { return a->tag < b->tag ? -1 : a->tag > b->tag ? 1 : 0; }
michael@0:   };
michael@0: 
michael@0:   struct lookup_map_t {
michael@0:     unsigned short index;
michael@0:     unsigned short auto_zwj : 1;
michael@0:     hb_mask_t mask;
michael@0: 
michael@0:     static int cmp (const lookup_map_t *a, const lookup_map_t *b)
michael@0:     { return a->index < b->index ? -1 : a->index > b->index ? 1 : 0; }
michael@0:   };
michael@0: 
michael@0:   typedef void (*pause_func_t) (const struct hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer);
michael@0: 
michael@0:   struct stage_map_t {
michael@0:     unsigned int last_lookup; /* Cumulative */
michael@0:     pause_func_t pause_func;
michael@0:   };
michael@0: 
michael@0: 
michael@0:   hb_ot_map_t (void) { memset (this, 0, sizeof (*this)); }
michael@0: 
michael@0:   inline hb_mask_t get_global_mask (void) const { return global_mask; }
michael@0: 
michael@0:   inline hb_mask_t get_mask (hb_tag_t feature_tag, unsigned int *shift = NULL) const {
michael@0:     const feature_map_t *map = features.bsearch (&feature_tag);
michael@0:     if (shift) *shift = map ? map->shift : 0;
michael@0:     return map ? map->mask : 0;
michael@0:   }
michael@0: 
michael@0:   inline bool needs_fallback (hb_tag_t feature_tag) const {
michael@0:     const feature_map_t *map = features.bsearch (&feature_tag);
michael@0:     return map ? map->needs_fallback : false;
michael@0:   }
michael@0: 
michael@0:   inline hb_mask_t get_1_mask (hb_tag_t feature_tag) const {
michael@0:     const feature_map_t *map = features.bsearch (&feature_tag);
michael@0:     return map ? map->_1_mask : 0;
michael@0:   }
michael@0: 
michael@0:   inline unsigned int get_feature_index (unsigned int table_index, hb_tag_t feature_tag) const {
michael@0:     const feature_map_t *map = features.bsearch (&feature_tag);
michael@0:     return map ? map->index[table_index] : HB_OT_LAYOUT_NO_FEATURE_INDEX;
michael@0:   }
michael@0: 
michael@0:   inline unsigned int get_feature_stage (unsigned int table_index, hb_tag_t feature_tag) const {
michael@0:     const feature_map_t *map = features.bsearch (&feature_tag);
michael@0:     return map ? map->stage[table_index] : (unsigned int) -1;
michael@0:   }
michael@0: 
michael@0:   inline void get_stage_lookups (unsigned int table_index, unsigned int stage,
michael@0: 				 const struct lookup_map_t **plookups, unsigned int *lookup_count) const {
michael@0:     if (unlikely (stage == (unsigned int) -1)) {
michael@0:       *plookups = NULL;
michael@0:       *lookup_count = 0;
michael@0:       return;
michael@0:     }
michael@0:     assert (stage <= stages[table_index].len);
michael@0:     unsigned int start = stage ? stages[table_index][stage - 1].last_lookup : 0;
michael@0:     unsigned int end   = stage < stages[table_index].len ? stages[table_index][stage].last_lookup : lookups[table_index].len;
michael@0:     *plookups = &lookups[table_index][start];
michael@0:     *lookup_count = end - start;
michael@0:   }
michael@0: 
michael@0:   HB_INTERNAL void collect_lookups (unsigned int table_index, hb_set_t *lookups) const;
michael@0:   template <typename Proxy>
michael@0:   HB_INTERNAL inline void apply (const Proxy &proxy,
michael@0: 				 const struct hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) const;
michael@0:   HB_INTERNAL void substitute (const struct hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) const;
michael@0:   HB_INTERNAL void position (const struct hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) const;
michael@0: 
michael@0:   inline void finish (void) {
michael@0:     features.finish ();
michael@0:     for (unsigned int table_index = 0; table_index < 2; table_index++)
michael@0:     {
michael@0:       lookups[table_index].finish ();
michael@0:       stages[table_index].finish ();
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   public:
michael@0:   hb_tag_t chosen_script[2];
michael@0:   bool found_script[2];
michael@0: 
michael@0:   private:
michael@0: 
michael@0:   HB_INTERNAL void add_lookups (hb_face_t    *face,
michael@0: 				unsigned int  table_index,
michael@0: 				unsigned int  feature_index,
michael@0: 				hb_mask_t     mask,
michael@0: 				bool          auto_zwj);
michael@0: 
michael@0:   hb_mask_t global_mask;
michael@0: 
michael@0:   hb_prealloced_array_t<feature_map_t, 8> features;
michael@0:   hb_prealloced_array_t<lookup_map_t, 32> lookups[2]; /* GSUB/GPOS */
michael@0:   hb_prealloced_array_t<stage_map_t, 4> stages[2]; /* GSUB/GPOS */
michael@0: };
michael@0: 
michael@0: enum hb_ot_map_feature_flags_t {
michael@0:   F_NONE		= 0x0000,
michael@0:   F_GLOBAL		= 0x0001,
michael@0:   F_HAS_FALLBACK	= 0x0002,
michael@0:   F_MANUAL_ZWJ		= 0x0004
michael@0: };
michael@0: /* Macro version for where const is desired. */
michael@0: #define F_COMBINE(l,r) (hb_ot_map_feature_flags_t ((unsigned int) (l) | (unsigned int) (r)))
michael@0: inline hb_ot_map_feature_flags_t
michael@0: operator | (hb_ot_map_feature_flags_t l, hb_ot_map_feature_flags_t r)
michael@0: { return hb_ot_map_feature_flags_t ((unsigned int) l | (unsigned int) r); }
michael@0: inline hb_ot_map_feature_flags_t
michael@0: operator & (hb_ot_map_feature_flags_t l, hb_ot_map_feature_flags_t r)
michael@0: { return hb_ot_map_feature_flags_t ((unsigned int) l & (unsigned int) r); }
michael@0: inline hb_ot_map_feature_flags_t
michael@0: operator ~ (hb_ot_map_feature_flags_t r)
michael@0: { return hb_ot_map_feature_flags_t (~(unsigned int) r); }
michael@0: inline hb_ot_map_feature_flags_t&
michael@0: operator |= (hb_ot_map_feature_flags_t &l, hb_ot_map_feature_flags_t r)
michael@0: { l = l | r; return l; }
michael@0: inline hb_ot_map_feature_flags_t&
michael@0: operator &= (hb_ot_map_feature_flags_t& l, hb_ot_map_feature_flags_t r)
michael@0: { l = l & r; return l; }
michael@0: 
michael@0: 
michael@0: struct hb_ot_map_builder_t
michael@0: {
michael@0:   public:
michael@0: 
michael@0:   HB_INTERNAL hb_ot_map_builder_t (hb_face_t *face_,
michael@0: 				   const hb_segment_properties_t *props_);
michael@0: 
michael@0:   HB_INTERNAL void add_feature (hb_tag_t tag, unsigned int value,
michael@0: 				hb_ot_map_feature_flags_t flags);
michael@0: 
michael@0:   inline void add_global_bool_feature (hb_tag_t tag)
michael@0:   { add_feature (tag, 1, F_GLOBAL); }
michael@0: 
michael@0:   inline void add_gsub_pause (hb_ot_map_t::pause_func_t pause_func)
michael@0:   { add_pause (0, pause_func); }
michael@0:   inline void add_gpos_pause (hb_ot_map_t::pause_func_t pause_func)
michael@0:   { add_pause (1, pause_func); }
michael@0: 
michael@0:   HB_INTERNAL void compile (struct hb_ot_map_t &m);
michael@0: 
michael@0:   inline void finish (void) {
michael@0:     feature_infos.finish ();
michael@0:     for (unsigned int table_index = 0; table_index < 2; table_index++)
michael@0:     {
michael@0:       stages[table_index].finish ();
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   private:
michael@0: 
michael@0:   struct feature_info_t {
michael@0:     hb_tag_t tag;
michael@0:     unsigned int seq; /* sequence#, used for stable sorting only */
michael@0:     unsigned int max_value;
michael@0:     hb_ot_map_feature_flags_t flags;
michael@0:     unsigned int default_value; /* for non-global features, what should the unset glyphs take */
michael@0:     unsigned int stage[2]; /* GSUB/GPOS */
michael@0: 
michael@0:     static int cmp (const feature_info_t *a, const feature_info_t *b)
michael@0:     { return (a->tag != b->tag) ?  (a->tag < b->tag ? -1 : 1) : (a->seq < b->seq ? -1 : 1); }
michael@0:   };
michael@0: 
michael@0:   struct stage_info_t {
michael@0:     unsigned int index;
michael@0:     hb_ot_map_t::pause_func_t pause_func;
michael@0:   };
michael@0: 
michael@0:   HB_INTERNAL void add_pause (unsigned int table_index, hb_ot_map_t::pause_func_t pause_func);
michael@0: 
michael@0:   public:
michael@0: 
michael@0:   hb_face_t *face;
michael@0:   hb_segment_properties_t props;
michael@0: 
michael@0:   hb_tag_t chosen_script[2];
michael@0:   bool found_script[2];
michael@0:   unsigned int script_index[2], language_index[2];
michael@0: 
michael@0:   private:
michael@0: 
michael@0:   unsigned int current_stage[2]; /* GSUB/GPOS */
michael@0:   hb_prealloced_array_t<feature_info_t, 32> feature_infos;
michael@0:   hb_prealloced_array_t<stage_info_t, 8> stages[2]; /* GSUB/GPOS */
michael@0: };
michael@0: 
michael@0: 
michael@0: 
michael@0: #endif /* HB_OT_MAP_PRIVATE_HH */