gdipp_server/glyph_cache.h

   1 #pragma once
   2
   3 #include "gdipp_lib/lru.h"
   4 #include "gdipp_server/glyph_run.h"
   5
   6 namespace gdipp
   7 {
   8
   9 class glyph_cache
  10 {
  11 public:
  12         typedef uint128_t string_id_type;
  13         typedef uint128_t char_id_type;
  14
  15         static string_id_type get_string_id(const wchar_t *string, unsigned int count, bool is_glyph_index);
  16         static char_id_type get_char_id(uint128_t render_trait, FT_UInt index, bool is_glyph_index);
  17
  18         ~glyph_cache();
  19
  20         void initialize();
  21         const FT_Glyph lookup_glyph(char_id_type char_id) const;
  22         bool store_glyph(char_id_type char_id, const FT_Glyph glyph);
  23         const glyph_run *lookup_glyph_run(uint128_t string_id, uint128_t render_trait) const;
  24         bool store_glyph_run(uint128_t string_id, uint128_t render_trait, glyph_run *a_glyph_run);
  25
  26 private:
  27         // std::map from render trait to glyph run
  28         typedef std::map<uint128_t, glyph_run *> trait_to_run_map;
  29
  30         // std::map from character ID (including character index and render trait) to its glyph
  31         std::map<char_id_type, const FT_Glyph> _glyph_store;
  32         // std::map from string ID to glyph run
  33         // use hierarchical design so that when LRU string is evicted, all associated glyph runs are erased
  34         std::map<uint128_t, trait_to_run_map> _glyph_run_store;
  35
  36         // least recently used glyph runs, indexed by string ID
  37         lru_list<uint128_t> _glyph_run_lru;
  38 };
  39
  40 }