reorganize BB file loading abstractions

src/RareItemSet.hh

@@ -6,24 +6,31 @@
 
 
 
-struct RareItemDrop {
-  uint8_t probability;
-  uint8_t item_code[3];
-} __attribute__((packed));
+class RareItemSet {
+public:
+  struct Table {
+    // TODO: It looks like this structure can actually vary. We see the offsets
+    // 0194 and 01B2 in the unused section, along with the value 1E (number of
+    // box rares). In PSOGC, these all appear to be the same size/format, but
+    // that's probably not strictly required to be the case.
+    // 0x280 in size; describes one difficulty, section ID, and episode
+    struct Drop {
+      uint8_t probability;
+      uint8_t item_code[3];
+    } __attribute__((packed));
+    Drop monster_rares[0x65];     // 0000 - 0194 in file
+    uint8_t box_areas[0x1E];      // 0194 - 01B2 in file
+    Drop box_rares[0x1E]; // 01B2 - 022A in file
+    uint8_t unused[0x56];
+  } __attribute__((packed));
 
-struct RareItemSet {
-  // TODO: It looks like this structure can actually vary. We see the offsets
-  // 0194 and 01B2 in the unused section, along with the value 1E (number of box
-  // rares). In PSOGC, these all appear to be the same size/format, but that's
-  // probably not strictly required to be the case.
-  // 0x280 in size; describes one difficulty, section ID, and episode
-  RareItemDrop rares[0x65];     // 0000 - 0194 in file
-  uint8_t box_areas[0x1E];      // 0194 - 01B2 in file
-  RareItemDrop box_rares[0x1E]; // 01B2 - 022A in file
-  uint8_t unused[0x56];
+  RareItemSet(std::shared_ptr<const std::string> data);
 
-  RareItemSet(const char* filename, uint8_t episode, uint8_t difficulty,
-  	  uint8_t secid);
-} __attribute__((packed));
+  const Table& get_table(uint8_t episode, uint8_t difficulty, uint8_t secid) const;
 
-bool sample_rare_item(std::mt19937& rand, uint8_t pc);
+  static bool sample(std::mt19937& rand, uint8_t probability);
+
+private:
+  std::shared_ptr<const std::string> data;
+  const Table* tables;
+};