implement proper equip/unequip tracking

src/CommandFormats.hh

@@ -3918,12 +3918,20 @@ struct G_TeleportPlayer_6x24 {
 } __packed__;
 
 // 6x25: Equip item
-// 6x26: Unequip item
 
-struct G_EquipOrUnequipItem_6x25_6x26 {
+struct G_EquipItem_6x25 {
   G_ClientIDHeader header;
   le_uint32_t item_id = 0;
-  le_uint32_t equip_slot = 0; // Unused for 6x26 (unequip item)
+  // Values here match the EquipSlot enum (in ItemData.hh)
+  le_uint32_t equip_slot = 0;
+} __packed__;
+
+// 6x26: Unequip item
+
+struct G_UnequipItem_6x26 {
+  G_ClientIDHeader header;
+  le_uint32_t item_id = 0;
+  le_uint32_t unused = 0;
 } __packed__;
 
 // 6x27: Use item

src/ItemData.cc

@@ -567,6 +567,26 @@ bool ItemData::is_s_rank_weapon() const {
   return false;
 }
 
+bool ItemData::can_be_equipped_in_slot(EquipSlot slot) const {
+  switch (slot) {
+    case EquipSlot::MAG:
+      return (this->data1[0] == 0x02);
+    case EquipSlot::ARMOR:
+      return ((this->data1[0] == 0x01) && (this->data1[1] == 0x01));
+    case EquipSlot::SHIELD:
+      return ((this->data1[0] == 0x01) && (this->data1[1] == 0x02));
+    case EquipSlot::UNIT_1:
+    case EquipSlot::UNIT_2:
+    case EquipSlot::UNIT_3:
+    case EquipSlot::UNIT_4:
+      return ((this->data1[0] == 0x01) && (this->data1[1] == 0x03));
+    case EquipSlot::WEAPON:
+      return (this->data1[0] == 0x00);
+    default:
+      throw runtime_error("invalid equip slot");
+  }
+}
+
 bool ItemData::compare_for_sort(const ItemData& a, const ItemData& b) {
   for (size_t z = 0; z < 12; z++) {
     if (a.data1[z] < b.data1[z]) {

src/ItemData.hh

@@ -6,10 +6,21 @@
 #include "Text.hh"
 #include "Version.hh"
 
-constexpr uint32_t MESETA_IDENTIFIER = 0x00040000;
+constexpr uint32_t MESETA_IDENTIFIER = 0x040000;
 
 class ItemParameterTable;
 
+enum class EquipSlot {
+  MAG = 0x01,
+  ARMOR = 0x02,
+  SHIELD = 0x03,
+  WEAPON = 0x06,
+  UNIT_1 = 0x09,
+  UNIT_2 = 0x0A,
+  UNIT_3 = 0x0B,
+  UNIT_4 = 0x0C,
+};
+
 struct ItemMagStats {
   uint16_t iq;
   uint16_t synchro;
@@ -152,6 +163,8 @@ struct ItemData { // 0x14 bytes
   bool has_bonuses() const;
   bool is_s_rank_weapon() const;
 
+  bool can_be_equipped_in_slot(EquipSlot slot) const;
+
   bool empty() const;
 
   static bool compare_for_sort(const ItemData& a, const ItemData& b);

src/Items.cc

@@ -36,7 +36,7 @@ void player_use_item(shared_ptr<Client> c, size_t item_index) {
       throw runtime_error("incorrect grinder value");
     }
 
-    auto& weapon = player->inventory.items[player->inventory.find_equipped_weapon()];
+    auto& weapon = player->inventory.items[player->inventory.find_equipped_item(EquipSlot::WEAPON)];
     // Don't enforce the weapon's grind limit on V1 and V2. This is necessary
     // because the V2 client replaces its inventory items on the fly with items
     // compatible with V1 when sending the 61 and 98 commands. There appears to
@@ -107,7 +107,7 @@ void player_use_item(shared_ptr<Client> c, size_t item_index) {
     }
 
   } else if ((item_identifier & 0xFFFF00) == 0x030F00) { // AddSlot
-    auto& armor = player->inventory.items[player->inventory.find_equipped_armor()];
+    auto& armor = player->inventory.items[player->inventory.find_equipped_item(EquipSlot::ARMOR)];
     if (armor.data.data1[5] >= 4) {
       throw runtime_error("armor already at maximum slot count");
     }
@@ -140,32 +140,32 @@ void player_use_item(shared_ptr<Client> c, size_t item_index) {
 
   } else if (item_identifier == 0x030C00) {
     // Cell of MAG 502
-    auto& mag = player->inventory.items[player->inventory.find_equipped_mag()];
+    auto& mag = player->inventory.items[player->inventory.find_equipped_item(EquipSlot::MAG)];
     mag.data.data1[1] = (player->disp.visual.section_id & 1) ? 0x1D : 0x21;
 
   } else if (item_identifier == 0x030C01) {
     // Cell of MAG 213
-    auto& mag = player->inventory.items[player->inventory.find_equipped_mag()];
+    auto& mag = player->inventory.items[player->inventory.find_equipped_item(EquipSlot::MAG)];
     mag.data.data1[1] = (player->disp.visual.section_id & 1) ? 0x27 : 0x22;
 
   } else if (item_identifier == 0x030C02) {
     // Parts of RoboChao
-    auto& mag = player->inventory.items[player->inventory.find_equipped_mag()];
+    auto& mag = player->inventory.items[player->inventory.find_equipped_item(EquipSlot::MAG)];
     mag.data.data1[1] = 0x28;
 
   } else if (item_identifier == 0x030C03) {
     // Heart of Opa Opa
-    auto& mag = player->inventory.items[player->inventory.find_equipped_mag()];
+    auto& mag = player->inventory.items[player->inventory.find_equipped_item(EquipSlot::MAG)];
     mag.data.data1[1] = 0x29;
 
   } else if (item_identifier == 0x030C04) {
     // Heart of Pian
-    auto& mag = player->inventory.items[player->inventory.find_equipped_mag()];
+    auto& mag = player->inventory.items[player->inventory.find_equipped_item(EquipSlot::MAG)];
     mag.data.data1[1] = 0x2A;
 
   } else if (item_identifier == 0x030C05) {
     // Heart of Chao
-    auto& mag = player->inventory.items[player->inventory.find_equipped_mag()];
+    auto& mag = player->inventory.items[player->inventory.find_equipped_item(EquipSlot::MAG)];
     mag.data.data1[1] = 0x2B;
 
   } else if ((item_identifier & 0xFFFF00) == 0x031500) {

src/PlayerSubordinates.cc

@@ -525,67 +525,84 @@ size_t PlayerInventory::find_item_by_primary_identifier(uint32_t primary_identif
   throw out_of_range("item not present");
 }
 
-size_t PlayerInventory::find_equipped_weapon() const {
+size_t PlayerInventory::find_equipped_item(EquipSlot slot) const {
   ssize_t ret = -1;
   for (size_t y = 0; y < this->num_items; y++) {
-    if (!(this->items[y].flags & 0x00000008)) {
+    const auto& i = this->items[y];
+    if (!(i.flags & 0x00000008)) {
       continue;
     }
-    if (this->items[y].data.data1[0] != 0) {
+    if (!i.data.can_be_equipped_in_slot(slot)) {
       continue;
     }
+
+    // Units can be equipped in multiple slots, so the currently-equipped slot
+    // is stored in the item data itself.
+    if (((slot == EquipSlot::UNIT_1) && (i.data.data1[4] != 0x00)) ||
+        ((slot == EquipSlot::UNIT_2) && (i.data.data1[4] != 0x01)) ||
+        ((slot == EquipSlot::UNIT_3) && (i.data.data1[4] != 0x02)) ||
+        ((slot == EquipSlot::UNIT_4) && (i.data.data1[4] != 0x03))) {
+      continue;
+    }
+
     if (ret < 0) {
       ret = y;
     } else {
-      throw runtime_error("multiple weapons are equipped");
+      throw runtime_error("multiple items are equipped in the same slot");
     }
   }
   if (ret < 0) {
-    throw out_of_range("no weapon is equipped");
+    throw out_of_range("no item is equipped in this slot");
   }
   return ret;
 }
 
-size_t PlayerInventory::find_equipped_armor() const {
+bool PlayerInventory::has_equipped_item(EquipSlot slot) const {
-  ssize_t ret = -1;
+  try {
-  for (size_t y = 0; y < this->num_items; y++) {
+    this->find_equipped_item(slot);
-    if (!(this->items[y].flags & 0x00000008)) {
+    return true;
-      continue;
+  } catch (const out_of_range&) {
-    }
+    return false;
-    if (this->items[y].data.data1[0] != 1 || this->items[y].data.data1[1] != 1) {
-      continue;
-    }
-    if (ret < 0) {
-      ret = y;
-    } else {
-      throw runtime_error("multiple armors are equipped");
-    }
   }
-  if (ret < 0) {
-    throw out_of_range("no armor is equipped");
-  }
-  return ret;
 }
 
-size_t PlayerInventory::find_equipped_mag() const {
+void PlayerInventory::equip_item(uint32_t item_id, EquipSlot slot) {
-  ssize_t ret = -1;
+  size_t index = this->find_item(item_id);
-  for (size_t y = 0; y < this->num_items; y++) {
+  auto& item = this->items[index];
-    if (!(this->items[y].flags & 0x00000008)) {
+
-      continue;
+  if (!item.data.can_be_equipped_in_slot(slot)) {
-    }
+    throw runtime_error("incorrect item type for equip slot");
-    if (this->items[y].data.data1[0] != 2) {
+  }
-      continue;
+  if (this->has_equipped_item(slot)) {
-    }
+    throw runtime_error("equip slot is already in use");
-    if (ret < 0) {
+  }
-      ret = y;
+
-    } else {
+  item.flags |= 0x00000008;
-      throw runtime_error("multiple mags are equipped");
+  // Units store which slot they're equipped in within the item data itself
+  if ((item.data.data1[0] == 0x01) && (item.data.data1[1] == 0x03)) {
+    item.data.data1[4] = static_cast<uint8_t>(slot) - 9;
+  }
+}
+
+void PlayerInventory::unequip_item(uint32_t item_id) {
+  size_t index = this->find_item(item_id);
+  auto& item = this->items[index];
+
+  item.flags &= (~0x00000008);
+  // Units store which slot they're equipped in within the item data itself
+  if ((item.data.data1[0] == 0x01) && (item.data.data1[1] == 0x03)) {
+    item.data.data1[4] = 0x00;
+  }
+  // If the item is an armor, remove all units too
+  if ((item.data.data1[0] == 0x01) && (item.data.data1[1] == 0x01)) {
+    for (size_t z = 0; z < 30; z++) {
+      auto& unit = this->items[z];
+      if ((unit.data.data1[0] == 0x01) && (unit.data.data1[1] == 0x03)) {
+        unit.flags &= (~0x00000008);
+        unit.data.data1[4] = 0x00;
+      }
     }
   }
-  if (ret < 0) {
-    throw out_of_range("no mag is equipped");
-  }
-  return ret;
 }
 
 size_t PlayerInventory::remove_all_items_of_type(uint8_t data1_0, int16_t data1_1) {

src/PlayerSubordinates.hh

@@ -71,9 +71,10 @@ struct PlayerInventory {
   size_t find_item(uint32_t item_id) const;
   size_t find_item_by_primary_identifier(uint32_t primary_identifier) const;
 
-  size_t find_equipped_weapon() const;
+  size_t find_equipped_item(EquipSlot slot) const;
-  size_t find_equipped_armor() const;
+  bool has_equipped_item(EquipSlot slot) const;
-  size_t find_equipped_mag() const;
+  void equip_item(uint32_t item_id, EquipSlot slot);
+  void unequip_item(uint32_t item_id);
 
   size_t remove_all_items_of_type(uint8_t data0, int16_t data1 = -1);
 

src/ReceiveSubcommands.cc

@@ -625,7 +625,7 @@ static void on_player_died(shared_ptr<Client> c, uint8_t command, uint8_t flag,
   if (l->check_flag(Lobby::Flag::ITEM_TRACKING_ENABLED)) {
     try {
       auto& inventory = c->game_data.character()->inventory;
-      size_t mag_index = inventory.find_equipped_mag();
+      size_t mag_index = inventory.find_equipped_item(EquipSlot::MAG);
       auto& data = inventory.items[mag_index].data;
       data.data2[0] = max<int8_t>(static_cast<int8_t>(data.data2[0] - 5), 0);
     } catch (const out_of_range&) {
@@ -1146,8 +1146,27 @@ static void on_pick_up_item_request(shared_ptr<Client> c, uint8_t command, uint8
   }
 }
 
-static void on_equip_unequip_item(shared_ptr<Client> c, uint8_t command, uint8_t flag, const void* data, size_t size) {
+static void on_equip_item(shared_ptr<Client> c, uint8_t command, uint8_t flag, const void* data, size_t size) {
-  const auto& cmd = check_size_t<G_EquipOrUnequipItem_6x25_6x26>(data, size);
+  const auto& cmd = check_size_t<G_EquipItem_6x25>(data, size);
+
+  if (cmd.header.client_id != c->lobby_client_id) {
+    return;
+  }
+
+  auto l = c->require_lobby();
+  if (l->check_flag(Lobby::Flag::ITEM_TRACKING_ENABLED)) {
+    EquipSlot slot = static_cast<EquipSlot>(cmd.equip_slot.load());
+    auto p = c->game_data.character();
+    p->inventory.equip_item(cmd.item_id, slot);
+  } else if (l->base_version == GameVersion::BB) {
+    throw logic_error("item tracking not enabled in BB game");
+  }
+
+  forward_subcommand(c, command, flag, data, size);
+}
+
+static void on_unequip_item(shared_ptr<Client> c, uint8_t command, uint8_t flag, const void* data, size_t size) {
+  const auto& cmd = check_size_t<G_UnequipItem_6x26>(data, size);
 
   if (cmd.header.client_id != c->lobby_client_id) {
     return;
@@ -1156,12 +1175,7 @@ static void on_equip_unequip_item(shared_ptr<Client> c, uint8_t command, uint8_t
   auto l = c->require_lobby();
   if (l->check_flag(Lobby::Flag::ITEM_TRACKING_ENABLED)) {
     auto p = c->game_data.character();
-    size_t index = p->inventory.find_item(cmd.item_id);
+    p->inventory.unequip_item(cmd.item_id);
-    if (cmd.header.subcommand == 0x25) { // Equip
-      p->inventory.items[index].flags |= 0x00000008;
-    } else { // Unequip
-      p->inventory.items[index].flags &= 0xFFFFFFF7;
-    }
   } else if (l->base_version == GameVersion::BB) {
     throw logic_error("item tracking not enabled in BB game");
   }
@@ -1833,7 +1847,7 @@ static void on_steal_exp_bb(shared_ptr<Client> c, uint8_t, uint8_t, const void*
   auto p = c->game_data.character();
   const auto& enemy = l->map->enemies.at(cmd.enemy_index);
   const auto& inventory = p->inventory;
-  const auto& weapon = inventory.items[inventory.find_equipped_weapon()];
+  const auto& weapon = inventory.items[inventory.find_equipped_item(EquipSlot::WEAPON)];
 
   auto item_parameter_table = s->item_parameter_table_for_version(c->version());
 
@@ -2524,8 +2538,8 @@ subcommand_handler_t subcommand_handlers[0x100] = {
     /* 6x22 */ on_forward_check_size_client,
     /* 6x23 */ on_set_player_visibility,
     /* 6x24 */ on_forward_check_size_game,
-    /* 6x25 */ on_equip_unequip_item,
+    /* 6x25 */ on_equip_item,
-    /* 6x26 */ on_equip_unequip_item,
+    /* 6x26 */ on_unequip_item,
     /* 6x27 */ on_use_item,
     /* 6x28 */ on_feed_mag,
     /* 6x29 */ on_destroy_inventory_item,