add extension for fractional EXP multipliers on BB

src/CommandFormats.hh

@@ -6404,12 +6404,21 @@ struct G_Episode4BossActions_BB_6xDC {
 
 // 6xDD: Set EXP multiplier (BB)
 // header.param specifies the EXP multiplier. It is 1-based, so the value 2
-// means all EXP is doubled, for example.
+// means all EXP is doubled, for example. This only affects what the client
+// shows when an enemy is killed; actual EXP gains are controlled by the server
+// in response to the 6xC8 command.
+// newserv supports an extension to this command that supports fractional
+// multipliers. This is implemented in FractionalEXPMultiplier.59NL.patch.s.
 
 struct G_SetEXPMultiplier_BB_6xDD {
   G_ParameterHeader header;
 } __packed_ws__(G_SetEXPMultiplier_BB_6xDD, 4);
 
+struct G_SetFractionalEXPMultiplier_Extension_BB_6xDD {
+  G_ParameterHeader header;
+  le_float multiplier;
+} __packed_ws__(G_SetEXPMultiplier_BB_6xDD, 4);
+
 // 6xDE: Exchange Secret Lottery Ticket (BB; handled by server)
 // The client sends this when it executes an F95C quest opcode.
 // There appears to be a bug in the client here: it sets the subcommand size to

src/Lobby.cc

@@ -154,8 +154,8 @@ Lobby::Lobby(shared_ptr<ServerState> s, uint32_t id, bool is_game)
       episode(Episode::NONE),
       mode(GameMode::NORMAL),
       difficulty(0),
-      base_exp_multiplier(1),
-      exp_share_multiplier(0.5),
+      base_exp_multiplier(1.0f),
+      exp_share_multiplier(0.5f),
       challenge_exp_multiplier(1.0f),
       random_seed(phosg::random_object<uint32_t>()),
       rand_crypt(make_shared<DisabledRandomGenerator>()),

src/Lobby.hh

@@ -120,7 +120,7 @@ struct Lobby : public std::enable_shared_from_this<Lobby> {
   Episode episode;
   GameMode mode;
   uint8_t difficulty; // 0-3
-  uint16_t base_exp_multiplier;
+  float base_exp_multiplier;
   float exp_share_multiplier;
   float challenge_exp_multiplier;
   std::string password;

src/ReceiveSubcommands.cc

@@ -4040,11 +4040,7 @@ static asio::awaitable<void> on_enemy_exp_request_bb(shared_ptr<Client> c, Subco
             l->challenge_exp_multiplier *
             (is_ep2 ? 1.3 : 1.0);
         if (lc->check_flag(Client::Flag::DEBUG_ENABLED)) {
-          send_text_message_fmt(
-              lc, "$C5+{} E-{:03X} {}",
-              player_exp,
-              ene_st->e_id,
-              phosg::name_for_enum(type));
+          send_text_message_fmt(lc, "$C5+{} E-{:03X} {}", player_exp, ene_st->e_id, phosg::name_for_enum(type));
         }
         if (lc->character_file()->disp.stats.level < 199) {
           add_player_exp(lc, player_exp);

src/SendCommands.cc

@@ -3261,7 +3261,11 @@ void send_set_exp_multiplier(shared_ptr<Lobby> l) {
   if (!l->is_game()) {
     throw logic_error("6xDD can only be sent in games (not in lobbies)");
   }
-  G_SetEXPMultiplier_BB_6xDD cmd = {{0xDD, sizeof(G_SetEXPMultiplier_BB_6xDD) / 4, (l->mode == GameMode::CHALLENGE) ? 1 : l->base_exp_multiplier}};
+  G_SetFractionalEXPMultiplier_Extension_BB_6xDD cmd = {{0xDD, sizeof(G_SetEXPMultiplier_BB_6xDD) / 4, 1}, 1.0f};
+  if (l->mode != GameMode::CHALLENGE) {
+    cmd.header.param = l->base_exp_multiplier;
+    cmd.multiplier = l->base_exp_multiplier;
+  }
   for (auto lc : l->clients) {
     if (lc && (lc->version() == Version::BB_V4)) {
       send_command_t(lc, 0x60, 0x00, cmd);

src/ServerState.cc

@@ -1083,9 +1083,9 @@ void ServerState::load_config_early() {
     }
   }
 
-  this->bb_global_exp_multiplier = this->config_json->get_int("BBGlobalEXPMultiplier", 1);
-  this->exp_share_multiplier = this->config_json->get_float("BBEXPShareMultiplier", 0.5);
-  this->server_global_drop_rate_multiplier = this->config_json->get_float("ServerGlobalDropRateMultiplier", 1);
+  this->bb_global_exp_multiplier = this->config_json->get_float("BBGlobalEXPMultiplier", 1.0f);
+  this->exp_share_multiplier = this->config_json->get_float("BBEXPShareMultiplier", 0.5f);
+  this->server_global_drop_rate_multiplier = this->config_json->get_float("ServerGlobalDropRateMultiplier", 1.0f);
 
   if (this->is_debug) {
     set_all_log_levels(phosg::LogLevel::L_DEBUG);

src/ServerState.hh

@@ -241,9 +241,9 @@ struct ServerState : public std::enable_shared_from_this<ServerState> {
   std::vector<QuestF960Result> quest_F960_success_results;
   QuestF960Result quest_F960_failure_results;
   std::vector<ItemData> secret_lottery_results;
-  uint16_t bb_global_exp_multiplier = 1;
-  float exp_share_multiplier = 0.5;
-  double server_global_drop_rate_multiplier = 1.0;
+  float bb_global_exp_multiplier = 1.0f;
+  float exp_share_multiplier = 0.5f;
+  float server_global_drop_rate_multiplier = 1.0f;
 
   std::shared_ptr<Episode3::TournamentIndex> ep3_tournament_index;
 

system/client-functions/BlueBurstExclusive/FractionalEXPMultiplier.59NL.patch.s

@@ -0,0 +1,63 @@
+# This patch changes the 6xDD command to support fractional multipliers.
+
+.meta name="Fractional EXP multiplier"
+.meta description=""
+.meta hide_from_patches_menu
+
+entry_ptr:
+reloc0:
+  .offsetof start
+start:
+  call      install_hook
+  call      apply_static_patches
+  fild      st0, dword [0x009F9EE0]
+  fstp      dword [0x009F9EE0], st0
+  ret
+
+
+
+install_hook:
+  pop       ecx
+  push      7
+  push      0x0078747E
+  call      get_code_size
+  .deltaof  hook_start, hook_end
+get_code_size:
+  pop       eax
+  push      dword [eax]
+  call      hook_end
+hook_start:  # [eax, ebx]() -> void
+  push      edx
+  fild      st0, dword [esp]
+  fld       st0, dword [0x009F9EE0]
+  fmulp     st1, st0
+  fistp     dword [esp], st0
+  pop       edx
+  ret
+hook_end:
+  push      ecx
+  .include  WriteCallToCode-59NL
+
+
+
+apply_static_patches:
+  .include WriteCodeBlocksBB
+  .data    0x00787998
+  .deltaof handle_6xDD_start, handle_6xDD_end
+handle_6xDD_start:  # [std](G_6xDD* cmd @ [esp + 4]) -> void
+  mov      eax, [esp + 4]
+  test     eax, eax
+  je       handle_6xDD_ret
+  cmp      byte [eax + 1], 1
+  jg       handle_6xDD_use_float
+  fild     st0, word [eax + 2]
+  jmp      handle_6xDD_write_float
+handle_6xDD_use_float:
+  fld      st0, dword [eax + 4]
+handle_6xDD_write_float:
+  fstp     dword [0x009F9EE0], st0
+handle_6xDD_ret:
+  ret
+handle_6xDD_end:
+  .data    0x00000000
+  .data    0x00000000