add patch to show EXP gains from the server

src/CommandFormats.hh

@@ -6172,12 +6172,23 @@ struct G_ChangeLobbyMusic_Ep3_6xBF {
 } __packed_ws__(G_ChangeLobbyMusic_Ep3_6xBF, 8);
 
 // 6xBF: Give EXP (BB) (server->client only)
+// newserv implements an extension that causes this command to show the purple
+// EXP numbers which are normally generated by the client instead. This
+// requires the server to also send the enemy ID that generated the EXP, hence
+// the extension struct here. See ServerEXPDisplay.59NL.patch.s for details.
 
 struct G_GiveExperience_BB_6xBF {
   G_ClientIDHeader header;
   le_uint32_t amount = 0;
 } __packed_ws__(G_GiveExperience_BB_6xBF, 8);
 
+struct G_GiveExperience_Extension_BB_6xBF {
+  G_ClientIDHeader header;
+  le_uint32_t amount = 0;
+  le_uint16_t from_enemy_id = 0;
+  le_uint16_t unused = 0;
+} __packed_ws__(G_GiveExperience_Extension_BB_6xBF, 0x0C);
+
 // 6xC0: Sell item at shop (BB) (protected on V3/V4)
 
 struct G_SellItemAtShop_BB_6xC0 {
@@ -6433,18 +6444,11 @@ struct G_Episode4BossActions_BB_6xDC {
 // 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_SetFractionalEXPMultiplier_Extension_BB_6xDD, 8);
-
 // 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/ReceiveSubcommands.cc

@@ -3863,13 +3863,13 @@ static asio::awaitable<void> on_level_up(shared_ptr<Client> c, SubcommandMessage
   forward_subcommand(c, msg);
 }
 
-static void add_player_exp(shared_ptr<Client> c, uint32_t exp) {
+static void add_player_exp(shared_ptr<Client> c, uint32_t exp, uint16_t from_enemy_id) {
   auto s = c->require_server_state();
   auto p = c->character_file();
 
   p->disp.stats.experience += exp;
   if (c->version() == Version::BB_V4) {
-    send_give_experience(c, exp);
+    send_give_experience(c, exp, from_enemy_id);
   }
 
   bool leveled_up = false;
@@ -3994,7 +3994,7 @@ static asio::awaitable<void> on_steal_exp_bb(shared_ptr<Client> c, SubcommandMes
         ene_st->e_id, enemy_exp, percent, stolen_exp);
     send_text_message_fmt(c, "$C5+{} E-{:03X} {}", stolen_exp, ene_st->e_id, phosg::name_for_enum(type));
   }
-  add_player_exp(c, stolen_exp);
+  add_player_exp(c, stolen_exp, cmd.enemy_index | 0x1000);
 }
 
 static asio::awaitable<void> on_enemy_exp_request_bb(shared_ptr<Client> c, SubcommandMessage& msg) {
@@ -4081,7 +4081,7 @@ static asio::awaitable<void> on_enemy_exp_request_bb(shared_ptr<Client> c, Subco
         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));
         }
-        add_player_exp(lc, player_exp);
+        add_player_exp(lc, player_exp, cmd.enemy_index | 0x1000);
       }
     }
 
@@ -4582,7 +4582,7 @@ static asio::awaitable<void> on_battle_level_up_bb(shared_ptr<Client> c, Subcomm
     if (exp_delta > 0) {
       s->level_table(lc->version())->advance_to_level(lp->disp.stats, target_level, lp->disp.visual.char_class);
       if (lc->version() == Version::BB_V4) {
-        send_give_experience(lc, exp_delta);
+        send_give_experience(lc, exp_delta, 0xFFFF);
         send_level_up(lc);
       }
     }

src/SendCommands.cc

@@ -3311,14 +3311,14 @@ void send_level_up(shared_ptr<Client> c) {
   send_command_t(l, 0x60, 0x00, cmd);
 }
 
-void send_give_experience(shared_ptr<Client> c, uint32_t amount) {
+void send_give_experience(shared_ptr<Client> c, uint32_t amount, uint16_t from_enemy_id) {
   auto l = c->require_lobby();
   if (c->version() != Version::BB_V4) {
     throw logic_error("6xBF can only be sent to BB clients");
   }
   uint16_t client_id = c->lobby_client_id;
-  G_GiveExperience_BB_6xBF cmd = {
-      {0xBF, sizeof(G_GiveExperience_BB_6xBF) / 4, client_id}, amount};
+  G_GiveExperience_Extension_BB_6xBF cmd = {
+      {0xBF, sizeof(G_GiveExperience_Extension_BB_6xBF) / 4, client_id}, amount, from_enemy_id, 0};
   send_command_t(l, 0x60, 0x00, cmd);
 }
 
@@ -3326,11 +3326,9 @@ 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_SetFractionalEXPMultiplier_Extension_BB_6xDD cmd = {
-      {0xDD, sizeof(G_SetFractionalEXPMultiplier_Extension_BB_6xDD) / 4, 1}, 1.0f};
+  G_SetEXPMultiplier_BB_6xDD cmd = {0xDD, sizeof(G_SetEXPMultiplier_BB_6xDD) / 4, 1};
   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)) {

src/SendCommands.hh

@@ -399,7 +399,7 @@ void send_item_identify_result(std::shared_ptr<Client> c);
 void send_bank(std::shared_ptr<Client> c);
 void send_shop(std::shared_ptr<Client> c, uint8_t shop_type);
 void send_level_up(std::shared_ptr<Client> c);
-void send_give_experience(std::shared_ptr<Client> c, uint32_t amount);
+void send_give_experience(std::shared_ptr<Client> c, uint32_t amount, uint16_t entity_id);
 void send_set_exp_multiplier(std::shared_ptr<Lobby> l);
 void send_rare_enemy_index_list(std::shared_ptr<Client> c, const std::vector<size_t>& indexes);
 

system/client-functions/System/WriteCallToCode-59NL.x86.inc.s

@@ -18,7 +18,7 @@ write_call_to_code:
   # [esp + 0x04] = code ptr
   # [esp + 0x08] = code size
   # [esp + 0x0C] = jump callsite
-  # [esp + 0x10] = callsite size
+  # [esp + 0x10] = callsite size (if zero, write the address instead of a call)
 
   # Allocate memory for the copied code
   mov       ecx, [0x00AAB404]
@@ -41,8 +41,16 @@ memcpy_again:
   jne       memcpy_again
   pop       ebx
 
-  # Write the call or jmp opcode
   mov       edx, [esp + 0x0C]  # edx = jump callsite
+
+  # If the callsite size is zero, just write the address directly
+  cmp       dword [esp + 0x10], 0
+  jne       write_call_or_jmp
+  mov       [edx], eax
+  jmp       done
+
+  # Write the call or jmp opcode
+write_call_or_jmp:
   lea       ecx, [eax - 5]
   sub       ecx, edx  # ecx = (dest code addr) - (jump callsite) - 5
   cmp       dword [esp + 0x10], 0

system/config.example.json

@@ -811,8 +811,9 @@
     "Friday": ["Monomate x1", "Dimate x1", "Trimate x1", "Monofluid x1", "Difluid x1", "Trifluid x1", "Sol Atomizer x1", "Moon Atomizer x1", "Antidote x1", "Antiparalysis x1", "Telepipe x1", "Trap Vision x1"],
     "Saturday": ["Monomate x1", "Dimate x1", "Trimate x1", "Monofluid x1", "Difluid x1", "Trifluid x1", "Sol Atomizer x1", "Moon Atomizer x1", "Antidote x1", "Antiparalysis x1", "Telepipe x1", "Trap Vision x1"],
   },
-  // EXP multiplier for BB games. This must be an integer due to a client
-  // limitation, and must be at least 1.
+  // EXP multiplier for BB games. If this is not an integer, the client will
+  // display incorrect EXP values, unless you also add "ServerEXPDisplay" to
+  // BBRequiredPatches.
   "BBGlobalEXPMultiplier": 1,
   // EXP share multiplier for BB games. The logic for EXP computation is:
   // - If the player lands the killing blow on an enemy they get full EXP (or