Add support for legendary fusion

include/constants/form_change_types.h

@@ -11,6 +11,7 @@
 #define DAY    1
 #define NIGHT  2
 
+#define FUSION_TERMINATOR                       0xFF
 #define FORM_CHANGE_TERMINATOR                  0
 
 // Form change that activates when the specified item is given to or taken from the selected Pokémon.

include/constants/party_menu.h

@@ -80,6 +80,7 @@
 #define PARTY_MSG_DO_WHAT_WITH_MAIL         25
 #define PARTY_MSG_ALREADY_HOLDING_ONE       26
 #define PARTY_MSG_WHICH_APPLIANCE           27
+#define PARTY_MSG_CHOOSE_SECOND_FUSION      28
 #define PARTY_MSG_NONE                      127
 
 // IDs for DisplayPartyPokemonDescriptionText, to display a message in the party pokemon's box

include/item_use.h

@@ -31,6 +31,7 @@ void ItemUseOutOfBattle_FormChange(u8);
 void ItemUseOutOfBattle_FormChange_ConsumedOnUse(u8);
 void ItemUseOutOfBattle_RotomCatalog(u8);
 void ItemUseOutOfBattle_ZygardeCube(u8);
+void ItemUseOutOfBattle_Fusion(u8);
 void ItemUseOutOfBattle_Honey(u8);
 void ItemUseOutOfBattle_CannotUse(u8);
 void ItemUseOutOfBattle_ExpShare(u8);

include/party_menu.h

@@ -68,6 +68,7 @@ void ItemUseCB_FormChange(u8 taskId, TaskFunc task);
 void ItemUseCB_FormChange_ConsumedOnUse(u8 taskId, TaskFunc task);
 void ItemUseCB_RotomCatalog(u8 taskId, TaskFunc task);
 void ItemUseCB_ZygardeCube(u8 taskId, TaskFunc task);
+void ItemUseCB_Fusion(u8 taskId, TaskFunc task);
 const u8* GetItemEffect(u16 item);
 u8 GetItemEffectType(u16 item);
 void CB2_PartyMenuFromStartMenu(void);

include/pokemon.h

@@ -426,6 +426,19 @@ struct FormChange
     u16 param3;
 };
 
+struct Fusion
+{
+    u16 fusionStorageIndex;
+    u16 itemId;
+    u16 targetSpecies1;
+    u16 targetSpecies2;
+    u16 fusingIntoMon;
+    u16 fusionMove;
+    u16 unfuseForgetMove;
+};
+
+extern const struct Fusion *const gFusionTablePointers[NUM_SPECIES];
+
 #define NUM_UNOWN_FORMS 28
 
 #define GET_UNOWN_LETTER(personality) ((   \

include/pokemon_storage_system.h

@@ -6,6 +6,7 @@
 #define IN_BOX_COLUMNS          6 // Number of columns, 5 Pokémon per column
 #define IN_BOX_COUNT            (IN_BOX_ROWS * IN_BOX_COLUMNS)
 #define BOX_NAME_LENGTH         8
+#define MAX_FUSION_STORAGE      4
 
 /*
             COLUMNS
@@ -22,6 +23,7 @@ struct PokemonStorage
     /*0x0001*/ struct BoxPokemon boxes[TOTAL_BOXES_COUNT][IN_BOX_COUNT];
     /*0x8344*/ u8 boxNames[TOTAL_BOXES_COUNT][BOX_NAME_LENGTH + 1];
     /*0x83C2*/ u8 boxWallpapers[TOTAL_BOXES_COUNT];
+    /*0x8432*/ struct Pokemon fusions[MAX_FUSION_STORAGE];
 };
 
 extern struct PokemonStorage *gPokemonStoragePtr;

include/strings.h

@@ -944,6 +944,7 @@ extern const u8 gText_UsedVar2WildLured[];
 extern const u8 gText_UsedVar2WildRepelled[];
 extern const u8 gText_BoxFull[];
 extern const u8 gText_WontHaveEffect[];
+extern const u8 gText_NextFusionMon[];
 
 extern const u8 gText_LevelSymbol[];
 extern const u8 gText_PkmnInfo[];

src/data/items.h

@@ -8502,6 +8502,7 @@ const struct Item gItems[] =
     {
         .name = _("Gracidea"),
         .price = 0,
+        .importance = 1,
         .description = sGracideaDesc,
         .pocket = POCKET_KEY_ITEMS,
         .type = ITEM_USE_PARTY_MENU,
@@ -8512,6 +8513,7 @@ const struct Item gItems[] =
     {
         .name = _("Reveal Glass"),
         .price = 0,
+        .importance = 1,
         .description = sRevealGlassDesc,
         .pocket = POCKET_KEY_ITEMS,
         .type = ITEM_USE_PARTY_MENU,
@@ -8522,10 +8524,11 @@ const struct Item gItems[] =
     {
         .name = _("DNA Splicers"),
         .price = 0,
+        .importance = 1,
         .description = sDNASplicersDesc,
         .pocket = POCKET_KEY_ITEMS,
-        .type = ITEM_USE_BAG_MENU,
-        .fieldUseFunc = ItemUseOutOfBattle_CannotUse, // Todo: ItemUseOutOfBattle_FormChange_Fusion
+        .type = ITEM_USE_PARTY_MENU,
+        .fieldUseFunc = ItemUseOutOfBattle_Fusion,
     },
 
     [ITEM_ZYGARDE_CUBE] =
@@ -8543,6 +8546,7 @@ const struct Item gItems[] =
     {
         .name = _("Prison Bottle"),
         .price = 0,
+        .importance = 1,
         .description = sPrisonBottleDesc,
         .pocket = POCKET_KEY_ITEMS,
         .type = ITEM_USE_PARTY_MENU,
@@ -8553,30 +8557,33 @@ const struct Item gItems[] =
     {
         .name = _("N-Solarizer"),
         .price = 0,
+        .importance = 1,
         .description = sNSolarizerDesc,
         .pocket = POCKET_KEY_ITEMS,
-        .type = ITEM_USE_BAG_MENU,
-        .fieldUseFunc = ItemUseOutOfBattle_CannotUse, // Todo: ItemUseOutOfBattle_FormChange_Fusion
+        .type = ITEM_USE_PARTY_MENU,
+        .fieldUseFunc = ItemUseOutOfBattle_Fusion,
     },
 
     [ITEM_N_LUNARIZER] =
     {
         .name = _("N-Lunarizer"),
         .price = 0,
+        .importance = 1,
         .description = sNLunarizerDesc,
         .pocket = POCKET_KEY_ITEMS,
-        .type = ITEM_USE_BAG_MENU,
-        .fieldUseFunc = ItemUseOutOfBattle_CannotUse, // Todo: ItemUseOutOfBattle_FormChange_Fusion
+        .type = ITEM_USE_PARTY_MENU,
+        .fieldUseFunc = ItemUseOutOfBattle_Fusion,
     },
 
     [ITEM_REINS_OF_UNITY] =
     {
         .name = _("ReinsOfUnity"),
         .price = 0,
+        .importance = 1,
         .description = sReinsOfUnityDesc,
         .pocket = POCKET_KEY_ITEMS,
-        .type = ITEM_USE_BAG_MENU,
-        .fieldUseFunc = ItemUseOutOfBattle_CannotUse, // Todo: ItemUseOutOfBattle_FormChange_Fusion
+        .type = ITEM_USE_PARTY_MENU,
+        .fieldUseFunc = ItemUseOutOfBattle_Fusion,
     },
 
 // Battle Mechanic Key Items

src/data/party_menu.h

@@ -658,6 +658,7 @@ static const u8 *const sActionStringTable[] =
     [PARTY_MSG_DO_WHAT_WITH_MAIL]      = gText_DoWhatWithMail,
     [PARTY_MSG_ALREADY_HOLDING_ONE]    = gText_AlreadyHoldingOne,
     [PARTY_MSG_WHICH_APPLIANCE]        = gText_WhichAppliance,
+    [PARTY_MSG_CHOOSE_SECOND_FUSION]   = gText_NextFusionMon,
 };
 
 static const u8 *const sDescriptionStringTable[] =

src/data/pokemon/form_change_table_pointers.h

@@ -375,3 +375,28 @@ const struct FormChange *const gFormChangeTablePointers[NUM_SPECIES] =
     [SPECIES_OGERPON_CORNERSTONE_MASK_TERA] = sOgerponFormChangeTable,
 #endif
 };
+
+const struct Fusion *const gFusionTablePointers[NUM_SPECIES] =
+{
+#if P_GEN_5_POKEMON == TRUE
+    [SPECIES_KYUREM] = sKyuremFusionTable,
+    [SPECIES_KYUREM_BLACK] = sKyuremFusionTable,
+    [SPECIES_KYUREM_WHITE] = sKyuremFusionTable,
+    [SPECIES_RESHIRAM] = sKyuremFusionTable,
+    [SPECIES_ZEKROM] = sKyuremFusionTable,
+#endif
+#if P_GEN_7_POKEMON == TRUE
+    [SPECIES_NECROZMA] = sNecrozmaFusionTable,
+    [SPECIES_NECROZMA_DAWN_WINGS] = sNecrozmaFusionTable,
+    [SPECIES_NECROZMA_DUSK_MANE] = sNecrozmaFusionTable,
+    [SPECIES_SOLGALEO] = sNecrozmaFusionTable,
+    [SPECIES_LUNALA] = sNecrozmaFusionTable,
+#endif
+#if P_GEN_8_POKEMON == TRUE
+    [SPECIES_CALYREX] = sCalyrexFusionTable,
+    [SPECIES_CALYREX_ICE_RIDER] = sCalyrexFusionTable,
+    [SPECIES_CALYREX_SHADOW_RIDER] = sCalyrexFusionTable,
+    [SPECIES_SPECTRIER] = sCalyrexFusionTable,
+    [SPECIES_GLASTRIER] = sCalyrexFusionTable,
+#endif
+};

src/data/pokemon/form_change_tables.h

@@ -407,6 +407,12 @@ static const struct FormChange sLandorusFormChangeTable[] = {
     {FORM_CHANGE_TERMINATOR},
 };
 
+static const struct Fusion sKyuremFusionTable[] = {
+    {0, ITEM_DNA_SPLICERS,   SPECIES_KYUREM,   SPECIES_RESHIRAM,  SPECIES_KYUREM_WHITE},
+    {0, ITEM_DNA_SPLICERS,   SPECIES_KYUREM,   SPECIES_ZEKROM,    SPECIES_KYUREM_BLACK},
+    {FUSION_TERMINATOR},
+};
+
 static const struct FormChange sKeldeoFormChangeTable[] = {
     {FORM_CHANGE_MOVE, SPECIES_KELDEO_RESOLUTE, MOVE_SECRET_SWORD, WHEN_LEARNED},
     {FORM_CHANGE_MOVE, SPECIES_KELDEO_ORDINARY, MOVE_SECRET_SWORD, WHEN_FORGOTTEN},
@@ -588,6 +594,13 @@ static const struct FormChange sMiniorYellowFormChangeTable[] = {
     {FORM_CHANGE_END_BATTLE,        SPECIES_MINIOR_CORE_YELLOW},
     {FORM_CHANGE_TERMINATOR},
 };
+
+static const struct Fusion sNecrozmaFusionTable[] = {
+    {1, ITEM_N_SOLARIZER,    SPECIES_NECROZMA, SPECIES_SOLGALEO,  SPECIES_NECROZMA_DUSK_MANE,   MOVE_SUNSTEEL_STRIKE, MOVE_CONFUSION},
+    {2, ITEM_N_LUNARIZER,    SPECIES_NECROZMA, SPECIES_LUNALA,    SPECIES_NECROZMA_DAWN_WINGS,  MOVE_MOONGEIST_BEAM,  MOVE_CONFUSION},
+    {FUSION_TERMINATOR},
+};
+
 static const struct FormChange sNecrozmaDuskManeFormChangeTable[] = {
     {FORM_CHANGE_BATTLE_ULTRA_BURST,    SPECIES_NECROZMA_ULTRA, ITEM_ULTRANECROZIUM_Z},
     {FORM_CHANGE_TERMINATOR},
@@ -635,6 +648,12 @@ static const struct FormChange sZamazentaFormChangeTable[] = {
     {FORM_CHANGE_TERMINATOR},
 };
 
+static const struct Fusion sCalyrexFusionTable[] = {
+    {3, ITEM_REINS_OF_UNITY, SPECIES_CALYREX,  SPECIES_GLASTRIER, SPECIES_CALYREX_ICE_RIDER,    MOVE_GLACIAL_LANCE,   MOVE_CONFUSION},
+    {3, ITEM_REINS_OF_UNITY, SPECIES_CALYREX,  SPECIES_SPECTRIER, SPECIES_CALYREX_SHADOW_RIDER, MOVE_ASTRAL_BARRAGE,  MOVE_CONFUSION},
+    {FUSION_TERMINATOR},
+};
+
 static const struct FormChange sEnamorusFormChangeTable[] = {
     {FORM_CHANGE_ITEM_USE, SPECIES_ENAMORUS_INCARNATE, ITEM_REVEAL_GLASS},
     {FORM_CHANGE_ITEM_USE, SPECIES_ENAMORUS_THERIAN,   ITEM_REVEAL_GLASS},

src/item_use.c

@@ -1344,6 +1344,13 @@ void ItemUseOutOfBattle_ZygardeCube(u8 taskId)
     }
 }
 
+void ItemUseOutOfBattle_Fusion(u8 taskId)
+{
+    gItemUseCB = ItemUseCB_Fusion;
+    gTasks[taskId].data[0] = FALSE;
+    SetUpItemUseCallback(taskId);
+}
+
 void Task_UseHoneyOnField(u8 taskId)
 {
     //ResetInitialPlayerAvatarState();