Introduced FORM_BATTLE form changes

For species such as Xerneas and Zacian.

include/constants/pokemon.h

@@ -324,6 +324,8 @@
 #define FORM_WITHDRAW           4
 #define FORM_ITEM_HOLD_ABILITY  5
 #define FORM_ITEM_USE_TIME      6
+#define FORM_BATTLE_BEGIN       7
+#define FORM_BATTLE_END         8
 
 #define NUM_MALE_LINK_FACILITY_CLASSES   8
 #define NUM_FEMALE_LINK_FACILITY_CLASSES 8

src/battle_main.c

@@ -481,6 +481,7 @@ void CB2_InitBattle(void)
 static void CB2_InitBattleInternal(void)
 {
     s32 i;
+    u16 targetSpecies;
 
     SetHBlankCallback(NULL);
     SetVBlankCallback(NULL);
@@ -571,6 +572,19 @@ static void CB2_InitBattleInternal(void)
     for (i = 0; i < PARTY_SIZE; i++)
         AdjustFriendship(&gPlayerParty[i], FRIENDSHIP_EVENT_LEAGUE_BATTLE);
 
+    // Apply party-wide start-of-battle form changes
+    for (i = 0; i < PARTY_SIZE; i++)
+    {
+        // Player's side
+        targetSpecies = GetFormChangeTargetSpecies(&gPlayerParty[i], FORM_BATTLE_BEGIN, 0);
+        if (targetSpecies != SPECIES_NONE)
+            SetMonData(&gPlayerParty[i], MON_DATA_SPECIES, &targetSpecies);
+        // Opponent's side
+        targetSpecies = GetFormChangeTargetSpecies(&gEnemyParty[i], FORM_BATTLE_BEGIN, 0);
+        if (targetSpecies != SPECIES_NONE)
+            SetMonData(&gEnemyParty[i], MON_DATA_SPECIES, &targetSpecies);
+    }
+
     gBattleCommunication[MULTIUSE_STATE] = 0;
 }
 

src/battle_util.c

@@ -9588,7 +9588,7 @@ void UndoMegaEvolution(u32 monId)
 
 void UndoFormChange(u32 monId, u32 side, bool32 isSwitchingOut)
 {
-    u32 i, currSpecies;
+    u32 i, currSpecies, targetSpecies;
     struct Pokemon *party = (side == B_SIDE_PLAYER) ? gPlayerParty : gEnemyParty;
     static const u16 species[][3] =
     {
@@ -9622,6 +9622,21 @@ void UndoFormChange(u32 monId, u32 side, bool32 isSwitchingOut)
             break;
         }
     }
+    if (!isSwitchingOut)
+    {
+        // Apply party-wide end-of-battle form changes
+        for (i = 0; i < PARTY_SIZE; i++)
+        {
+            // Player's side
+            targetSpecies = GetFormChangeTargetSpecies(&gPlayerParty[i], FORM_BATTLE_END, 0);
+            if (targetSpecies != SPECIES_NONE)
+                SetMonData(&gPlayerParty[i], MON_DATA_SPECIES, &targetSpecies);
+            // Opponent's side
+            targetSpecies = GetFormChangeTargetSpecies(&gEnemyParty[i], FORM_BATTLE_END, 0);
+            if (targetSpecies != SPECIES_NONE)
+                SetMonData(&gEnemyParty[i], MON_DATA_SPECIES, &targetSpecies);
+        }
+    }
 }
 
 bool32 DoBattlersShareType(u32 battler1, u32 battler2)

src/data/pokemon/form_change_table_pointers.h

@@ -31,11 +31,13 @@ const struct FormChange *const gFormChangeTablePointers[NUM_SPECIES] =
     [SPECIES_LANDORUS_THERIAN] = sLandorusTherianFormChangeTable,
     [SPECIES_KELDEO] = sKeldeoFormChangeTable,
     [SPECIES_KELDEO_RESOLUTE] = sKeldeoResoluteFormChangeTable,
-    [SPECIES_GENESECT] = sGenesectFormChangeTable, 
+    [SPECIES_GENESECT] = sGenesectFormChangeTable,
     [SPECIES_GENESECT_DOUSE_DRIVE] = sGenesectFormChangeTable,
     [SPECIES_GENESECT_SHOCK_DRIVE] = sGenesectFormChangeTable,
     [SPECIES_GENESECT_BURN_DRIVE] = sGenesectFormChangeTable,
     [SPECIES_GENESECT_CHILL_DRIVE] = sGenesectFormChangeTable,
+    [SPECIES_XERNEAS] = sXerneasFormChangeTable,
+    [SPECIES_XERNEAS_ACTIVE] = sXerneasFormChangeTable,
     [SPECIES_HOOPA] = sHoopaFormChangeTable,
     [SPECIES_HOOPA_UNBOUND] = sHoopaUnboundFormChangeTable,
     [SPECIES_ORICORIO] = sOricorioFormChangeTable,
@@ -60,5 +62,9 @@ const struct FormChange *const gFormChangeTablePointers[NUM_SPECIES] =
     [SPECIES_SILVALLY_ROCK] = sSilvallyFormChangeTable,
     [SPECIES_SILVALLY_STEEL] = sSilvallyFormChangeTable,
     [SPECIES_SILVALLY_WATER] = sSilvallyFormChangeTable,
+    [SPECIES_ZACIAN] = sZacianFormChangeTable,
+    [SPECIES_ZACIAN_CROWNED_SWORD] = sZacianFormChangeTable,
+    [SPECIES_ZAMAZENTA] = sZamazentaFormChangeTable,
+    [SPECIES_ZAMAZENTA_CROWNED_SHIELD] = sZamazentaFormChangeTable,
 #endif
 };

src/data/pokemon/form_change_tables.h

@@ -33,6 +33,14 @@ FORM_ITEM_USE_TIME:
     param1 = item to use
     param2 = DAY if form change activates in the daytime
              NIGHT if form change activates at nighttime
+
+FORM_BATTLE_BEGIN:
+    Form change activates when the Pokémon is sent out at the beginning of a battle
+    param1 = item to hold, optional
+
+FORM_BATTLE_END:
+    Form change activates at the end of a battle
+    param1 = item to hold, optional
 */
 
 // FORM_MOVE param2 Arguments
@@ -185,5 +193,23 @@ static const struct FormChange sSilvallyFormChangeTable[] = {
 };
 #endif
 
+static const struct FormChange sXerneasFormChangeTable[] = {
+    {FORM_BATTLE_BEGIN, SPECIES_XERNEAS_ACTIVE, ITEM_NONE},
+    {FORM_BATTLE_END,   SPECIES_XERNEAS,        ITEM_NONE},
+    {FORM_CHANGE_END},
+};
+
+static const struct FormChange sZacianFormChangeTable[] = {
+    {FORM_BATTLE_BEGIN, SPECIES_ZACIAN_CROWNED_SWORD, ITEM_RUSTED_SWORD},
+    {FORM_BATTLE_END,   SPECIES_ZACIAN,               ITEM_RUSTED_SWORD},
+    {FORM_CHANGE_END},
+};
+
+static const struct FormChange sZamazentaFormChangeTable[] = {
+    {FORM_BATTLE_BEGIN, SPECIES_ZAMAZENTA_CROWNED_SHIELD, ITEM_RUSTED_SHIELD},
+    {FORM_BATTLE_END,   SPECIES_ZAMAZENTA,                ITEM_RUSTED_SHIELD},
+    {FORM_CHANGE_END},
+};
+
 #undef WHEN_LEARNED
 #undef WHEN_FORGOTTEN

src/pokemon.c

@@ -8237,13 +8237,13 @@ u8 GetFormIdFromFormSpeciesId(u16 formSpeciesId)
     return targetFormId;
 }
 
-u16 GetFormChangeTargetSpecies(struct Pokemon *mon, u16 method, u32 arg) 
+u16 GetFormChangeTargetSpecies(struct Pokemon *mon, u16 method, u32 arg)
 {
     return GetFormChangeTargetSpeciesBoxMon(&mon->box, method, arg);
 }
 
 // Returns SPECIES_NONE if no form change is possible
-u16 GetFormChangeTargetSpeciesBoxMon(struct BoxPokemon *mon, u16 method, u32 arg) 
+u16 GetFormChangeTargetSpeciesBoxMon(struct BoxPokemon *mon, u16 method, u32 arg)
 {
     u32 i;
     u16 targetSpecies = SPECIES_NONE;
@@ -8264,6 +8264,8 @@ u16 GetFormChangeTargetSpeciesBoxMon(struct BoxPokemon *mon, u16 method, u32 arg
                 switch (method)
                 {
                 case FORM_ITEM_HOLD:
+                case FORM_BATTLE_BEGIN:
+                case FORM_BATTLE_END:
                     if (heldItem == formChanges[i].param1 || formChanges[i].param1 == ITEM_NONE)
                         targetSpecies = formChanges[i].targetSpecies;
                     break;