Allow other species to have Shedinja HP handling (#9135)

include/config/pokemon.h

@@ -61,6 +61,7 @@
 #define P_ONLY_OBTAINABLE_SHINIES        FALSE       // If TRUE, Pokémon encountered in the Battle Pyramid or while catching is disabled won't be Shiny.
 #define P_NO_SHINIES_WITHOUT_POKEBALLS   FALSE       // If TRUE, Pokémon encountered when the player is out of Poké Balls won't be Shiny.
 #define P_SHOW_DYNAMIC_TYPES             FALSE       // If TRUE, all moves with dynamic type changes will be reflected as their current type in battle/summary screens instead of just select ones like in vanilla.
+#define P_BASE_HP_1_SHEDINJA_HANDLING    FALSE       // If TRUE, all species with 1 Base HP will have their handling match Shedinja's.
 
 // Learnset helper toggles
 #define P_LEARNSET_HELPER_TEACHABLE      TRUE   // If FALSE, make sure to remove teachable_learnset.h from your .gitignore file. If TRUE, teachable_learnsets.h will be populated by tools/learnset_helpers/make_teachables.py using the included JSON files based on available TMs and tutors.

include/pokemon.h

@@ -943,5 +943,6 @@ bool32 IsSpeciesOfType(u32 species, enum Type type);
 struct BoxPokemon *GetSelectedBoxMonFromPcOrParty(void);
 u32 GiveScriptedMonToPlayer(struct Pokemon *mon, u8 slot);
 void ChangePokemonNicknameWithCallback(void (*callback)(void));
+bool32 HasShedinjaHPHandling(u32 species);
 
 #endif // GUARD_POKEMON_H

src/battle_dome.c

@@ -2132,7 +2132,7 @@ static void CalcDomeMonStats(const struct TrainerMon *fmon, int level, u8 ivs, i
             evs[i] = 0;
     }
 
-    if (fmon->species == SPECIES_SHEDINJA)
+    if (HasShedinjaHPHandling(fmon->species))
     {
         stats[STAT_HP] = 1;
     }

src/battle_dynamax.c

@@ -131,8 +131,10 @@ bool32 IsGigantamaxed(enum BattlerId battler)
 // Applies the HP Multiplier for Dynamaxed Pokemon and Raid Bosses.
 void ApplyDynamaxHPMultiplier(struct Pokemon* mon)
 {
-    if (GetMonData(mon, MON_DATA_SPECIES) == SPECIES_SHEDINJA)
+    if (HasShedinjaHPHandling(GetMonData(mon, MON_DATA_SPECIES)))
+    {
         return;
+    }
     else
     {
         uq4_12_t multiplier = GetDynamaxLevelHPMultiplier(GetMonData(mon, MON_DATA_DYNAMAX_LEVEL), FALSE);
@@ -146,8 +148,10 @@ void ApplyDynamaxHPMultiplier(struct Pokemon* mon)
 // Returns the non-Dynamax HP of a Pokemon.
 u32 GetNonDynamaxHP(enum BattlerId battler)
 {
-    if (GetActiveGimmick(battler) != GIMMICK_DYNAMAX || gBattleMons[battler].species == SPECIES_SHEDINJA)
+    if (GetActiveGimmick(battler) != GIMMICK_DYNAMAX || HasShedinjaHPHandling(gBattleMons[battler].species))
+    {
         return gBattleMons[battler].hp;
+    }
     else
     {
         struct Pokemon *mon = GetBattlerMon(battler);
@@ -160,8 +164,10 @@ u32 GetNonDynamaxHP(enum BattlerId battler)
 // Returns the non-Dynamax Max HP of a Pokemon.
 u32 GetNonDynamaxMaxHP(enum BattlerId battler)
 {
-    if (GetActiveGimmick(battler) != GIMMICK_DYNAMAX || gBattleMons[battler].species == SPECIES_SHEDINJA)
+    if (GetActiveGimmick(battler) != GIMMICK_DYNAMAX || HasShedinjaHPHandling(gBattleMons[battler].species))
+    {
         return gBattleMons[battler].maxHP;
+    }
     else
     {
         struct Pokemon *mon = GetBattlerMon(battler);

src/party_menu.c

@@ -4744,7 +4744,7 @@ static void GetMedicineItemEffectMessage(enum Item item, u32 statusCured)
 
 static bool32 NotUsingHPEVItemOnShedinja(struct Pokemon *mon, enum Item item)
 {
-    if (GetItemEffectType(item) == ITEM_EFFECT_HP_EV && GetMonData(mon, MON_DATA_SPECIES) == SPECIES_SHEDINJA)
+    if (GetItemEffectType(item) == ITEM_EFFECT_HP_EV && HasShedinjaHPHandling(GetMonData(mon, MON_DATA_SPECIES)))
         return FALSE;
     return TRUE;
 }
@@ -5243,7 +5243,7 @@ static u16 ItemEffectToMonEv(struct Pokemon *mon, u8 effectType)
     switch (effectType)
     {
     case ITEM_EFFECT_HP_EV:
-        if (GetMonData(mon, MON_DATA_SPECIES) != SPECIES_SHEDINJA)
+        if (!HasShedinjaHPHandling(GetMonData(mon, MON_DATA_SPECIES)))
             return GetMonData(mon, MON_DATA_HP_EV);
         break;
     case ITEM_EFFECT_ATK_EV:

src/pokemon.c

@@ -1855,7 +1855,7 @@ void CalculateMonStats(struct Pokemon *mon)
         return;
 #endif
 
-    if (species == SPECIES_SHEDINJA)
+    if (HasShedinjaHPHandling(species))
     {
         newMaxHP = 1;
     }
@@ -7445,3 +7445,12 @@ void ChangePokemonNicknameWithCallback(void (*callback)(void))
     GetBoxMonData(boxMon, MON_DATA_NICKNAME, gStringVar2);
     DoNamingScreen(NAMING_SCREEN_NICKNAME, gStringVar2, GetBoxMonData(boxMon, MON_DATA_SPECIES), GetBoxMonGender(boxMon), GetBoxMonData(boxMon, MON_DATA_PERSONALITY), callback);
 }
+
+bool32 HasShedinjaHPHandling(u32 species)
+{
+    if (species == SPECIES_SHEDINJA)
+        return TRUE;
+    if (P_BASE_HP_1_SHEDINJA_HANDLING && GetSpeciesBaseHP(species) == 1)
+        return TRUE;
+    return FALSE;
+}