Fixed non-regional forms breeding incorrectly

include/constants/regions.h

@@ -0,0 +1,19 @@
+#ifndef GUARD_CONSTANTS_REGIONS_H
+#define GUARD_CONSTANTS_REGIONS_H
+
+// Core-series regions
+#define REGION_KANTO    0
+#define REGION_JOHTO    1
+#define REGION_HOENN    2
+#define REGION_SINNOH   3
+#define REGION_UNOVA    4
+#define REGION_KALOS    5
+#define REGION_ALOLA    6
+#define REGION_GALAR    7
+#define REGION_HISUI    8
+#define REGION_PALDEA   9
+
+// TODO: Since there's no current multi-region support, we have this constant for the purposes of regional form comparisons.
+#define REGION_CURRENT  REGION_HOENN
+
+#endif  // GUARD_CONSTANTS_REGIONS_H

include/pokemon.h

@@ -3,6 +3,7 @@
 
 #include "sprite.h"
 #include "constants/items.h"
+#include "constants/regions.h"
 #include "constants/region_map_sections.h"
 #include "constants/map_groups.h"
 #include "contest_effect.h"
@@ -804,5 +805,7 @@ u16 GetSpeciesPreEvolution(u16 species);
 void HealPokemon(struct Pokemon *mon);
 void HealBoxPokemon(struct BoxPokemon *boxMon);
 const u8 *GetMoveName(u16 moveId);
+u16 GetRegionalForm(u32 species, u32 region);
+bool32 IsSpeciesForeignRegionalForm(u32 species, u32 currentRegion);
 
 #endif // GUARD_POKEMON_H

src/daycare.c

@@ -1039,7 +1039,8 @@ static u16 DetermineEggSpeciesAndParentSlots(struct DayCare *daycare, u8 *parent
     u16 i;
     u16 species[DAYCARE_MON_COUNT];
     u16 eggSpecies, parentSpecies;
-    bool8 hasMotherEverstone, hasFatherEverstone;
+    bool32 hasMotherEverstone, hasFatherEverstone, motherIsForeign, fatherIsForeign;
+    bool32 motherEggSpecies, fatherEggSpecies;
 
     for (i = 0; i < DAYCARE_MON_COUNT; i++)
     {
@@ -1056,15 +1057,21 @@ static u16 DetermineEggSpeciesAndParentSlots(struct DayCare *daycare, u8 *parent
         }
     }
 
+    motherEggSpecies = GetEggSpecies(species[parentSlots[0]]);
+    fatherEggSpecies = GetEggSpecies(species[parentSlots[1]]);
     hasMotherEverstone = ItemId_GetHoldEffect(GetBoxMonData(&daycare->mons[0].mon, MON_DATA_HELD_ITEM)) == HOLD_EFFECT_PREVENT_EVOLVE;
     hasFatherEverstone = ItemId_GetHoldEffect(GetBoxMonData(&daycare->mons[1].mon, MON_DATA_HELD_ITEM)) == HOLD_EFFECT_PREVENT_EVOLVE;
-
-    if (hasMotherEverstone)
-        parentSpecies = species[parentSlots[0]];
-    else if (hasFatherEverstone && GET_BASE_SPECIES_ID(GetEggSpecies(species[parentSlots[0]])) == GET_BASE_SPECIES_ID(GetEggSpecies(species[parentSlots[1]])))
-        parentSpecies = species[parentSlots[1]];
+    motherIsForeign = IsSpeciesForeignRegionalForm(motherEggSpecies, REGION_CURRENT);
+    fatherIsForeign = IsSpeciesForeignRegionalForm(fatherEggSpecies, REGION_CURRENT);
+
+    if (motherIsForeign && hasMotherEverstone)
+        parentSpecies = motherEggSpecies;
+    else if (fatherIsForeign && hasFatherEverstone && GET_BASE_SPECIES_ID(motherEggSpecies) == GET_BASE_SPECIES_ID(fatherEggSpecies))
+        parentSpecies = fatherEggSpecies;
+    else if (motherIsForeign)
+        parentSpecies = GetRegionalForm(motherEggSpecies, REGION_CURRENT);
     else
-        parentSpecies = GET_BASE_SPECIES_ID(GetEggSpecies(species[parentSlots[0]]));
+        parentSpecies = motherEggSpecies;
 
     eggSpecies = GetEggSpecies(parentSpecies);
 

src/pokemon.c

@@ -52,6 +52,7 @@
 #include "constants/items.h"
 #include "constants/layouts.h"
 #include "constants/moves.h"
+#include "constants/regions.h"
 #include "constants/songs.h"
 #include "constants/trainers.h"
 #include "constants/union_room.h"
@@ -6573,3 +6574,33 @@ const u8 *GetMoveName(u16 moveId)
 {
     return gMovesInfo[moveId].name;
 }
+
+u16 GetRegionalForm(u32 species, u32 region)
+{
+    u32 formId = 0;
+    u32 foundSpecies = 0;
+
+    if (GetSpeciesFormTable(species) != NULL)
+    {
+        for (formId = 0; GetSpeciesFormTable(species)[formId] != FORM_SPECIES_END; formId++)
+        {
+            foundSpecies = GetSpeciesFormTable(species)[formId];
+            if ((gSpeciesInfo[foundSpecies].isAlolanForm   && region == REGION_ALOLA)
+             || (gSpeciesInfo[foundSpecies].isGalarianForm && region == REGION_GALAR)
+             || (gSpeciesInfo[foundSpecies].isHisuianForm  && region == REGION_HISUI)
+             || (gSpeciesInfo[foundSpecies].isPaldeanForm  && region == REGION_PALDEA))
+                return foundSpecies;
+        }
+    }
+    return species;
+}
+
+bool32 IsSpeciesForeignRegionalForm(u32 species, u32 currentRegion)
+{
+    if ((gSpeciesInfo[species].isAlolanForm   && currentRegion != REGION_ALOLA)
+     || (gSpeciesInfo[species].isGalarianForm && currentRegion != REGION_GALAR)
+     || (gSpeciesInfo[species].isHisuianForm  && currentRegion != REGION_HISUI)
+     || (gSpeciesInfo[species].isPaldeanForm  && currentRegion != REGION_PALDEA))
+        return TRUE;
+    return FALSE;
+}