Implement Exp Charm and unevolved Exp multipliers + Exp formula fixes (#3301)

Co-authored-by: Eduardo Quezada D'Ottone <eduardo602002@gmail.com>

include/config/battle.h

@@ -14,6 +14,7 @@
 #define B_TRAINER_EXP_MULTIPLIER    GEN_LATEST // In Gen7+, trainer battles no longer give a 1.5 multiplier to EXP gain.
 #define B_SPLIT_EXP                 GEN_LATEST // In Gen6+, all participating mon get full experience.
 #define B_SCALED_EXP                GEN_LATEST // In Gen5 and Gen7+, experience is weighted by level difference.
+#define B_UNEVOLVED_EXP_MULTIPLIER  GEN_LATEST // In Gen6+, if the Pokémon is at or past the level where it would be able to evolve, but it has not, it gets a ~1.2 multiplier to EXP gain. Only applies to Pokémon with EVO_LEVEL method.
 
 // Stat settings
 #define B_BADGE_BOOST               GEN_LATEST // In Gen4+, Gym Badges no longer boost a Pokémon's stats.

include/pokemon.h

@@ -543,6 +543,7 @@ u8 *UseStatIncreaseItem(u16 itemId);
 u8 GetNature(struct Pokemon *mon);
 u8 GetNatureFromPersonality(u32 personality);
 u16 GetEvolutionTargetSpecies(struct Pokemon *mon, u8 type, u16 evolutionItem, struct Pokemon *tradePartner);
+bool8 IsMonPastEvolutionLevel(struct Pokemon *mon);
 u16 HoennPokedexNumToSpecies(u16 hoennNum);
 u16 NationalPokedexNumToSpecies(u16 nationalNum);
 u16 NationalToHoennOrder(u16 nationalNum);

src/battle_script_commands.c

@@ -4087,6 +4087,9 @@ static void Cmd_getexp(void)
                 calculatedExp = gSpeciesInfo[gBattleMons[gBattlerFainted].species].expYield * gBattleMons[gBattlerFainted].level / 7;
             #endif
 
+            if (B_TRAINER_EXP_MULTIPLIER <= GEN_7 && gBattleTypeFlags & BATTLE_TYPE_TRAINER)
+                calculatedExp = (calculatedExp * 150) / 100;
+
             #if B_SPLIT_EXP < GEN_6
                 if (viaExpShare) // at least one mon is getting exp via exp share
                 {
@@ -4179,14 +4182,9 @@ static void Cmd_getexp(void)
                     {
                         // check if the pokemon doesn't belong to the player
                         if (gBattleTypeFlags & BATTLE_TYPE_INGAME_PARTNER && gBattleStruct->expGetterMonId >= 3)
-                        {
                             i = STRINGID_EMPTYSTRING4;
-                        }
                         else
-                        {
-                            gBattleMoveDamage = (gBattleMoveDamage * 150) / 100;
                             i = STRINGID_ABOOSTED;
-                        }
                     }
                     else
                     {
@@ -16029,13 +16027,15 @@ void ApplyExperienceMultipliers(s32 *expAmount, u8 expGetterMonId, u8 faintedBat
     else
         holdEffect = ItemId_GetHoldEffect(item);
 
+    if (IsTradedMon(&gPlayerParty[expGetterMonId]))
+        *expAmount = (*expAmount * 150) / 100;
     if (holdEffect == HOLD_EFFECT_LUCKY_EGG)
         *expAmount = (*expAmount * 150) / 100;
-    if (B_TRAINER_EXP_MULTIPLIER <= GEN_7 && gBattleTypeFlags & BATTLE_TYPE_TRAINER)
+    if (B_UNEVOLVED_EXP_MULTIPLIER >= GEN_6 && IsMonPastEvolutionLevel(&gPlayerParty[expGetterMonId]))
-        *expAmount = (*expAmount * 150) / 100;
+        *expAmount = (*expAmount * 4915) / 4096;
     if (B_AFFECTION_MECHANICS == TRUE && GetBattlerFriendshipScore(expGetterMonId) >= FRIENDSHIP_50_TO_99)
-        *expAmount = (*expAmount * 120) / 100;
+        *expAmount = (*expAmount * 4915) / 4096;
-    if (IsTradedMon(&gPlayerParty[expGetterMonId]))
+    if (CheckBagHasItem(ITEM_EXP_CHARM, 1)) //is also for other exp boosting Powers if/when implemented
         *expAmount = (*expAmount * 150) / 100;
 
     if (B_SCALED_EXP >= GEN_5 && B_SCALED_EXP != GEN_6)

src/pokemon.c

@@ -6770,6 +6770,26 @@ u16 GetEvolutionTargetSpecies(struct Pokemon *mon, u8 mode, u16 evolutionItem, s
     return targetSpecies;
 }
 
+bool8 IsMonPastEvolutionLevel(struct Pokemon *mon)
+{
+    int i;
+    u16 species = GetMonData(mon, MON_DATA_SPECIES, 0);
+    u8 level = GetMonData(mon, MON_DATA_LEVEL, 0);
+    
+    for (i = 0; i < EVOS_PER_MON; i++)
+    {
+        switch (gEvolutionTable[species][i].method)
+        {
+        case EVO_LEVEL:
+            if (gEvolutionTable[species][i].param <= level)
+                return TRUE;
+            break;
+        }
+    }
+
+    return FALSE;
+}
+
 u16 HoennPokedexNumToSpecies(u16 hoennNum)
 {
     u16 species;