Refactor CanThrowLastUsedBall and related functions

include/item_use.h

@@ -33,6 +33,14 @@ void ItemUseInBattle_EnigmaBerry(u8);
 void Task_UseDigEscapeRopeOnField(u8 taskId);
 u8 CanUseDigOrEscapeRopeOnCurMap(void);
 u8 CheckIfItemIsTMHMOrEvolutionStone(u16 itemId);
-u32 CanThrowBall(void);
+
+enum {
+    BALL_FAIL_TWO_PRESENT_MONS,
+    BALL_FAIL_NO_ROOM,
+    BALL_FAIL_SEMI_INVULNERABLE,
+    BALL_SUCCESS,
+};
+
+bool32 CanThrowBall(void);
 
 #endif // GUARD_ITEM_USE_H

src/battle_interface.c

@@ -3276,19 +3276,23 @@ static const struct SpriteSheet sSpriteSheet_LastUsedBallWindow =
 
 bool32 CanThrowLastUsedBall(void)
 {
-    #if B_LAST_USED_BALL == FALSE
+#if B_LAST_USED_BALL == FALSE
+    return FALSE;
+#else
+    if (!CanThrowBall())
+        return FALSE;
+    if (gBattleTypeFlags & BATTLE_TYPE_TRAINER)
+        return FALSE;
+    if (!CheckBagHasItem(gLastThrownBall, 1))
         return FALSE;
-    #else
-        return (!(CanThrowBall() != 0
-         || (gBattleTypeFlags & BATTLE_TYPE_TRAINER)
-         || !CheckBagHasItem(gLastThrownBall, 1)));
-     #endif
-}
 
+    return TRUE;
+#endif
+}
 
 void TryAddLastUsedBallItemSprites(void)
 {
-    #if B_LAST_USED_BALL == TRUE
+#if B_LAST_USED_BALL == TRUE
     if (gLastThrownBall == 0
       || (gLastThrownBall != 0 && !CheckBagHasItem(gLastThrownBall, 1)))
     {
@@ -3298,9 +3302,7 @@ void TryAddLastUsedBallItemSprites(void)
         gLastThrownBall = gBagPockets[BALLS_POCKET].itemSlots[0].itemId;
     }
 
-    if (CanThrowBall() != 0
-     || (gBattleTypeFlags & BATTLE_TYPE_TRAINER)
-     || !CheckBagHasItem(gLastThrownBall, 1))
+    if (!CanThrowLastUsedBall())
         return;
 
     // ball
@@ -3325,7 +3327,7 @@ void TryAddLastUsedBallItemSprites(void)
                                                        LAST_USED_WIN_Y, 5);
         gSprites[gBattleStruct->ballSpriteIds[0]].sHide = FALSE;   // restore
     }
-    #endif
+#endif
 }
 
 static void DestroyLastUsedBallWinGfx(struct Sprite *sprite)
@@ -3380,7 +3382,7 @@ static void SpriteCB_LastUsedBall(struct Sprite *sprite)
 
 static void TryHideOrRestoreLastUsedBall(u8 caseId)
 {
-    #if B_LAST_USED_BALL == TRUE
+#if B_LAST_USED_BALL == TRUE
     if (gBattleStruct->ballSpriteIds[0] == MAX_SPRITES)
         return;
 
@@ -3399,23 +3401,22 @@ static void TryHideOrRestoreLastUsedBall(u8 caseId)
             gSprites[gBattleStruct->ballSpriteIds[1]].sHide = FALSE;   // restore
         break;
     }
-    #endif
+#endif
 }
 
 void TryHideLastUsedBall(void)
 {
-    #if B_LAST_USED_BALL == TRUE
+#if B_LAST_USED_BALL == TRUE
     TryHideOrRestoreLastUsedBall(0);
-    #endif
+#endif
 }
 
 void TryRestoreLastUsedBall(void)
 {
-    #if B_LAST_USED_BALL == TRUE
+#if B_LAST_USED_BALL == TRUE
     if (gBattleStruct->ballSpriteIds[0] != MAX_SPRITES)
         TryHideOrRestoreLastUsedBall(1);
     else
         TryAddLastUsedBallItemSprites();
-    #endif
+#endif
 }
-

src/item_use.c

@@ -936,34 +936,33 @@ void ItemUseOutOfBattle_EvolutionStone(u8 taskId)
     SetUpItemUseCallback(taskId);
 }
 
-u32 CanThrowBall(void)
+static u32 GetBallThrowFailState(void)
 {
     if (IsBattlerAlive(GetBattlerAtPosition(B_POSITION_OPPONENT_LEFT))
         && IsBattlerAlive(GetBattlerAtPosition(B_POSITION_OPPONENT_RIGHT)))
-    {
-        return 1;   // There are two present pokemon.
-    }
+        return BALL_FAIL_TWO_PRESENT_MONS;
     else if (IsPlayerPartyAndPokemonStorageFull() == TRUE)
-    {
-        return 2;   // No room for mon
-    }
-    #if B_SEMI_INVULNERABLE_CATCH >= GEN_4
+        return BALL_FAIL_NO_ROOM;
+#if B_SEMI_INVULNERABLE_CATCH >= GEN_4
     else if (gStatuses3[GetCatchingBattler()] & STATUS3_SEMI_INVULNERABLE)
-    {
-        return 3;   // in semi-invulnerable state
-    }
-    #endif
+        return BALL_FAIL_SEMI_INVULNERABLE;
+#endif
 
-    return 0;   // usable 
+    return BALL_SUCCESS;
+}
+
+bool32 CanThrowBall(void)
+{
+    return (GetBallThrowFailState() == BALL_SUCCESS);
 }
 
 static const u8 sText_CantThrowPokeBall_TwoMons[] = _("Cannot throw a ball!\nThere are two Pokémon out there!\p");
 static const u8 sText_CantThrowPokeBall_SemiInvulnerable[] = _("Cannot throw a ball!\nThere's no Pokémon in sight!\p");
 void ItemUseInBattle_PokeBall(u8 taskId)
 {
-    switch (CanThrowBall())
+    switch (GetBallThrowFailState())
     {
-    case 0: // usable
+    case BALL_SUCCESS:
     default:
         RemoveBagItem(gSpecialVar_ItemId, 1);
         if (!InBattlePyramid())
@@ -971,20 +970,20 @@ void ItemUseInBattle_PokeBall(u8 taskId)
         else
             CloseBattlePyramidBag(taskId);
         break;
-    case 1:  // There are two present pokemon.
+    case BALL_FAIL_TWO_PRESENT_MONS:
         if (!InBattlePyramid())
             DisplayItemMessage(taskId, 1, sText_CantThrowPokeBall_TwoMons, CloseItemMessage);
         else
             DisplayItemMessageInBattlePyramid(taskId, sText_CantThrowPokeBall_TwoMons, Task_CloseBattlePyramidBagMessage);
         break;
-    case 2: // No room for mon
+    case BALL_FAIL_NO_ROOM:
         if (!InBattlePyramid())
             DisplayItemMessage(taskId, 1, gText_BoxFull, CloseItemMessage);
         else
             DisplayItemMessageInBattlePyramid(taskId, gText_BoxFull, Task_CloseBattlePyramidBagMessage);
         break;
     #if B_SEMI_INVULNERABLE_CATCH >= GEN_4
-    case 3: // Semi-Invulnerable
+    case BALL_FAIL_SEMI_INVULNERABLE:
         if (!InBattlePyramid())
             DisplayItemMessage(taskId, 1, sText_CantThrowPokeBall_SemiInvulnerable, CloseItemMessage);
         else