Document AI Anti Mill strategy

5 files changed, 112 insertions, 68 deletions

diff --git a/src/constants/duel_constants.asm b/src/constants/duel_constants.asm
index 9cdc73b..47ca1ad 100644
--- a/src/constants/duel_constants.asm
+++ b/src/constants/duel_constants.asm
@@ -263,3 +263,8 @@ AI_ENERGY_FLAG_SKIP_ARENA_CARD EQU 1 << 7 ; whether to include Arena card in det
 	const AI_TRAINER_CARD_PHASE_13 ; $d
 	const AI_TRAINER_CARD_PHASE_14 ; $e
 	const AI_TRAINER_CARD_PHASE_15 ; $f
+
+; used by wAIBarrierFlagCounter to determine
+; whether Player is running Mewtwo1 mill deck.
+; flag set means true, flag not set means false.
+AI_FLAG_MEWTWO_MILL EQU 1 << 7
diff --git a/src/engine/bank05.asm b/src/engine/bank05.asm
index 989225e..7162983 100644
--- a/src/engine/bank05.asm
+++ b/src/engine/bank05.asm
@@ -1233,7 +1233,7 @@ _AIMainTurnLogic: ; 1468b (5:468b)
 
 	ld a, AI_TRAINER_CARD_PHASE_01
 	call AIProcessHandTrainerCards
-	farcall Func_227d3
+	farcall HandleAIAntiMewtwoDeckStrategy
 	jp nc, .try_attack
 
 	farcall HandleAIGoGoRainDanceEnergy
@@ -1719,10 +1719,11 @@ InitAIDuelVars: ; 15636 (5:5636)
 	ld [wcda5], a
 	ret
 
-; initializes some variables and
-; sets value of wcda7.
+; initializes some variables and sets value of wAIBarrierFlagCounter.
+; if Player uses Barrier 3 times in a row, AI checks if Player's deck
+; has only Mewtwo1 Pokemon cards (running a Mewtwo1 mill deck).
 InitAITurnVars: ; 15649 (5:5649)
-; increase Pokedex counter by one
+; increase Pokedex counter by 1
 	ld a, [wAIPokedexCounter]
 	inc a
 	ld [wAIPokedexCounter], a
@@ -1733,30 +1734,43 @@ InitAITurnVars: ; 15649 (5:5649)
 	ld [wcddc], a
 	ld [wce03], a
 
+; checks if the Player used an attack last turn
+; and if it was the second attack of their card.
 	ld a, [wPlayerAttackingMoveIndex]
 	cp $ff
-	jr z, .asm_156b1
+	jr z, .check_flag
 	or a
-	jr z, .asm_156b1
+	jr z, .check_flag
 	ld a, [wPlayerAttackingCardIndex]
 	cp $ff
-	jr z, .asm_156b1
+	jr z, .check_flag
 
+; if the card is Mewtwo1, it means the Player
+; used its second attack, Barrier.
 	call SwapTurn
 	call GetCardIDFromDeckIndex
 	call SwapTurn
 	ld a, e
 	cp MEWTWO1
-	jr nz, .asm_156b1
+	jr nz, .check_flag
+	; Player used Barrier last turn
 
-; handle Mewtwo1-only deck
-	ld a, [wcda7]
+; check if flag was already set, if so,
+; reset wAIBarrierFlagCounter to $80.
+	ld a, [wAIBarrierFlagCounter]
 	bit 7, a
-	jr nz, .asm_156aa
+	jr nz, .set_flag
+
+; if not, increase it by 1 and check if it exceeds 2.
 	inc a
-	ld [wcda7], a
-	cp $03
+	ld [wAIBarrierFlagCounter], a
+	cp 3
 	jr c, .done
+
+; this means that the Player used Barrier
+; at least 3 turns in a row.
+; check if Player is running Mewtwo1-only deck,
+; if so, set wAIBarrierFlagCounter flag.
 	ld a, DUELVARS_ARENA_CARD
 	call GetNonTurnDuelistVariable
 	call SwapTurn
@@ -1764,31 +1778,33 @@ InitAITurnVars: ; 15649 (5:5649)
 	call SwapTurn
 	ld a, e
 	cp MEWTWO1
-	jr nz, .asm_156a4
+	jr nz, .reset_1
 	farcall CheckIfPlayerHasPokemonOtherThanMewtwo1
-	jr nc, .asm_156aa
-.asm_156a4
-; reset wcda7
+	jr nc, .set_flag
+.reset_1
+; reset wAIBarrierFlagCounter
 	xor a
-	ld [wcda7], a
+	ld [wAIBarrierFlagCounter], a
 	jr .done
-.asm_156aa
-	ld a, $80
-	ld [wcda7], a
+
+.set_flag
+	ld a, AI_FLAG_MEWTWO_MILL + 0
+	ld [wAIBarrierFlagCounter], a
 	jr .done
 
-.asm_156b1
-	ld a, [wcda7]
+.check_flag
+; increase counter by 1 if flag is set
+	ld a, [wAIBarrierFlagCounter]
 	bit 7, a
-	jr z, .asm_156be
+	jr z, .reset_2
 	inc a
-	ld [wcda7], a
+	ld [wAIBarrierFlagCounter], a
 	jr .done
 
-.asm_156be
-; reset wcda7
+.reset_2
+; reset wAIBarrierFlagCounter
 	xor a
-	ld [wcda7], a
+	ld [wAIBarrierFlagCounter], a
 .done
 	ret
 ; 0x156c3
@@ -4520,11 +4536,12 @@ AIProcessEnergyCards: ; 164fc (5:64fc)
 	jr nz, .bench
 
 ; arena
-	ld a, [wcda7]
+	ld a, [wAIBarrierFlagCounter]
 	bit 7, a
 	jr z, .add_to_score
 
-; subtract from score
+; subtract from score instead
+; if Player is running Mewtwo1 mill deck.
 	ld a, 5
 	call SubFromAIScore
 	jr .check_defending_can_ko
@@ -5455,8 +5472,10 @@ AIProcessAttacks: ; 169fc (5:69fc)
 	jr .attack_chosen
 
 .no_pluspower
-	ld a, [wcda7]
-	cp $80
+; if Player is running Mewtwo1 mill deck,
+; skip attack if Barrier counter is 0.
+	ld a, [wAIBarrierFlagCounter]
+	cp AI_FLAG_MEWTWO_MILL + 0
 	jp z, .dont_attack
 
 ; determine AI score of both attacks.
diff --git a/src/engine/bank08.asm b/src/engine/bank08.asm
index 1c6f82a..8d6d462 100644
--- a/src/engine/bank08.asm
+++ b/src/engine/bank08.asm
@@ -4698,19 +4698,22 @@ AIPlay_Gambler: ; 2182d (8:582d)
 ; 0x21875
 
 ; checks whether to play Gambler.
-; aside from Imakuni, all other opponents only
-; play if there's less than 4 cards in the deck.
+; aside from Imakuni?, all other opponents only
+; play this card if Player is running Mewtwo1-only deck.
 AIDecide_Gambler: ; 21875 (8:5875)
 ; Imakuni? has his own routine
 	ld a, [wOpponentDeckID]
 	cp IMAKUNI_DECK_ID
 	jr z, .imakuni
 
-	ld a, [wcda7]
-	and $80
+; check if flag is set for Player using Mewtwo1 only deck
+	ld a, [wAIBarrierFlagCounter]
+	and AI_FLAG_MEWTWO_MILL
 	jr z, .no_carry
 
-; set carry if number of cards in deck <= 4
+; set carry if number of cards in deck <= 4.
+; this is done to counteract the deck out strategy
+; of Mewtwo1 deck, by replenishing the deck with hand cards.
 	ld a, DUELVARS_NUMBER_OF_CARDS_NOT_IN_DECK
 	call GetTurnDuelistVariable
 	cp DECK_SIZE - 4
@@ -7487,26 +7490,37 @@ CheckIfPlayerHasPokemonOtherThanMewtwo1: ; 227a9 (8:67a9)
 	ret
 ; 0x227d3
 
-; checks wcda7 and Pokemon in Play Area that are set up.
-; if there's at least 4, goes to AI_TRAINER_CARD_PHASE_05.
-; else, returns carry.
-Func_227d3: ; 227d3 (8:67d3)
-	ld a, [wcda7]
+; returns no carry if, given the Player is using a Mewtwo1 mill deck,
+; the AI already has a Bench fully set up, in which case it
+; will process some Trainer cards in hand (namely Energy Removals).
+; this is used to check whether to skip some normal AI routines
+; this turn and jump right to the attacking phase.
+HandleAIAntiMewtwoDeckStrategy: ; 227d3 (8:67d3)
+; return carry if Player is not playing Mewtwo1 mill deck
+	ld a, [wAIBarrierFlagCounter]
 	bit 7, a
 	jr z, .set_carry
-	cp %10000010
-	jr c, .asm_227e4
 
-; reset wcda7
+; else, check if there's been less than 2 turns
+; without the Player using Barrier.
+	cp AI_FLAG_MEWTWO_MILL + 2
+	jr c, .count_bench
+
+; if there has been, reset wAIBarrierFlagCounter
+; and return carry.
 	xor a
-	ld [wcda7], a
+	ld [wAIBarrierFlagCounter], a
 	jr .set_carry
 
-.asm_227e4
+; else, check number of Pokemon that are set up in Bench
+; if less than 4, return carry.
+.count_bench
 	farcall CountNumberOfSetUpBenchPokemon
 	cp 4
 	jr c, .set_carry
 
+; if there's at least 4 Pokemon in the Bench set up,
+; process Trainer hand cards of AI_TRAINER_CARD_PHASE_05
 	ld a, AI_TRAINER_CARD_PHASE_05
 	farcall AIProcessHandTrainerCards
 	or a
diff --git a/src/engine/deck_ai.asm b/src/engine/deck_ai.asm
index e4edfdf..c93b8ce 100644
--- a/src/engine/deck_ai.asm
+++ b/src/engine/deck_ai.asm
@@ -58,8 +58,8 @@ Func_148ff: ; 148ff (5:48ff)
 	call InitAITurnVars

 	ld a, AI_TRAINER_CARD_PHASE_01

 	call AIProcessHandTrainerCards

-	farcall Func_227d3

-	jp nc, .asm_149de

+	farcall HandleAIAntiMewtwoDeckStrategy

+	jp nc, .try_attack

 	farcall HandleAIGoGoRainDanceEnergy

 	farcall HandleAIDamageSwap

 	farcall HandleAIPkmnPowers

@@ -105,7 +105,7 @@ Func_148ff: ; 148ff (5:48ff)
 	call AIProcessHandTrainerCards

 	ld a, [wPreviousAIFlags]

 	and AI_FLAG_USED_PROFESSOR_OAK

-	jr z, .asm_149de

+	jr z, .try_attack

 	ld a, AI_TRAINER_CARD_PHASE_01

 	call AIProcessHandTrainerCards

 	ld a, AI_TRAINER_CARD_PHASE_02

@@ -142,7 +142,7 @@ Func_148ff: ; 148ff (5:48ff)
 	farcall HandleAIGoGoRainDanceEnergy

 	ld a, AI_TRAINER_CARD_PHASE_13

 	call AIProcessHandTrainerCards

-.asm_149de

+.try_attack

 	call AIProcessAndTryToUseAttack

 	ret c

 	ld a, OPPACTION_FINISH_NO_ATTACK

@@ -277,7 +277,7 @@ Func_14a4a: ; 14a4a (5:4a4a)
 

 Func_14a81: ; 14a81 (5:4a81)

 	call InitAITurnVars

-	farcall Func_227d3

+	farcall HandleAIAntiMewtwoDeckStrategy

 	jp nc, .try_attack

 

 	ld a, AI_TRAINER_CARD_PHASE_02

@@ -474,8 +474,8 @@ Func_14b6c: ; 14b6c (5:4b6c)
 

 Func_14b9a: ; 14b9a (5:4b9a)

 	call InitAITurnVars

-	farcall Func_227d3

-	jp nc, .asm_14c01

+	farcall HandleAIAntiMewtwoDeckStrategy

+	jp nc, .try_attack

 	ld a, AI_TRAINER_CARD_PHASE_01

 	call AIProcessHandTrainerCards

 	ld a, AI_TRAINER_CARD_PHASE_04

@@ -522,7 +522,7 @@ Func_14b9a: ; 14b9a (5:4b9a)
 	ret c

 	ld a, AI_TRAINER_CARD_PHASE_13

 	call AIProcessHandTrainerCards

-.asm_14c01

+.try_attack

 	call AIProcessAndTryToUseAttack

 	ret c

 	ld a, OPPACTION_FINISH_NO_ATTACK

@@ -720,8 +720,8 @@ Func_14cf7: ; 14cf7 (5:4cf7)
 	call InitAITurnVars

 	ld a, AI_TRAINER_CARD_PHASE_01

 	call AIProcessHandTrainerCards

-	farcall Func_227d3

-	jp nc, .asm_14d56

+	farcall HandleAIAntiMewtwoDeckStrategy

+	jp nc, .try_attack

 	ld a, AI_TRAINER_CARD_PHASE_02

 	call AIProcessHandTrainerCards

 	call AIDecidePlayPokemonCard

@@ -741,7 +741,7 @@ Func_14cf7: ; 14cf7 (5:4cf7)
 	call AIProcessHandTrainerCards

 	ld a, [wPreviousAIFlags]

 	and AI_FLAG_USED_PROFESSOR_OAK

-	jr z, .asm_14d56

+	jr z, .try_attack

 	ld a, AI_TRAINER_CARD_PHASE_01

 	call AIProcessHandTrainerCards

 	ld a, AI_TRAINER_CARD_PHASE_02

@@ -757,7 +757,7 @@ Func_14cf7: ; 14cf7 (5:4cf7)
 	call AIProcessAndTryToPlayEnergy

 .asm_14d53

 	call AIDecidePlayPokemonCard

-.asm_14d56

+.try_attack

 	call AIProcessAndTryToUseAttack

 	ret c

 	ld a, OPPACTION_FINISH_NO_ATTACK

@@ -883,8 +883,8 @@ Func_14def: ; 14def (5:4def)
 	call InitAITurnVars

 	ld a, AI_TRAINER_CARD_PHASE_01

 	call AIProcessHandTrainerCards

-	farcall Func_227d3

-	jp nc, .asm_14e7f

+	farcall HandleAIAntiMewtwoDeckStrategy

+	jp nc, .try_attack

 	ld a, AI_TRAINER_CARD_PHASE_02

 	call AIProcessHandTrainerCards

 	call AIDecidePlayPokemonCard

@@ -923,7 +923,7 @@ Func_14def: ; 14def (5:4def)
 	call AIProcessHandTrainerCards

 	ld a, [wPreviousAIFlags]

 	and AI_FLAG_USED_PROFESSOR_OAK

-	jr z, .asm_14e7f

+	jr z, .try_attack

 	ld a, AI_TRAINER_CARD_PHASE_01

 	call AIProcessHandTrainerCards

 	ld a, AI_TRAINER_CARD_PHASE_02

@@ -943,7 +943,7 @@ Func_14def: ; 14def (5:4def)
 	call AIProcessAndTryToPlayEnergy

 .asm_14e7c

 	call AIDecidePlayPokemonCard

-.asm_14e7f

+.try_attack

 	call AIProcessAndTryToUseAttack

 	ret c

 	ld a, OPPACTION_FINISH_NO_ATTACK

@@ -2328,7 +2328,7 @@ Func_15507: ; 15507 (5:5507)
 	call LookForCardIDInHandList_Bank5

 	jr nc, .asm_15540

 	ldh [hTemp_ffa0], a

-	ld a, $01

+	ld a, OPPACTION_PLAY_BASIC_PKMN

 	bank1call AIMakeDecision

 .asm_15540

 	call AIDecidePlayPokemonCard

@@ -2351,7 +2351,7 @@ Func_15507: ; 15507 (5:5507)
 	call AIProcessHandTrainerCards

 	ld a, [wPreviousAIFlags]

 	and AI_FLAG_USED_PROFESSOR_OAK

-	jr z, .asm_155c8

+	jr z, .try_attack

 	ld a, AI_TRAINER_CARD_PHASE_01

 	call AIProcessHandTrainerCards

 	ld a, AI_TRAINER_CARD_PHASE_02

@@ -2373,7 +2373,7 @@ Func_15507: ; 15507 (5:5507)
 	call LookForCardIDInHandList_Bank5

 	jr nc, .asm_155a5

 	ldh [hTemp_ffa0], a

-	ld a, $01

+	ld a, OPPACTION_PLAY_BASIC_PKMN

 	bank1call AIMakeDecision

 .asm_155a5

 	call AIDecidePlayPokemonCard

@@ -2392,7 +2392,7 @@ Func_15507: ; 15507 (5:5507)
 .asm_155c4

 	call AIDecidePlayPokemonCard

 	ret c

-.asm_155c8

+.try_attack

 	call AIProcessAndTryToUseAttack

 	ret c

 	ld a, OPPACTION_FINISH_NO_ATTACK

diff --git a/src/wram.asm b/src/wram.asm
index cae7f88..5614b54 100644
--- a/src/wram.asm
+++ b/src/wram.asm
@@ -1192,7 +1192,13 @@ wcda5:: ; cda5
 wAIPokedexCounter:: ; cda6
 	ds $1
 
-wcda7:: ; cda7
+; variable to keep track of Mewtwo1's Barrier usage during Player' turn.
+; AI_FLAG_MEWTWO_MILL set means Player is running Mewtwo1 mill deck.
+; 	- when flag is not set, this counts how many turns in a row
+;	  Player used Mewtwo1's Barrier attack;
+; 	- when flag is set, this counts how many turns in a row
+;	  Player has NOT used Barrier attack.
+wAIBarrierFlagCounter:: ; cda7
 	ds $1
 
 wcda8:: ; cda8