rework loading Pikachu's unique moves in Yellow Forest

- gives Pikachu Surf via form check rather than special case player state check
- allows unique move macro to take form as parameter
- fixes bug where Surf or Fly Pikachu could only be male

data/pokemon/unique_wild_moves.asm

@@ -1,7 +1,12 @@
 MACRO unique_moves
 	db \1 ; landmark
-	dp \2 ; species
-	db \3 ; move
+	if _NARG == 4
+		dp \2, \3 ; species, form
+		db \4 ; move
+	else
+		dp \2 ; species
+		db \3 ; move
+	endc
 ENDM
 
 ; TODO: finish unique moves
@@ -30,7 +35,6 @@ UniqueWildMoves:
 	unique_moves BURNED_TOWER,     0,          0
 	unique_moves WHIRL_ISLANDS,    0,          0
 	unique_moves CLIFF_CAVE,       0,          0
-	unique_moves YELLOW_FOREST,    PIKACHU,    FLY          ; replaced with Surf if Surfing
 	unique_moves QUIET_CAVE,       MUNCHLAX,   GIGA_IMPACT  ; Snorlax move
 	unique_moves MT_MORTAR,        0,          0
 	unique_moves LAKE_OF_RAGE,     MAGIKARP,   HYDRO_PUMP   ; Pokéwalker move
@@ -82,4 +86,6 @@ UniqueWildMoves:
 	unique_moves ROUTE_23,         GYARADOS,   POWER_WHIP   ; Sw/Sh TR move
 	unique_moves ROUTE_44,         AIPOM,      ROCK_BLAST   ; new move
 	unique_moves ROUTE_49,         PARASECT,   CONFUSE_RAY  ; Prism tutor move
+	unique_moves YELLOW_FOREST,    PIKACHU,    PLAIN_FORM,        FLY  ; Yellow special move, assumed only Pikachu can learn Fly
+	unique_moves YELLOW_FOREST,    PIKACHU,    PIKACHU_SURF_FORM, SURF ; Yellow special move, assumed only Pikachu can learn Surf
 	db -1

data/wild/johto_water.asm

@@ -353,7 +353,7 @@
 	def_water_wildmons YELLOW_FOREST
 	db 6 percent ; encounter rate
 	wildmon LEVEL_FROM_BADGES - 4, MARILL
-	wildmon LEVEL_FROM_BADGES - 4, PIKACHU
+	wildmon LEVEL_FROM_BADGES - 4, PIKACHU, PIKACHU_SURF_FORM
 	wildmon LEVEL_FROM_BADGES - 4, PSYDUCK
 	end_water_wildmons
 

engine/battle/unique_wild_moves.asm

@@ -21,13 +21,12 @@ CheckUniqueWildMove:
 	; If form isn't specified in the unique wildmove list, any form will do.
 	ld a, [hli] ; form
 	ld b, a
-	and FORM_MASK
-	jr nz, .specific_form
+	and a, FORM_MASK
 	ld a, [wCurForm]
+	jr nz, .specific_form
 	and EXTSPECIES_MASK
 	jr .compare_form
 .specific_form
-	ld a, [wCurForm]
 	and SPECIESFORM_MASK
 .compare_form
 	cp b
@@ -45,19 +44,10 @@ CheckUniqueWildMove:
 	jr z, .TeachMove ; assume this is for Explosion in TeamRocketBaseB1F
 	cp UNION_CAVE
 	jr z, .TeachMove ; assume this is a Lapras in UnionCaveB2F
-	cp YELLOW_FOREST
-	jr nz, .ChanceToTeach
-	; assume this is a Pikachu in YellowForest; Surf (always teach) or Fly?
-	ld a, [wPlayerState]
-	cp PLAYER_SURF
-	jr z, .SurfingPikachu
-	cp PLAYER_SURF_PIKA
-	jr nz, .ChanceToTeach
-.SurfingPikachu
-	ld a, SURF
-	ld b, a
-	jr .TeachMove
-.ChanceToTeach
+	ld a, b
+	cp SURF
+	jr z, .TeachMove ; assume only Pikachu can learn Surf
+
 	call Random
 	add a
 	ret nc
@@ -79,11 +69,8 @@ CheckUniqueWildMove:
 	ld a, b
 	ld [hl], a
 
-	; assume only Pikachu can learn Surf or Fly
-	cp SURF
-	jr z, .UseSurfingPikachu
+	; assume only Pikachu can learn Fly
 	cp FLY
-	ld a, PIKACHU_FLY_FORM
 	jr z, .UseFlyingPikachu
 	ret
 
@@ -95,11 +82,9 @@ CheckUniqueWildMove:
 	inc hl
 	jr .loop
 
-.UseSurfingPikachu
-	ld a, PIKACHU_SURF_FORM
 .UseFlyingPikachu
-	ld b, a
-	ld a, [wCurForm]
+	ld b, PIKACHU_FLY_FORM
+	ld a, [wOTPartyMon1Form]
 	and ~FORM_MASK
 	or b
 	ld [wCurForm], a