1 files changed, 162 insertions, 0 deletions
diff --git a/event/poisonstep.asm b/event/poisonstep.asm
new file mode 100755
index 000000000..1fafd63a5
--- /dev/null
+++ b/event/poisonstep.asm
@@ -0,0 +1,162 @@
+DoPoisonStep:: ; 505da
+	ld a, [PartyCount]
+	and a
+	jr z, .no_faint
+
+	xor a
+	ld c, 7
+	ld hl, EngineBuffer1
+.loop_clearEngineBuffer1
+	ld [hli], a
+	dec c
+	jr nz, .loop_clearEngineBuffer1
+
+	xor a
+	ld [CurPartyMon], a
+.loop_check_poison
+	call .DamageMonIfPoisoned
+	jr nc, .not_poisoned
+; the output flag is stored in c, copy it to the ([CurPartyMon] + 2)nd EngineBuffer
+; and set the corresponding flag in EngineBuffer1
+	ld a, [CurPartyMon]
+	ld e, a
+	ld d, 0
+	ld hl, EngineBuffer2
+	add hl, de
+	ld [hl], c
+	ld a, [EngineBuffer1]
+	or c
+	ld [EngineBuffer1], a
+
+.not_poisoned
+	ld a, [PartyCount]
+	ld hl, CurPartyMon
+	inc [hl]
+	cp [hl]
+	jr nz, .loop_check_poison
+
+	ld a, [EngineBuffer1]
+	and %10
+	jr nz, .someone_has_fainted
+	ld a, [EngineBuffer1]
+	and %01
+	jr z, .no_faint
+	call .PlayPoisonSFX
+	xor a
+	ret
+
+.someone_has_fainted
+	ld a, BANK(.Script_MonFaintedToPoison)
+	ld hl, .Script_MonFaintedToPoison
+	call CallScript
+	scf
+	ret
+
+.no_faint
+	xor a
+	ret
+; 5062e
+
+.DamageMonIfPoisoned: ; 5062e
+; check if mon is poisoned, return if not
+	ld a, MON_STATUS
+	call GetPartyParamLocation
+	ld a, [hl]
+	and 1 << PSN
+	ret z
+
+; check if mon is already fainted, return if so
+	ld a, MON_HP
+	call GetPartyParamLocation
+	ld a, [hli]
+	ld b, a
+	ld c, [hl]
+	or c
+	ret z
+
+; do 1 HP damage
+	dec bc
+	ld [hl], c
+	dec hl
+	ld [hl], b
+
+; check if mon has fainted as a result of poison damage
+	ld a, b
+	or c
+	jr nz, .not_fainted
+
+; the mon has fainted, reset its status, set carry, and return %10
+	ld a, MON_STATUS
+	call GetPartyParamLocation
+	ld [hl], 0
+	ld c, %10
+	scf
+	ret
+
+.not_fainted
+; set carry and return %01
+	ld c, %01
+	scf
+	ret
+; 50658
+
+.PlayPoisonSFX: ; 50658
+	ld de, SFX_POISON
+	call PlaySFX
+	ld b, $2
+	predef Functioncbcdd
+	call DelayFrame
+	ret
+; 50669
+
+.Script_MonFaintedToPoison: ; 50669
+	callasm .PlayPoisonSFX
+	loadfont
+	callasm .CheckWhitedOut
+	iffalse .whiteout
+	loadmovesprites
+	end
+; 50677
+
+.whiteout: ; 50677
+	farjump Script_OverworldWhiteout
+; 5067b
+
+.CheckWhitedOut: ; 5067b
+	xor a
+	ld [CurPartyMon], a
+	ld de, EngineBuffer2
+.party_loop
+	push de
+	ld a, [de]
+	and %10
+	jr z, .mon_not_fainted
+	ld c, HAPPINESS_POISONFAINT
+	callba ChangeHappiness
+	callba GetPartyNick
+	ld hl, .PoisonFaintText
+	call PrintText
+
+.mon_not_fainted
+	pop de
+	inc de
+	ld hl, CurPartyMon
+	inc [hl]
+	ld a, [PartyCount]
+	cp [hl]
+	jr nz, .party_loop
+	predef CheckPlayerPartyForFitPkmn
+	ld a, d
+	ld [ScriptVar], a
+	ret
+; 506b2
+
+.PoisonFaintText: ; 506b2
+	text_jump UnknownText_0x1c0acc
+	db "@"
+; 506b7
+
+.PoisonWhiteOutText: ; 506b7
+	text_jump UnknownText_0x1c0ada
+	db "@"
+; 506bc