1 files changed, 193 insertions, 0 deletions
diff --git a/audio/engine_4.asm b/audio/engine_4.asm
new file mode 100644
index 00000000..f152ff80
--- /dev/null
+++ b/audio/engine_4.asm
@@ -0,0 +1,193 @@
+Audio4_PlaySound::
+; Duplicate of Audio3_PlaySound
+	ld [wSoundID], a
+	ld a, [wSoundID]
+	cp $ff
+	jp z, Audio4_7d18e
+	cp $98
+	jp z, Audio4_7d12d
+	jp c, Audio4_7d12d
+	cp $a3
+	jr z, .asm_7d127
+	jp nc, Audio4_7d12d
+
+.asm_7d127
+	call InitMusicVariables
+	jp Audio4_7d192
+
+Audio4_7d12d:
+	ld l, a
+	ld e, a
+	ld h, $0
+	ld d, h
+	add hl, hl
+	add hl, de
+	ld de, SFX_Headers_4
+	add hl, de
+	ld a, h
+	ld [wSfxHeaderPointer], a
+	ld a, l
+	ld [wSfxHeaderPointer + 1], a
+	ld a, [hl]
+	and $c0
+	rlca
+	rlca
+	ld c, a
+.asm_7d146
+	ld d, c
+	ld a, c
+	add a
+	add c
+	ld c, a
+	ld b, $0
+	ld a, [wSfxHeaderPointer]
+	ld h, a
+	ld a, [wSfxHeaderPointer + 1]
+	ld l, a
+	add hl, bc
+	ld c, d
+	ld a, [hl]
+	and $f
+	ld e, a
+	ld d, $0
+	ld hl, wChannelSoundIDs
+	add hl, de
+	ld a, [hl]
+	and a
+	jr z, .asm_7d182
+	ld a, e
+	cp $7
+	jr nz, .asm_7d179
+	ld a, [wSoundID]
+	cp $14
+	jr nc, .asm_7d172
+	ret
+
+.asm_7d172
+	ld a, [hl]
+	cp $14
+	jr z, .asm_7d182
+	jr c, .asm_7d182
+.asm_7d179
+	ld a, [wSoundID]
+	cp [hl]
+	jr z, .asm_7d182
+	jr c, .asm_7d182
+	ret
+
+.asm_7d182
+	call InitSFXVariables
+	ld a, c
+	and a
+	jp z, Audio4_7d192
+	dec c
+	jp .asm_7d146
+
+Audio4_7d18e:
+	call StopAllAudio
+	ret
+
+Audio4_7d192:
+	ld a, [wSoundID]
+	ld l, a
+	ld e, a
+	ld h, $0
+	ld d, h
+	add hl, hl
+	add hl, de
+	ld de, SFX_Headers_4
+	add hl, de
+	ld e, l
+	ld d, h
+	ld hl, wChannelCommandPointers
+	ld a, [de] ; get channel number
+	ld b, a
+	rlca
+	rlca
+	and $3
+	ld c, a
+	ld a, b
+	and $f
+	ld b, c
+	inc b
+	inc de
+	ld c, $0
+.asm_7d1b4
+	cp c
+	jr z, .asm_7d1bc
+	inc c
+	inc hl
+	inc hl
+	jr .asm_7d1b4
+.asm_7d1bc
+	push af
+	push hl
+	push bc
+	ld b, $0
+	ld c, a
+	cp $3
+	jr c, .asm_7d1cc
+	ld hl, wChannelFlags1
+	add hl, bc
+	set 2, [hl]
+.asm_7d1cc
+	pop bc
+	pop hl
+	ld a, [de] ; get channel pointer
+	ld [hli], a
+	inc de
+	ld a, [de]
+	ld [hli], a
+	inc de
+	pop af
+	push hl
+	push bc
+	ld b, $0
+	ld c, a
+	ld hl, wChannelSoundIDs
+	add hl, bc
+	ld a, [wSoundID]
+	ld [hl], a
+	pop bc
+	pop hl
+	inc c
+	dec b
+	ld a, b
+	and a
+	ld a, [de]
+	inc de
+	jr nz, .asm_7d1b4
+	ld a, [wSoundID]
+	cp $14
+	jr nc, .asm_7d1f5
+	jr .asm_7d21f
+
+.asm_7d1f5
+	ld a, [wSoundID]
+	cp $86
+	jr z, .asm_7d21f
+	jr c, .asm_7d200
+	jr .asm_7d21f
+.asm_7d200
+	ld hl, wChannelSoundIDs + CH4
+	ld [hli], a
+	ld [hli], a
+	ld [hli], a
+	ld [hl], a
+	ld hl, wChannelCommandPointers + CH6 * 2 ; sfx noise channel pointer
+	ld de, Noise4_endchannel
+	ld [hl], e
+	inc hl
+	ld [hl], d ; overwrite pointer to point to endchannel
+	ld a, [wSavedVolume]
+	and a
+	jr nz, .asm_7d21f
+	ld a, [rNR50]
+	ld [wSavedVolume], a
+	ld a, $77
+	ld [rNR50], a
+.asm_7d21f
+	ret
+
+Noise4_endchannel:
+	endchannel