Pull a lot of engine out of main.asm

engine/overworld/elevator.asm

@@ -0,0 +1,69 @@
+ShakeElevator: ; 7bf15 (1e:7f15)
+	ld de, $ffe0
+	call Func_7bf64
+	ld de, $240
+	call Func_7bf64
+	call Delay3
+	ld a, $ff
+	call PlaySound
+	ld a, [$ffaf]
+	ld d, a
+	ld e, $1
+	; number of times to play collision sfx
+	ld b, $64
+.asm_7bf30
+	ld a, e
+	xor $fe
+	ld e, a
+	add d
+	ld [$ffaf], a
+	push bc
+	ld c, BANK(SFX_02_5b)
+	ld a, (SFX_02_5b - SFX_Headers_02) / 3
+	call PlayMusic
+	pop bc
+	ld c, $2
+	call DelayFrames
+	dec b
+	jr nz, .asm_7bf30
+	ld a, d
+	ld [$ffaf], a
+	ld a, $ff
+	call PlaySound
+	ld c, BANK(SFX_02_5f)
+	ld a, (SFX_02_5f - SFX_Headers_02) / 3
+	call PlayMusic
+.asm_7bf57
+	ld a, [$c02a]
+	cp $b9
+	jr z, .asm_7bf57
+	call UpdateSprites
+	jp Func_2307
+
+Func_7bf64: ; 7bf64 (1e:7f64)
+	ld hl, $d527
+	ld a, [hld]
+	push af
+	ld a, [hl]
+	push af
+	push hl
+	push hl
+	ld a, [hli]
+	ld h, [hl]
+	ld l, a
+	add hl, de
+	ld a, h
+	and $3
+	or $98
+	ld d, a
+	ld a, l
+	pop hl
+	ld [hli], a
+	ld [hl], d
+	call ScheduleNorthRowRedraw
+	pop hl
+	pop af
+	ld [hli], a
+	pop af
+	ld [hl], a
+	jp Delay3