Add subdirectories to engine/ similar to pokecrystal

engine/overworld/dust_smoke.asm

@@ -0,0 +1,93 @@
+AnimateBoulderDust:
+	ld a, $1
+	ld [wWhichAnimationOffsets], a ; select the boulder dust offsets
+	ld a, [wUpdateSpritesEnabled]
+	push af
+	ld a, $ff
+	ld [wUpdateSpritesEnabled], a
+	ld a, %11100100
+	ld [rOBP1], a
+	call LoadSmokeTileFourTimes
+	callba WriteCutOrBoulderDustAnimationOAMBlock
+	ld c, 8 ; number of steps in animation
+.loop
+	push bc
+	call GetMoveBoulderDustFunctionPointer
+	ld bc, .returnAddress
+	push bc
+	ld c, 4
+	jp hl
+.returnAddress
+	ld a, [rOBP1]
+	xor %01100100
+	ld [rOBP1], a
+	call Delay3
+	pop bc
+	dec c
+	jr nz, .loop
+	pop af
+	ld [wUpdateSpritesEnabled], a
+	jp LoadPlayerSpriteGraphics
+
+GetMoveBoulderDustFunctionPointer:
+	ld a, [wSpriteStateData1 + 9] ; player's sprite facing direction
+	ld hl, MoveBoulderDustFunctionPointerTable
+	ld c, a
+	ld b, $0
+	add hl, bc
+	ld a, [hli]
+	ld [wCoordAdjustmentAmount], a
+	ld a, [hli]
+	ld e, a
+	ld a, [hli]
+	ld h, [hl]
+	ld l, a
+	push hl
+	ld hl, wOAMBuffer + $90
+	ld d, $0
+	add hl, de
+	ld e, l
+	ld d, h
+	pop hl
+	ret
+
+MoveBoulderDustFunctionPointerTable:
+; facing down
+	db $FF,$00
+	dw AdjustOAMBlockYPos
+
+; facing up
+	db $01,$00
+	dw AdjustOAMBlockYPos
+
+; facing left
+	db $01,$01
+	dw AdjustOAMBlockXPos
+
+; facing right
+	db $FF,$01
+	dw AdjustOAMBlockXPos
+
+LoadSmokeTileFourTimes::
+	ld hl, vChars1 + $7c0
+	ld c, $4
+.loop
+	push bc
+	push hl
+	call LoadSmokeTile
+	pop hl
+	ld bc, $10
+	add hl, bc
+	pop bc
+	dec c
+	jr nz, .loop
+	ret
+
+LoadSmokeTile:
+	ld de, SSAnneSmokePuffTile
+	lb bc, BANK(SSAnneSmokePuffTile), (SSAnneSmokePuffTileEnd - SSAnneSmokePuffTile) / $10
+	jp CopyVideoData
+
+SSAnneSmokePuffTile:
+	INCBIN "gfx/overworld/smoke.2bpp"
+SSAnneSmokePuffTileEnd: