Add subdirectories to engine/ similar to pokecrystal

engine/overworld/tilesets.asm

@@ -0,0 +1,60 @@
+LoadTilesetHeader:
+	call GetPredefRegisters
+	push hl
+	ld d, 0
+	ld a, [wCurMapTileset]
+	add a
+	add a
+	ld b, a
+	add a
+	add b ; a = tileset * 12
+	jr nc, .noCarry
+	inc d
+.noCarry
+	ld e, a
+	ld hl, Tilesets
+	add hl, de
+	ld de, wTilesetBank
+	ld c, $b
+.copyTilesetHeaderLoop
+	ld a, [hli]
+	ld [de], a
+	inc de
+	dec c
+	jr nz, .copyTilesetHeaderLoop
+	ld a, [hl]
+	ld [hTilesetType], a
+	xor a
+	ld [$ffd8], a
+	pop hl
+	ld a, [wCurMapTileset]
+	push hl
+	push de
+	ld hl, DungeonTilesets
+	ld de, $1
+	call IsInArray
+	pop de
+	pop hl
+	jr c, .asm_c797
+	ld a, [wCurMapTileset]
+	ld b, a
+	ld a, [hPreviousTileset]
+	cp b
+	jr z, .done
+.asm_c797
+	ld a, [wDestinationWarpID]
+	cp $ff
+	jr z, .done
+	call LoadDestinationWarpPosition
+	ld a, [wYCoord]
+	and $1
+	ld [wYBlockCoord], a
+	ld a, [wXCoord]
+	and $1
+	ld [wXBlockCoord], a
+.done
+	ret
+
+INCLUDE "data/dungeon_tilesets.asm"
+
+INCLUDE "data/tileset_headers.asm"