**************************************
*				     *
*  Tile Search Routine. For TOME     *
*  Checks in area x1,y1-x2,y2 for    *
*  1st Occurence of Tile             *
*  returns with Dreg(0)=-1 if not    *
*  Found, Dreg(0)=X+Y*xsize if found *
**************************************
* Enter with D0=x1,d1=y1,d2=x2,d3=y2,d4=Tile,a0=address of map
xsize	equ	0
ysize	equ	2
x1	equ	4
y1	equ	6
x2	equ	8
y2	equ	10
tile	equ	12

	lea	darta(pc),a6
	move.w	0(a0),xsize(a6)
	move.w	2(a0),ysize(a6)
	move.w	d0,x1(a6)
	move.w	d1,y1(a6)
	move.w	d2,x2(a6)
	move.w	d3,y2(a6)
	move.b	d4,tile(a6)
	add.l	#4,a0
yloop	move.w	x1(a6),d0
	move.w	xsize(a6),d2
	move.w	d1,d3
	mulu	d2,d3
	move.l	a0,a1
	add.l	d3,a1
	move.b	tile(a6),d3
xloop	move.b	0(a1,d0),d2
	cmp.b	d2,d3
	beq	gottit
	addq.w	#1,d0
	move.w	x2(a6),d2
	cmp.w	d0,d2
	bne	xloop
	addq.w	#1,d1
	move.w	y2(a6),d2
	cmp.w	d1,d2
	bne	yloop
	move.w	#-1,d0
	rts
gottit	move.w	xsize(a6),d2
	mulu.w	d1,d2
	add.w	d2,d0
	rts

darta	ds.w	8