INCDIR	Include:
INCLUDE hardware/dmabits.i
INCLUDE hardware/custom.i
INCDIR	ASM:Source/Own/KampSpil/
INCLUDE	gfx.i

Section	gfx_code, code
displaybuf:
	; a0 : ptr to screenbuffer
	movem.l	A0-A6/D0-D7, -(SP)

	LEA.l	cop_planes, A1

	move.l	#4, D1
	db_l1:
		move.l	A0, D0
		move.w	D0, 6(a1)
		swap	D0
		move.w	d0, 2(a1)
		add.l	#8, A1
		add.l	#10240, A0
	dbra	D1, db_l1

	movem.l	(SP)+, A0-A6/D0-D7
rts

display_visual:
	move.l	A0, -(SP)
	move.l	visual, A0
	jsr		displaybuf
	move.l	(SP)+, A0
rts

clearmem:
	; a0 : ptr to mem
	; D0 : size in bytes
	movem.l	A0-A6/D0-D7, -(SP)

	lsr.l	#2, D0
	sub.l	#1, D0
	cm_l1:
		move.l	#0, (A0)+
	dbra	D0, cm_l1

	movem.l	(SP)+, A0-A6/D0-D7
rts

copymem:
	; a0 : ptr to source
	; a1 : ptr to dest
	; D0 : size in bytes
	movem.l	A0-A6/D0-D7, -(SP)

	lsr.l	#2, D0	; d0 = d0/4
	sub.l	#1, D0
	cm2_l1:
		move.l	(A0)+, (A1)+
	dbra	D0, cm2_l1

	movem.l	(SP)+, A0-A6/D0-D7
rts


putobj:
	; a0 : ptr to object
	; a1 : ptr to screenbuffer
	; a2 : ptr to objectmask
	; d0 : width of obj in pixels
	; d1 : height of obj in pixels
	; d2 : xpos to put obj at
	; d3 : ypos to put obj at

	jsr	waitblit

	movem.l	A0-A6/D0-D7, -(SP)

;	;a0=sourceA, a1=sourceB, a2=mask, a3=dest

	;calculate shift
	move.w	D2, D5
	and.w	#%0000000000001111, D5
	ror.w	#4, D5
	; move x and y
	lsr.l	#3, d2	; d2=d2/16
	add.l	D2, A1
	mulu.w	#40, D3
	add.l	D3, A1
	move.l	A1, A3

	move.w	#($200!$100!$800!$400!%11100010),D4	;function etc.
	or.w	D5, D4	; shift

	move.w	#4,D7	;5 bitplanes
	putobj_l1:
		bsr	waitblit
		move.l	custom,A4
		move.l	A0,bltApt(A4)
		move.l	A2,bltBpt(a4)
		move.l	A1,bltCpt(A4)
		move.l	A3,bltDpt(a4)			;destpic1
		move.w	#0,BLTaMOD(A4)
		move.w	#0,BLTbMOD(A4)
		move.w	#(320-80)/8,BLTcMOD(A4)
		move.w	#(320-80)/8,BLTdMOD(A4)
		move.w	d4,BltCon0(a4)
		move.w	d5,bltcon1(a4)
		move.w	#%0010000000000101,BLTSIZE(A4)	;128 lines 5 words
		add.l	#1280,A0
		add.l	#10240,A1
		add.l	#10240,A3
	dbra	d7,putobj_l1


	movem.l	(SP)+, A0-A6/D0-D7
rts


waitblit:
	movem.l	A0,-(SP)
	move.l	custom,A0
	btst.b	#DMAB_BLTDONE-8,DMACONR(A0)
waitblit2:
	btst.b	#DMAB_BLTDONE-8,DMACONR(A0)
	bne waitblit2
	movem.l	(SP)+,A0
rts


wait_for_rast:
	cmp.b	#$ff,$DFF006	;Wait for rasterbeam
	bne		wait_for_rast
rts


swapscreens:
	move.l	A0, -(SP)

	move.l	active, A0
	move.l	visual, active
	move.l	A0, visual
	jsr		wait_for_rast
	jsr		display_visual

	move.l	(SP)+, A0
rts

custom:dc.l	$DFF000
active:	dc.l	0	; active and visual screenbuffer (ptr to)
visual:	dc.l	0
.