;
; test.p -- test
;

	include 'include.i'
	include	'offsets.i'
	include	'macro.i'

SysBase	equ	4

; point

X	equ	0
Y	equ	2

; window

XL	equ	0
YB	equ	2
XR	equ	4
YT	equ	6

; vars

lastvar	set	0

	var.l IntuitionBase
	var.l GfxBase
	var.l screen
	var.l rp
	var.w line,4
	var.w rndseed

;

start	link	vr,#lastvar		; alloc & clear vars
	move.w	#-lastvar/2,d0
	lea	lastvar(vr),a0
	bra.s	001$
000$	clr.w	(a0)+
001$	dbra	d0,000$

	lea	GfxName(pc),a1		; open graphics
	moveq	#0,d0
	call	SysBase,OpenLibrary
	move.l	d0,GfxBase(vr)
	beq	exit

	lea	IntuitionName(pc),a1	; open intuition
	moveq	#0,d0
	call	OpenLibrary
	move.l	d0,IntuitionBase(vr)
	beq	exit

	move.l	d0,a6			; open screen
	lea	newscr(pc),a0
	call	OpenScreen
	move.l	d0,screen(vr)
	beq	exit
	
	move.l	d0,a0			; get RastPort address
	lea	sc_RastPort(a0),a0
	move.l	a0,rp(vr)

	move.w	#7051,rndseed(vr)	; init rndseed

	lea	wind(pc),a2		; load window ptr

	move.l	GfxBase(vr),a6

	moveq	#1,d0
	move.l	rp(vr),a1
	call	SetAPen
	move.l	#RP_COMPLEMENT,d0
	move.l	rp(vr),a1
	call	SetDrMd

	move.w	#319,d2			; draw 10000 lines

yyy	move.w	d2,line(vr)
	move.w	#0,line+2(vr)
	move.w	#319,line+4(vr)
	sub.w	d2,line+4(vr)
	move.w	#255,line+6(vr)
	lea	line(vr),a0
	lea	line+4(vr),a1
	bsr	clip
	dbra	d2,yyy

	move.w	#255,d2

aaa	move.w	#0,line(vr)
	move.w	d2,line+2(vr)
	move.w	#319,line+4(vr)
	move.w	#255,line+6(vr)
	sub.w	d2,line+6(vr)
	lea	line(vr),a0
	lea	line+4(vr),a1
	bsr	clip
bbb	dbra	d2,aaa


	moveq	#100,d2			; wait 2 seconds
zzz	call	WaitTOF
	dbra	d2,zzz

exit	tst.l	IntuitionBase(vr)	; test intuition
	beq.s	000$
	tst.l	screen(vr)		; test screen
	beq.s	001$
	move.l	screen(vr),a0		; close screen
	call	IntuitionBase(vr),CloseScreen
001$	move.l	IntuitionBase(vr),a1	; close intuition
	call	SysBase,CloseLibrary
000$	tst.l	GfxBase(vr)		; test graphics
	beq.s	002$
	move.l	GfxBase(vr),a1		; close graphics
	call	SysBase,CloseLibrary
	unlk	vr			; restore stack
	moveq	#0,d0			; exit(0)
002$	rts
	
rnd	
	move.w rndseed(vr),d0
	muls.w #31421,d0
	add.w #6927,d0
	move.w d0,rndseed(vr)
	ext.l d0
	divs.w #320,d0
	swap d0
	rts

; code (a0),(a2) -> d0 -- calculate visibility code for clip

code	moveq	#0,d0
	move.w X(a0),d0
	cmp.w XL(a2),d0
	bge if.000
	bset #16,d0
	bra if.001
if.000
	cmp.w XR(a2),d0
	ble if.002
	bset #17,d0
if.002
if.001
	move.w Y(a0),d0
	cmp.w YB(a2),d0
	bge if.003
	bset #18,d0
	bra if.004
if.003
	cmp.w YT(a2),d0
	ble if.005
	bset #19,d0
if.005
if.004
	swap d0
	rts

; clip (a0)-(a1),(a2) ->d0 -- clip line (a0)-(a1) to window (a2), d0=0 if succ

clip	movem.l	d2-d5,-(sp)

	bsr	code
	exg.l	a1,a0
	move.w	d0,d1
	bsr	code
beg.006
	move.w d0,d3
	and.w d1,d3
	bne	exclip
	tst.w d0
	bne if.007
	exg.w a1,a0
	exg.w d1,d0
if.007
	tst.w d0
	beq whl.008
	btst #0,d0
	beq if.009
	move.w Y(a1),d3
	sub.w Y(a0),d3
	move.w XL(a2),d4
	sub.w X(a0),d4
	move.w X(a1),d5
	sub.w X(a0),d5
	muls.w d4,d3
	divs.w d5,d3
	add.w d3,Y(a0)
	move.w XL(a2),X(a0)
	bra if.010
if.009
	btst #1,d0
	beq if.011
	move.w Y(a1),d3
	sub.w Y(a0),d3
	move.w XR(a2),d4
	sub.w X(a0),d4
	move.w X(a1),d5
	sub.w X(a0),d5
	muls.w d4,d3
	divs.w d5,d3
	add.w d3,Y(a0)
	move.w XR(a2),X(a0)
	bra if.012
if.011
	btst #2,d0
	beq if.013
	move.w X(a1),d3
	sub.w X(a0),d3
	move.w YB(a2),d4
	sub.w Y(a0),d4
	move.w Y(a1),d5
	sub.w Y(a0),d5
	muls.w d4,d3
	divs.w d5,d3
	add.w d3,X(a0)
	move.w YB(a2),Y(a0)
	bra if.014
if.013
	btst #3,d0
	beq if.015
	move.w X(a1),d3
	sub.w X(a0),d3
	move.w YT(a2),d4
	sub.w Y(a0),d4
	move.w Y(a1),d5
	sub.w Y(a0),d5
	muls.w d4,d3
	divs.w d5,d3
	add.w d3,X(a0)
	move.w YT(a2),Y(a0)
if.015
if.014
if.012
if.010
	bsr	code
	bra beg.006
whl.008
	move.l	a1,-(sp)		; draw line
	movem.w	(a0),d0-d1
	move.l	rp(vr),a1
	call	Move
	move.l	(sp)+,a0
	movem.w	(a0),d0-d1
	move.l	rp(vr),a1
	call	Draw
exclip	movem.l	(sp)+,d2-d5

	rts

; data

newscr	dc.w	0,0,320,256,		; left top widht height
	dc.w	2,			; depth
	dc.b	0,1,			; detailpen blockpen
	dc.w	0,CUSTOMSCREEN,		; wiewmodes type
	dc.l	font,			; font
	dc.l	title,			; title
	dc.l	0,0			; gadgets custombitmap

font	dc.l	fontnam,
	dc.w	TOPAZ_EIGHTY,
	dc.b	FS_NORMAL,FPF_ROMFONT

wind	dc.w	50,50,270,205

IntuitionName
	dc.b	'intuition.library',0
GfxName	dc.b	'graphics.library',0

title	dc.b	'Test screen',0
fontnam	dc.b	'topaz.font',0

	ds.w	0

	end