;POBS DEMO
;---------
;This demo originally came from the HowToCode series.
;
;This demo took just 15 minutes in being converted to a multi-tasking demo,
;without any speed loss in run-time.

	opt	o+,c+

	INCLUDE	"exec/exec_lib.i"
	INCLUDE	"games/games_lib.i"
	INCLUDE	"games/games.i"

CALL	MACRO
	jsr	_LVO\1(a6)
	ENDM

width	EQU	40
height	EQU	256

	SECTION	"Pobs",CODE

;==========================================================================;
;                             INITIALISE DEMO
;==========================================================================;

Start:	MOVEM.L	A0-A6/D1-D7,-(SP)
	move.l	($4).w,a6
	lea	GMS_Name(pc),a1
	moveq	#$00,d0
	CALL	OpenLibrary
	move.l	d0,GMS_Base
	beq.s	.Error_GMS

	move.l	GMS_Base(pc),a6
	sub.l	a0,a0
	CALL	SetUserPrefs

	lea	Screen(pc),a0
	CALL	Add_Screen
	tst.l	d0
	bne.s	.Error_Screen

	CALL	Show_Screen

	bsr.s	Main

.ReturnToDOS
	move.l	GMS_Base(pc),a6
	lea	Screen(pc),a0
	CALL	Delete_Screen
.Error_Screen
	move.l	GMS_Base(pc),a1
	move.l	($4).w,a6
	CALL	CloseLibrary
.Error_GMS
	MOVEM.L	(SP)+,A0-A6/D1-D7
	moveq	#$00,d0
	rts

;==========================================================================;
;                                MAIN LOOP
;==========================================================================;

Main:	bsr.w	InPtabs
	bsr.w	Rmasks

.loop	move.l	GMS_Base(pc),a6
	CALL	Wait_OSVBL
	lea	Screen(pc),a0
	CALL	SwapBuffers

	moveq	#BUFFER3,d0
	CALL	ClrScreen

	bsr.w	Calc
	bsr.w	Put

	cmp.w	#293-1,number
	beq.b	.mouse
	addq.w	#1,number

.mouse	move.l	GMS_Base(pc),a6
	moveq	#JPORT1,d0
	CALL	Read_Mouse
	btst	#MB_LMB,d0
	beq.s	.loop
	rts

;===========================================================================;
;                            SET UP POB TABLES
;===========================================================================;

InPtabs	lea	pob_xbuffer,a0	;a0 = Ptr to XBuffer.
	moveq	#$00,d0	;d0 = 00.
.xloop	move.w	d0,d1
	and.w	#$000f,d1	;d1 = $000x
	lsl.w	#6,d1	;d1 = <<6
	move.w	d1,(a0)+	;a0 = +d1
	move.w	d0,d1
	and.w	#$fff0,d1	;d2 = $xxx0
	ror.w	#3,d1	;d2 = $?xxx
	move.w	d1,(a0)+	;a0 = +d2
	addq.w	#1,d0	;d0 = ++1
	cmp.w	#width*8,d0	;d0 > Is d0 == ScreenWidth?
	bne.b	.xloop

	lea	pob_ybuffer,a0
	moveq	#$00,d0
.yloop	move.w	d0,d1
	mulu	#width,d1
	move.l	d1,(a0)+
	addq.w	#1,d0
	cmp.w	#height,d0
	bne.b	.yloop
	rts

;===========================================================================;
;
;===========================================================================;

Rmasks:	moveq	#0,d7
	lea	shape_buffer,a1
.loop1	lea	pob_shape(pc),a0
	move.w	#16,d6
.loop2	move.l	(a0)+,d0
	ror.l	d7,d0
	move.l	d0,(a1)+
	subq.w	#1,d6
	bne.b	.loop2
	addq.w	#1,d7
	cmpi.w	#16,d7
	bne.b	.loop1
	rts

;===========================================================================;
;                       ADJUST POB SCREEN POSITIONS
;===========================================================================;

Calc:	move.w	#$eeee,d0
	move.w	#720,d6
	lea	sinx_pointer1(pc),a0

	movem.l	(a0),a2/a3/a4/a5
	movem.w	sinx_add1(pc),d2/d3/d4/d5

	adda.w	d2,a2
	cmp.w	(a2),d0
	bne.b	.bkip1
	suba.w	d6,a2

.bkip1:	adda.w	d3,a3
	cmp.w	(a3),d0
	bne.b	.bkip2
	suba.w	d6,a3

.bkip2:	adda.w	d4,a4
	cmp.w	(a4),d0
	bne.b	.bkip3
	suba.w	d6,a4

.bkip3:	adda.w	d5,a5
	cmp.w	(a5),d0
	bne.b	.bkip4
	suba.w	d6,a5

.bkip4:	movem.l	a2/a3/a4/a5,(a0)
	lea	coord_stack,a0
	movem.w	sinx_dist1(pc),d3-d4/a1/a6
	move.w	d0,d5
	move.w	number(pc),d7	;d7 = Number of Pobs.
.loop	add.w	d3,a2
	add.w	d4,a3
	cmp.w	(a2),d5
	bne.b	.not_x1
	suba.w	d6,a2
.not_x1	cmp.w	(a3),d5
	bne.b	.not_x2
	suba.w	d6,a3
.not_x2	move.w	(a2),d0
	add.w	(a3),d0
	add.w	a1,a4
	add.w	a6,a5
	cmp.w	(a4),d5
	bne.b	.not_y1
	suba.w	d6,a4
.not_y1	cmp.w	(a5),d5
	bne.b	.not_y2
	suba.w	d6,a5
.not_y2	move.w	(a4),d1
	add.w	(a5),d1
	move.w	d0,(a0)+
	move.w	d1,(a0)+
	dbf	d7,.loop
	rts

;===========================================================================;
;                          PLACE POBS ON SCREEN
;===========================================================================;

Put:	lea	pob_xbuffer,a0
	lea	pob_ybuffer,a1
	lea	shape_buffer,a4
	move.l	Active(pc),a6
	lea	coord_stack,a5

	move.w	number(pc),d7
.loop	movem.w	(a5)+,d0/d1	;d0 = X, d1 = Y
	lsl.w	#2,d0	;d0 = (XCoord)*4 [long]
	lsl.w	#2,d1	;d0 = (YCoord)*4 [long]
	move.l	(a0,d0.w),d0
	lea	width(a6,d0.w),a3
	add.l	(a1,d1.w),a3
	swap	d0
	lea	(a4,d0.w),a2
	movem.l	(a2),d0-d5		;d0..d5 = POB Gfx Data. 
	or.l	d0,(a3)
	or.l	d1,width(a3)
	or.l	d2,width*2(a3)
	or.l	d3,width*3(a3)
	or.l	d4,width*4(a3)
	or.l	d5,width*5(a3)
	dbf	d7,.loop
	rts

;===========================================================================;
;
;===========================================================================;

sinx_pointer1:
	dc.l	sin_xtab
sinx_pointer2:
	dc.l	sin_xtab
siny_pointer1:
	dc.l	sin_ytab
siny_pointer2:
	dc.l	sin_ytab
sinx_add1:
	dc.w	1*2	;change values here to obtain
sinx_add2:
	dc.w	5*2	;new patterns
siny_add1:
	dc.w	3*2
siny_add2:
	dc.w	2*2
sinx_dist1:
	dc.w	4*2
sinx_dist2:
	dc.w	3*2
siny_dist1:
	dc.w	1*2
siny_dist2:
	dc.w	2*2
number:	dc.w	0			;number of 'pobs'

sin_xtab:
	dc.w	75,76,78,79,80,82,83,84
	dc.w	85,87,88,89,91,92,93,94
	dc.w	96,97,98,99,101,102,103,104
	dc.w	106,107,108,109,110,111,112,114
	dc.w	115,116,117,118,119,120,121,122
	dc.w	123,124,125,126,127,128,129,130
	dc.w	131,132,132,133,134,135,136,136
	dc.w	137,138,139,139,140,141,141,142
	dc.w	142,143,144,144,145,145,145,146
	dc.w	146,147,147,147,148,148,148,149
	dc.w	149,149,149,149,150,150,150,150
	dc.w	150,150,150,150,150,150,150,150
	dc.w	150,149,149,149,149,149,148,148
	dc.w	148,147,147,147,146,146,145,145
	dc.w	145,144,144,143,142,142,141,141
	dc.w	140,139,139,138,137,136,136,135
	dc.w	134,133,132,132,131,130,129,128
	dc.w	127,126,125,124,123,122,121,120
	dc.w	119,118,117,116,115,114,113,111
	dc.w	110,109,108,107,106,104,103,102
	dc.w	101,99,98,97,96,94,93,92
	dc.w	91,89,88,87,85,84,83,82
	dc.w	80,79,78,76,75,74,72,71
	dc.w	70,68,67,66,65,63,62,61
	dc.w	59,58,57,56,54,53,52,51
	dc.w	49,48,47,46,44,43,42,41
	dc.w	40,39,38,36,35,34,33,32
	dc.w	31,30,29,28,27,26,25,24
	dc.w	23,22,21,20,19,18,18,17
	dc.w	16,15,14,14,13,12,11,11
	dc.w	10,9,9,8,8,7,6,6
	dc.w	5,5,5,4,4,3,3,3
	dc.w	2,2,2,1,1,1,1,1
	dc.w	0,0,0,0,0,0,0,0
	dc.w	0,0,0,0,0,1,1,1
	dc.w	1,1,2,2,2,3,3,3
	dc.w	4,4,5,5,5,6,6,7
	dc.w	8,8,9,9,10,11,11,12
	dc.w	13,14,14,15,16,17,18,18
	dc.w	19,20,21,22,23,24,25,26
	dc.w	27,28,29,30,31,32,33,34
	dc.w	35,36,37,39,40,41,42,43
	dc.w	44,46,47,48,49,51,52,53
	dc.w	54,56,57,58,59,61,62,63
	dc.w	65,66,67,68,70,71,72,74
	dc.w	75
	dc.w	$eeee,$eeee,$eeee,$eeee
	dc.w	$eeee,$eeee,$eeee,$eeee
	dc.w	$eeee,$eeee,$eeee,$eeee
	dc.w	$eeee,$eeee,$eeee,$eeee
	dc.w	$eeee,$eeee,$eeee,$eeee
	dc.w	$eeee,$eeee,$eeee,$eeee
	dc.w	$eeee,$eeee,$eeee,$eeee
	dc.w	$eeee,$eeee,$eeee,$eeee
	dc.w	$eeee,$eeee,$eeee,$eeee
	dc.w	$eeee,$eeee,$eeee,$eeee

sin_ytab:
	dc.w	57,59,60,61,62,63,64,65
	dc.w	66,66,67,68,69,70,71,72
	dc.w	73,74,75,76,77,78,79,80
	dc.w	81,82,83,84,84,85,86,87
	dc.w	88,89,90,90,91,92,93,94
	dc.w	94,95,96,97,97,98,99,100
	dc.w	100,101,102,102,103,103,104,105
	dc.w	105,106,106,107,107,108,108,109
	dc.w	109,110,110,110,111,111,112,112
	dc.w	112,112,113,113,113,114,114,114
	dc.w	114,114,114,115,115,115,115,115
	dc.w	115,115,115,115,115,115,115,115
	dc.w	115,115,114,114,114,114,114,114
	dc.w	113,113,113,112,112,112,112,111
	dc.w	111,110,110,110,109,109,108,108
	dc.w	107,107,106,106,105,105,104,103
	dc.w	103,102,102,101,100,100,99,98
	dc.w	97,97,96,95,94,94,93,92
	dc.w	91,90,90,89,88,87,86,85
	dc.w	84,84,83,82,81,80,79,78
	dc.w	77,76,75,74,73,72,71,70
	dc.w	69,68,67,66,66,65,64,63
	dc.w	62,61,60,59,58,56,55,54
	dc.w	53,52,51,50,49,49,48,47
	dc.w	46,45,44,43,42,41,40,39
	dc.w	38,37,36,35,34,33,32,31
	dc.w	31,30,29,28,27,26,25,25
	dc.w	24,23,22,21,21,20,19,18
	dc.w	18,17,16,15,15,14,13,13
	dc.w	12,12,11,10,10,9,9,8
	dc.w	8,7,7,6,6,5,5,5
	dc.w	4,4,3,3,3,3,2,2
	dc.w	2,1,1,1,1,1,1,0
	dc.w	0,0,0,0,0,0,0,0
	dc.w	0,0,0,0,0,0,1,1
	dc.w	1,1,1,1,2,2,2,3
	dc.w	3,3,3,4,4,5,5,5
	dc.w	6,6,7,7,8,8,9,9
	dc.w	10,10,11,12,12,13,13,14
	dc.w	15,15,16,17,18,18,19,20
	dc.w	21,21,22,23,24,25,25,26
	dc.w	27,28,29,30,31,31,32,33
	dc.w	34,35,36,37,38,39,40,41
	dc.w	42,43,44,45,46,47,48,49
	dc.w	49,50,51,52,53,54,55,56
	dc.w	57
	dc.w	$eeee,$eeee,$eeee,$eeee
	dc.w	$eeee,$eeee,$eeee,$eeee
	dc.w	$eeee,$eeee,$eeee,$eeee
	dc.w	$eeee,$eeee,$eeee,$eeee
	dc.w	$eeee,$eeee,$eeee,$eeee
	dc.w	$eeee,$eeee,$eeee,$eeee
	dc.w	$eeee,$eeee,$eeee,$eeee
	dc.w	$eeee,$eeee,$eeee,$eeee
	dc.w	$eeee,$eeee,$eeee,$eeee
	dc.w	$eeee,$eeee,$eeee,$eeee

pob_shape:
	dc.w	%0000000110000000,0
	dc.w	%0000000110000000,0
	dc.w	%0000011111100000,0
	dc.w	%0000011111100000,0
	dc.w	%0000000110000000,0
	dc.w	%0000000110000000,0

;===========================================================================;
;                                  DATA
;===========================================================================;

GMS_Name:
	dc.b	"games.library",0
	even
GMS_Base:
	dc.l	0

AMT_PLANES =	1

Screen:	dc.l	GSV1,0
Visual	dc.l	ScreenMem	;Screen_Mem1
Active	dc.l	ScreenMem+height*width	;Screen_Mem2
Clear	dc.l	ScreenMem+height*width*2 ;Screen_Mem3
	dc.l	0	;Screen link.
	dc.l	.Palette	;Address of screen palette.
	dc.l	0	;Address of rasterlist.
	dc.l	0	;Amt of colours in palette.
	dc.w	320,256	;Screen Width and Height.
	dc.w	320/8,256	;Picture Width/8 and Height.
	dc.w	AMT_PLANES	;Amt_Planes
	dc.w	0,0	;X/Y screen offset.
	dc.w	0,0	;X/Y picture offset.
	dc.l	TPLBUFFER	;Special attributes.
	dc.w	LORES|COL12BIT	;Screen mode.
	dc.b	PLANAR	;Screen type
	dc.b	0	;Reserved.
	even

.Palette
	dc.w	$0000,$0ff0


	SECTION	Screens,BSS_C

ScreenMem:
	ds.b	(height*width*3)+(width*50)

shape_buffer:
	ds.l	256
pob_xbuffer:
	ds.l	(width*8)
pob_ybuffer:
	ds.l	height

coord_stack:
	ds.l	1500