;**************************************************************************
;*
;* v scroll test
;*
;**************************************************************************
	
	org $2000			   ;prg start
	
	icl "custom.i"

START:

	;

	sei				  ;disable irqs
	lda	#$00
	sta	NMIEN			  ;NMIEN all off 
	sta	DMACTL			  ;DMACTL all off

	;set display list (use shadow regs)
	
	lda	#<displayList
	sta	DLISTL	
	lda	#>displayList
	sta	DLISTH
	
	;set display list interrupt
	  
	lda	#<dli_irq
        sta	VDSLSTL           
        lda	#>dli_irq
        sta	VDSLSTH    
	
	;vertical blank interrupt 
	
	lda 	#>vbi_irq
	sta	VVBLKIH	
	lda 	#<vbi_irq
	sta	VVBLKIL	
	
	;os key remove
	
	lda	#<noKeyRead
        sta	VSERINL        
        lda	#>noKeyRead
        sta	VSERINH        
	
	;chbase
	
	lda	#$E0
	sta	CHBASE
	
	;color setup
	
	lda	#$0	
	sta	COLBK
	lda	#$4	
	sta	COLPF0
	lda	#$2	
	sta	COLPF1
	lda	#$6	
	sta	COLPF2
	lda	#$88				
	sta	COLPF3
				
	;disable player/missile dma
	
	lda	#$00
	sta	GRACTL
	
	;setup displays
	   
	lda	#DMACTL_DL|DMACTL_PF_NORMAL		
		
		;enable display list dma 			
		;playfield normal display (40)
			
	sta	DMACTL	;DMACTL
	
	lda	#$0
	sta	HSCROL
	
	;enable dli
	
	lda	#NMIEN_VBI|NMIEN_DLI
	sta	NMIEN	;VBI + DLI enbable
	
	;
	
	cli		;irq enable

loop
	
	;Wait VBlank

?WaitVC0
        lda	VCOUNT		
        beq	?WaitVC0   	
?WaitVCnot0
        lda	VCOUNT		
        bne	?WaitVCnot0   
	
	
	jmp loop			;end
	
	
;************************************************
;*
;* dummy
;*
;************************************************
	
noKeyRead	
	rts
	
;************************************************
;*
;* vertical blank interrupt (immidiate, x,y regs save bei os rom)
;*
;************************************************

vbi_irq

	;
	
	lda	#0
	sta	dliCounter
	
	;
	
	lda	wordCounter
	clc	
	adc	#55
	sta	wordCounter
	lda	wordCounter+1
	adc	#0
	sta	wordCounter+1
	
	;
	
	and	#$f
	sta	VSCROL	
	
	;
	
	
	lda	wordCounter+1
	lsr
	lsr
	lsr
	lsr			;AB -> 0A
	
	asl			;*2
	tay
	lda	mul40,y
	sta	zd0
	iny
	lda	mul40,y
	sta	zd1
	jsr	copyOffsets

	;prolog (like XITVBL)
	
	pla					  
	tay
	pla					  
	tax
	pla					  
	rti
	
wordCounter	.word	0

mul40	.rept	16
	.word	40*#
	.endr

yMapOffsets
	.rept	12+12		;12 visible + 12 invisible 
	.word	charData+#*40
	.endr	
	
	;with repts
	
copyOffsets

	ldx	#0
	ldy	#0
	
?copyOffsetsLoop	
	lda	yMapOffsets,x
	;clc				
	adc	zd0
	sta	displayListYRept+1,y
	lda	yMapOffsets+1,x
	adc	zd1
	sta	displayListYRept+2,y
	
	inx
	inx
	iny
	iny
	iny
	cpx	#12*2
	bne	?copyOffsetsLoop
	
	;unrolled
	;.rept	12
	;lda	yMapOffsets+#*2
	;clc
	;adc	zd0
	;sta	displayListYRept+1+#*3
	;lda	yMapOffsets+1+#*2
	;adc	#0
	;sta	displayListYRept+2+#*3
	;.endr
	rts
	
			
;************************************************
;*
;* display list interrupt
;*
;************************************************

dli_irq

	;prolog

        pha 
	txa	
	pha
	tya	
	pha
	
	;
	
	inc	dliCounter	
		
	;epilog
	
        pla					  
	tay
	pla					  
	tax
	pla
        rti   	;direct (no stack used)
		
dliCounter	.byte	0


;************************************************
;*
;* display list interrupt
;*
;************************************************


; display list

	;7	6	5	4	3	2	1	0
	;DLI	LMS	VSCROLL	HSCOLL	Mode
	;
	;Mode 0 Blank lines 7..4 is count+1 of blank lines
	;Mode 1 JMP (use with LMS to set destination)
	;Mode $2-$f is ANTIC mode

	.align $400
		
displayList	 
	.byte 0			;Mode 0
	.byte $70		;8 blank lines	
	.byte $70		;8 blank lines
	.byte $70	 	;8 blank lines

displayListYRept	
	.rept	12
	.byte 	$7|DL_LMS|DL_HSCROLL|DL_VSCROLL	;Mode 7 + LMS + HSCROLL
	.word	charData+#*40	
	.endr
	
	.byte	DL_JUMPVB
	.word	displayList	; wait vblank, restart same display list on next frame	
	
	org	$4000
	 
	;
	
charData

	;        --------------------////////////////////
	;
	;                  111111111122222222223333333333
	;        0123456789012345678901234567890123456789	40 width
	
	.byte	"#00000000000000000000000000000000000000#"	;color mux by map
	.byte	"#1X                 X                 1#"
	.byte	"#2 X               X                  2#"
	.byte   "#3  X             X     HELLO         3#"
	.byte	"#4   X           X                    4#"
	.byte	"#5    X         X                     5#"
	.byte	"#6     X       X                      6#"
	.byte	"#7      X     X                       7#"
	.byte	"#8       X   X                        8#"
	.byte	"#9        X X                         9#"
	.byte	"#A         X                          A#"
	.byte	"#BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB#"
	.byte	"#CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC#"
	.byte	"#DDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDD#"
	.byte	"#D DDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDD#"
	.byte	"#DD DDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDD#"
	.byte	"#DDD DDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDD#"
	.byte	"#DDDD DDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDD#"
	.byte	"#DDDDD DDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDD#"
	.byte	"#DDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDD#"
	
	
	org	$6000

stoneTiles	ins	"gfx/stones2_4x8x2.raw"		;3072 (64 x 64*3)