include "base.s"

********* CONST ***********************************

W = 320				; screen/bitplane width in memory (in px)
H = 256				; screen/bitplane height in memoty (in px)
BPLS = 5			; number of bitplanes
LEFF = 320			; effective screen width (DDFSTOP-DDFSTRT)*2+16
MODULOS = W/8*BPLS-LEFF/8	; number of bytes to skip per line
				; W/8-LEFF/8 if non IL
				; W/8*BPLS-LEFF/8 if IL
BPLSIZE = W/8			; bytes taken by one bitplane
				; W/8*H if non IL ; W/8 if IL
LINESIZE = W/8*BPLS		; Lentght of image line in bytes
				; W/8 if non IL   ; W/8*BPLS if IL

********* INIT ************************************

run:
	lea CUSTOM,a6			; move the base to a6
	move.w #$8380,DMACON(a6)	; activate copper+ BPL in DMA channel

	move.l #copper,COP1LCH(a6)	; move new copper to copper register
	move.w #0,COPJMP1(a6)		; (H and L) & activate new copper

	lea copperbpl,a0		; set the needed variables before
	move.l #screen,d0		; branching to rotine to 
	bsr pokebpls			; poke bpls memoory ptr to copper

********* MAIN ************************************

main:
	bsr waitVBI		; wait for the vertical blanc
				; before updating the screen
	
	btst #6,$BFE001		; is lmb prssed
	bne main		; 0 = pressed

	rts



********* ROUTINES ***********************************

*** poke bipls addresses into copper
*   a0: bpls pointer in copperlist
*   d0: address of bpls in memory
pokebpls:
	moveq #BPLS-1,d7		; loop counter = number of bpls
loopbpl:
	move.w d0,6(a0)			; low word in BPL1PTL
	swap d0				; swap low and high
	move.w d0,2(a0)			; high word into BPL1PTH
	swap d0				; original address back
	add.l #BPLSIZE,d0		; d0 points to bpl2 data
	add.l #8,a0			; a0 points to next bplptr
	dbf d7,loopbpl
	rts

********* DATA in FAST MEM ************************

********* DATA in CHIP MEM ************************

	section copperlist,data_C
copper:
	dc.w BPLCON0,BPLS<<12!$0200 ; set bitplane number

	dc.w DIWSTRT,$2C81	; define display window size
	dc.w DIWSTOP,$F4C1	; 320 X 200 pixels
				; $F4C1 for 200 px high
				; $2CC1 dor 256 px high
	dc.w DDFSTRT,$38	; define display data fetch
	dc.w DDFSTOP,$D0	; size to 320 pxels

	dc.w BPL1MOD,MODULOS	; skip xxx px per line
	dc.w BPL2MOD,MODULOS 

copperbpl:
	dc.w BPL1PTH,$0000	; give denise the pointer
	dc.w BPL1PTL,$0000	; to the first bitplane
	dc.w BPL2PTH,$0000	; give denise the pointer
	dc.w BPL2PTL,$0000	; to the second bitplane
	dc.w BPL3PTH,$0000	; give denise the pointer
	dc.w BPL3PTL,$0000	; to the third bitplane
	dc.w BPL4PTH,$0000	; give denise the pointer
	dc.w BPL4PTL,$0000	; to the fotrh bitplane
	dc.w BPL5PTH,$0000	; give denise the pointer
	dc.w BPL5PTL,$0000	; to the fifth bitplane
	dc.w BPL6PTH,$0000	; give denise the pointer
	dc.w BPL6PTL,$0000	; to the sixth bitplane

palette:
	include "AH_KingTut.palette"

	dc.w $FFFF,$FFFE	; copper end

screen:
	incbin "AH_KingTutIL320x256x5.raw"