***	CODE		ROTATING_COPPER_BARS
***	CODER		MARC_B


***	constants	***

chip		equ	2
clear		equ	$10000
Plane_Size	equ	320/8*256


*******************************************
*		INCLUDE FILES		  *
*******************************************


	incdir		sys:include/
	include		source:include/hardware.i
	include		exec/exec.i
	include		exec/exec_lib.i

	lea		$dff000,a5		;custom base address


**********************************************************
*	OPEN GFX LIBRARY AND SAVE SYSTEM COPPER		 *
**********************************************************

	
	move.l		#gfxname,a1
	moveq		#0,d0
	CALLEXEC	OpenLibrary
	tst		d0			
	beq		the_end			
	move.l		d0,gfxbase		
	move.l		d0,a0			;put gfxbase in a0 
	move.l		38(a0),systemcopper	;save the copper address 



****************************************************
*	ALLOCATE MEMORY FOR BIT PLANES		   *
****************************************************

	
	move.l		#Plane_Size,d0		;memory for 1 bitplanes
	move.l		#chip+clear,d1		;chip memory and wipe it 
	CALLEXEC	AllocMem
	tst		d0			;fail 
	beq		exit			;yep 
	move.l		d0,bitbase		;save  pointer


*****************************************************************
*	LOAD BITPLANE AND SPRITE POINTERS INTO COPPER LIST      *
*****************************************************************


	move.l		bitbase,d0
	lea		copper,a0
	move.w		d0,6(a0)	
	swap		d0
	move.w		d0,2(a0)
	swap		d0
	

***************************************************************
*		START CUSTOM COPPER LIST		      *
***************************************************************	

	move.l		#copper,COP1LCH(a5)
	move.l		#0,COPJMP1(a5)
	CALLEXEC	Forbid

*************************************************************
*		    MAIN CODE LOOP    			    *
*************************************************************

	move.l		#table,store
wait
	move.l		VPOSR(a5),d0	;read current beam position
	and.l		#$0001ff00,d0	;mask all but the vertical pos
	lsr.l		#8,d0		
	cmp.w		#$0106,d0	;wait for end of display
	bne		wait
	btst		#6,CIAAPRA	;check left mouse button
	beq		clean_up	;end if pressed
	add.b		#1,counter
	cmp.b		#12,counter
	beq		do_loop
	bra		wait

;this routine is only called every 12 frames at which point the
;colour cycle routines are called this is done to slow down
;the effect ,which when called every frame becomes a flicker

do_loop
	bsr		loop
	move.b		#0,counter
	bra		wait

**********************************************************
*			RESTORE SYSTEM 			 *
**********************************************************

clean_up
	move.l		systemcopper,COP1LCH(a5)
	move.l		#0,COPJMP1(a5)
	CALLEXEC	Permit
	

exit1
	
	move.l		#Plane_Size,d0
	move.l		bitbase,a1
	CALLEXEC	FreeMem

exit
	move.l		gfxbase,a1		;close the graphics library
	CALLEXEC	CloseLibrary
	
the_end
	rts					;exit from program

	
********************************************
*		CYCLE COLOURS		   *
********************************************

;this routine first takes the last colour in the buffer (store)
;and loads it into d1,then it moves all the other entries down
;one place,when this is complete it then loads d1 into the
;first entry in the buffer,so rotating the colours through
;the buffer

loop
	move.l		store,a0
	move.w		16(a0),d1
	move.w		14(a0),16(a0)
	move.w		12(a0),14(a0)
	move.w		10(a0),12(a0)
	move.w		8(a0),10(a0)
	move.w		6(a0),8(a0)
	move.w		4(a0),6(a0)
	move.w		2(a0),4(a0)
	move.w		(a0),2(a0)
	move.w		d1,(a0)



;this routine loads the first bar into a1 and then calls the load_bar
;routine which loads the colour table in the buffer (store) into a0
;the contents are then moved into the copper_bar at the 
;dc.w	COLOR00,$0000 positions,when the routine returns
;the second copper bar (copper_bar1)is loaded into a1 and the
;process repeated

	lea		copper_bar,a1
	bsr		load_bar
	lea		copper_bar1,a1

load_bar
	move.l		store,a0
	move.w		(a0),6(a1)
	move.w		2(a0),14(a1)
	move.w		4(a0),22(a1)
	move.w		6(a0),30(a1)
	move.w		8(a0),38(a1)
	move.w		10(a0),46(a1)
	move.w		12(a0),54(a1)
	move.w		14(a0),62(a1)
	move.w		16(a0),70(a1)
	rts





***********************************************************
*		   CUSTOM COPPER LIST			  *
***********************************************************

	SECTION		copper.list,CODE_C
copper
	dc.w	BPL1PTH,0000		;next 4 blank words
	dc.w	BPL1PTL,0000		;are where we load
	dc.w	BPL2PTH,0000		;the bitplane pointers
	dc.w	BPL2PTL,0000
	dc.w	SPR0PTH,0000
	dc.w	SPR0PTL,0000		;sprite 0 pointer
	dc.w	SPR1PTH,0000
	dc.w	SPR1PTL,0000		;sprite 1 pointer
	dc.w	SPR2PTH,0000
	dc.w	SPR2PTL,0000		;sprite 2 pointer
	dc.w	SPR3PTH,0000
	dc.w	SPR3PTL,0000		;sprite 3 pointer
	dc.w	SPR4PTH,0000
	dc.w	SPR4PTL,0000		;sprite 4 pointer
	dc.w	SPR5PTH,0000
	dc.w	SPR5PTL,0000		;sprite 5 pointer
	dc.w	SPR6PTH,0000
	dc.w	SPR6PTL,0000		;sprite 6 pointer
	dc.w	SPR7PTH,0000
	dc.w	SPR7PTL,0000		;sprite 7 pointer
	dc.l 	$2b01fffe		;wait for line 43
	dc.w	DIWSTRT,$2c81		;where we start displaying
	dc.w	DIWSTOP,$2cc1		;where we stop!
	dc.w	BPLCON0,$0200		;this is for Amiga 1000 owners
	dc.w	BPLCON2,$0024		
	dc.w	DDFSTRT,$0038		;where to start the horizontal display
	dc.w	DDFSTOP,$00d0		;and where we stop
	dc.w	BPLCON1,$0000
	dc.w	BPL1MOD,$0000		;not a scroller
	dc.w	BPL2MOD,$0000		;so these are blank
	dc.w	COLOR00,$0000		;background colour black
	dc.w	COLOR01,$0fff		;colour 1 
	dc.w	COLOR02,$0e00		;colour 2 
	dc.w	COLOR03,$00a1		;colour 3 
	dc.w	COLOR04,$0d80
	dc.w	COLOR05,$0c70
	dc.w	COLOR06,$0c71
	dc.w	COLOR07,$0b61
	dc.w	COLOR08,$0b62
	dc.w	COLOR09,$0a52
	dc.w	COLOR10,$0a52
	dc.w	COLOR11,$0fb0
	dc.w	COLOR12,$000f
	dc.w	COLOR13,$0f00
	dc.w	COLOR14,$0f82
	dc.w	COLOR15,$0ff3
	dc.w	COLOR16,$0000
	dc.w	COLOR17,$0d80
	dc.w	COLOR18,$0b61
	dc.w	COLOR19,$0a52
	dc.w	COLOR20,$0333
	dc.w	COLOR21,$0444
	dc.w	COLOR22,$0555
	dc.w	COLOR23,$0666
	dc.w	COLOR24,$0777
	dc.w	COLOR25,$0888
	dc.w	COLOR26,$0999
	dc.w	COLOR27,$0aaa
	dc.w	COLOR28,$0ccc
	dc.w	COLOR29,$0ddd
	dc.w	COLOR30,$0eee
	dc.w	COLOR31,$06f8


copper_bar

	dc.l	$7001fffe
	dc.w	COLOR00,$0000		
	dc.l	$7401fffe
	dc.w	COLOR00,$0000
	dc.l	$7801fffe
	dc.w	COLOR00,$0000
	dc.l	$7c01fffe
	dc.w	COLOR00,$0000
	dc.l	$8001fffe
	dc.w	COLOR00,$0000
	dc.l	$8401fffe
	dc.w	COLOR00,$0000
	dc.l	$8801fffe
	dc.w	COLOR00,$0000
	dc.l	$8a01fffe
	dc.w	COLOR00,$0000
	dc.l	$8e01fffe
	dc.w	COLOR00,$0000
	dc.l	$9201fffe
	dc.w	COLOR00,$0000
	dc.l	$9601fffe
	dc.w	COLOR00,$0000
	dc.l	$9a01fffe
	dc.w	COLOR00,$0000
	dc.l	$9e01fffe
	dc.w	COLOR00,$0000
	dc.l	$9201fffe
	dc.w	COLOR00,$0000
bar_end


copper_bar1

	dc.l	$b001fffe
	dc.w	COLOR00,$0000		
	dc.l	$b401fffe
	dc.w	COLOR00,$0000
	dc.l	$b801fffe
	dc.w	COLOR00,$0000
	dc.l	$bc01fffe
	dc.w	COLOR00,$0000
	dc.l	$c001fffe
	dc.w	COLOR00,$0000
	dc.l	$c401fffe
	dc.w	COLOR00,$0000
	dc.l	$c801fffe
	dc.w	COLOR00,$0000
	dc.l	$ca01fffe
	dc.w	COLOR00,$0000
	dc.l	$ce01fffe
	dc.w	COLOR00,$0000
	dc.l	$d201fffe
	dc.w	COLOR00,$0000
	dc.l	$d601fffe
	dc.w	COLOR00,$0000
	dc.l	$da01fffe
	dc.w	COLOR00,$0000
	dc.l	$de01fffe
	dc.w	COLOR00,$0000
	dc.l	$d201fffe
	dc.w	COLOR00,$0000
bar_end1

	dc.l	$2c01fffe		;wait for line 44
	dc.w	BPLCON0,$1200		;turn on bit planes

	dc.l	$fffffffe		;wait for the impossible
endcopper

copperlen	equ	endcopper-copper


table	dc.w	$f,$d,$b,$a,$9,$a,$b,$d,$f
	
************************************************************
*			VARIABLES	 		   *
************************************************************


gfxbase		dc.l 0
bitbase		dc.l 0
systemcopper	dc.l 0
store		dc.l 0
counter		dc.b 0
gfxname		dc.b 'graphics.library',0


end