.include	common.inc

	.globl	SCROLL
	.globl	GND__INIT

	.globl	__scroll_speed_flag

	.even
*--------------------
SCROLL *()
	sSUPER
	M	<tst __scroll_speed_flag>,	<bNE @F>
		M	<tst __2_count>,	<bNE ~no_y_scroll__SCROLL>
	@@:
		sub	#1,__GSy
		BSR	DRAW_GR
*		BSR	PUT_BG
	~no_y_scroll__SCROLL:

	m	<move __num__GNDx_scroll,d0>,	<sub d0,__GSx>
	lea	_CRTC_GS0_SCx,a0
	move.l	__GSxy,(a0)+
	move.l	__GSxy,(a0)+
*	move.l	__GSxy,(a0)+
*	move.l	__GSxy,(a0)+
	sUSER
RTS ()
*---------------------
DRAW_GR *()
	M	<sub #1,__16dot_ctr>,	<bNE @F>
		BSR	READ_地形CODE *()
		move	#$10,__16dot_ctr
		move	#$A,__BACKを10回に分けて描くCOUNTER	*6回は休み
		M	<sub	#1,__GND2関係>,	<bNE @F>
			move	#$20,__GND2関係
			PUSH	D0/A0
				lea	__地形table＆,a0
				m	<moveq #0,D0>,	<move	__area2,D0>,	<add	#1,D0>
				IFn NE,	<cmp #$32,D0>,	<move	#8,D0>
				move	D0,__area2
				m	<lsl #2,D0>,	<add.l D0,A0>,	<move.l	(A0),A0>

				sub.l	#$a0000,a0
				add.l	#__地形table＆,a0

				m	<move.l	A0,__ptr_地形table>,	<BSR READ_地形CODE>
			POP	D0/A0
@@;
	M	<tst __BACKを10回に分けて描くCOUNTER>,	<bEQ EXIT__DRAW_GR>
	PUSH	D0-D1/A0-A1
		m	<move.l	__地形code_buf内のpointer,A1>,	<move.l	__gr_pointer,A0>
		m	<BSR SUB__DRAW_GR>,	<add.l #$20,A0>
		m	<BSR SUB__DRAW_GR>,	<add.l #$20,A0>
		m	<move.l	A1,__地形code_buf内のpointer>,	<move.l	A0,__gr_pointer>
		M	<sub #1,__BACKを10回に分けて描くCOUNTER>,	<bNE @F>
			m	<move.l	__gr_pointer,A0>,	<sub.l #$4280,A0 *\17024>
			IFn CC,	<cmp.l #_GRAM,A0>,	<lea $C7C000,A0>
			move.l	A0,__gr_pointer
@@;
	POP	D0-D1/A0-A1
EXIT__DRAW_GR	RTS ()
*--
SUB__DRAW_GR *( A0:__gr_pointer , A1	)	85AB4
	move	(A1)+,D1
	m	<moveq #0,D0>,	<move D1,D0>,	<and #$FFC,D0>,	<lsr #2,D0>
	m	<rol #4,D1>,	<and.b #$F,D1>
	BSR	DRAW_GR_16×16DOT
 RTS ( a1 )
*--
DRAW_GR_16×16DOT *( A0:__gr_pointer , D0 , D1	)	85D7E
	PUSH	D0-D1/A0-A1
	m	<lsl.l #8,D0>,	<add.l D0,D0>,	<lea __地形pcg_data,A1>,	<add.l D0,A1>
	lsl.b	#4,D1

	REPT	16
		m	<move (A1)+,D0>,	<add.b D1,D0>,	<move D0,(A0)+>
	ENDM

	REPT	15
		add.l	#$3E0,A0
		REPT	16
			m	<move (A1)+,D0>,	<add.b D1,D0>,	<move D0,(A0)+>
		ENDM
	ENDM								*計16*16
	POP	D0-D1/A0-A1
 RTS
*------------------
READ_地形CODE *()
	PUSH	D0-D2/A0-A1
	m	<move.l	__ptr_地形table,A1>,	<lea __buf_地形code,A0>,	<move #$13,D1>
~LOOP__READ_地形CODE
@@			move	(A1)+,D0
			M	<btst #1,D0>,	<bNE ~FLAG_ON__READ_地形CODE>
			M	<btst #0,D0>,	<bNE @F>
			move	D0,(A0)+
		dbF	D1,@B
		BRA	EXIT__READ_地形CODE

@@:		lsr	#2,D0					*　最下位bitが1の時
		move	(A1)+,D2
@@			move	D2,(A0)+			*　loop{
			M	<subq.w	#1,D1>,	<bCS EXIT__READ_地形CODE> *　　dbF代わり&break
		M	<subq.w	#1,D0>,	<bNE @B>		*　}
	BRA	~LOOP__READ_地形CODE

~FLAG_ON__READ_地形CODE;					*　第一bitが1の時
	M	<btst #$E,D0>,	<bNE @F>
		move	#-1,__no_縦scroll_flag
		BRA	~LOOP__READ_地形CODE			*　　　continue

@@:		move	#-1,__on_the_GND_flag
*		addq.w	#1,$86688
		BRA	~LOOP__READ_地形CODE			*　　　continue
*~}

EXIT__READ_地形CODE
	move.l	#__buf_地形code,__地形code_buf内のpointer
	move.l	A1,__ptr_地形table
	POP	D0-D2/A0-A1
 RTS
*-----------------
GND__INIT
	sSUPER
	lea	_CRTC_GS0_SCx,A1
*	move.l	#$200100,D0	*032,256
	move.l	#((_offset_x-16)<<16)+(_offset_y+128),d0
	m	<move.l	D0,(A1)+>,	<move.l	D0,(A1)+>
	m	<move.l	D0,(A1)+>,	<move.l	D0,(A1)>
	move.l	D0,__GSxy

	lea	__地形table＆,A0
	m	<moveq #0,D0>,	<*move	__area2,D0>	*初期化時に0にされて……
	m	<lsl #2,D0>,	<add.l D0,A0>,	<move.l	(A0),A1>

	sub.l	#$a0000,a1
	add.l	#__地形table＆,a1

	lea	$C7C000,A0
	move	#$10,D7
	~LOOP1__GND__INIT:
		move	#$13,D6
		~~LOOP2_GND__INIT:
				move	(A1)+,D1
			M	<btst #1,D1>,	<bNE ~~LOOP2_GND__INIT>	*continue
			M	<btst #0,D1>,	<bNE L85B2E>	*別の内容のLOOPへ

			m	<BSR SUB__GND__INIT>,	<add.l #$20,A0>
		dbF	D6,~~LOOP2_GND__INIT
		sub.l	#$4280,A0
	dbF	D7,~LOOP1__GND__INIT
	BRA	EXIT__GND__INIT		*break

L85B2E
			m	<lsr #2,D1>,	<move D1,D5>,	<subq.w	#1,D5>
			move	(A1)+,D1
@@				m	<BSR.s SUB__GND__INIT>,	<add.l #$20,A0>
				M	<subq.w	#1,D6>,	<bCS L85B48>	*break

			dbF	D5,@B
		BRA.s	~~LOOP2_GND__INIT
L85B48
		sub.l	#$4280,A0
	dbF	D7,~LOOP1__GND__INIT
*	BRA	EXIT__GND__INIT
EXIT__GND__INIT
	m	<move.l	A1,__ptr_地形table>,	<BSR READ_地形CODE>
	move.l	A0,__gr_pointer
	move	#$A,__BACKを10回に分けて描くCOUNTER
	move	#$10,__16dot_ctr
	move.b	#$F,__GND2関係
	sUSER
 RTS
*--
SUB__GND__INIT	*85B7E
	move	D1,-(A7)
	m	<moveq #0,D0>,	<move D1,D0>,	<and #$FFC,D0>,	<lsr #2,D0>
	m	<rol #4,D1>,	<and.b #$F,D1>
	BSR	DRAW_GR_16×16DOT
	move	(A7)+,D1
RTS
*---------------------

	.bss
__BACKを10回に分けて描くCOUNTER	.ds.w	1
__地形code_buf内のpointer	.ds.l	1
__ptr_地形table	.ds.l	1
__buf_地形code	.ds.w	$14
__GND2関係	.ds.w	1
__GSxy:
__GSx	.ds.w	1
__GSy	.ds.w	1

__scroll_speed_flag	.ds.w	1


	.data
__gr_pointer	.dc.l	$C7C000	*G_PAGE1の半分の所
__GNDy	.dc.w	$100
__16dot_ctr	.dc.w	1
__area2	.dc.w	0