;Scroll Screen 336
;-----------------
;This demo allows you to legally scroll up to 50 screens in either
;direction by setting the HBUFFER flag.  Normally we would blit blocks down
;the left and right hand side to give an impression of heaps of screens -
;maybe later...

	opt	o+,c+

	INCLUDE	"exec/exec_lib.i"
	INCLUDE	"games/games_lib.i"
	INCLUDE	"games/games.i
CALL	MACRO
	jsr	_LVO\1(a6)
	ENDM

	SECTION	"ScrollScreen336",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

	lea	Picture(pc),a1	;Load the picture.
	move.l	GS_MemPtr1(a0),PIC_Data(a1)
	CALL	LoadPic
	tst.w	d0
	bne.s	.Error_Picture

	move.l	PIC_Palette(a1),GS_Palette(a0)
	CALL	UpdatePalette

	CALL	Show_Screen
	CALL	InitJoyPorts

	bsr.s	Main

.ReturnToDOS
	move.l	GMS_Base(pc),a6
	lea	Picture(pc),a1
	CALL	FreePic
.Error_Picture
	move.l	GMS_Base(pc),a6
	lea	Screen(pc),a0
	CALL	Delete_Screen	;Give back screen memory etc.
.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:	moveq	#JPORT1,d0
	CALL	Read_Mouse
	btst	#MB_LMB,d0
	bne.s	.done
	asr.w	#8,d0			;d0 = X Change
	add.w	d0,GS_PicXOffset(a0)
	CALL	Move_Picture
	CALL	Wait_OSVBL
	bra.s	Main
.done	rts

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

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

AMT_PLANES =	5

Screen:	dc.l	GSV1,0
	dc.l	0,0,0	;Screen_Mem1/2/3
	dc.l	0	;Screen link.
	dc.l	0	;Address of 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	336/8,256	;Picture Width/8 and Height.
	dc.w	AMT_PLANES	;Amt_Planes
	dc.w	0,0	;X/Y Top Of Screen
	dc.w	0,0	;X/Y Pic Offset (for scrolling).
	dc.l	HSCROLL|HBUFFER	;Special attributes.
	dc.w	LORES|COL12BIT	;Screen mode.
	dc.b	INTERLEAVED	;Screen type
	dc.b	0	;Reserved.
	even

Picture	dc.l	PCV1,0	;Version header.
	dc.l	0	;Source data.
	dc.w	336/8,256	;Width, Height.
	dc.w	AMT_PLANES	;Amount of Planes.
	dc.l	32	;Amount of colours.
	dc.l	0	;Source palette (remap).
	dc.w	LORES|COL12BIT	;Screen mode.
	dc.w	INTERLEAVED	;Destination
	dc.l	GETPALETTE	;Parameters.
	dc.l	.File
.File	dc.b	"GAMESLIB:data/IFF.Pic336",0
	even