;-------T-------T------------------------T----------------------------------;
;Name:      Scroll Memory
;Author:    Paul Manias
;Copyright: DreamWorld Productions (c) 1996-1997.  Freely distributable.
;
;This demo shows you the power of the scrolling features by allowing you
;to scroll all over your chip ram :-).  Usually you would set limits to stop
;you from going over the boundaries, but that's up to you.
;
;Use mouse to move around, LMB exits.

	INCDIR	"INCLUDES:"
	INCLUDE	"games/games_lib.i"
	INCLUDE	"games/games.i"

	SECTION	"Demo",CODE

;===========================================================================;
;                             INITIALISE DEMO
;===========================================================================;

	STARTGMS

Start:	MOVEM.L	A0-A6/D1-D7,-(SP)
	move.l	GMSBase(pc),a6
	lea	ScreenTags(pc),a0
	CALL	AddScreen
	tst.l	d0
	beq.s	.Error_Screen

	move.l	Screen(pc),a0
	lea	PictureTags(pc),a1
	move.l	GS_MemPtr1(a0),PicData
	CALL	LoadPic
	tst.l	d0
	beq.s	.Error_Picture

	CALL	ShowScreen
	CALL	InitJoyPorts
	bsr.s	Main

.ReturnToDOS
	move.l	GMSBase(pc),a6
	move.l	Picture(pc),a1
	CALL	FreePic
.Error_Picture
	move.l	Screen(pc),a0
	CALL	DeleteScreen
.Error_Screen
	MOVEM.L	(SP)+,A0-A6/D1-D7
	moveq	#ERR_OK,d0
	rts

;===========================================================================;
;                                MAIN LOOP
;===========================================================================;

Main:	move.l	Screen(pc),a0
.loop	moveq	#JPORT1,d0
	moveq	#JT_ZBXY,d1
	CALL	ReadJoyPort
	btst	#MB_RMB,d0
	bne.s	.done
	move.w	d0,d1
	asr.w	#8,d0	;d0 = X Change
	ext.w	d1

	;btst	#MB_LMB,d0
	;bne.s	.MoveScreen
.MovePicture
	add.w	d0,GS_PicXOffset(a0)
	add.w	d1,GS_PicYOffset(a0)
	CALL	RemakeScreen
	CALL	MovePicture
	CALL	WaitVBL
	bra.s	.loop

.MoveScreen
	add.w	d0,GS_ScrXOffset(a0)
	add.w	d1,GS_ScrYOffset(a0)
	CALL	RemakeScreen
	CALL	MovePicture
	CALL	WaitVBL
	bra.s	.loop
.done	rts

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

ScreenTags:
	dc.l	TAGS_GAMESCREEN
Screen:	dc.l	0
	dc.l	GSA_Palette,Palette
	dc.l	GSA_ScrWidth,320
	dc.l	GSA_ScrHeight,256
	dc.l	GSA_AmtColours,32
	dc.l	GSA_Attrib,HSCROLL|VSCROLL|SBUFFER|CENTRE
	dc.l	TAGEND

Palette	dc.l	$000000,$103000,$F0C0B0,$F0A090,$D08080,$906050,$604040,$201010
	dc.l	$400000,$404040,$F0F000,$403020,$C0C000,$105000,$500010,$808000
	dc.l	$206010,$207010,$308020,$409020,$50A030,$50B040,$607070,$60C040
	dc.l	$708080,$90A0A0,$B0C0C0,$800010,$900010,$A00020,$700010,$600010

PictureTags:
	dc.l	TAGS_PICTURE
Picture	dc.l	0
	dc.l	PCA_Data
PicData	dc.l	0
	dc.l	PCA_Width,320
	dc.l	PCA_Height,256
	dc.l	PCA_AmtColours,32
	dc.l	PCA_Palette,Palette
	dc.l	PCA_File,.file
	dc.l	TAGEND

.file	dc.b	"GMS:demos/data/PIC.Green",0
	even