( Mouse:
	Paint with 3 colors with each mouse button. )

|00 @System &vector $2 &wst $1 &rst $1 &pad $4 &r $2 &g $2 &b $2 &debug $1 &halt $1
|20 @Screen &vector $2 &width $2 &height $2 &auto $1 &pad $1 &x $2 &y $2 &addr $2 &pixel $1 &sprite $1
|90 @Mouse &vector $2 &x $2 &y $2 &state $1 &pad $3 &modx $2 &mody $2

|0000

@line
	&x $2 &y $2 &dx $2 &dy $2 &e1 $2
@length $2
@frame $2
@pen 
	&x $2 &y $2 &x2 $2 &y2 $2
@pointer
	&x $2 &y $2 &lastx $2 &lasty $2 &state $1

|0100 ( -> )

	( theme )
	#4cfd .System/r DEO2
	#4cf3 .System/g DEO2
	#dcf2 .System/b DEO2

	( vectors )
	;on-mouse .Mouse/vector DEO2
	;on-frame .Screen/vector DEO2

BRK

@on-frame ( -> )

	.Mouse/state DEI ?&skip
		;run DUP2 JSR2 JSR2
		&skip

BRK

@on-mouse ( -> )

	;pointer-icn .Screen/addr DEO2
	( clear last cursor )
	.pointer/x LDZ2 .Screen/x DEO2
	.pointer/y LDZ2 .Screen/y DEO2
	[ LIT2 40 -Screen/sprite ] DEO
	( draw new cursor )
	.Mouse/x DEI2 DUP2 .pointer/x STZ2 .Screen/x DEO2
	.Mouse/y DEI2 DUP2 .pointer/y STZ2 .Screen/y DEO2
	#42 .Mouse/state DEI #00 NEQ ADD .Screen/sprite DEO
	( on down )
	.Mouse/state DEI #00 NEQ .pointer/state LDZ #00 EQU AND ?on-mouse-down
	( on drag )
	.Mouse/state DEI ?on-mouse-drag
	.Mouse/state DEI .pointer/state STZ

BRK

@on-mouse-down ( -> )

	#0000 DUP2 .length STZ2 .frame STZ2
	clear-screen
	( record start position )
	.Mouse/x DEI2 DUP2 .pointer/x STZ2 .pointer/lastx STZ2
	.Mouse/y DEI2 DUP2 .pointer/y STZ2 .pointer/lasty STZ2
	.Mouse/state DEI .pointer/state STZ

BRK

@on-mouse-drag ( -> )

	( record )
	;stroke .length LDZ2 #20 SFT2 ADD2 STH2
		.pointer/x LDZ2 .pointer/lastx LDZ2 SUB2 STH2kr STA2
		.pointer/y LDZ2 .pointer/lasty LDZ2 SUB2 STH2r INC2 INC2 STA2
	( move ptr )
	.length LDZ2 INC2 .length STZ2 
	( draw line )
	.pointer/lastx LDZ2
	.pointer/lasty LDZ2
	.pointer/x LDZ2
	.pointer/y LDZ2
		#01 draw-line
	( record last position )
	.Mouse/x DEI2 
		DUP2 .pointer/lastx STZ2 
		DUP2 .pen/x STZ2
		.pen/x2 STZ2
	.Mouse/y DEI2 
		DUP2 .pointer/lasty STZ2 
		DUP2 .pen/y STZ2
		.pen/y2 STZ2
	.Mouse/state DEI .pointer/state STZ

BRK

@run ( -- )

	( read )
	;stroke .frame LDZ2 #20 SFT2 ADD2 STH2
		.pen/x LDZ2 STH2kr LDA2 ADD2 .pen/x STZ2
		.pen/y LDZ2 STH2r INC2 INC2 LDA2 ADD2 .pen/y STZ2
	( line )
	.pen/x LDZ2 .pen/y LDZ2
	.pen/x2 LDZ2 .pen/y2 LDZ2
		.frame LDZ2 #01 SFT2 NIP #01 AND INC draw-line
	( history )
	.pen/x LDZ2 .pen/x2 STZ2
	.pen/y LDZ2 .pen/y2 STZ2
	( incr frame )
	.frame LDZ2 INC2 .length LDZ2 INC2 ( mod2 ) DIV2k MUL2 SUB2 .frame STZ2

JMP2r

@draw-line ( x1* y1* x2* y2* color -- )

	( load ) STH ,&y STR2 ,&x STR2 .line/y STZ2 .line/x STZ2
	,&x LDR2 .line/x LDZ2 SUB2 abs2 .line/dx STZ2
	#0000 ,&y LDR2 .line/y LDZ2 SUB2 abs2 SUB2 .line/dy STZ2
	#ffff #00 .line/x LDZ2 ,&x LDR2 lts2 DUP2 ADD2 ADD2 ,&sx STR2
	#ffff #00 .line/y LDZ2 ,&y LDR2 lts2 DUP2 ADD2 ADD2 ,&sy STR2
	.line/dx LDZ2 .line/dy LDZ2 ADD2 .line/e1 STZ2
	&loop
		.line/x LDZ2 DUP2 .Screen/x DEO2 [ LIT2 &x $2 ] EQU2
		.line/y LDZ2 DUP2 .Screen/y DEO2 [ LIT2 &y $2 ] EQU2
			STHkr .Screen/pixel DEO
			AND ?&end
		.line/e1 LDZ2 DUP2 ADD2 DUP2
		.line/dy LDZ2 lts2 ?&skipy
			.line/e1 LDZ2 .line/dy LDZ2 ADD2 .line/e1 STZ2
			.line/x LDZ2 [ LIT2 &sx $2 ] ADD2 .line/x STZ2
		&skipy
		.line/dx LDZ2 gts2 ?&skipx
			.line/e1 LDZ2 .line/dx LDZ2 ADD2 .line/e1 STZ2
			.line/y LDZ2 [ LIT2 &sy $2 ] ADD2 .line/y STZ2
		&skipx
		!&loop
	&end
	POPr

JMP2r

@abs2 DUP2 #0f SFT2 EQU #05 JCN #0000 SWP2 SUB2 JMP2r
@lts2 #8000 STH2k ADD2 SWP2 STH2r ADD2 GTH2 JMP2r
@gts2 #8000 STH2k ADD2 SWP2 STH2r ADD2 LTH2 JMP2r

@clear-screen ( -- )

	.Screen/height DEI2 #03 SFT2 NIP #00
	&y
		#00 OVR #30 SFT2 .Screen/y DEO2
		.Screen/width DEI2 #03 SFT2 NIP #00
		&x
			#00 OVR #30 SFT2 .Screen/x DEO2
			[ LIT2 00 -Screen/sprite ] DEO
			INC GTHk ?&x
		POP2
		INC GTHk ?&y
	POP2

JMP2r

@pointer-icn
	80c0 e0f0 f8e0 1000

@stroke