( dev/mouse )

%RTN   { JMP2r }
%ABS2  { DUP2 #0f SFT2 EQU #05 JCN #0000 SWP2 SUB2 }
%LTS2  { #8000 ADD2 SWP2 #8000 ADD2 GTH2 }
%GTS2  { #8000 ADD2 SWP2 #8000 ADD2 LTH2 }
%2** { #10 SFT2 }

( devices )

|00 @System     [ &vector $2 &pad     $6 &r      $2 &g     $2 &b      $2 ]
|20 @Screen     [ &vector $2 &width   $2 &height $2 &pad   $2 &x      $2 &y $2 &addr $2 &pixel $1 &sprite $1 ]
|90 @Mouse      [ &vector $2 &x       $2 &y      $2 &state $1 &wheel $1 ]

|0000

@color $1
@line    [ &x0 $2 &y0 $2 &x     $2 &y     $2 &sx    $2 &sy $2 &dx $2 &dy $2 &e1 $2 &e2 $2 ]
@pointer [ &x  $2 &y  $2 &lastx $2 &lasty $2 &state $1 ]

( program )

|0100 ( -> )

	( theme ) 
	#f030 .System/r DEO2 
	#f04f .System/g DEO2 
	#f050 .System/b DEO2

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

BRK

@on-mouse ( -> )

	;draw-cursor JSR2

	( on down )
	.Mouse/state DEI #00 NEQ .pointer/state LDZ #00 EQU #0101 EQU2 ,on-mouse-down JCN

	( on drag )
	.Mouse/state DEI ,on-mouse-drag JCN
	.Mouse/state DEI .pointer/state STZ

BRK 

@on-mouse-down ( -> )

	( 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 ( -> )
	
	( draw line )
	.pointer/lastx LDZ2 
	.pointer/lasty LDZ2 
	.pointer/x LDZ2 
	.pointer/y LDZ2 
	#01 [ .Mouse/state DEI #10 EQU DUP ADD ADD ] 
	;draw-line JSR2

	( record last position )
	.Mouse/x DEI2 .pointer/lastx STZ2 
	.Mouse/y DEI2 .pointer/lasty STZ2
	.Mouse/state DEI .pointer/state STZ

BRK

@draw-cursor ( -- )
	
	;pointer_icn .Screen/addr DEO2
	( clear last cursor )
	.pointer/x LDZ2 .Screen/x DEO2
	.pointer/y LDZ2 .Screen/y DEO2
	#40 .Screen/sprite DEO

	( record pointer positions )
	.Mouse/x DEI2 .pointer/x STZ2 
	.Mouse/y DEI2 .pointer/y STZ2

	( draw new cursor )
	.pointer/x LDZ2 .Screen/x DEO2
	.pointer/y LDZ2 .Screen/y DEO2
	#43 .Mouse/state DEI #00 NEQ DUP ADD SUB .Screen/sprite DEO

RTN

@draw-line ( x1 y1 x2 y2 color -- )
	
	( load ) .color STZ .line/y0 STZ2 .line/x0 STZ2 .line/y STZ2 .line/x STZ2
	.line/x0 LDZ2 .line/x LDZ2 SUB2 ABS2 .line/dx STZ2
	.line/y0 LDZ2 .line/y LDZ2 SUB2 ABS2 #0000 SWP2 SUB2 .line/dy STZ2
	#ffff #00 .line/x LDZ2 .line/x0 LDZ2 LTS2 2** ADD2 .line/sx STZ2
	#ffff #00 .line/y LDZ2 .line/y0 LDZ2 LTS2 2** ADD2 .line/sy STZ2
	.line/dx LDZ2 .line/dy LDZ2 ADD2 .line/e1 STZ2
	&loop
		.line/x LDZ2 .Screen/x DEO2 
		.line/y LDZ2 .Screen/y DEO2 
		.color LDZ .Screen/pixel DEO
		[ .line/x LDZ2 .line/x0 LDZ2 EQU2 ] 
		[ .line/y LDZ2 .line/y0 LDZ2 EQU2 ] #0101 EQU2 ,&end JCN
		.line/e1 LDZ2 2** .line/e2 STZ2
		.line/e2 LDZ2 .line/dy LDZ2 LTS2 ,&skipy JCN
			.line/e1 LDZ2 .line/dy LDZ2 ADD2 .line/e1 STZ2
			.line/x LDZ2 .line/sx LDZ2 ADD2 .line/x STZ2
		&skipy
		.line/e2 LDZ2 .line/dx LDZ2 GTS2 ,&skipx JCN
			.line/e1 LDZ2 .line/dx LDZ2 ADD2 .line/e1 STZ2
			.line/y LDZ2 .line/sy LDZ2 ADD2 .line/y STZ2
		&skipx
		;&loop JMP2
	&end

RTN

@pointer_icn [ 80c0 e0f0 f8e0 1000 ]