( usage: uxnemu sand.rom
	mouse1 water
	mouse2 sand
	mouse3 rock )

|00 @System &vector $2 &wst $1 &rst $1 &pad $4 &r $2 &g $2 &b $2 &debug $1 &halt $1
|10 @Console &vector $2 &read $1 &pad $5 &write $1 &error $1
|20 @Screen &vector $2 &width $2 &height $2 &auto $1 &pad $1 &x $2 &y $2 &addr $2 &pixel $1 &sprite $1
|80 @Controller &vector $2 &button $1 &key $1
|90 @Mouse &vector $2 &x $2 &y $2 &state $1 &pad $3 &scrollx $2 &scrolly $2
|a0 @File &vector $2 &success $2 &stat $2 &delete $1 &append $1 &name $2 &length $2 &read $2 &write $2
|c0 @DateTime &year $2 &month $1 &day $1 &hour $1 &minute $1 &second $1 &dotw $1 &doty $2 &isdst $1

|0100

(
@|vectors )

@on-reset

	( theme )
	#07cf .System/r DEO2
	#0caf .System/g DEO2
	#0faf .System/b DEO2

	#0100 .Screen/width DEO2
	#0100 .Screen/height DEO2

	;on-frame .Screen/vector DEO2
	;on-mouse .Mouse/vector DEO2

	prng-init

	#010e DEO

BRK

@on-frame ( -> )

	eval
	redraw

BRK

@on-mouse ( -> )

	[ LIT2 00 -Mouse/state ] DEI NEQ #41 ADD ;cursor-icn update-cursor

	( read mouse state )
	.Mouse/state DEI ?&on-touch BRK

&on-touch ( -> )

	( A mouse button was pressed )
	.Mouse/state DEI DUP #04 EQU SUB
	.Mouse/y DEI2 NIP
	.Mouse/x DEI2 NIP
		set-cell

BRK

(
@|core )

@eval-sand ( y x cell -- y x )

	POP
	OVR #ff EQU ?eval/resume
	( south )
	SWPk INC SWP STH2k get-cell #01 GTH ?&has-s
		DUP2 STH2r swap-cells !eval/resume
		&has-s
	POP2r
	( south sides )
	SWPk INC SWP #01ff prng ADD #01 AND [ JMP SWP POP ] ADD STH2k get-cell #01 GTH ?&has-s2
		DUP2 STH2r swap-cells !eval/resume
		&has-s2
	POP2r

!eval/resume

@eval-water ( y x cell -- y x )

	POP
	OVR #ff EQU ?eval/resume
	( south )
	SWPk INC SWP STH2k get-cell ?&has-s
		DUP2 STH2r swap-cells !eval/resume
		&has-s
	POP2r
	( south sides )
	DUP2 #01ff prng ADD #01 AND [ JMP SWP POP ] ADD STH2k get-cell ?&has-s2
		DUP2 STH2r swap-cells !eval/resume
		&has-s2
	POP2r

!eval/resume

@eval-rock ( y x cell -- y x )

	POP
	OVR #ff EQU ?eval/resume
	( south )
	SWPk INC SWP STH2k get-cell #01 GTH ?&has-s
		DUP2 STH2r swap-cells !eval/resume
		&has-s
	POP2r

!eval/resume

@eval ( -- )

	#ffff
	&l
		DUP2 get-cell
		DUP #01 EQU ?eval-water
		DUP #02 EQU ?eval-sand
		DUP #03 EQU ?eval-rock
		POP
		&resume
		#0001 SUB2 ORAk ?&l
	POP2

@redraw ( -- )

	#0000
	&l
		DUP2 #00ff AND2 .Screen/x DEO2
		DUP2 #0100 DIV2 .Screen/y DEO2
		DUP2 get-cell .Screen/pixel DEO
		INC2 ORAk ?&l
	POP2

JMP2r

@swap-cells ( a* b* -- )

	#02 SFT2 ;world ADD2 LDAk STH ,&a STR2
	#02 SFT2 ;world ADD2 LDAk STH ,&b STR2
	STHr [ LIT2 &a $2 ] STA
	STHr [ LIT2 &b $2 ] STA

JMP2r

@set-cell ( type y x -- )

	#02 SFT2 ;world ADD2 STA

JMP2r

@get-cell ( y x -- type )

	#02 SFT2 ;world ADD2 LDA

JMP2r

(
@|drawing )

@update-cursor ( color addr* -- )

	[ LIT2 00 -Screen/auto ] DEO
	#40 draw-cursor
	.Mouse/x DEI2 ,draw-cursor/x STR2
	.Mouse/y DEI2 ,draw-cursor/y STR2
	.Screen/addr DEO2

@draw-cursor ( color -- )

	[ LIT2 &x $2 ] .Screen/x DEO2
	[ LIT2 &y $2 ] .Screen/y DEO2
	.Screen/sprite DEO

JMP2r

(
@|stdlib )

@prng-init ( -- )

	( seed )
	#00 .DateTime/second DEI
	#00 .DateTime/minute DEI #60 SFT2 EOR2
	#00 .DateTime/hour DEI #c0 SFT2 EOR2 ,prng/x STR2
	#00 .DateTime/hour DEI #04 SFT2
	#00 .DateTime/day DEI #10 SFT2 EOR2
	#00 .DateTime/month DEI #60 SFT2 EOR2
		.DateTime/year DEI2 #a0 SFT2 EOR2 ,prng/y STR2

JMP2r

@prng ( -- number* )

	LIT2 &x $2
	DUP2 #50 SFT2 EOR2
	DUP2 #03 SFT2 EOR2
	LIT2 &y $2 DUP2 ,&x STR2
	DUP2 #01 SFT2 EOR2 EOR2
	,&y STR2k POP

JMP2r

(
@|assets )

@cursor-icn [
	80c0 e0f0 f8e0 1000 ]

@world