Octo Chip8 Program

readme.txt

Play this game by pasting the program into http://johnearnest.github.io/Octo/

options.json

{"tickrate":"20","backgroundColor":"#640","fillColor":"#A5A","buzzColor":"#FFAA00","quietColor":"#000000","shiftQuirks":false,"loadStoreQuirks":false}

prog.ch8

# Chip8 Mr Worm
# rmmh 2014

:alias wafflex v4
:alias waffley v5

:alias headx v6
:alias heady v7
:alias headdir v8

:alias tailx v9
:alias taily vA
:alias growth vB

:proto queue
:alias queuehead vC
:alias queuetail vD

:const STARTLENGTH 12
:const NDIRS 12
:const LASTDIR 11  # NDIRS - 1
:const TAILHEIGHT 5

: title-MrW 0xF8 0x04 0xA8 0x05 0xAB 0x85 0xAA 0x05 0xAA 0x05 0xAA 0x07 0x00 0x00 0x00 0x00 0x00 0x80 0x6D 0xCA 0xA6 0x8E 0xCA 0x8E 0x6E 0xCE 0x00 0x00 0x00 0x00 0x00 0x00 
: title-orm 0x40 0x00 0x40 0x00 0x5D 0xDF 0x55 0x15 0x55 0x15 0xDD 0x15 0x00 0x00 0x00 0x00 0x05 0x40 0xCA 0x5B 0x7F 0x6A 0xAA 0x71 0xEA 0x5B 0x00 0x00 0x00 0x00 0x00 0x00 
: dead-score 0xC0 0x00 0x80 0x00 0x80 0x00 0xDB 0xB7 0x52 0xA5 0x52 0xA7 0x52 0xA4 0xDB 0xA7 0x00 0x00 0x15 0x04 0x14 0x04 0x1D 0x77 0x15 0x55 0x15 0x75 0x00 0x10 0x00 0x70 

:const WAFFLEHEIGHT 5
: waffle-sprite 0xF8 0xA8 0xF8 0xA8 0xF8 

: worm-dirtab
# struct { char offx, offy, _padding, sprite[5]; };
: worm-ul  -1 -2  0  0x70 0xF8 0xC0 0x80 0x00
: worm-u    0 -2  0  0x70 0xF8 0x88 0x00 0x00
: worm-ur  +1 -2  0  0x70 0xF8 0x18 0x08 0x00
: worm-ru  +2 -1  0  0x70 0x38 0x18 0x18 0x10
: worm-r   +2  0  0  0x30 0x18 0x18 0x18 0x30
: worm-rd  +2 +1  0  0x10 0x18 0x18 0x38 0x70
: worm-dr  +1 +2  0  0x00 0x08 0x18 0xF8 0x70
: worm-d    0 +2  0  0x00 0x00 0x88 0xF8 0x70
: worm-dl  -1 +2  0  0x00 0x80 0xC0 0xF8 0x70
: worm-ld  -2 +1  0  0x40 0xC0 0xC0 0xE0 0x70
: worm-l   -2  0  0  0x60 0xC0 0xC0 0xC0 0x60
: worm-lu  -2 -1  0  0x70 0xE0 0xC0 0xC0 0x40

: queue-get  # ( -- v0=item )
	i := queue
	i += queuetail
	load v0
	queuetail += 1
;

: queue-put  # ( v0=item -- )
	i := queue
	i += queuehead
	save v0
	queuehead += 1
;

: queue-init  # ( -- )
	queuehead := 0
	queuetail := 0
;

:proto move-worm
: place-waffle
	i := waffle-sprite
	loop
		wafflex := random 0xFF
		waffley := random 0xFF
		sprite wafflex waffley WAFFLEHEIGHT
		if vf == 0 then return
		sprite wafflex waffley WAFFLEHEIGHT
	again
;

:proto score
:proto hiscore
: init
	clear
	hires

	# clear score
	i := score
	v0 := 0
	save v0
	
	# random ortho direction
	v0 := random 0x3
	headdir <<= v0
	headdir += v0
	# random pos (remember, it wraps)
	headx := random 0xFF
	heady := random 0xFF
	
	queue-init

	tailx := headx
	taily := heady
	growth := STARTLENGTH

	move-worm
	place-waffle
;

: hit-waffle?
	i := waffle-sprite
	sprite wafflex waffley WAFFLEHEIGHT
	sprite wafflex waffley WAFFLEHEIGHT
	v0 := vF
;

: eat-waffle
	sprite wafflex waffley WAFFLEHEIGHT
	place-waffle
	growth += 3
	i := score
	load v0
	v0 += 1
	i := score
	save v0
;

: bcd-temp 0 0 0

: draw-digits # ( v3=num, v4=x, v5=y )
	i := bcd-temp
	bcd v3
	load v2
	:proto nohundred
	if v3 < 100 then jump nohundred
	i := hex v0
	sprite v4 v5 5
	i := hex v1
	: nohundred
	:proto noten
	v4 += 5
	if v3 < 10 then jump noten
	sprite v4 v5 5
	: noten
	v4 += 5
	i := hex v2
	sprite v4 v5 5
;
	
: set-hiscore
	i := hiscore
	v0 := v3
	save v0
;
	

: show-score
	lores
	i := dead-score
	v4 := 15
	v5 := 8
	sprite v4 v5 0

	v4 += 20
	v5 += 3

	:next score v3 := 0
	draw-digits
	
	v4 += -10
	v5 += 6
	:next hiscore v0 := 0
	
	if v3 > v0 then set-hiscore
	v3 := v0

	draw-digits

	# busy loop so score stays up for a second
	v0 := 100
	loop
		v0 += -1
	if v0 != 0 then again 

	vF := key
;
 
: collision
	hit-waffle?
	if v0 == 1 then jump eat-waffle
	show-score
	init
;

: remove-segment
	queue-get
	# i = worm-dirtab + 8 * v0
	i := worm-dirtab
	v0 <<= v0
	v0 <<= v0
	v0 <<= v0
	i += v0
	# move worm
	load v2  # i now points at the sprite
	tailx += v0
	taily += v1
	# draw segment
	sprite tailx taily TAILHEIGHT
;

: move-worm
	# store current dir for tail
	v0 := headdir
	queue-put
	# remove tail ?
	if growth == 0 then remove-segment
	if growth != 0 then growth += -1
	# i = worm-dirtab + 8 * headdir
	i := worm-dirtab
	v0 <<= headdir
	v0 <<= v0
	v0 <<= v0
	i += v0
	# move worm
	load v2  # i now points at the sprite
	headx += v0
	heady += v1
	# draw segment
	sprite headx heady TAILHEIGHT
	if vf == 1 then collision
;

: title
	i := title-MrW
	v0 := 16
	v1 := 9
	sprite v0 v1 0
	i := title-orm
	v0 += 16
	sprite v0 v1 0
	vF := key
;

: main
	title
	init
	loop
		v0 := 7
		if v0 key then headdir += -1
		v0 := 9
		if v0 key then headdir += 1
		if headdir == NDIRS then headdir := 0
		if headdir == -1 then headdir := LASTDIR
		move-worm
	again

: queue