.gitignore

prog.sublime-project
prog.sublime-workspace

8sRevenge.txt

A game for the Octo Chip-8 assembler/simulator. Play by visiting:

http://johnearnest.github.io/Octo/index.html?gist=537dfc6201dc356ef457

options.json

{"tickrate":"100","fillColor":"#306230","fillColor2":"#8BAC0F","blendColor":"#9BBC0F","backgroundColor":"#0F380F","buzzColor":"#333333","quietColor":"#000000","shiftQuirks":false,"loadStoreQuirks":false,"vfOrderQuirks":false,"enableXO":true}

prog.ch8

# 8s Revenge is a remake of the Atari VCS classic Yars Revenge, made by
# Corwyn Kalenda (ckalenda@gmail.com) for Octo-ber II, the 2015 Octo Game 
# Jam.
#
# WASD to move, V to fire.
#
# Chip8 is a virtual machine designed in 1977 for programming video games.
# Octo is a high level assembler, disassembler and simulator for Chip8.


:alias px v3
:alias py v4
:alias qx v5
:alias qy v6
:alias mx v7
:alias my v8
:alias bx v9
:alias by va
:alias zx vb
:alias zy vc
:alias flags vd
:alias frame ve

:const swirlyAnimMask 0b00000011
:const swirlyPrepMask 0b00000100
:const swirlyMoveMask 0b00001000
:const shieldModeMask 0b00010000
:const zorlonPrepMask 0b00100000
:const zorlonShotMask 0b01000000
:const playerAnimMask 0b10000000

: score
	0x00 0x00

: shieldoffset
	0x00

: main
	hires
	flags := 0b01000011	# explicitly initialize, because assumptions.
	
	zx := 0
	zy := 32

	plane 2
	px := 8
	py := 28
	v0 := 8
	i := playerright
	i += v0
	sprite px py 8

	qx := 116
	qy := 28
	i := quotile
	sprite qx qy 9

	plane 3
	mx := 108
	my := 32
	i := missile
	sprite mx my 1

	loop

: nzstart
		# redraw the neutral zone
		plane 1
		i := main
		v0 := random 0b1111111
		i += v0
		v1 := 50
		v2 := 0
		v0 := 16

		sprite v1 v2 0
		v2 += v0
		i += v0
		sprite v1 v2 0
		v2 += v0
		i += v0
		sprite v1 v2 0
		v2 += v0
		i += v0
		sprite v1 v2 0

: zorlonstart
		plane 3
		i := zorlon

: zorlonprep
		v0 := zorlonPrepMask
		v0 &= flags
		if v0 == 0 then jump zorlonshot
		
		sprite zx zy 2

		zx := 0
		zy := py
		zy += 3

		i := main
		v0 := random 0b1111111
		i += v0
		load v1
		i := zorlon
		save v1
		i := main
		v0 := random 0b1111111
		i += v0
		load v1
		i := zorlon
		v2 := 2
		i += v2
		save v1

		i := zorlon
		sprite zx zy 2

: zorlonshot
		v0 := zorlonShotMask
		v0 &= flags
		if v0 == 0 then jump zorlonDone
		sprite zx zy 2

		zx += 4

		v0 := 0b10000000
		v0 &= zx
		
		if v0 != 0 then jump zorlonreset	#zx is >= 128

		i := main
		v0 := random 0b1111111
		i += v0
		load v1
		i := zorlon
		save v1
		i := main
		v0 := random 0b1111111
		i += v0
		load v1
		i := zorlon
		v2 := 2
		i += v2
		save v1

		i := zorlon
		sprite zx zy 2

		jump zorlonDone
: zorlonreset
		v0 := zorlonShotMask
		v1 := 0xFF
		v0 ^= v1
		flags &= v0

: zorlonDone

: quotilestart
		# erase, update, and redraw Quotile
		v0 := swirlyAnimMask
		v0 &= flags
		if v0 == 3 
		begin 
			i := quotile
			sprite qx qy 9

			#update position here

			sprite qx qy 9
		else
			i := swirly

			if v0 == 0
			begin
				v1 := 0
			else
				if v0 == 1
				begin
					v1 := 8
					i += v1
				else
					if v0 == 2
					begin
						v1 := 16
						i += v1
					end
				end
			end

			sprite qx qy 8

			# set frame to next, draw, and update flags register
			v0 += 1
			v1 := 8
			if v0 == 3 
			begin 
				v0 := 0 
				i := swirly 
			else 
				i += v1 
			end

			sprite qx qy 8

			v1 := 0b11111100
			flags &= v1
			flags |= v0
		end

: missileStart
		plane 3
		v0 := 3
		v0 &= frame
		if v0 != 0 then jump missileDone

		i := missile
		sprite mx my 1

		v0 := px
		v0 += 4
		if mx == v0 then jump missileY
			v0 -= mx
			v1 := 0b10000000
			v0 &= v1
			if v0 == 0 begin mx += 1 else mx += -1 end

: missileY
		v0 := py
		v0 += 4
		if my == v0 then jump missileDraw
			v0 -= my
			v1 := 0b10000000
			v0 &= v1
			if v0 == 0 begin my += 1 else my += -1 end

: missileDraw
		sprite mx my 1

: missileDone

: playerstart
		plane 2
		# erase player
		i := playerright
		v0 := playerAnimMask
		v0 &= flags
		if v0 == 0 
		begin 
			v0 := 8
			i += v0
		end
		sprite px py 8

		# update player position
		v0 := 5   if v0 key begin py += -2 if py == 252 then py := 60 end 	# keyboard W
		v0 := 8   if v0 key begin py +=  2 if py == 60 then py := 252 end 	# keyboard S
		v0 := 7   if v0 key begin if px != 8   then px += -2 end 			# keyboard A
		v0 := 9   if v0 key begin if px != 114 then px +=  2 end 			# keyboard D
		
		# redraw player
		i := playerright
		v0 := playerAnimMask
		flags ^= v0	# advance the animation frame by toggling the flag from last frame
		v0 &= flags
		if v0 == 0 
		begin 
			v0 := 8
			i += v0
		end

		sprite px py 8

: bulletstart
		plane 1
		#first check to see if a bullet is active. If not, check for input
		if bx != 0 then jump updatebullet
		
		v0 := 0x0F
		if v0 -key then jump bulletdone

		bx := px
		bx += 8
		by := py
		by += 3
		i := bullet
		sprite bx by 1

: updatebullet
		# erase bullet, update, redraw
		i := bullet
		sprite bx by 1
		bx += 4
		v0 := 0b10000000
		v0 &= bx
		
		if v0 == 0 then jump bulletdraw	#bx is < 128

		bx := 0
		jump bulletdone

: bulletdraw
		sprite bx by 1

: bulletdone

: framedone
		# lock the framerate of this program via the delay timer:
		loop
			vf := delay
			if vf != 0 then
		again
		vf := 2
		delay := vf
		frame += 1

	again

: playerright
	0x1C 0x10 0x99 0xE6 0xE6 0x99 0x10 0x1C
	0x40 0x70 0x99 0xE6 0xE6 0x99 0x70 0x40

: quotile
	0x0F 0x1B 0x33 0xE3 0xFF 0xE3 0x33 0x1B 
	0x0F

: swirly
	0x18 0x20 0x26 0x99 0x99 0x64 0x04 0x18
	0x0C 0x10 0x90 0x9E 0x79 0x09 0x08 0x30
	0x20 0x4E 0x49 0x78 0x1E 0x92 0x72 0x04 

: bullet
	0x80

: missile
	0x7E 0x7E

: zorlon
	0x00 0x00 0x00 0x00

: shield 
	#two copies of sheild buffer for scrolling/rotation purposes
	0xFF 0xFF 0xFF 0xFF 0xFF 0xFF 0xFF 0xFF 0xFF 0xFF 0xFF 0xFF 0xFF 0xFF 0xFF 0xFF
	0xFF 0xFF 0xFF 0xFF 0xFF 0xFF 0xFF 0xFF 0xFF 0xFF 0xFF 0xFF 0xFF 0xFF 0xFF 0xFF