gemcatcher.8o

# Gem Catcher
# by Dakota Hernandez
#
# You play the role of an adventurer who has found themselves in a magical cave,
# rumored to once be the home of a powerful wizard. Deep within its tunnels, 
# they come across an enchanted room where gems drop from the ceiling! 
# Eager to strike it rich, the adventurer scrambles to catch as many as they can. 
# The room has some powerful protection, however – if five gems touch the ground, 
# then a powerful wave of magic will force the adventurer out of the cave. 
# How many gems can they catch before they are forced out?
#
# Controls
# A: move left
# D: move right
#
# Collect gems for as long as you can! Touch a gem to collect it.
# After 30 gems are collected, they fall at a faster rate.
# Let 5 touch the ground, and it's game over.
# Good luck!
#
# Works best at 15 Cycles/Frame, but try 20 for a tougher (and more difficult-to-control) mode.
#
# Last Edited: October 29, 2017

# sprites
: gem 0x7A 0x76 0x3C 0x18
: adventurer 0x5A 0xE7 0xBD 0x5A 0x3C 0x18 0x18 0x24
: adventurer-walk1 0x5A 0xE7 0xBD 0x5A 0x3C 0x18 0x38 0x04  
: adventurer-walk2 0x5A 0xE7 0xBD 0x5A 0x3C 0x18 0x1C 0x20 
: edge   0xFF 0xFF
: game-over1 0xAE 0xAA 0x4A 0x4E
: game-over2 0xA4 0xA4 0xA4 0xE6
: game-over3 0xEE 0xAC 0xA6 0xEE
: game-over4 0xE8 0x88 0xC0 0xE8


# List of Register Aliases
# Position, Lives, and Points for Adventurer
:alias advx     ve
:alias advy	vd
:alias lives	vc
:alias points	vb
:alias anim-frame va
# Gem Variables: Counter, Positions, timer, speed
:alias counter	v9
:alias gemx	v1
:alias gemy	v2
:alias gemspeed v8

# v0, v3-v6, and vf are left as temporaries

# temporary storage for gem data - First number is # of frames before spawning, the other two store the positions of the gems.
: g1  1 0 0
: g2 20 0 0
: g3 40 0 0
: g4 90 0 0

:const ADV_Y 23
:const INITIAL_SPEED 1
:const SPEED_UP 2

: main
	init-game
	# Main game loop
	loop
		move-adventurer
		update-gems
		if lives == 0 then jump gameover
		if points == 30 then gemspeed := SPEED_UP
	again

: init-game
# Initialize registers
	# Default positions
	advx := 28
	v3 := ADV_Y
	points := 0
	lives := 5
	counter := 0
	gemspeed := INITIAL_SPEED
# Draw the scene - we take advantage of sprite looping and just use one sprite command to draw the border.
	i := edge
	v0 := 0
	v4 := 31
	loop
		sprite v0 v4 2
		v0 += 8
		if v0 != 64 then
	again
	i := adventurer
	sprite advx v3 8
;

# Movement code for the player character
# Based on code from John Earnest's Octo Intermediate Tutorial for the Outlaw recreation.

: move-adventurer
	v4 := advx
	v5 := ADV_Y
	# update "position" depending on what key is held.
	v0 := 7
	if v0 key then v4 += -3
	v0 := 9
	if v0 key then v4 +=  3

	# Tweak v0 for animation purposes
	# Give it the proper offset for anim-frame later on
	# Since the adventurer is drawn with a size of 8, the offsets are 8 and 16,
	# ...each for a different frame.
	v0 := 0
	if v4 != advx then v0 := 16
	if anim-frame == 16 then v0 := 8

	# Erase, move, and redraw sprite
	i := adventurer
	i += anim-frame
	sprite advx v5 8
	advx := v4
	anim-frame := v0
	i := adventurer
	i += anim-frame
	sprite advx v5 8
;

# Gem Logic
# Based on code written by John Earnest for deep8.
# In deep8, enemies needed to be avoided and hit with bombs.
# In this game, however, the player wants to collide with gems and prevent them from touching the floor.

# Spawns a gem in a random horizontal position between 0 and 57.
# 0-57 is chosen so that no gems spawn in-between the wraparound portions of the play area.
: spawn-gem
	gemx := random 57
	gemy := 1
	i := gem
	sprite gemx gemy 4
;

: count-gem
	v0 -= v3
	if v0 == 0 then spawn-gem
;

# Update the position of the gem.
: update-gem
	if v0 != 0 then jump count-gem
	i := gem
	sprite gemx gemy 4
	gemy += gemspeed

	# decrement lives if the gem hits the surface. We also decrement points to counter the increment that happens when the gem disappears
	if gemy == 27 begin
		lives += -1
		points += -1
	end
	i := gem
	sprite gemx gemy 4

	# Increment score if the adventurer grabs a gem.
	if vf == 0 then return
	sprite gemx gemy 4
	v0 := random 31
	v0 += 10
	points += 1
;

: update-gems
	v3 := 1
	counter ^= v3
	if counter == 0 then return
	# We load the exact vertical position we want for each of the four possible gems.
	# Get gx, load it, x, and y from gemy, update it, save in gx
	i := g1 load gemy update-gem i := g1 save gemy
	i := g2 load gemy update-gem i := g2 save gemy
	i := g3 load gemy update-gem i := g3 save gemy
	i := g4 load gemy update-gem i := g4 save gemy
;

# When lives are 0, this code runs to "pause" the game and activate the buzzer. This buzzer remains for a few frames, then...
: gameover
	v0 := 32
	buzzer := v0
	delay  := v0
	loop
		v0 := delay
		if v0 != 0 then
	again
	lose-game	

# ...we clear the screen and we draw "YOU LOSE!"
: lose-game
	clear
	va := 18
	vb := 10
	i  := game-over1
	sprite va vb 4
	i  := game-over2
	va += 8
	sprite va vb 4
	i  := game-over3
	va += 8
	sprite va vb 4
	i  := game-over4
	va += 8
	sprite va vb 4
	loop again
;