tic80-stuff/shmup/shmup.lua

-- title:  untitled shmup
-- author: game developer
-- desc:   something like Gradius/Nemesis/Salamander/Life Force
-- script: lua

t=0

local bullet_speed = 6
local bullet_timer = 0
local bullet_timer_start = 10

local player_bullets = {}

local player = {
	x=0,y=0,
	vx=0,vy=0,
	speed=1.5,
	sp=256,
	fire_t=0,
	fire_held=false,
}

-- TODO: various types
function add_bullet()
	sfx(0, 'D-6', 10, 0, 11, 4)
	table.insert(player_bullets, {
		x=player.x + 10,
		y=player.y + 5,
		vx = 0,
		vy = 0,
	})
end

function draw_player()
	spr(player.sp, player.x, player.y, 0, 1, 0, 0, 2, 2)
end

function draw_bullets()
	for key,val in ipairs(player_bullets) do
		spr(258, val.x, val.y, 0)
	end
end

function handle_input()
	player.vx = 0
	player.vy = 0
	if btn(0) then
		player.vy=-player.speed
	end
	if btn(1) then
		player.vy=player.speed
	end
	if btn(2) then
		player.vx=-player.speed
	end
	if btn(3) then
		player.vx=player.speed
	end

	-- slow down diagonal movements
	if player.vx * player.vy ~= 0 then
		player.vx = player.vx * 0.707
		player.vy = player.vy * 0.707
	end

	player.x = player.x + player.vx
	player.y = player.y + player.vy

	player.fire_held = false
	if btn(4) then
		if player.fire_t <= 0 then
			player.fire_t = bullet_timer_start
			add_bullet()
		else
			player.fire_t = player.fire_t - 1
		end
		player.fire_held = true
	else
		player.fire_t = 0
	end
end

function TIC()
	handle_input()

	for key,val in ipairs(player_bullets) do
		val.x = val.x + bullet_speed
		if val.x > 240 then
			table.remove(player_bullets, key)
		end
	end

	cls(0)
	draw_player()
	draw_bullets()

	dbg(tostring(player.fire_t), 0)
	dbg(tostring(player.fire_held), 1)
	dbg(tostring(player.vx), 2)
	dbg(tostring(player.vy), 3)
	t=t+1
end

function dbg(msg, line_no)
	print(msg, 5, line_no * 7, 5, true, 1, true)
end

-- <SPRITES>
-- 000:00000000000000000000000000000000ede00000ecdef0000edddef00fcccc8b
-- 001:000000000000000000000000000000000000000000000000000000009cde0000
-- 002:0000000000000000000000004040440030303300000000000000000000000000
-- 016:cf9edd99dfb8eeee00db8ddd00008cce00000000000000000000000000000000
-- 017:aaeddcefeeeccde0ccde00000000000000000000000000000000000000000000
-- </SPRITES>

-- <WAVES>
-- 000:123345667889abbcdeff1fedcba86642
-- </WAVES>

-- <SFX>
-- 000:00d050808060c040d020e020f010f010f000f000f000f000f000f000f000f000f000f000f000f000f000f000f000f000f000f000f000f000f000f000502000000000
-- </SFX>

-- <PALETTE>
-- 000:1a1c2c5d275db13e53ef7d57ffcd75a7f07038b76425717929366f3b5dc941a6f673eff7f4f4f494b0c2566c86333c57
-- </PALETTE>