TIC-80 HealthBar

healthBarIndication.lua

-- made for my Devtober2022 entry
-- you can read the corresponding devlog on: 
-- https://ko-fi.com/post/Eng-Devtober2020-2--Graphical-Enhancements-X8X3FKCIB
-- https://itch.io/jam/devtober-2022/topic/2406837/achies-devlog-shmup-game

function add_enemy(_x,_tpe,_family)
	local enemy = {
		x = _x,
		y = -4,
		sx = 0,
		sy = 0.2,
		sprite = 64+(_family*16) + _tpe*2,
		hp = 2*(1+_tpe),
		maxHp = 2*(1+_tpe),
		tpe = _tpe,
		isTarget = false,
		nextShoot = 10,
		shoot = 0,
		damaged = 0 --added a new variable to signal the time it was damaged
	}
	table.insert(enemies, enemy)
end

-- in the enemy update loop I added:
if enemy.shoot > 0 then
  enemy.shoot = enemy.shoot - 1
end

-- and in the bullet collision check i just set the timer for the fade
if collide(bul, enemy) then
  local damage = 1
  if bul.tpe == 1 then damage = 4 end
  enemy.hp = enemy.hp - damage
  table.remove(bullets,_)
  enemy.damaged = 90
end

-- After all this setup
-- in the enemy draw call I can do such:
if enemy.damaged > 0 then
  draw_healthbar(enemy.x-1,enemy.y-4,enemy.hp,enemy.maxHp,3,1)
end


-- Two color values one for the darker background, one for
-- the acutal color for contrast.
function draw_healthbar(_x,_y,_hp,_maxHp,_clrHp,_clrMax)
	rect(_x,_y,10,3,12)
	rect(_x+1,_y+1,8,1,_clrMax)
  -- calculate the percentage of the HP and draw the healthbar
  -- according to that length
	rect(_x+1,_y+1,8*(_hp/_maxHp),1,_clrHp)
end