Upgrade System

upgradeSystem.lua

-- made for Rogala, my Devtober 2022 entry
-- you can read the corresponding devlog on: 
-- https://ko-fi.com/Post/Eng-Devtober2022-3--MORE-UPGRADES-R6R3FL67S
-- https://itch.io/jam/devtober-2022/topic/2406837/achies-devlog-shmup-game


-- globals we need
levelUp = false
lvl = 1
upgrades = {5,0,0,0,0,3}
levelUpgrades = {}
upgradeIndicator = 0
playerXP = 0

-- in update upon player level up
if (playerXP >= lvl*2) and (not levelUp) then
		-- generate the random pickups and put them in the collection
    for i=0,3 do
			table.insert(levelUpgrades,math.random(0,5))
		end
    -- set variable to true, so we change controls from game mode
    -- to upgrade selection mode
		levelUp = true
    -- 0 our XP and increase the level
		playerXP = 0
		lvl = lvl+1
	end

  -- now we check if we use the level up dialog controls or regular
  -- gameplay ones
	if levelUp then
		if btn(4) then
			
      -- upon button press, we resume to the game
      levelUp = false
			
      -- save the currently indicated upgrade
			local choosenUpgrade = levelUpgrades[upgradeIndicator]
			-- and increase the player upgrades slot corresponding to the upgrade, hence saving
      -- the increased number of the selected upgrade
      upgrades[choosenUpgrade+1] = upgrades[choosenUpgrade+1]+1
			levelUpgrades = {}
		end
    
    -- this code just handles the hand cycling correctly between the shown upgrades
		if btnp(0) then
			upgradeIndicator = upgradeIndicator-1
		end
		if btnp(1) then
			upgradeIndicator = upgradeIndicator+1
		end
		
		if upgradeIndicator < 1 then
			upgradeIndicator = 4
		end
			
		if upgradeIndicator > 4 then
			upgradeIndicator = 1
		end	
			
	else
  -- player controls
  end
 end
 
 -- in draw call
 -- level up dialog
if (levelUp==true) then
  -- create the local collection for names
  local names = {"rocket","afterburner","Chain reloader","ion shield","repair bot","mini turrets"}
  -- draw a background so stage elements don't obscure anything
  rect(20,20,160,90,0)
  
  -- flash the level up text and the hand that indicates the choosen upgrade
  if t%20 > 10 then	
    print("--- level up ---",60,20,5)
    spr(12,18,20+upgradeIndicator*20,0)		
    print(levelUpgrades[upgradeIndicator],8,20+upgradeIndicator*20,3)
  end
  
  -- draw the randomly generated upgrades with offsets
  for _,up in ipairs(levelUpgrades) do
    rectb(26,18+_*20,14,14,5)
    spr(16+up, 30, 20+_*20, 0)
    print(names[up+1],50 ,20+_*20,5)
  end
end