[Beginner / Lua, LOVE2D] How to fix this bullet spawning?

Hi everyone,

I've seen in some researches on Google that this forum is about helping people programming. I may be wrong and in that case please let me know. Otherwise, here is something I'm bothered with :

I've been learning and following this YouTube tutorials to learn the basics of Lua and LOVE2D. In this video in particular ( https://www.youtube.com/watch?v=FUiz1kL0QtI&list=PLz-rYTT-2nItPbZaj8pt10h49HofbWVQT ) the author tells us how to spawn bullets in between a cooldown condition, make those bullets move from the player's body to the top of the window and then make them disappear.

To do this, the method he's used - and that I've followed - is by adding the bullets (as tables) in a table (player.bullets) every time the user presses "space". Then, if I get everything right, the program checks if there is any bullet item in the player.bullets table and draw them. Then, it updates itself with the conditions we've wirtten, making them go up until they reach y = -10 and then delete them from the table.

Here is the code he's used :

function love.load()
  player = {}
  player.x = 0
  player.y = 550
  player.bullets = {}
  player.cooldown = 20
  player.speed = 10
  player.fire = function()
    if player.cooldown <= 0 then
      player.cooldown = 20
      bullet = {}
      bullet.x = player.x + 35
      bullet.y = player.y
      table.insert(player.bullets, bullet)
    end
  end
end

function love.update(dt)
  player.cooldown = player.cooldown - 1

  if love.keyboard.isDown("right") then
    player.x = player.x + player.speed
  elseif love.keyboard.isDown("left") then
    player.x = player.x - player.speed
  end

  if love.keyboard.isDown(" ") then
    player.fire()
  end

  for i,b in ipairs(player.bullets) do
    if b.y < -10 then
      table.remove(player.bullets, i)
    end
    b.y = b.y - 10
  end
end

function love.draw()
  -- draw the player
  love.graphics.setColor(0, 0, 255)
  love.graphics.rectangle("fill", player.x, player.y, 80, 20)


  -- draw bullets
  love.graphics.setColor(255, 255, 255)
  for _,b in pairs(player.bullets) do
    love.graphics.rectangle("fill", b.x, b.y, 10, 10)
  end
end

I wanted to play around with the code to better understand its mechanics. Thus, I tried to play with the player.bullets table and add two types of items in it, just to check what it would do. So I decided to make "multi bullets" spawn with a longer cooldown and make them have a different moving pattern.

Thus I made this code : (note that there is more code not used, it's because there is a bit of the tutorial's next lesson in there, but not much and I believe most of it is in commentary)

function love.load()
--
player = {}
player.x = 0
player.y=575
player.speed=7.5 
player.bullets={}
player.cooldown=0
player.cooldownMulti=0 
player.fire = function()
  if player.cooldown <= 0 then
    -- + long cooldown = + lent shooting
    player.cooldown=10
    bullet = {}
    bullet.x = player.x + 7.5
    bullet.y = player.y
    table.insert (player.bullets, bullet)
  end
  if player.cooldownMulti <= 0 then
    player.cooldownMulti=50
    multiBulletL = {}
    multiBulletL.x = player.x - 15
    multiBulletL.y = player.y
    table.insert (player.bullets, multiBulletL)
    multiBulletR = {}
    multiBulletR.x = player.x + 30
    multiBulletR.y = player.y
    table.insert (player.bullets, multiBulletR)
  end
  
end

 --y = 0

ennemies_controller = {}
ennemies_controller.ennemies = {}
end

--[[function ennemies_controller:spawnEnnemy()

enemy = {}
ennemy.x = 0
ennemy.y=0
ennemy.speed=7.5 
ennemy.bullets={}
ennemy.cooldown=0
end

function ennemy:fire()
 if self.cooldown <= 0 then
    -- cooldown <=> vitesse
    self.cooldown=10
    bullet = {}
    bullet.x = self.x + 7.5
    bullet.y = self.y
    table.insert (self.bullets, bullet)
  end 
end]]


--               dt=delta time
function love.update(dt)
  player.cooldown=0 --player.cooldown-1
  player.cooldownMulti=0 --player.cooldownMulti-1
  
  if love.keyboard.isDown("right") then
    player.x = player.x+player.speed
  end
  if love.keyboard.isDown("left") then
    player.x = player.x-player.speed
  end
  -- gauche droite
  --[[if love.keyboard.isDown("up") then
    player.y = player.y-1
  end
  if love.keyboard.isDown("down") then
    player.y = player.y+1
  end]]
  if love.keyboard.isDown("space") then
    player.fire()
  end
  
  for i,v in ipairs (player.bullets) do

    -- vitesse bullets
    if v==bullet then
    v.y = v.y-8
    end
    if v==multiBulletL then
    v.x = v.x-1    
    v.y = v.y-6.5
    end
    if v==multiBulletR then
    v.x = v.x+1    
    v.y = v.y-6.5
    end
    
        if v.y < -10 then
      table.remove(player.bullets, i)
    end
    end
  
end
function love.draw()
  --                     r    v     b  (max 255)  
  love.graphics.setColor(1, 0, 0)
  --                              x          y   l   h
  love.graphics.rectangle("fill", player.x, player.y, 30, 30)

  
  for _,v in pairs(player.bullets) do
    if v==bullet then
      love.graphics.setColor(200, 1, 1)  
      love.graphics.rectangle("fill", v.x, v.y, 15, 15)
    end
    if v==multiBulletL then
      love.graphics.setColor(0, 1, 1)  
      love.graphics.rectangle("fill", v.x, v.y, 15, 15) 
    end
    if v==multiBulletR then
      love.graphics.setColor(0, 1, 1)  
      love.graphics.rectangle("fill", v.x, v.y, 15, 15) 
    end
  
end
end

But the behaviour of the bullets is weird now. It actually draws the new bullets and they have the moving pattern I wanted but something made that :

1. they don't launch until we release the space (instead of shooting while we press space) ,
2. they disappear every time we press space.

If someone would be kind enough to try to explain to me what went wrong when I tried to upgrade this code, I'd glady appreciate.

Bye ! pl4typus

Thanks for the proposition, I'll try to search for one.

However, in the first version (the one of the tutorial), it's still the same checking love.keyboard.isDown , so I assume it's not where the problem is.

By trying different things, I have understood that something is up with the if statements I have put in my for k,v in pairs(t) loop. Then, I assume that it is the checking v==bullet that is causing an issue(where v is the value of items in the table t called earlier in the for loop, and bullet would be the value of items in this table). I assume this because in the working, tutorial, version of the code, there is a working if statement inside a for loop in the form of if b.y < -10 then.

Hence, I'm LOST ( :'( ) hahaha. So, yeah. What do you think ?