Why do they keep going to the same position

[Seth144k]

So right now I'm trying to work on an enemy spawner I want the y to be the same but the x needs to be random. It is random and they are being spawned... But at the same spot. I've tried changing the seed but it still doesn't work. can anyone please help here is my love file

[darkfrei]

The lib src/enemy.lua must have such structure:

Code: Select all

local enemy = {} -- it is local!

function enemy:load()

end

function enemy:update(dt)

end

function enemy:draw()

end

return enemy -- return the local table

and the main.lua:

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local enemy = require("src/enemy")

You can call the math random as https://love2d.org/wiki/love.math.random

[Seth144k]

i updated it with

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function enemy:load()
    enemy.spawnTime = 0.1
    enemy.x = love.math.random(0, 800)
    enemy.y = 50
    enemy.w = 20
    enemy.h = 20
    table.insert(enemies, enemy)
    table.insert(enemies, enemy)
end

and it does the same thing as before

[Seth144k]

oh wait actually it makes the enemies freak out and glitch all over the screen how can i make it so that they just stay where their random number picked

[ReFreezed]

There are several problems in the code, one of which is there seems to be confusion about what the global 'enemy' variable represents. Is it supposed to be a kind of manager for multiple enemies, or is the (one and only) enemy. (Same with the global 'player' variable.) 'enemy' currently references the exact same table at all times. You also assign a new table to the global variable 'bullet', and another different new table to player.bullet (which is not referenced anywhere else in the code), in the player.shoot function. The global variable 'bullet' will thus always reference the last "spawned" bullet.

Another issue is that pairs() is used in loops when ipairs() should be used. The former doesn't care about the order of the items in the table (and is slower). Note that both ipairs() and pairs() may/will skip one element in the two places you call table.remove(player.bullets,i) inside the loops. Removals needs to happen something like this:

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for i = #player.bullets, 1, -1 do -- Loop backwards.
	if whatever then
		table.remove(player.bullets, i) -- Changes position of all bullets after 'i' (that we have already looped through as we loop backwards, so we don't care that their position changed).
	end
end

You should read up on local variables, modules, and classes.

[Seth144k]

thank you for helping me make it better but how can I do random generation? I just want it to spawn at a fixed y axis but always have the x value be random and i want it to spawn every 0.1 seconds. I got the actual generation working with a random value but no matter what happens the enemies get spawned at the same position when I want it to be diffrent

[darkfrei]

You are need:

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local function makeNewEnemy ()
	local enemy = {} -- new table, not your library
	enemy.spawnTime = 0.1
	enemy.x = love.math.random(0, 800)
	enemy.y = 50
	enemy.w = 20
	enemy.h = 20
	return enemy
end

function enemy:load()
	 -- self is your library enemy, it has methods self:load, self:update and self:draw; 
	self.enemies = {} -- also your library has now a new empty list of enemies
	local newEnemy = makeNewEnemy ()
	table.insert (self.enemies, newEnemy) -- adding new enemy to the list of enemies
end

So you can draw it as

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function enemy:draw()
	for i, enemy in ipairs (self.enemies) do -- iterate your list of enemies
		love.graphics.rectangle ('line', enemy.x, enemy.y, enemy.w, enemy.h)
	end
end

[ReFreezed]

Here's one way to spawn enemies dynamically at a fixed interval:

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local enemies = {}

local function spawnNewEnemy()
	local enemy = {
		x = math.random(0, 800),
		y = 50,
		w = 20,
		h = 20,
	}

	function enemy:update(dt)
		self.y = self.y + 40 * dt
	end

	function enemy:draw()
		love.graphics.rectangle("line", self.x,self.y, self.w,self.h)
	end

	table.insert(enemies, enemy)
end

local enemySpawnTimer = 0

local function updateEnemySpawner(dt)
	enemySpawnTimer = enemySpawnTimer - dt

	if enemySpawnTimer < 0 then
		enemySpawnTimer = 0.1
		spawnNewEnemy()
	end
end

function love.update(dt)
	-- Update enemies and other stuff.
	updateEnemySpawner(dt)

	for _, enemy in ipairs(enemies) do
		enemy:update(dt)
	end

	-- Despawn off-screen enemies and other stuff.
	for i = #enemies, 1, -1 do
		local enemy = enemies[i]

		if enemy.y > love.graphics.getHeight() then
			table.remove(enemies, i)
		end
	end
end

function love.draw()
	for _, enemy in ipairs(enemies) do
		enemy:draw()
	end

	love.graphics.print("Enemies: " .. #enemies)
end