Hey Miguel, let's tackle those two frustrating missile problems in your 2D shooter—they're super common when you're first working with object management in Love2D, so we'll get them sorted quickly.

1. Why Subsequent Missiles Keep Speeding Up #

This almost always happens because you're not treating each missile as an independent object with its own fixed speed. Here's the likely culprit:

• You might be using a global missile_speed variable that's getting incremented every time you fire, or you're accidentally modifying the speed value in your update loop for all missiles instead of leaving it static.
• Or, you're reusing the same missile object and updating its speed each time you fire, rather than creating a fresh object with a reset speed.

Fix: Give Each Missile Its Own Speed Property #

Store all missiles in a table, and initialize each new missile with a fixed speed value. This way, every projectile starts with the same velocity, no matter when it's fired.

-- Initialize a global table to track all active missiles
missiles = {}

-- Player setup (adjust to match your existing player code)
player = {
    x = love.graphics.getWidth()/2 - 15,
    y = love.graphics.getHeight() - 50,
    width = 30,
    height = 40
}

function love.keypressed(key)
    if key == "space" then
        -- Create a NEW missile object with a fixed initial speed
        local new_missile = {
            x = player.x + player.width/2 - 2, -- Center missile on player
            y = player.y,
            width = 4,
            height = 12,
            speed = -9 -- Fixed upward speed (negative = decrease Y position)
        }
        table.insert(missiles, new_missile) -- Add to our missiles table
    end
end

function love.update(dt)
    -- Update every missile in the table (iterate backward to safely remove entries)
    for i = #missiles, 1, -1 do
        local missile = missiles[i]
        missile.y = missile.y + missile.speed * dt

        -- Remove missiles that have left the top of the screen
        if missile.y + missile.height < 0 then
            table.remove(missiles, i)
        end
    end
end

2. Why Old Missiles Disappear When Firing New Ones #

This is a classic case of overwriting a single missile variable instead of storing multiple missiles. If you're doing something like missile = {x=..., y=...} every time you fire, you're replacing the old missile data with the new one—so only the latest missile exists.

Fix: Use a Table to Track All Active Missiles #

We already started this in the fix above, but let's make sure your draw loop is also iterating over the entire missiles table to render every projectile:

function love.draw()
    -- Draw your player ship first
    love.graphics.rectangle("fill", player.x, player.y, player.width, player.height)

    -- Draw EVERY missile in the missiles table
    for _, missile in ipairs(missiles) do
        love.graphics.rectangle("fill", missile.x, missile.y, missile.width, missile.height)
    end
end

Quick Checklist to Verify #

• Are you using a table to store missiles, not a single variable?
• Is each new missile initialized with a fixed speed value, not a global variable that's being modified?
• Are you iterating over the entire missiles table in both update and draw functions?

If you had any custom logic (like missile acceleration power-ups), you can adjust individual missile speeds later, but starting with independent, fixed-speed objects will solve both your current issues.

内容的提问来源于stack exchange，提问作者Miguel