love2d-core

LÖVE (Love2D) Core

Set up and debug the foundation of a LÖVE game in Lua: the callback loop, frame-rate- independent movement, input, and screen states. Targets LÖVE 11.5.

When to use

• Use when starting a LÖVE game, wiring up main.lua/conf.lua, or fixing the core loop, movement that runs at the wrong speed, input handling, or screen switching.
• Use when the workspace has main.lua calling love.*, a conf.lua, or a .love file.

When not to use: Lua language questions unrelated to LÖVE; physics bodies/joints (LÖVE uses Box2D via love.physics — a separate concern); shader code (love.graphics GLSL is its own topic). For cross-engine save/load patterns, use save-systems.

Core workflow

1. Confirm the entry points. A LÖVE game runs main.lua; it should define love.load() (one-time setup), love.update(dt) (state), and love.draw() (rendering). Window/version setup goes in conf.lua (run before modules load).
2. Pin the version. Set t.version = "11.5" in conf.lua so LÖVE warns on mismatch.
3. Drive all motion by dt (delta time, in seconds) so speed is frame-rate independent.
4. Handle input two ways: polled (love.keyboard.isDown in update, for held keys) and event (love.keypressed callback, for discrete presses).
5. Manage screens (menu, game, pause) with a small state stack rather than a pile of if flags — see Patterns and references/state-stack.md.
6. Run and observe. Launch with love . from the project folder; verify the window, motion speed, and input on screen before assuming it works.

Patterns

1. main.lua skeleton (the callback loop + input)

-- main.lua — LÖVE calls these callbacks for you. Colors are 0–1 in LÖVE 11.x.
function love.load()
    -- One-time setup. speed is in PIXELS PER SECOND, not per frame.
    player = { x = 100, y = 100, size = 40, speed = 220 }
    love.graphics.setBackgroundColor(0.1, 0.1, 0.12)
end

function love.update(dt)
    -- Polled input: good for continuous movement while a key is held.
    if love.keyboard.isDown("right") then player.x = player.x + player.speed * dt end
    if love.keyboard.isDown("left")  then player.x = player.x - player.speed * dt end
    if love.keyboard.isDown("down")  then player.y = player.y + player.speed * dt end
    if love.keyboard.isDown("up")    then player.y = player.y - player.speed * dt end
end

function love.draw()
    love.graphics.setColor(0.2, 0.8, 1.0)                 -- tint ON
    love.graphics.rectangle("fill", player.x, player.y, player.size, player.size)
    love.graphics.setColor(1, 1, 1)                       -- reset tint before text/images
    love.graphics.print("Arrow keys to move, Esc to quit", 10, 10)
end

function love.keypressed(key)
    -- Event input: fires once per physical press. Use for menus, jumps, toggles.
    if key == "escape" then love.event.quit() end
end