Introduction to LÖVE and Lua

Your First Game Engine

To create a game, you don't have to start from scratch. A game engine or framework gives you the basic tools to handle things like drawing graphics, playing sounds, and getting input from the keyboard or mouse. This lets you focus on the fun part: designing the game itself.

We'll be using LÖVE, a popular, free framework for making 2D games. It's known for being easy to pick up and powerful enough for complex projects. One of its best features is that it's cross-platform. You can write your game once and run it on Windows, macOS, Linux, and even mobile devices with minimal changes.

LÖVE is open-source, which means its code is publicly available and supported by a community of developers. If you get stuck, there's a friendly community and lots of documentation to help you out.

Meet Lua

Every game engine needs a programming language to tell it what to do. LÖVE uses Lua. Lua is a scripting language known for its simplicity and speed. It was designed to be lightweight and easy to embed in other applications, which makes it perfect for game development.

If you've never coded before, Lua is a great place to start. Its syntax is clean and often reads like plain English. You don't need to worry about complex rules or confusing symbols. Let's look at the basics.

-- This is a comment. The computer ignores it.

-- Variables store information.
score = 100 -- This is a number
playerName = "Alex" -- This is a string (text)
isGameOver = false -- This is a boolean (true or false)

-- You can change a variable's value.
score = score + 10 -- score is now 110

In Lua, you create variables simply by giving them a name and a value using the equals sign. Comments, which are notes for humans, start with two hyphens --. These are the fundamental building blocks you'll use to create your game's logic.

Lua is a powerful and fast programming language that is easy to learn and use and to embed into your application.

The LÖVE Lifecycle

Every LÖVE game is built around three special functions. Think of them as the three acts of a play that repeats over and over, very quickly.

love.load(): This runs only once, right when your game starts. It's where you set everything up: load images, create variables, and prepare the stage.
love.update(dt): This runs continuously, over and over. It's where all your game's logic happens. Did the player press a key? Should an enemy move? The dt stands for "delta time," which is the tiny fraction of a second that has passed since the last update. Using dt ensures your game runs at the same speed on fast and slow computers.
love.draw(): This also runs continuously, right after each update. Its only job is to draw everything to the screen in its current state. You don't change any game logic here, you just show the results of the last update.

This structure keeps your code organized. Setup logic goes in love.load, game rules go in love.update, and drawing instructions go in love.draw.

A Simple Example

Let's see this in action. Here is the complete code for a simple LÖVE program that draws a white circle and moves it across the screen. All LÖVE games need a file named main.lua to start.

function love.load()
    -- Set up our circle's starting position.
    -- x is the horizontal position, y is the vertical.
    circleX = 100
end

function love.update(dt)
    -- Move the circle to the right every frame.
    -- We multiply by dt to keep the speed consistent.
    circleX = circleX + 200 * dt 
end

function love.draw()
    -- Set the drawing color to white.
    love.graphics.setColor(1, 1, 1)

    -- Draw a filled circle at our updated position.
    -- love.graphics.circle(mode, x, y, radius)
    love.graphics.circle("fill", circleX, 300, 50)
end

First, love.load creates a variable circleX and sets it to 100. Then, love.update repeatedly adds a small amount to circleX, making it bigger over time. Finally, love.draw clears the screen and draws a circle at the current circleX position.

That's it! You now understand the core concepts of making games with LÖVE and Lua. We've covered the engine, the language, and the main lifecycle of a LÖVE application.

Quiz Questions 1/5

What is the primary purpose of using a game framework like LÖVE?

Quiz Questions 2/5

Which LÖVE callback function is responsible for handling game logic, such as moving characters and checking for collisions?

Build Apps with LÖVE