While a moving spaceship is cool, what’s even cooler? A spaceship that shoots!

So, you’ve got your spaceship moving left and right on your screen using Codea Lua. That’s great! But let’s be honest, what’s a spaceship without some serious firepower? In this tutorial, we’ll add the ability to shoot bullets from our spaceship.

Step 1: Add the Bullet Sprite

First, let’s declare a table to keep track of our bullets. Add this line at the beginning of your code.

bullets = {}

Step 2: Modify the Spaceship Position

Move your spaceship lower on the screen to make room for the bullets. Update your setup() function as follows:

function setup() 

 viewer.mode = FULLSCREEN 

 shipX = WIDTH/2 

 shipY = HEIGHT/4 

 end

Step 3: Draw the Bullets

Add this loop inside your draw() function to draw and move the bullets:

for i, bullet in ipairs(bullets) do 

 ellipse(bullet.x, bullet.y, 10)

 bullet.y = bullet.y + 5

if bullet.y > HEIGHT then 

 table.remove(bullets, i) 

 end 

 end

Step 4: Shoot Bullets with Touch

Finally, let’s modify the touched(touch) function to shoot bullets when we tap the screen:

function touched(touch) 

 if touch.state == BEGAN then 

 table.insert(bullets, {x = shipX, y = shipY})

 end

if touch.x < shipX then

shipX = shipX – 5

elseif touch.x > shipX then 

 shipX = shipX + 5 

 end

Complete Code Listing

Here’s your complete updated code:

bullets = {}

function setup() 

 viewer.mode = FULLSCREEN 

 shipX = WIDTH/2 

 shipY = HEIGHT/4 

 end

function draw() 

 background(40, 40, 50) 

 sprite(asset.builtin.Space_Art.Red_Ship, shipX, shipY)

for i, bullet in ipairs(bullets) do 

 ellipse(bullet.x, bullet.y, 10)

 bullet.y = bullet.y + 5

if bullet.y > HEIGHT then

 table.remove(bullets, i)

 end

end

end

function touched(touch) if touch.state == BEGAN then 

 table.insert(bullets, {x = shipX, y = shipY}) 

 end

if touch.x < shipX then

shipX = shipX – 5

elseif touch.x > shipX then 

 shipX = shipX + 5 

 end

end

And there you have it! Your spaceship not only moves but also shoots bullets upwards. Imagine the possibilities now—dodging asteroids, shooting down alien invaders—you’re limited only by your creativity!

I hope this tutorial helps you take your Codea Lua game to the next level. Happy coding!