• setup(), draw(), and mousePressed() are special p5.js lifecycle functions
• They must live at the top/global level

┌────────────────────────────┐ │ Global Scope │ │ │ │ function setup() { } │ │ function draw() { } │ │ │ │ function generateArt() { │ │ // helper code │ │ } │ │ │ │ function mousePressed() { │ │ generateArt(); │ │ } │ └────────────────────────────┘

✅ The rule

In p5.js, all event functions must be defined in the global scope:

• mousePressed()
• mouseReleased()
• mouseMoved()
• keyPressed()
• keyReleased()
• keyTyped()

If they are inside another function, they will not run.

🧠 Why this is true (conceptually)

p5.js works like this:

“At startup, I scan the global scope to see if you defined any event handlers.

If I don’t see them there, I assume they don’t exist.”

p5.js does not search inside your own functions.