var ps; var xy; function setup() { createCanvas(window.innerWidth, window.innerHeight); ps = new ParticleSystem(createVector(width / 2, height / 2)); } function draw() { xy = new p5.Vector(mouseX,mouseY) background(0, 0, 0,20); if (mouseIsPressed == true || millis() <1000) { ps.addParticle(); } ps.run(); }