36 lines, no comments · 279 tokens, written in 3 seconds for $0.0031

 1  let circles = [];
 2  
 3  function setup() {
 4    createCanvas(windowWidth, windowHeight);
 5    noFill();
 6  }
 7  
 8  function draw() {
 9    background(30);
10    let cx = width / 2;
11    let cy = height / 2;
12    let maxRadius = min(width, height) * 0.6;
13  
14    stroke(255, 150);
15    strokeWeight(2);
16  
17    for (let i = 0; i < circles.length; i++) {
18      let circle = circles[i];
19      let radius = map(circle.age, 0, circle.lifetime, 0, maxRadius);
20      ellipse(cx, cy, radius * 2);
21      circle.age++;
22  
23      if(circle.age > circle.lifetime) {
24        circles.splice(i, 1);
25        i--;
26      }
27    }
28  
29    if (frameCount % 20 === 0) {
30      circles.push({ age: 0, lifetime: 150 });
31    }
32  }
33  
34  function windowResized() {
35    resizeCanvas(windowWidth, windowHeight);
36  }