78 lines, 2 of them comments · 1,061 tokens, written in 13 seconds for $0.056

 1  let particles = [];
 2  const NUM_PARTICLES = 900;
 3  let noiseScale = 0.0035;
 4  let hueBase;
 5  
 6  function setup() {
 7    createCanvas(windowWidth, windowHeight);
 8    colorMode(HSB, 360, 100, 100, 100);
 9    background(230, 40, 8);
10    hueBase = random(360);
11    for (let i = 0; i < NUM_PARTICLES; i++) {
12      particles.push(newParticle());
13    }
14    strokeWeight(1.2);
15  }
16  
17  function newParticle() {
18    return {
19      x: random(width),
20      y: random(height),
21      px: 0,
22      py: 0,
23      life: random(100, 400),
24      speed: random(0.8, 2.2),
25      hueOff: random(-40, 40)
26    };
27  }
28  
29  function draw() {
30    // very subtle fade for long trails
31    noStroke();
32    fill(230, 40, 8, 1.2);
33    rect(0, 0, width, height);
34  
35    for (let p of particles) {
36      p.px = p.x;
37      p.py = p.y;
38  
39      let n = noise(p.x * noiseScale, p.y * noiseScale, frameCount * 0.0015);
40      let angle = n * TWO_PI * 3;
41  
42      p.x += cos(angle) * p.speed;
43      p.y += sin(angle) * p.speed;
44      p.life--;
45  
46      let h = (hueBase + p.hueOff + n * 90) % 360;
47      if (h < 0) h += 360;
48      stroke(h, 70, 95, 28);
49      line(p.px, p.py, p.x, p.y);
50  
51      if (p.life <= 0 || p.x < -10 || p.x > width + 10 || p.y < -10 || p.y > height + 10) {
52        let np = newParticle();
53        p.x = np.x;
54        p.y = np.y;
55        p.life = np.life;
56        p.speed = np.speed;
57        p.hueOff = np.hueOff;
58      }
59    }
60  }
61  
62  function mousePressed() {
63    // reseed the field and palette on click
64    noiseSeed(floor(random(100000)));
65    hueBase = random(360);
66    background(230, 40, 8);
67    for (let p of particles) {
68      p.x = random(width);
69      p.y = random(height);
70      p.life = random(100, 400);
71    }
72  }
73  
74  function windowResized() {
75    resizeCanvas(windowWidth, windowHeight);
76    background(230, 40, 8);
77  }
78