85 lines, no comments · 1,132 tokens, written in 11 seconds for $0.030

 1  let particles = [];
 2  let zoff = 0;
 3  const num = 900;
 4  const scl = 20;
 5  let cols, rows;
 6  
 7  function setup() {
 8    createCanvas(windowWidth, windowHeight);
 9    cols = floor(width / scl) + 1;
10    rows = floor(height / scl) + 1;
11    colorMode(HSB, 360, 100, 100, 100);
12    background(0);
13    for (let i = 0; i < num; i++) {
14      particles.push(new Particle());
15    }
16  }
17  
18  function draw() {
19    noStroke();
20    fill(0, 0, 0, 6);
21    rect(0, 0, width, height);
22  
23    let yoff = 0;
24    let flow = [];
25    for (let y = 0; y < rows; y++) {
26      let xoff = 0;
27      flow[y] = [];
28      for (let x = 0; x < cols; x++) {
29        let angle = noise(xoff, yoff, zoff) * TWO_PI * 2;
30        let v = p5.Vector.fromAngle(angle);
31        v.setMag(0.4);
32        flow[y][x] = v;
33        xoff += 0.1;
34      }
35      yoff += 0.1;
36    }
37    zoff += 0.003;
38  
39    for (let p of particles) {
40      let cx = constrain(floor(p.pos.x / scl), 0, cols - 1);
41      let cy = constrain(floor(p.pos.y / scl), 0, rows - 1);
42      p.applyForce(flow[cy][cx]);
43      p.update();
44      p.edges();
45      p.show();
46    }
47  }
48  
49  class Particle {
50    constructor() {
51      this.pos = createVector(random(width), random(height));
52      this.vel = createVector(0, 0);
53      this.acc = createVector(0, 0);
54      this.maxSpeed = 2.5;
55      this.hue = random(360);
56    }
57    applyForce(f) {
58      this.acc.add(f);
59    }
60    update() {
61      this.vel.add(this.acc);
62      this.vel.limit(this.maxSpeed);
63      this.pos.add(this.vel);
64      this.acc.mult(0);
65      this.hue = (this.hue + 0.3) % 360;
66    }
67    edges() {
68      if (this.pos.x > width) this.pos.x = 0;
69      if (this.pos.x < 0) this.pos.x = width;
70      if (this.pos.y > height) this.pos.y = 0;
71      if (this.pos.y < 0) this.pos.y = height;
72    }
73    show() {
74      noStroke();
75      fill(this.hue, 70, 100, 40);
76      ellipse(this.pos.x, this.pos.y, 2.5, 2.5);
77    }
78  }
79  
80  function windowResized() {
81    resizeCanvas(windowWidth, windowHeight);
82    cols = floor(width / scl) + 1;
83    rows = floor(height / scl) + 1;
84    background(0);
85  }