// Attraction / Repulsion

// https://thecodingtrain.com/challenges/56-attraction-and-repulsion-forces

​

let attractors = [];

let particles = [];

​

function setup() {

  createCanvas(windowWidth, windowHeight);

}

​

function mousePressed() {

  attractors.push(createVector(mouseX, mouseY));

}

​

function draw() {

  background(51);

  stroke(255);

  strokeWeight(4);

  particles.push(new Particle(random(width), random(height)));

​

  if (particles.length > 100) {

    particles.splice(0, 1);

  }

​

  for (let i = 0; i < attractors.length; i++) {

    stroke(0, 255, 0);

    point(attractors[i].x, attractors[i].y);

  }

  for (let i = 0; i < particles.length; i++) {

    let particle = particles[i];

    for (let j = 0; j < attractors.length; j++) {

      particle.attracted(attractors[j]);

    }

    particle.update();

    particle.show();

  }

​

}