// Daniel Shiffman

// http://natureofcode.com

​

let particle;

let prevPos;

let t = 0;

​

function setup() {

  createCanvas(windowWidth, windowHeight);

  particle = new Particle();

}

​

function mousePressed() {

  prevPos = createVector(mouseX, mouseY);

}

​

function mouseReleased() {

  let dx = mouseX - prevPos.x;

  let dy = mouseY - prevPos.y;

  let force = createVector(dx, dy);

  force.setMag(15);

  particle.applyForce(force);

  // particle.update();

}

​

​

function draw() {

  background(0);

​

  let gravity = createVector(0, 0.5);

  particle.applyForce(gravity);

  let wx = map(noise(t), 0, 1, -0.2, 1);

  let wind = createVector(wx, 0);

  particle.applyForce(wind);

  t += 0.02;

​

  if (mouseIsPressed) {

    let force = particle.acceleration.copy();

    force.mult(-1);

    particle.applyForce(force);

    particle.velocity.mult(0);

    particle.position.x = mouseX;

    particle.position.y = mouseY;

  }

​

  particle.update();

  particle.checkEdges();

​

  if (mouseIsPressed) {

    //particle.position.x = mouseX;

    //particle.position.y = mouseY;

​

  }

​

  particle.display();

}