let easing = 0.05;

const FACT = 1.0 / 1000.0;

​

let tx, ty;

​

function setup() {

  createCanvas(1000, 1000);

  tx = random(width);

  ty = random(height);

​

  particles = [];

  for (let i = 0; i < 50; i++) {

    // let tx = width/2;

    // let ty = height / 2;

    particles.push(

      new Particle(

        random(width),

        random(height),

        tx, //random(width),//width / 2,

        ty, //height / 2,

        random(255),

        random(10),

        random(40, 120)

      )

    );

  }

​

  background(220);

  strokeWeight(15);

}

​

function draw() {

  for (let i = particles.length-1; i >= 0; i--) {

    let p = particles[i];

    let r = p.update();

    let c = color(p.col);

    c.setAlpha(p.alph);

    stroke(c);

    point(p.x, p.y);

    if (!r) particles.splice(i,1);

  }

  if (random() > 0.5 && particles.length < 5000) {

    particles.push(

      new Particle(

        random(width),

        random(height),

        tx, //random(width),//width / 2,

        ty, //height / 2,

        color(random(255),random(255),random(255)),

        random(10),

        random(40, 120)

      )

    );

  }

  if (frameCount % 1000 == 0) {

    let _tx = random(width);

    let _ty = random(height);

    for (let p of particles) {

      p.tx = _tx;

      p.ty = _ty;

    }

  }

}

​

class Particle {

  constructor(x, y, tx, ty, col, size, alph) {

    this.x = x;

    this.y = y;

    this.tx = tx;

    this.ty = ty;

    this.col = col;

    this.size = size;

    this.alph = alph;

    this.t = 0;

  }

​

  update() {

    //     let dx = this.tx - this.x;

    //     this.x += dx * easing;

    //     let dy = this.ty - this.y;

    //     this.y += dy * easing;

    //     distance = to.x - from.x;

    // angleToPoint = atan2(to.y - from.y, to.x - from.x);

    // distanceFactor = 1/1000;

    // angleCorrection = (PI*0.18) * (distance * distanceFactor);

    // velocity.X = cos(angleToPoint+angleCorrection) * power;

    // velocity.Y = sin(angleToPoint+angleCorrection) * power;

    // let dist = sqrt((this.tx - this.x)**2 - (this.ty - this.y)**2);

    let dist = this.tx - this.x;

    let angleToPoint = atan2(this.ty - this.y, this.tx - this.x);

    let angleCorr = (PI * 0.18) * (dist * FACT);

    let vx = cos(angleToPoint + angleCorr) * 1.0;

    let vy = sin(angleToPoint + angleCorr) * 1.0;

    this.x += vx;

    this.y += vy;

    if (abs(dist) < 0.01 && abs(this.ty - this.y) < 0.01) return false;

    return true;

  }

}

​