Planet.js

//This is the Sketch
var planet;
var blackhole;

var particles = [];


function setup() {
  createCanvas(1000, 950);

  planet = new Planet(300, 300, 100);
  blackhole = new Blackhole(-300, -300, 100);

  for (var i = 0; i < 100; i++) {

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

function draw() {
  background(255);

  push();
  translate(width / 2, height / 2);


  //for the blackhole
  for (var i = 0; i < particles.length; i++) {
    var p = particles[i];

    //gravity
    var gravity = p5.Vector.sub(blackhole.pos, p.pos);
    gravity.normalize();
    gravity.mult(blackhole.cGravity * p.mass);
    p.applyForce(gravity);

    var distance = p.pos.dist(blackhole.pos);

    //blackhole
    if (distance < blackhole.rad) {
      var resistance = p5.Vector.mult(p.vel, -1);
      resistance.normalize();
      var speed = p.vel.mag();
      resistance.mult(speed * speed * blackhole.cWaterResistance);
      resistance.limit(speed);
      // console.log(resistance);
      p.applyForce(resistance);
    }
  }


  for (var i = 0; i < particles.length; i++) {
    var p = particles[i];

    // gravity
    var gravity = p5.Vector.sub(planet.pos, p.pos);
    gravity.normalize();
    gravity.mult(planet.cGravity * p.mass);
    p.applyForce(gravity);

    var distance = p.pos.dist(planet.pos);

    // core
    if (distance < planet.coreRad) {
      p.vel.mult(planet.cCoreRestitution);
    }
    // water 
    else if (distance < planet.waterRad) {
      var resistance = p5.Vector.mult(p.vel, -1);
      resistance.normalize();
      var speed = p.vel.mag();
      resistance.mult(speed * speed * planet.cWaterResistance);
      resistance.limit(speed); 
      p.applyForce(resistance);
    }
    // air 
    else if (distance < planet.rad) {
      var resistance = p5.Vector.mult(p.vel, -1);
      resistance.normalize();
      var speed = p.vel.mag();
      resistance.mult(speed * speed * planet.cAirResistance);
      resistance.limit(speed); 
      p.applyForce(resistance);
      // wind
      var wind = p.vel.copy();
      wind.normalize();
      wind.rotate(radians(60));
      wind.mult(planet.cWindMagnitude);
      p.applyForce(wind);
    }

    p.update();
    p.display();
  }
  planet.update();
  planet.display();


  blackhole.update();
  blackhole.display();
  pop();
}


function mousePressed(){
  // console.log('mouse');
  var count = 0;
    for (var i = 0; i < particles.length; i++) {
      var p = particles[i];
      var distance = p.pos.dist(blackhole.pos);
      
      if(distance < blackhole.rad){
        count += 1;
        p.pos = createVector(random(270, 330), random(270, 330));
        p.vel = createVector(random(-5,5), random(-5,5));
      }
  }
  
  console.log('Number in black hole: ' + count);
}

//This is Particles.js
"use strict";

class Particle {
  constructor(x, y) {
    this.pos = createVector(x, y);
    this.vel = createVector(random(-5,5), random(-5,5));
    this.acc = createVector();
    this.dia = 2;
    this.mass = random(1, 10);
  }
  applyForce(f) {
    f.div(this.mass);
    this.acc.add(f);
  }
  update() {
    this.vel.add(this.acc);
    this.pos.add(this.vel);
    this.acc.mult(0);
  }
  display() {
    push();
    translate(this.pos.x, this.pos.y);
    noStroke();
    fill(225,248,249);
    ellipse(0, 0, this.dia * this.mass, this.dia * this.mass);
    pop();
  }
}

//This is Blackhole.js
"use strict";

class Blackhole{
  constructor(x,y,radius){
    this.pos = createVector(x,y);
    this.rad = radius;
    this.cGravity = radius*0.002;
    this.cWaterResistance = 0.03;
    
  }
  
  update(){
    
  }
  
  display(){
    push();
    
    fill(252,248,225,150);
    noStroke();
    ellipse(this.pos.x,this.pos.y,this.rad * 2,this.rad * 2);
    
    pop();
    
  }
}