/*https://editor.p5js.org/p5/sketches/Simulate:_Particle
 * @name Particles
 * @description There is a light-weight JavaScript library named
 * particle.js which creates a very pleasing particle system.
 * This is an attempt to recreate that particle system using p5.js.
 * Inspired by Particle.js, contributed by Sagar Arora.
 */


// this class describes the properties of a single particle.
class Particle {
// setting the co-ordinates, radius and the
// speed of a particle in both the co-ordinates axes.
  constructor(){
    this.x = random(0,width);
    this.y = random(0,height);
    this.r = random(1,8);
    this.xSpeed = random(-2,2);
    this.ySpeed = random(-1,1.5);
  }

// creation of a particle.
  createParticle() {
    noStroke();
    fill('rgba(200,169,169,0.5)');
    circle(this.x,this.y,this.r);
  }

// setting the particle in motion.
  moveParticle() {
    if(this.x < 0 || this.x > width)
      this.xSpeed*=-1;
    if(this.y < 0 || this.y > height)
      this.ySpeed*=-1;
    this.x+=this.xSpeed;
    this.y+=this.ySpeed;
  }

// this function creates the connections(lines)
// between particles which are less than a certain distance apart
  joinParticles(particles) {
    particles.forEach(element =>{
      let dis = dist(this.x,this.y,element.x,element.y);
      if(dis<85) {
        stroke('rgba(255,255,255,0.04)');
        line(this.x,this.y,element.x,element.y);
      }
    });
  }
}

// an array to add multiple particles
let particles = [];

function setup() {
  createCanvas(720, 400);
  for(let i = 0;i<width/10;i++){
    particles.push(new Particle());
  }
}

function draw() {
  background('#0f0f0f');
  for(let i = 0;i<particles.length;i++) {
    particles[i].createParticle();
    particles[i].moveParticle();
    particles[i].joinParticles(particles.slice(i));
  }
}