// this class describes the properties of a single particle.
 var palette = ["#04ff00", "#00ccff", "#ee00ff"];
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);
  }
  
  randomColor(){
    var colnum = Math.floor(Math.random() * 3);
    var color = palette[colnum];
  }

// creation of a particle.
  createParticle() {
    var colnum = Math.floor(Math.random() * 3);
    var color = palette[colnum];
    noStroke();
    fill(color);
    star(this.x, this.y, this.r, this.r, 3);
  }

// 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) {
        var colnum = Math.floor(Math.random() * 3);
    var color = palette[colnum];
    particles.forEach(element =>{
      let dis = dist(this.x,this.y,element.x,element.y);
      if(dis<85) {
        stroke(color);
        line(this.x,this.y,element.x,element.y);
      }
    });
  }
}

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

function setup() {
  createCanvas(800, 600);
  for(let i = 0;i<width/10;i++){
    particles.push(new Particle());
  }
}

function star(x, y, radius1, radius2, npoints) {
  let angle = TWO_PI / npoints;
  let halfAngle = angle / 2.0;
  beginShape();
  for (let a = 0; a < TWO_PI; a += angle) {
    let sx = x + cos(a) * radius2;
    let sy = y + sin(a) * radius2;
    vertex(sx, sy);
    sx = x + cos(a + halfAngle) * radius1;
    sy = y + sin(a + halfAngle) * radius1;
    vertex(sx, sy);
  }
  endShape(CLOSE);
}

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