Fun with Perlin noise #2

let R = 200;

let test;

let ParticleSystem = [];

let h,s,b;

​

function setup() {

  createCanvas(500, 500);

  background(0);

  colorMode(HSB,100);

  h = 93//random(0,360);

  s = 82//random(40,100);

  b = 59//random(50,100);

  //frameRate(240);

  //noiseSeed(144); 

  for (let i=0; i<50; i++) { 

    let x = random(-R,R);

    let y = random(-sqrt(R*R-x*x),sqrt(R*R-x*x));

    ParticleSystem[i] = new Particle(0,0);

  }

}

​

function draw() {

  drawingContext.shadowBlur=0;

  translate(width/2,height/2);

  fill(0,0,0,5);

  rectMode(CENTER);

  rect(0,0,width,height);

  noFill();

  stroke(h,s,b,100);

  strokeWeight(2);

  drawingContext.shadowBlur=10;

  drawingContext.shadowColor=color(h,s,b,60);

  ellipse(0,0,2*R,2*R);

  drawingContext.shadowBlur=0;

  for(let i=0; i<ParticleSystem.length;i++){

    ParticleSystem[i].update();

    ParticleSystem[i].draw();

    if(ParticleSystem[i].isDead()){ParticleSystem.splice(i,1);}

  }

  if(random(0,1)<0.5){

    //let x = random(-R,R);

    //let y = random(-sqrt(R*R-x*x),sqrt(R*R-x*x));

    ParticleSystem.push(new Particle(0,0));}

}

​

​

class Particle{

  constructor(x,y){

    this.x=x;

    this.y=y;

    this.color = color(h+random(-30,30),s+random(-30,30),b+random(-10,10),100);

    this.radius = random(2,4);

    this.noiseScale = random(0.01,0.1);

    this.speed = random(2,6);

    this.theta = random(0,2*PI);

    if (random(0,1)<0.5){this.speed=-this.speed;}

    this.K1 = random(0,500);

  }

  update(){

    this.theta += 0.2*(noise(this.K1*this.noiseScale)-0.5);

    //this.theta += random(-0.1,0.1);

    let dx1 = 0.2*this.speed*cos(this.theta);

    let dy1 = 0.2*this.speed*sin(this.theta);

    if(pow((this.x+dx1),2)+pow(this.y+dy1,2)<R*R){

      this.x+=dx1;

      this.y+=dy1;

    }

    else{

      //this.x = - this.x;

      //this.y= - this.y;

      this.speed = -this.speed;

    }

​

    this.radius *= 0.999;

    this.K1++;

}

  isDead(){

    if(this.radius<0.5){return true;}

    else{return false;}

  }

  draw(){

    noStroke();

    fill(this.color);

    ellipse(this.x,this.y,2*this.radius,2*this.radius);

  }

}