var new_particle;

var inscreen = false;

var sound;

const particles = new ParticleSystem();

​

function preload() {

  let file = loadSound('explosion-small.wav');

  sound = () => {

    if(getAudioContext().state !== 'running') return;

    file.play(-0.5, 1.45);

  }

}

​

​

function setup() {

  const can = createCanvas(700, 700);

  colorMode(HSB, 360, 100, 100);

  can.mouseOver( () => inscreen = true );

  can.mouseOut( () => inscreen =  false ); 

​

  vel = p5.Vector.fromAngle(random(-PI,PI)).setMag(random(64,128))

  particles.add(new Circle(width/2, height/2, vel, random(25, 45), random(0,360)))

  btn3 = createButton('Audio: '+(getAudioContext().state == 'running' ? 'ON':'OFF'));

  btn3.parent('#div1')

  btn3.mouseClicked( () => {

     if (getAudioContext().state !== 'running'){

       getAudioContext().resume();

       btn3.html('Audio: ON');

     }else {

        getAudioContext().suspend();

        btn3.html('Audio: OFF');

     }

  });

  div2 = createDiv('s');

  div2.parent('#div1')

  div = createDiv('Credits: '+

      '<a href="https://freesound.org/people/ReadeOnly/sounds/186955/"> Freesounds.org </a>');

  div.parent('#div1')

​

​

  frameRate(60);

}

​

function mousePressed () {

  if(!inscreen) return;

  start_vec = createVector(mouseX, mouseY);

  new_particle = new Circle(mouseX, mouseY, createVector(0, 0),

                              random(15,45), random(0,360));

}

function mouseReleased () {

  if(!new_particle) return;

  // calculate velocity vector

  end_vec = createVector(mouseX, mouseY);

  new_particle.vel = end_vec.sub(start_vec).mult(0.05);

  // create standart velocity vector when too small

  if(new_particle.vel.mag() < 0.1)

    new_particle.vel = createVector(0, random(2, 4))

  // add particle to system

  particles.add(new_particle);

  new_particle = null;

}

​

​

function draw() {

  background(0, 0, 0, 0.25);

  if(new_particle){

    new_particle.x = mouseX;

    new_particle.y = mouseY;

    new_particle.show();

  }

​

  particles.render();

​

  div2.html('ParticleCount: '+ particles.particleCount)

}

​

​