var ball_num;

var ballX = [];

var ballY = [];

var speedX = [];

var speedY = [];

var ball_color = [];

var ball_diameter = [];



var colors = [];



function setup() {

  createCanvas(windowWidth,

               windowHeight);



  ball_num = 8000;



  colors.push(color(192, 192, 192));

  colors.push(color(192, 192, 200));

  colors.push(color(128, 64, 0));

  colors.push(color(64, 0, 128));

  colors.push(color(64, 64, 64));

  colors.push(color(0, 64, 128));

  colors.push(color(128, 128, 128));

  colors.push(color(255, 255, 255));



  for (var i = 0; i < ball_num; i = i + 1) {

    ballX[i] = random(3, windowWidth);

    ballY[i] = random(5, windowHeight);

    speedX[i] = random(-2.0, 5.0);

    speedY[i] = random(-6.0, 2.0);

    ball_color[i] = floor(random(0, colors.length));

    ball_diameter[i] = random(5, 20);

  }

}



function draw() {

  background(238, 238, 238, 80);

  noStroke();



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

    ballX[i] = ballX[i] + speedX[i];

    ballY[i] = ballY[i] + speedY[i];



    if (ballX[i] > windowWidth || ballX[i] < 0) {

      speedX[i] = -1 * speedX[i];

    }



    if (ballY[i] > windowHeight || ballY[i] < 0) {

      speedY[i] = -1 * speedY[i];

    }

  }



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

    fill(colors[ball_color[i]]);

    ellipse(ballX[i], ballY[i], ball_diameter[i]);

  }



}