X = 0

let speed = 3

​

function setup() {

  createCanvas(400, 400);

}

​

function draw() {

  background(bgColor);

  if (mouseIsPressed == true && mouseX < width/2){

    //print(mouseX + " " + mouseY);

    bgColor = 0;

  } else if (mouseIsPressed == true && mouseX >= width/2){

    bgColor = 255;

  } else {

    bgColor = 127;

    stroke(25);

    strokeWeight(1);

    fill(255);

    ellipse(X, 200, 100, 100);

    if (X > width)

      speed = -3;

      X = X + speed;  

​

  }

}