let circlePosY;

let speedX = 5;

let speedY = 5;

let circleRadius;

​

function setup() {

  createCanvas(600, 400);

  circleRadius = width / 32;

  circlePosX = circleRadius;

  circlePosY = circleRadius;

  noFill();

  stroke(0,50);

}

​

function draw() {

  // fill(255, 20);

  // rect(0,0,width, height);

​

  //noStroke();

 // fill(255, 120, 0, 200);

  circle(circlePosX, circlePosY, circleRadius * 2);

​

  circlePosX += speedX;

  circlePosY += speedY;

​

  if (circlePosX > width - circleRadius || circlePosX < circleRadius) {

    speedX *= -1;

  }

​

  if (circlePosY > height - circleRadius || circlePosY < circleRadius) {

    speedY *= -1;

  }

}

​