var angle = 0;

function setup() {
  createCanvas(400, 400);
}

function draw() {
  background(255);
  noFill();

  rect(200, 200, 55, 100);
  ellipse(255, 200, 80);

  // Calculate target box coordinate
  x = 180;
  w = 255 - 40 * sin(angle) - 180;
  y = 200 + 40 * cos(angle);
  h = 310 - y;
  rect(x, y, w, h);

  // Calculate IoU
  xmin_max = max(200, x);
  xmin_min = min(200, x);
  xmax_min = min(255, x+w);
  xmax_max = max(255, x+w);
  ymin_max = max(200, y);
  ymin_min = min(200, y);
  ymax_min = min(300, y+h);
  ymax_max = max(300, y+h);
  iou = ((xmax_min - xmin_max) * (ymax_min - ymin_max)) / (w * h + 55 * 100 - (xmax_min - xmin_max) * (ymax_min - ymin_max))
  iou = iou.toFixed(2)
  textSize(32);
  fill(0, 102, 153);
  text('iou = ' + str(iou), 50, 150);

  // Update angle
  if (angle >= (2 * PI)) {
    angle = 0;
  } else {
    angle += (PI / 200);
  }
}