float leftEyeX, leftEyeY;
float leftPupilX, leftPupilY;
float rightEyeX, rightEyeY;
float rightPupilX, rightPupilY;

void setup() {
  size(800, 400);

  leftEyeX = width * 0.25;
  leftEyeY = height * 0.5;

  rightEyeX = width * 0.75;
  rightEyeY = height * 0.5;
}

void draw() {
  background(200);

  if (mouseX > 0 && mouseY > 0 && mouseX < width && mouseY < height)
  {

    // --- LEFT PUPIL ---
    float a = leftEyeX - 40;
    float b = leftEyeX + 40;
    float c = leftEyeY - 40;
    float d = leftEyeY + 40;
    leftPupilX = map(mouseX, 0, 800, a, b);
    leftPupilY = map(mouseY, 0, 400, c, d);

    // --- RIGHT PUPIL ---
    a = rightEyeX - 40;
    b = rightEyeX + 40;
    c = rightEyeY - 40;
    d = rightEyeY + 40;
    rightPupilX = map(mouseX, 0, 800, a, b);
    rightPupilY = map(mouseY, 0, 400, c, d);
  }

  // --- DRAW EYEBALLS ---
  fill(255);
  ellipse(leftEyeX, leftEyeY, 200, 200);
  ellipse(rightEyeX, rightEyeY, 200, 200);

  // --- DRAW PUPILS ---
  fill(0);
  ellipse(leftPupilX, leftPupilY, 80, 80);
  ellipse(rightPupilX, rightPupilY, 80, 80);
}