boolean isColliding() {
    int distanceX = abs(x - player.x);
    int distanceY = abs(y - player.y);

    if (distanceX > (player.size/2 + radius)) { return false; }
    if (distanceY > (player.h/2 + radius)) { return false; }

    if (distanceX <= (player.size/2)) { return true; }
    if (distanceY <= (player.h/2)) { return true; }

    int cornerDistance_sq = (distanceX - player.size/2)^2 +
                         (distanceY - player.h/2)^2;

    return (cornerDistance_sq <= (radius^2));
  }