docs: private static int code(Rectangle r, Point p) {
          int code = INSIDE;
          if (p.x < r.left) {
              // to the left of clip window
              code |= LEFT;
          } else if (p.x > r.right) {
              // to the right of clip window
              code |= RIGHT;
          }
  
          if (p.y > r.bottom) {
              // below the clip window
              code |= BOTTOM;
          } else if (p.y < r.top) {
              // above the clip window
              code |= TOP;
          }
          return code;
      }