public class Shapes
{
   // MAKE THE FOUR POLYGON VERTICES FOR A THICK LINE SEGMENT

   static void thickLine(int ax, int ay, int bx, int by, int r, int X[], int Y[]) {
      double dx = bx - ax;
      double dy = by - ay;
      double d = Math.sqrt(dx * dx + dy * dy);
      dx = dx * r / d;
      dy = dy * r / d;

      X[0] = (int)(ax + dy);
      X[1] = (int)(bx + dy);
      X[2] = (int)(bx - dy);
      X[3] = (int)(ax - dy);

      Y[0] = (int)(ay - dx);
      Y[1] = (int)(by - dx);
      Y[2] = (int)(by + dx);
      Y[3] = (int)(ay + dx);
  }
}