<Bresenham's circle algorithm>=
public void bresCircle(int r) {
  int x = 0;
  int y = r;
  int g = 3 - 2*r;
  int diagonalInc = 10 - 4*r;
  int rightInc = 6;
  while (x <= y) {
    symmetricPlot (x, y);
    if (g >=  0) {
      g += diagonalInc; 
      diagonalInc += 8;
      y -= 1;
    }
    else {
      g += rightInc;
      diagonalInc += 4;
    }
    rightInc += 4;
    x += 1;
  }
}