Kosoctverce

public Point selectPoint(int xp, int yp) {
            double x1, y1, x2, y2, x3, y3, x4, y4, x5, y5;
            //step 1: wide x, set y
            x1 = (double) xp * (double) y0 / (double) x0;
            y1 = (double) yp;

            //step2: rotate 45° CCW
            y2 = x1;
            x2 = -y1;

            //step3: round
            double base = y0 * Math.pow(2, 1 / 2);
            x3 = base * Math.round(x2 / base);
            y3 = base * Math.round(y2 / base);

            //step4: rotate 45° CW
            x4 = y3;
            y4 = -x3;

            //step5: un-wide x, copy y
            x5 = x4 * (double) x0 / (double) y0;
            y5 = y4;

            //final step: return
            return new Point((int) Math.round(x5), (int) Math.round(y5));
        }