[LIBGDX] Cantor pairing

[LIBGDX] Cantor pairing

package rma.ox.engine.core.math;

import com.badlogic.gdx.math.Vector2;

/****
 * When I need to flat 2D coord to an ID
 * https://en.wikipedia.org/wiki/Pairing_function
 */
public class CantorPairing {

    //𝜋(𝑎,𝑏)=(1/2)(𝑎+𝑏)(𝑎+𝑏+1)+𝑏 .
    public static double pair(double x, double y){
        return (0.5f * (x+y) * (x+y+1) + y);
    }

    public static Vector2 unpair(double z){
        Vector2 result = new Vector2();
        double t = Math.floor((Math.sqrt((8 * z + 1)) - 1) / 2);
        double x = t * (t + 3) / 2 - z;
        double y = z - t * (t + 1) / 2;
        result.set((float) x, (float) y);
        return result;
    }
}