/* 
 * PROJECT: NyARToolkitCS(Extension)
 * --------------------------------------------------------------------------------
 * The NyARToolkitCS is C# edition ARToolKit class library.
 * Copyright (C)2008-2009 Ryo Iizuka
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 * 
 * For further information please contact.
 *	http://nyatla.jp/nyatoolkit/
 *	<airmail(at)ebony.plala.or.jp> or <nyatla(at)nyatla.jp>
 * 
 */
using System;
using System.Collections.Generic;
using System.Text;

namespace jp.nyatla.nyartoolkit.cs.core
{
    public class NyARMath
    {
        /**
         * p2-p1ベクトルのsquare normを計算する。
         * @param i_p1
         * @param i_p2
         * @return
         */
        public static double sqNorm(NyARDoublePoint2d i_p1, NyARDoublePoint2d i_p2)
        {
            double x, y;
            x = i_p2.x - i_p1.x;
            y = i_p2.y - i_p1.y;
            return x * x + y * y;
        }
        public static double sqNorm(double i_p1x, double i_p1y, double i_p2x, double i_p2y)
        {
            double x, y;
            x = i_p2x - i_p1x;
            y = i_p2y - i_p1y;
            return x * x + y * y;
        }
        /**
         * p2-p1ベクトルのsquare normを計算する。
         * @param i_p1
         * @param i_p2
         * @return
         */
        public static double sqNorm(NyARDoublePoint3d i_p1, NyARDoublePoint3d i_p2)
        {
            double x, y, z;
            x = i_p2.x - i_p1.x;
            y = i_p2.y - i_p1.y;
            z = i_p2.z - i_p1.z;
            return x * x + y * y + z * z;
        }
        /**
         * 3乗根を求められないシステムで、３乗根を求めます。
         * http://aoki2.si.gunma-u.ac.jp/JavaScript/src/3jisiki.html
         * @param i_in
         * @return
         */
        public static double cubeRoot(double i_in)
        {
            double res = Math.Pow(Math.Abs(i_in), 1.0 / 3.0);
            return (i_in >= 0) ? res : -res;
        }

    }
}
