/* 
 * PROJECT: NyARToolkitCS
 * --------------------------------------------------------------------------------
 * This work is based on the original ARToolKit developed by
 *   Hirokazu Kato
 *   Mark Billinghurst
 *   HITLab, University of Washington, Seattle
 * http://www.hitl.washington.edu/artoolkit/
 *
 * The NyARToolkitCS is Java 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;
namespace jp.nyatla.nyartoolkit.cs.core
{



    /**
     * このクラスは、三次元ベクトルを格納します。
     * 一部の計算関数は、{@link NyARRotMatrixV2}へ移動しました。
     * 通常、ユーザがこのクラスを使うことはありません。{@link NyARRotMatrix}クラスから使います。
     */
    public class NyARRotVector
    {
        /** ベクトル要素1*/
        public double v1;
        /** ベクトル要素2*/
        public double v2;
        /** ベクトル要素3*/
        public double v3;

        /**
         * コンストラクタです。
         * 初期値を持たないインスタンスを生成します。
         * @
         */
        public NyARRotVector()
        {
        }
        /**
         * この関数は、ARToolKitのcheck_rotationに相当する計算をします。
         * 詳細は不明です。(2つのベクトルの関係を調整？)
         * @
         */
        public static bool checkRotation(NyARRotVector io_vec1, NyARRotVector io_vec2)
        {
            double w;
            int f;

            double vec10 = io_vec1.v1;
            double vec11 = io_vec1.v2;
            double vec12 = io_vec1.v3;
            double vec20 = io_vec2.v1;
            double vec21 = io_vec2.v2;
            double vec22 = io_vec2.v3;

            double vec30 = vec11 * vec22 - vec12 * vec21;
            double vec31 = vec12 * vec20 - vec10 * vec22;
            double vec32 = vec10 * vec21 - vec11 * vec20;
            w = Math.Sqrt(vec30 * vec30 + vec31 * vec31 + vec32 * vec32);
            if (w == 0.0)
            {
                return false;
            }
            vec30 /= w;
            vec31 /= w;
            vec32 /= w;

            double cb = vec10 * vec20 + vec11 * vec21 + vec12 * vec22;
            if (cb < 0)
            {
                cb = -cb;//cb *= -1.0;			
            }
            double ca = (Math.Sqrt(cb + 1.0) + Math.Sqrt(1.0 - cb)) * 0.5;

            if (vec31 * vec10 - vec11 * vec30 != 0.0)
            {
                f = 0;
            }
            else
            {
                if (vec32 * vec10 - vec12 * vec30 != 0.0)
                {
                    w = vec11; vec11 = vec12; vec12 = w;
                    w = vec31; vec31 = vec32; vec32 = w;
                    f = 1;
                }
                else
                {
                    w = vec10; vec10 = vec12; vec12 = w;
                    w = vec30; vec30 = vec32; vec32 = w;
                    f = 2;
                }
            }
            if (vec31 * vec10 - vec11 * vec30 == 0.0)
            {
                return false;
            }

            double k1, k2, k3, k4;
            double a, b, c, d;
            double p1, q1, r1;
            double p2, q2, r2;
            double p3, q3, r3;
            double p4, q4, r4;


            k1 = (vec11 * vec32 - vec31 * vec12) / (vec31 * vec10 - vec11 * vec30);
            k2 = (vec31 * ca) / (vec31 * vec10 - vec11 * vec30);
            k3 = (vec10 * vec32 - vec30 * vec12) / (vec30 * vec11 - vec10 * vec31);
            k4 = (vec30 * ca) / (vec30 * vec11 - vec10 * vec31);

            a = k1 * k1 + k3 * k3 + 1;
            b = k1 * k2 + k3 * k4;
            c = k2 * k2 + k4 * k4 - 1;

            d = b * b - a * c;
            if (d < 0)
            {
                return false;
            }
            r1 = (-b + Math.Sqrt(d)) / a;
            p1 = k1 * r1 + k2;
            q1 = k3 * r1 + k4;
            r2 = (-b - Math.Sqrt(d)) / a;
            p2 = k1 * r2 + k2;
            q2 = k3 * r2 + k4;
            if (f == 1)
            {
                w = q1; q1 = r1; r1 = w;
                w = q2; q2 = r2; r2 = w;
                w = vec11; vec11 = vec12; vec12 = w;
                w = vec31; vec31 = vec32; vec32 = w;
                f = 0;
            }
            if (f == 2)
            {
                w = p1; p1 = r1; r1 = w;
                w = p2; p2 = r2; r2 = w;
                w = vec10; vec10 = vec12; vec12 = w;
                w = vec30; vec30 = vec32; vec32 = w;
                f = 0;
            }

            if (vec31 * vec20 - vec21 * vec30 != 0.0)
            {
                f = 0;
            }
            else
            {
                if (vec32 * vec20 - vec22 * vec30 != 0.0)
                {
                    w = vec21; vec21 = vec22; vec22 = w;
                    w = vec31; vec31 = vec32; vec32 = w;
                    f = 1;
                }
                else
                {
                    w = vec20; vec20 = vec22; vec22 = w;
                    w = vec30; vec30 = vec32; vec32 = w;
                    f = 2;
                }
            }
            if (vec31 * vec20 - vec21 * vec30 == 0.0)
            {
                return false;
            }
            k1 = (vec21 * vec32 - vec31 * vec22) / (vec31 * vec20 - vec21 * vec30);
            k2 = (vec31 * ca) / (vec31 * vec20 - vec21 * vec30);
            k3 = (vec20 * vec32 - vec30 * vec22) / (vec30 * vec21 - vec20 * vec31);
            k4 = (vec30 * ca) / (vec30 * vec21 - vec20 * vec31);

            a = k1 * k1 + k3 * k3 + 1;
            b = k1 * k2 + k3 * k4;
            c = k2 * k2 + k4 * k4 - 1;

            d = b * b - a * c;
            if (d < 0)
            {
                return false;
            }
            r3 = (-b + Math.Sqrt(d)) / a;
            p3 = k1 * r3 + k2;
            q3 = k3 * r3 + k4;
            r4 = (-b - Math.Sqrt(d)) / a;
            p4 = k1 * r4 + k2;
            q4 = k3 * r4 + k4;
            if (f == 1)
            {
                w = q3; q3 = r3; r3 = w;
                w = q4; q4 = r4; r4 = w;
                w = vec21; vec21 = vec22; vec22 = w;
                w = vec31; vec31 = vec32; vec32 = w;
                f = 0;
            }
            if (f == 2)
            {
                w = p3; p3 = r3; r3 = w;
                w = p4; p4 = r4; r4 = w;
                w = vec20; vec20 = vec22; vec22 = w;
                w = vec30; vec30 = vec32; vec32 = w;
                f = 0;
            }

            double e1 = p1 * p3 + q1 * q3 + r1 * r3;
            if (e1 < 0)
            {
                e1 = -e1;
            }
            double e2 = p1 * p4 + q1 * q4 + r1 * r4;
            if (e2 < 0)
            {
                e2 = -e2;
            }
            double e3 = p2 * p3 + q2 * q3 + r2 * r3;
            if (e3 < 0)
            {
                e3 = -e3;
            }
            double e4 = p2 * p4 + q2 * q4 + r2 * r4;
            if (e4 < 0)
            {
                e4 = -e4;
            }
            if (e1 < e2)
            {
                if (e1 < e3)
                {
                    if (e1 < e4)
                    {
                        io_vec1.v1 = p1;
                        io_vec1.v2 = q1;
                        io_vec1.v3 = r1;
                        io_vec2.v1 = p3;
                        io_vec2.v2 = q3;
                        io_vec2.v3 = r3;
                    }
                    else
                    {
                        io_vec1.v1 = p2;
                        io_vec1.v2 = q2;
                        io_vec1.v3 = r2;
                        io_vec2.v1 = p4;
                        io_vec2.v2 = q4;
                        io_vec2.v3 = r4;
                    }
                }
                else
                {
                    if (e3 < e4)
                    {
                        io_vec1.v1 = p2;
                        io_vec1.v2 = q2;
                        io_vec1.v3 = r2;
                        io_vec2.v1 = p3;
                        io_vec2.v2 = q3;
                        io_vec2.v3 = r3;
                    }
                    else
                    {
                        io_vec1.v1 = p2;
                        io_vec1.v2 = q2;
                        io_vec1.v3 = r2;
                        io_vec2.v1 = p4;
                        io_vec2.v2 = q4;
                        io_vec2.v3 = r4;
                    }
                }
            }
            else
            {
                if (e2 < e3)
                {
                    if (e2 < e4)
                    {
                        io_vec1.v1 = p1;
                        io_vec1.v2 = q1;
                        io_vec1.v3 = r1;
                        io_vec2.v1 = p4;
                        io_vec2.v2 = q4;
                        io_vec2.v3 = r4;
                    }
                    else
                    {
                        io_vec1.v1 = p2;
                        io_vec1.v2 = q2;
                        io_vec1.v3 = r2;
                        io_vec2.v1 = p4;
                        io_vec2.v2 = q4;
                        io_vec2.v3 = r4;
                    }
                }
                else
                {
                    if (e3 < e4)
                    {
                        io_vec1.v1 = p2;
                        io_vec1.v2 = q2;
                        io_vec1.v3 = r2;
                        io_vec2.v1 = p3;
                        io_vec2.v2 = q3;
                        io_vec2.v3 = r3;
                    }
                    else
                    {
                        io_vec1.v1 = p2;
                        io_vec1.v2 = q2;
                        io_vec1.v3 = r2;
                        io_vec2.v1 = p4;
                        io_vec2.v2 = q4;
                        io_vec2.v3 = r4;
                    }
                }
            }
            return true;
        }
    }
}