CoordGeom.h

/* 
 *      Copyright (C) 2003-2005 Gabest
 *      http://www.gabest.org
 *
 *  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 2, 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 GNU Make; see the file COPYING.  If not, write to
 *  the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. 
 *  http://www.gnu.org/copyleft/gpl.html
 *
 */

#pragma once 

#ifndef PI
#define PI (3.141592654)
#endif

#define DegToRad(d) ((d)*PI/180.0)
#define RadToDeg(r) ((r)*180.0/PI)
#define Sgn(d) (IsZero(d) ? 0 : (d) > 0 ? 1 : -1)
#define SgnPow(d, p) (IsZero(d) ? 0 : (pow(fabs(d), p) * Sgn(d)))

class Vector
{
public:
        double x, y, z;

        Vector() {x = y = z = 0;}
        Vector(double x, double y, double z);
        void Set(double x, double y, double z);

        Vector Normal(Vector& a, Vector& b);
        double Angle(Vector& a, Vector& b);
        double Angle(Vector& a);
        void Angle(double& u, double& v); // returns spherical coords in radian, -PI/2 <= u <= PI/2, -PI <= v <= PI
        Vector Angle(); // does like prev., returns 'u' in 'ret.x', and 'v' in 'ret.y'

        Vector Unit();
        Vector& Unitalize();
        double Length();
        double Sum(); // x + y + z
        double CrossSum(); // xy + xz + yz
        Vector Cross(); // xy, xz, yz
        Vector Pow(double exp);

        Vector& Min(Vector& a);
        Vector& Max(Vector& a);
        Vector Abs();

        Vector Reflect(Vector& n);
        Vector Refract(Vector& n, double nFront, double nBack, double* nOut = NULL);
        Vector Refract2(Vector& n, double nFrom, double nTo, double* nOut = NULL);

        Vector operator - ();
        double& operator [] (int i);

        double operator | (Vector& v); // dot
        Vector operator % (Vector& v); // cross

        bool operator == (const Vector& v) const;
        bool operator != (const Vector& v) const;

        Vector operator + (double d);
        Vector operator + (Vector& v);
        Vector operator - (double d);
        Vector operator - (Vector& v);
        Vector operator * (double d);
        Vector operator * (Vector& v);
        Vector operator / (double d);
        Vector operator / (Vector& v);
        Vector& operator += (double d);
        Vector& operator += (Vector& v);
        Vector& operator -= (double d);
        Vector& operator -= (Vector& v);
        Vector& operator *= (double d);
        Vector& operator *= (Vector& v);
        Vector& operator /= (double d);
        Vector& operator /= (Vector& v);
};

class Ray
{
public:
        Vector p, d;

        Ray() {}
        Ray(Vector& p, Vector& d);
        void Set(Vector& p, Vector& d);

        double GetDistanceFrom(Ray& r); // r = plane
        double GetDistanceFrom(Vector& v); // v = point

        Vector operator [] (double t);
};

class XForm
{
        class Matrix
        {
        public:
                double mat[4][4];

                Matrix();
                void Initalize();

                Matrix operator * (Matrix& m);
                Matrix& operator *= (Matrix& m);
        } m;

        bool m_isWorldToLocal;

public:
        XForm() {}
        XForm(Ray& r, Vector& s, bool isWorldToLocal = true);

        void Initalize();
        void Initalize(Ray& r, Vector& s, bool isWorldToLocal = true);

        void operator *= (Vector& s); // scale
        void operator += (Vector& t); // translate
        void operator <<= (Vector& r); // rotate

        void operator /= (Vector& s); // scale
        void operator -= (Vector& t); // translate
        void operator >>= (Vector& r); // rotate

//      transformations
        Vector operator < (Vector& n); // normal
        Vector operator << (Vector& v); // vector
        Ray operator << (Ray& r); // ray
};

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