Hackers Magazine 57/CdHackersMagazineNr57.iso/Software/Multimedia/k3d-setup-0.7.11.0.exe/include/k3d/k3dsdk/point4.h

C/C++ Source or Header | 2008-12-16 | 5KB | 205 lines

#ifndef K3DSDK_POINT4_H
#define K3DSDK_POINT4_H

// K-3D
// Copyright (c) 1995-2006, Timothy M. Shead
//
// Contact: [e-mail]
//
// This library 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 of the License, or (at your option) any later version.
//
// This library 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 library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

/** \file
    \brief Vector (points, vectors and normals) routines
    \author Timothy M. Shead ([e-mail])
*/

/****************************************************************
*
* C++ Vector and Matrix Algebra routines
* Author: Jean-Francois DOUE
* Version 3.1 --- October 1993
*
****************************************************************/

//
//    From "Graphics Gems IV / Edited by Paul S. Heckbert
//    Academic Press, 1994, ISBN 0-12-336156-9
//    "You are free to use and modify this code in any way
//    you like." (p. xv)
//
//    Modified by J. Nagle, March 1997
//    -    All functions are inline.
//    -    All functions are const-correct.
//    -    All checking is via the standard "assert" macro.
//

// Modified by Tim Shead for use with K-3D, January 1998

#include "almost_equal.h"
#include "result.h"

#include <boost/io/ios_state.hpp>
#include <iomanip>

namespace k3d
{

class vector4;

/////////////////////////////////////////////////////////////////////////////
// point4

/// Encapsulates a four-dimensional location
class point4
{
public:
    /// Stores the point values
    double n[4];

    point4()
    {
        n[0] = n[1] = n[2] = n[3] = 0.0;
    }

    point4(const double x, const double y, const double z, const double w)
    {
        n[0] = x;
        n[1] = y;
        n[2] = z;
        n[3] = w;
    }

    /// Addition of a vector
    point4& operator+=(const vector4& v);

    /// Subtraction of a vector
    point4& operator-=(const vector4& v);

    /// Multiplication by a constant
    point4& operator*=(const double d)
    {
        n[0] *= d;
        n[1] *= d;
        n[2] *= d;
        n[3] *= d;
        return *this;
    }

    /// Division by a constant
    point4& operator/=(const double d)
    {
        return_val_if_fail(d, *this);

        double d_inv = 1./d;
        n[0] *= d_inv;
        n[1] *= d_inv;
        n[2] *= d_inv;
        n[3] *= d_inv;
        return *this;
    }

    /// Returns an indexed dimension by reference
    double& operator[](int i)
    {
        return n[i];
    }

    /// Returns an indexed dimension by value
    double operator[](int i) const
    {
        return n[i];
    }

    friend std::ostream& operator<<(std::ostream& Stream, const point4& RHS)
    {
        boost::io::ios_flags_saver stream_state(Stream);
        Stream << std::setprecision(17) << RHS.n[0] << " " << RHS.n[1] << " " << RHS.n[2] << " " << RHS.n[3];
        return Stream;
    }

    friend std::istream& operator>>(std::istream& Stream, point4& RHS)
    {
        Stream >> RHS.n[0] >> RHS.n[1] >> RHS.n[2] >> RHS.n[3];
        return Stream;
    }
};

/// Negation
inline const point4 operator-(const point4& a)
{
    return point4(-a.n[0],-a.n[1],-a.n[2],-a.n[3]);
}

/// Addition
/** \note We implement this as a convenience for the benefit of linear interpolation - adding two points has no geometric meaning */
inline const point4 operator+(const point4& a, const point4& b)
{
    return point4(a.n[0] + b.n[0], a.n[1] + b.n[1], a.n[2] + b.n[2], a.n[3] + b.n[3]);
}

/// Multiplication by a constant
inline const point4 operator*(const point4& a, const double d)
{
    return point4(d*a.n[0], d*a.n[1], d*a.n[2], d*a.n[3] );
}

/// Multiplication by a constant
inline const point4 operator*(const double d, const point4& a)
{
    return a*d;
}

/// Division by a constant
inline const point4 operator/(const point4& a, const double d)
{
    return_val_if_fail(d, point4());

    double d_inv = 1./d;
    return point4(a.n[0]*d_inv, a.n[1]*d_inv, a.n[2]*d_inv, a.n[3]*d_inv);
}

/// Equality
inline const bool operator==(const point4& a, const point4& b)
{
    return (a.n[0] == b.n[0]) && (a.n[1] == b.n[1]) && (a.n[2] == b.n[2]) && (a.n[3] == b.n[3]);
}

/// Inequality
inline bool operator!=(const point4& a, const point4& b)
{
    return !(a == b);
}

/// Specialization of almost_equal that tests two point4 objects for near-equality
template<>
class almost_equal<point4>
{
    typedef point4 T;
public:
    almost_equal(const boost::uint64_t Threshold) : threshold(Threshold) { }
    inline const bool operator()(const T& A, const T& B) const
    {
        return std::equal(A.n, A.n + 4, B.n, almost_equal<double>(threshold));
    }

private:
    const boost::uint64_t threshold;
};

} // namespace k3d

#endif // !K3DSDK_POINT4_H