utilities.h

Go to the documentation of this file.

/*
    toxic - A Global Illumination Renderer
    Copyright (C) 2003-2004 Francois Beaune
    Contact: http://toxicengine.sourceforge.net/

    This file is part of toxic.

    toxic 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.

    toxic 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 toxic; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

#ifndef TOXIC_RENDERER_UTILITIES_H
#define TOXIC_RENDERER_UTILITIES_H

#include "common/math/real.h"
#include "common/math/vector3.h"
#include "common/misc/types.h"
#include "globals.h"

#include <cassert>
#include <cmath>

namespace toxic {

    int IntSquareRoot(int n);
    bool IsSquare(int n);

    struct ConversionTables {
        static sheep::Real m_cos_phi[256];
        static sheep::Real m_sin_phi[256];
        static sheep::Real m_cos_theta[256];
        static sheep::Real m_sin_theta[256];
        static sheep::Vector3 m_direction[256];

        ConversionTables();
    };

    //! Converts from cartesian coordinates to spherical coordinates.
    //! v must be a unit-length vector.
    //! phi is in [0, 2*Pi], theta is in [0, Pi].
    void VectorToSphericalCoords(
        const sheep::Vector3 &v,
        sheep::Real *phi,
        sheep::Real *theta);

    //! Converts from spherical coordinates to cartesian coordinates.
    //! Returned vector is unit-length.
    sheep::Vector3 SphericalCoordsToVector(sheep::Real phi, sheep::Real theta);

    //! Packs a direction expressed in spherical coordinates to a compact
    //! 16-bit representation.
    void PackSphericalCoords(
        sheep::Real phi, sheep::Real theta,
        sheep::uint8 *qphi, sheep::uint8 *qtheta);

    //! Unpacks spherical coordinates from the 16-bit representation.
    //! phi is in [0, 2*Pi], theta is in [0, Pi].
    void UnpackSphericalCoords(
        sheep::uint8 qphi, sheep::uint8 qtheta,
        sheep::Real *phi, sheep::Real *theta);

    //! Packs a direction expressed in spherical coordinates to a compact
    //! 8-bit representation.
    void PackSphericalCoords(
        sheep::Real phi, sheep::Real theta,
        sheep::uint8 *q);

    //! Unpacks spherical coordinates from the 16-bit representation.
    //! phi is in [0, 2*Pi], theta is in [0, Pi].
    void UnpackSphericalCoords(
        sheep::uint8 q,
        sheep::Real *phi, sheep::Real *theta);

    //! Helper function.
    void PackDirection(
        const sheep::Vector3 &v,
        sheep::uint8 *qphi, sheep::uint8 *qtheta);

    //! Helper function.
    void PackDirection(const sheep::Vector3 &v, sheep::uint8 *q);

    //! Not a helper function. Same as UnpackSphericalCoords() followed by
    //! SphericalCoordsToVector(), but much faster.
    sheep::Vector3 UnpackDirection(sheep::uint8 qphi, sheep::uint8 qtheta);

    //! Not a helper function. Same as UnpackSphericalCoords() followed by
    //! SphericalCoordsToVector(), but much faster.
    sheep::Vector3 UnpackDirection(sheep::uint8 q);

#include "utilities.inl"

}

#endif  // !TOXIC_RENDERER_UTILITIES_H

---