/*
-----------------------------------------------------------------------------
This source file is part of OGRE
    (Object-oriented Graphics Rendering Engine)
For the latest info, see http://www.ogre3d.org/

Copyright (c) 2000-2005 The OGRE Team
Also see acknowledgements in Readme.html

This program is free software; you can redistribute it and/or modify it under
the terms of the GNU Lesser General Public License as published by the Free Software
Foundation; either version 2 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 Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along with
this program; if not, write to the Free Software Foundation, Inc., 59 Temple
Place - Suite 330, Boston, MA 02111-1307, USA, or go to
http://www.gnu.org/copyleft/lesser.txt.
-----------------------------------------------------------------------------
*/
#include "OgreStableHeaders.h"
#include "OgrePlane.h"
#include "OgreMatrix3.h"

namespace Ogre {
    //-----------------------------------------------------------------------
    Plane::Plane ()
    {
        normal = Vector3::ZERO;
        d = 0.0;
    }
    //-----------------------------------------------------------------------
    Plane::Plane (const Plane& rhs)
    {
        normal = rhs.normal;
        d = rhs.d;
    }
    //-----------------------------------------------------------------------
    Plane::Plane (const Vector3& rkNormal, Real fConstant)
    {
        normal = rkNormal;
        d = -fConstant;
    }
    //-----------------------------------------------------------------------
    Plane::Plane (const Vector3& rkNormal, const Vector3& rkPoint)
    {
        normal = rkNormal;
        d = -rkNormal.dotProduct(rkPoint);
    }
    //-----------------------------------------------------------------------
    Plane::Plane (const Vector3& rkPoint0, const Vector3& rkPoint1,
        const Vector3& rkPoint2)
    {
        redefine(rkPoint0, rkPoint1, rkPoint2);
    }
    //-----------------------------------------------------------------------
    Real Plane::getDistance (const Vector3& rkPoint) const
    {
        return normal.dotProduct(rkPoint) + d;
    }
    //-----------------------------------------------------------------------
    Plane::Side Plane::getSide (const Vector3& rkPoint) const
    {
        Real fDistance = getDistance(rkPoint);

        if ( fDistance < 0.0 )
            return Plane::NEGATIVE_SIDE;

        if ( fDistance > 0.0 )
            return Plane::POSITIVE_SIDE;

        return Plane::NO_SIDE;
    }
    //-----------------------------------------------------------------------
    void Plane::redefine(const Vector3& rkPoint0, const Vector3& rkPoint1,
        const Vector3& rkPoint2)
    {
        Vector3 kEdge1 = rkPoint1 - rkPoint0;
        Vector3 kEdge2 = rkPoint2 - rkPoint0;
        normal = kEdge1.crossProduct(kEdge2);
        normal.normalise();
        d = -normal.dotProduct(rkPoint0);
    }
	//-----------------------------------------------------------------------
	Vector3 Plane::projectVector(const Vector3& p)
	{
		// We know plane normal is unit length, so use simple method
		Matrix3 xform;
		xform[0][0] = normal.x * normal.x - 1.0f;
		xform[0][1] = normal.x * normal.y;
		xform[0][2] = normal.x * normal.z;
		xform[1][0] = normal.y * normal.x;
		xform[1][1] = normal.y * normal.y - 1.0f;
		xform[1][2] = normal.y * normal.z;
		xform[2][0] = normal.z * normal.x;
		xform[2][1] = normal.z * normal.y;
		xform[2][2] = normal.z * normal.z - 1.0f;
		return xform * p;

	}
    //-----------------------------------------------------------------------
    std::ostream& operator<< (std::ostream& o, Plane& p)
    {
        o << "Plane(normal=" << p.normal << ", d=" << p.d << ")";
        return o;
    }
} // namespace Ogre