plane_3d_ray_3d.h

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/** @file
 *  @author Bram de Greve (bram@cocamware.com)
 *  @author Tom De Muer (tom@cocamware.com)
 *
 *  *** BEGIN LICENSE INFORMATION ***
 *  
 *  The contents of this file are subject to the Common Public Attribution License 
 *  Version 1.0 (the "License"); you may not use this file except in compliance with 
 *  the License. You may obtain a copy of the License at 
 *  http://lass.sourceforge.net/cpal-license. The License is based on the 
 *  Mozilla Public License Version 1.1 but Sections 14 and 15 have been added to cover 
 *  use of software over a computer network and provide for limited attribution for 
 *  the Original Developer. In addition, Exhibit A has been modified to be consistent 
 *  with Exhibit B.
 *  
 *  Software distributed under the License is distributed on an "AS IS" basis, WITHOUT 
 *  WARRANTY OF ANY KIND, either express or implied. See the License for the specific 
 *  language governing rights and limitations under the License.
 *  
 *  The Original Code is LASS - Library of Assembled Shared Sources.
 *  
 *  The Initial Developer of the Original Code is Bram de Greve and Tom De Muer.
 *  The Original Developer is the Initial Developer.
 *  
 *  All portions of the code written by the Initial Developer are:
 *  Copyright (C) 2004-2011 the Initial Developer.
 *  All Rights Reserved.
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 *
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 *  GNU General Public License Version 2 or later (the GPL), in which case the 
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 *  deleting the provisions above and replace them with the notice and other 
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 */
 
#ifndef LASS_GUARDIAN_OF_INCLUSION_PRIM_PLANE_3D_RAY_3D_H
#define LASS_GUARDIAN_OF_INCLUSION_PRIM_PLANE_3D_RAY_3D_H
 
#include "prim_common.h"
#include "plane_3d.h"
#include "ray_3d.h"
#include "../num/floating_point_consistency.h"
 
namespace lass
{
namespace prim
{
 
/** Find the intersection of a plane and ray by their parameter t on the ray.
 *  @relates lass::prim::Plane3D
 *  @relates lass::prim::Ray3D
 *
 *  @param plane [in] the plane
 *  @param ray [in] the ray
 *  @param t [out] the parameter of the intersection point > @a tMin.
 *  @param tMin [in] the minimum t that may be returned as valid intersection.
 *  @return @arg rNone      no intersections > @a tMin found
 *                          @a t is not assigned.
 *          @arg rOne       exactly one intersection > @a tMin found
 *                          @a t represents it.
 *          @arg rInfinite  infinite many intersections found (ray is coincident with plane),
 *                          @a t is not assigned.
 *          @arg rInvalid   @a plane or @a ray is invalid, no intersection.
 *                          @a t is not assigned.
 */
template<typename T, class EPPlane, class NPPlane, class NPRay, class PPRay>
Result intersect(
        const Plane3D<T, EPPlane, NPPlane>& plane, const Ray3D<T, NPRay, PPRay>& ray,
        T& t, const T& tMin = T())
{
    typedef typename Vector3D<T>::TValue TValue;
    typedef typename Vector3D<T>::TNumTraits TNumTraits;
    typedef num::Consistent<T> TConsistent;
 
    if (!plane.isValid() || !ray.isValid())
    {
        return rInvalid;
    }
 
    const TValue nd = dot(plane.normal(), ray.direction());
    if (nd == TNumTraits::zero)
    {
        // ray is parallel to plane, but is it also coincident?
        const Side side = plane.classify(ray.support());
        LASS_ASSERT(side == sFront || side == sSurface || side == sBack);
        return side == sSurface ? rInfinite : rNone;
    }
    else
    {
        const TConsistent tCanidate = -plane.equation(ray.support()) / nd;
        LASS_ASSERT(!num::isNaN(tCanidate));
        if (tCanidate > tMin)
        {
            t = tCanidate.value();
            return rOne;
        }
        return rNone;
    }
}
 
}
}
 
#endif
 
// EOF