aabb_slab.h

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/** @file
 *  @author Bram de Greve (bramz@users.sourceforge.net)
 *  @author Tom De Muer (tomdemuer@users.sourceforge.net)
 *
 *  *** BEGIN LICENSE INFORMATION ***
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 *  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.
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 *  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.
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#ifndef LASS_GUARDIAN_OF_INCLUSION_PRIM_IMPL_AABB_SLAB_H
#define LASS_GUARDIAN_OF_INCLUSION_PRIM_IMPL_AABB_SLAB_H

#include "../prim_common.h"
#include "../../num/floating_point_consistency.h"

namespace lass
{
namespace prim
{
namespace impl
{

/** @internal
 */
template <typename T> inline
bool interectSlab(const T& iMin, const T& iMax, const T& iSupport, const T& iDirection, T& ioTNear, T& ioTFar)
{
    typedef num::Consistent<T> TConsistent;
    
    if (iDirection == num::NumTraits<T>::zero)
    {
        return iSupport >= iMin && iSupport <= iMax;
    }
    
    const T invDirection = num::inv(iDirection);
    TConsistent tNear = (iMin - iSupport) * invDirection;
    TConsistent tFar = (iMax - iSupport) * invDirection;
    if (tFar < tNear)
    {
        std::swap(tNear, tFar);
    }

    if (tNear > ioTFar || tFar < ioTNear)
    {
        return false;
    }
    ioTNear = std::max(ioTNear, tNear.value());
    ioTFar = std::min(ioTFar, tFar.value());
    return true;
}

}

}

}

#endif

// EOF