distance_alignedbox_alignedbox.hpp

#ifndef PASTELGEOMETRY_DISTANCE_ALIGNEDBOX_ALIGNEDBOX_HPP
#define PASTELGEOMETRY_DISTANCE_ALIGNEDBOX_ALIGNEDBOX_HPP

#include "pastel/geometry/distance/distance_alignedbox_alignedbox.h"
#include "pastel/geometry/distance/distance_point_point.h"

namespace Pastel
{

    template <
        typename Real, integer N, 
        typename NormBijection>
    Real distance(
        const AlignedBox<Real, N>& aBox,
        const AlignedBox<Real, N>& bBox,
        const NormBijection& normBijection)
    {
        return normBijection.toNorm(
            distance2(aBox, bBox, normBijection));
    }

    template <
        typename Real, integer N, 
        typename NormBijection>
    Real distance2(
        const AlignedBox<Real, N>& aBox,
        const AlignedBox<Real, N>& bBox,
        const NormBijection& normBijection)
    {
        PENSURE_OP(aBox.n(), ==, bBox.n());

        Real result = 0;

        integer n = aBox.n();
        for (integer i = 0;i < n;++i)
        {
            const Real& aMin = aBox.min()[i];
            const Real& aMax = aBox.max()[i];
            const Real& bMin = bBox.min()[i];
            const Real& bMax = bBox.max()[i];

            if (aMin > bMax)
            {
                result = normBijection.addAxis(result, 
                    normBijection.axis(aMin - bMax));
            }
            else if (bMin > aMax)
            {
                result = normBijection.addAxis(result, 
                    normBijection.axis(bMin - aMax));
            }
            // else the projection intervals overlap.
        }

        return result;
    }

    template <
        typename Real, integer N, 
        typename NormBijection>
    Real farthestDistance(
        const AlignedBox<Real, N>& aBox,
        const AlignedBox<Real, N>& bBox,
        const NormBijection& normBijection)
    {
        return normBijection.toNorm(
            farthestDistance2(aBox, bBox, normBijection));
    }

    template <
        typename Real, integer N, 
        typename NormBijection>
    Real farthestDistance2(
        const AlignedBox<Real, N>& aBox,
        const AlignedBox<Real, N>& bBox,
        const NormBijection& normBijection)
    {
        PENSURE_OP(aBox.n(), ==, bBox.n());

        Real result = 0;

        integer n = aBox.n();
        for (integer i = 0;i < n;++i)
        {
            const Real& aMin = aBox.min()[i];
            const Real& aMax = aBox.max()[i];
            const Real& bMin = bBox.min()[i];
            const Real& bMax = bBox.max()[i];

            if (aMin > bMin)
            {
                if (bMax > aMax)
                {
                    result = normBijection.addAxis(result, 
                        normBijection.axis(
                            std::max(bMax - aMin, aMax - bMin)));
                }
                else
                {
                    result = normBijection.addAxis(result, 
                        normBijection.axis(aMax - bMin));
                }
            }
            else 
            {
                if (bMax > aMax)
                {
                    result = normBijection.addAxis(result, 
                        normBijection.axis(bMax - aMin));
                }
                else
                {
                    result = normBijection.addAxis(result, 
                        normBijection.axis(
                            std::max(bMax - aMin, aMax - bMin)));
                }                
            }
        }

        return result;
    }

}

#endif