// David Eberly, Geometric Tools, Redmond WA 98052
// Copyright (c) 1998-2020
// Distributed under the Boost Software License, Version 1.0.
// https://www.boost.org/LICENSE_1_0.txt
// https://www.geometrictools.com/License/Boost/LICENSE_1_0.txt
// Version: 4.0.2019.08.13

#pragma once

#include <Mathematics/DistLine3Triangle3.h>
#include <Mathematics/DistPointTriangle.h>
#include <Mathematics/Segment.h>

namespace WwiseGTE
{
    template <typename Real>
    class DCPQuery<Real, Segment3<Real>, Triangle3<Real>>
    {
    public:
        struct Result
        {
            Real distance, sqrDistance;
            Real segmentParameter, triangleParameter[3];
            Vector3<Real> closestPoint[2];
        };

        Result operator()(Segment3<Real> const& segment, Triangle3<Real> const& triangle)
        {
            Result result;

            Vector3<Real> segCenter, segDirection;
            Real segExtent;
            segment.GetCenteredForm(segCenter, segDirection, segExtent);

            Line3<Real> line(segCenter, segDirection);
            DCPQuery<Real, Line3<Real>, Triangle3<Real>> ltQuery;
            auto ltResult = ltQuery(line, triangle);

            if (ltResult.lineParameter >= -segExtent)
            {
                if (ltResult.lineParameter <= segExtent)
                {
                    result.distance = ltResult.distance;
                    result.sqrDistance = ltResult.sqrDistance;
                    result.segmentParameter = ltResult.lineParameter;
                    result.triangleParameter[0] = ltResult.triangleParameter[0];
                    result.triangleParameter[1] = ltResult.triangleParameter[1];
                    result.triangleParameter[2] = ltResult.triangleParameter[2];
                    result.closestPoint[0] = ltResult.closestPoint[0];
                    result.closestPoint[1] = ltResult.closestPoint[1];
                }
                else
                {
                    DCPQuery<Real, Vector3<Real>, Triangle3<Real>> ptQuery;
                    Vector3<Real> point = segCenter + segExtent * segDirection;
                    auto ptResult = ptQuery(point, triangle);
                    result.sqrDistance = ptResult.sqrDistance;
                    result.distance = ptResult.distance;
                    result.segmentParameter = segExtent;
                    result.closestPoint[0] = point;
                    result.closestPoint[1] = ptResult.closest;
                }
            }
            else
            {
                DCPQuery<Real, Vector3<Real>, Triangle3<Real>> ptQuery;
                Vector3<Real> point = segCenter - segExtent * segDirection;
                auto ptResult = ptQuery(point, triangle);
                result.sqrDistance = ptResult.sqrDistance;
                result.distance = ptResult.distance;
                result.segmentParameter = segExtent;
                result.closestPoint[0] = point;
                result.closestPoint[1] = ptResult.closest;
            }
            return result;
        }
    };
}