tetrees/Plugins/Wwise/Source/AkAudio/Classes/GTE/Mathematics/ContCylinder3.h

// 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/ApprOrthogonalLine3.h>
#include <Mathematics/Cylinder3.h>
#include <Mathematics/DistPointLine.h>

namespace WwiseGTE
{
    // Compute the cylinder axis segment using least-squares fit.  The radius
    // is the maximum distance from points to the axis.  The height is
    // determined by projection of points onto the axis and determining the
    // containing interval.
    template <typename Real>
    bool GetContainer(int numPoints, Vector3<Real> const* points, Cylinder3<Real>& cylinder)
    {
        ApprOrthogonalLine3<Real> fitter;
        fitter.Fit(numPoints, points);
        Line3<Real> line = fitter.GetParameters();

        DCPQuery<Real, Vector3<Real>, Line3<Real>> plQuery;
        Real maxRadiusSqr = (Real)0;
        for (int i = 0; i < numPoints; ++i)
        {
            auto result = plQuery(points[i], line);
            if (result.sqrDistance > maxRadiusSqr)
            {
                maxRadiusSqr = result.sqrDistance;
            }
        }

        Vector3<Real> diff = points[0] - line.origin;
        Real wMin = Dot(line.direction, diff);
        Real wMax = wMin;
        for (int i = 1; i < numPoints; ++i)
        {
            diff = points[i] - line.origin;
            Real w = Dot(line.direction, diff);
            if (w < wMin)
            {
                wMin = w;
            }
            else if (w > wMax)
            {
                wMax = w;
            }
        }

        cylinder.axis.origin = line.origin + ((Real)0.5 * (wMax + wMin)) * line.direction;
        cylinder.axis.direction = line.direction;
        cylinder.radius = std::sqrt(maxRadiusSqr);
        cylinder.height = wMax - wMin;
        return true;
    }

    // Test for containment of a point by a cylinder.
    template <typename Real>
    bool InContainer(Vector3<Real> const& point, Cylinder3<Real> const& cylinder)
    {
        Vector3<Real> diff = point - cylinder.axis.origin;
        Real zProj = Dot(diff, cylinder.axis.direction);
        if (std::fabs(zProj) * (Real)2 > cylinder.height)
        {
            return false;
        }

        Vector3<Real> xyProj = diff - zProj * cylinder.axis.direction;
        return Length(xyProj) <= cylinder.radius;
    }
}