tetrees/Plugins/Wwise/Source/AkAudio/Classes/GTE/Mathematics/ExtremalQuery3PRJ.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/ExtremalQuery3.h>

namespace WwiseGTE
{
    template <typename Real>
    class ExtremalQuery3PRJ : public ExtremalQuery3<Real>
    {
    public:
        // Construction.
        ExtremalQuery3PRJ(Polyhedron3<Real> const& polytope)
            :
            ExtremalQuery3<Real>(polytope)
        {
            mCentroid = this->mPolytope.ComputeVertexAverage();
        }

        // Disallow copying and assignment.
        ExtremalQuery3PRJ(ExtremalQuery3PRJ const&) = delete;
        ExtremalQuery3PRJ& operator=(ExtremalQuery3PRJ const&) = delete;

        // Compute the extreme vertices in the specified direction and return
        // the indices of the vertices in the polyhedron vertex array.
        virtual void GetExtremeVertices(Vector3<Real> const& direction,
            int& positiveDirection, int& negativeDirection) override
        {
            Real minValue = std::numeric_limits<Real>::max(), maxValue = -minValue;
            negativeDirection = -1;
            positiveDirection = -1;

            auto vertexPool = this->mPolytope.GetVertexPool();
            for (auto i : this->mPolytope.GetUniqueIndices())
            {
                Vector3<Real> diff = vertexPool.get()->at(i) - mCentroid;
                Real dot = Dot(direction, diff);
                if (dot < minValue)
                {
                    negativeDirection = i;
                    minValue = dot;
                }
                if (dot > maxValue)
                {
                    positiveDirection = i;
                    maxValue = dot;
                }
            }
        }

    private:
        Vector3<Real> mCentroid;
    };
}