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89 lines
2.6 KiB
89 lines
2.6 KiB
3 months ago
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// David Eberly, Geometric Tools, Redmond WA 98052
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// Copyright (c) 1998-2021
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// Distributed under the Boost Software License, Version 1.0.
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// https://www.boost.org/LICENSE_1_0.txt
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// https://www.geometrictools.com/License/Boost/LICENSE_1_0.txt
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// Version: 4.0.2019.08.13
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#pragma once
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#include <Mathematics/Hypersphere.h>
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#include <Mathematics/Vector3.h>
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#include <vector>
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namespace gte
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{
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// Compute the smallest bounding sphere whose center is the average of
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// the input points.
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template <typename Real>
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bool GetContainer(int numPoints, Vector3<Real> const* points, Sphere3<Real>& sphere)
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{
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sphere.center = points[0];
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for (int i = 1; i < numPoints; ++i)
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{
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sphere.center += points[i];
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}
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sphere.center /= (Real)numPoints;
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sphere.radius = (Real)0;
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for (int i = 0; i < numPoints; ++i)
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{
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Vector3<Real> diff = points[i] - sphere.center;
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Real radiusSqr = Dot(diff, diff);
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if (radiusSqr > sphere.radius)
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{
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sphere.radius = radiusSqr;
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}
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}
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sphere.radius = std::sqrt(sphere.radius);
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return true;
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}
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template <typename Real>
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bool GetContainer(std::vector<Vector3<Real>> const& points, Sphere3<Real>& sphere)
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{
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return GetContainer(static_cast<int>(points.size()), points.data(), sphere);
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}
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// Test for containment of a point inside a sphere.
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template <typename Real>
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bool InContainer(Vector3<Real> const& point, Sphere3<Real> const& sphere)
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{
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Vector3<Real> diff = point - sphere.center;
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return Length(diff) <= sphere.radius;
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}
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// Compute the smallest bounding sphere that contains the input spheres.
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template <typename Real>
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bool MergeContainers(Sphere3<Real> const& sphere0, Sphere3<Real> const& sphere1, Sphere3<Real>& merge)
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{
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Vector3<Real> cenDiff = sphere1.center - sphere0.center;
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Real lenSqr = Dot(cenDiff, cenDiff);
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Real rDiff = sphere1.radius - sphere0.radius;
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Real rDiffSqr = rDiff * rDiff;
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if (rDiffSqr >= lenSqr)
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{
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merge = (rDiff >= (Real)0 ? sphere1 : sphere0);
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}
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else
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{
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Real length = std::sqrt(lenSqr);
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if (length > (Real)0)
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{
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Real coeff = (length + rDiff) / (((Real)2)*length);
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merge.center = sphere0.center + coeff * cenDiff;
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}
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else
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{
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merge.center = sphere0.center;
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}
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merge.radius = (Real)0.5 * (length + sphere0.radius + sphere1.radius);
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}
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return true;
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}
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}
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