/*global define*/
define([
'./Cartesian3',
'./Cartographic',
'./defaultValue',
'./defined',
'./DeveloperError',
'./Ellipsoid',
'./GeographicProjection',
'./Intersect',
'./Interval',
'./Matrix3',
'./Matrix4',
'./Plane',
'./Rectangle'
], function(
Cartesian3,
Cartographic,
defaultValue,
defined,
DeveloperError,
Ellipsoid,
GeographicProjection,
Intersect,
Interval,
Matrix3,
Matrix4,
Plane,
Rectangle) {
'use strict';
/**
* A bounding sphere with a center and a radius.
* @alias BoundingSphere
* @constructor
*
* @param {Cartesian3} [center=Cartesian3.ZERO] The center of the bounding sphere.
* @param {Number} [radius=0.0] The radius of the bounding sphere.
*
* @see AxisAlignedBoundingBox
* @see BoundingRectangle
* @see Packable
*/
function BoundingSphere(center, radius) {
/**
* The center point of the sphere.
* @type {Cartesian3}
* @default {@link Cartesian3.ZERO}
*/
this.center = Cartesian3.clone(defaultValue(center, Cartesian3.ZERO));
/**
* The radius of the sphere.
* @type {Number}
* @default 0.0
*/
this.radius = defaultValue(radius, 0.0);
}
var fromPointsXMin = new Cartesian3();
var fromPointsYMin = new Cartesian3();
var fromPointsZMin = new Cartesian3();
var fromPointsXMax = new Cartesian3();
var fromPointsYMax = new Cartesian3();
var fromPointsZMax = new Cartesian3();
var fromPointsCurrentPos = new Cartesian3();
var fromPointsScratch = new Cartesian3();
var fromPointsRitterCenter = new Cartesian3();
var fromPointsMinBoxPt = new Cartesian3();
var fromPointsMaxBoxPt = new Cartesian3();
var fromPointsNaiveCenterScratch = new Cartesian3();
/**
* Computes a tight-fitting bounding sphere enclosing a list of 3D Cartesian points.
* The bounding sphere is computed by running two algorithms, a naive algorithm and
* Ritter's algorithm. The smaller of the two spheres is used to ensure a tight fit.
*
* @param {Cartesian3[]} positions An array of points that the bounding sphere will enclose. Each point must have <code>x</code>, <code>y</code>, and <code>z</code> properties.
* @param {BoundingSphere} [result] The object onto which to store the result.
* @returns {BoundingSphere} The modified result parameter or a new BoundingSphere instance if one was not provided.
*
* @see {@link http://blogs.agi.com/insight3d/index.php/2008/02/04/a-bounding/|Bounding Sphere computation article}
*/
BoundingSphere.fromPoints = function(positions, result) {
if (!defined(result)) {
result = new BoundingSphere();
}
if (!defined(positions) || positions.length === 0) {
result.center = Cartesian3.clone(Cartesian3.ZERO, result.center);
result.radius = 0.0;
return result;
}
var currentPos = Cartesian3.clone(positions[0], fromPointsCurrentPos);
var xMin = Cartesian3.clone(currentPos, fromPointsXMin);
var yMin = Cartesian3.clone(currentPos, fromPointsYMin);
var zMin = Cartesian3.clone(currentPos, fromPointsZMin);
var xMax = Cartesian3.clone(currentPos, fromPointsXMax);
var yMax = Cartesian3.clone(currentPos, fromPointsYMax);
var zMax = Cartesian3.clone(currentPos, fromPointsZMax);
var numPositions = positions.length;
for (var i = 1; i < numPositions; i++) {
Cartesian3.clone(positions[i], currentPos);
var x = currentPos.x;
var y = currentPos.y;
var z = currentPos.z;
// Store points containing the the smallest and largest components
if (x < xMin.x) {
Cartesian3.clone(currentPos, xMin);
}
if (x > xMax.x) {
Cartesian3.clone(currentPos, xMax);
}
if (y < yMin.y) {
Cartesian3.clone(currentPos, yMin);
}
if (y > yMax.y) {
Cartesian3.clone(currentPos, yMax);
}
if (z < zMin.z) {
Cartesian3.clone(currentPos, zMin);
}
if (z > zMax.z) {
Cartesian3.clone(currentPos, zMax);
}
}
// Compute x-, y-, and z-spans (Squared distances b/n each component's min. and max.).
var xSpan = Cartesian3.magnitudeSquared(Cartesian3.subtract(xMax, xMin, fromPointsScratch));
var ySpan = Cartesian3.magnitudeSquared(Cartesian3.subtract(yMax, yMin, fromPointsScratch));
var zSpan = Cartesian3.magnitudeSquared(Cartesian3.subtract(zMax, zMin, fromPointsScratch));
// Set the diameter endpoints to the largest span.
var diameter1 = xMin;
var diameter2 = xMax;
var maxSpan = xSpan;
if (ySpan > maxSpan) {
maxSpan = ySpan;
diameter1 = yMin;
diameter2 = yMax;
}
if (zSpan > maxSpan) {
maxSpan = zSpan;
diameter1 = zMin;
diameter2 = zMax;
}
// Calculate the center of the initial sphere found by Ritter's algorithm
var ritterCenter = fromPointsRitterCenter;
ritterCenter.x = (diameter1.x + diameter2.x) * 0.5;
ritterCenter.y = (diameter1.y + diameter2.y) * 0.5;
ritterCenter.z = (diameter1.z + diameter2.z) * 0.5;
// Calculate the radius of the initial sphere found by Ritter's algorithm
var radiusSquared = Cartesian3.magnitudeSquared(Cartesian3.subtract(diameter2, ritterCenter, fromPointsScratch));
var ritterRadius = Math.sqrt(radiusSquared);
// Find the center of the sphere found using the Naive method.
var minBoxPt = fromPointsMinBoxPt;
minBoxPt.x = xMin.x;
minBoxPt.y = yMin.y;
minBoxPt.z = zMin.z;
var maxBoxPt = fromPointsMaxBoxPt;
maxBoxPt.x = xMax.x;
maxBoxPt.y = yMax.y;
maxBoxPt.z = zMax.z;
var naiveCenter = Cartesian3.multiplyByScalar(Cartesian3.add(minBoxPt, maxBoxPt, fromPointsScratch), 0.5, fromPointsNaiveCenterScratch);
// Begin 2nd pass to find naive radius and modify the ritter sphere.
var naiveRadius = 0;
for (i = 0; i < numPositions; i++) {
Cartesian3.clone(positions[i], currentPos);
// Find the furthest point from the naive center to calculate the naive radius.
var r = Cartesian3.magnitude(Cartesian3.subtract(currentPos, naiveCenter, fromPointsScratch));
if (r > naiveRadius) {
naiveRadius = r;
}
// Make adjustments to the Ritter Sphere to include all points.
var oldCenterToPointSquared = Cartesian3.magnitudeSquared(Cartesian3.subtract(currentPos, ritterCenter, fromPointsScratch));
if (oldCenterToPointSquared > radiusSquared) {
var oldCenterToPoint = Math.sqrt(oldCenterToPointSquared);
// Calculate new radius to include the point that lies outside
ritterRadius = (ritterRadius + oldCenterToPoint) * 0.5;
radiusSquared = ritterRadius * ritterRadius;
// Calculate center of new Ritter sphere
var oldToNew = oldCenterToPoint - ritterRadius;
ritterCenter.x = (ritterRadius * ritterCenter.x + oldToNew * currentPos.x) / oldCenterToPoint;
ritterCenter.y = (ritterRadius * ritterCenter.y + oldToNew * currentPos.y) / oldCenterToPoint;
ritterCenter.z = (ritterRadius * ritterCenter.z + oldToNew * currentPos.z) / oldCenterToPoint;
}
}
if (ritterRadius < naiveRadius) {
Cartesian3.clone(ritterCenter, result.center);
result.radius = ritterRadius;
} else {
Cartesian3.clone(naiveCenter, result.center);
result.radius = naiveRadius;
}
return result;
};
var defaultProjection = new GeographicProjection();
var fromRectangle2DLowerLeft = new Cartesian3();
var fromRectangle2DUpperRight = new Cartesian3();
var fromRectangle2DSouthwest = new Cartographic();
var fromRectangle2DNortheast = new Cartographic();
/**
* Computes a bounding sphere from an rectangle projected in 2D.
*
* @param {Rectangle} rectangle The rectangle around which to create a bounding sphere.
* @param {Object} [projection=GeographicProjection] The projection used to project the rectangle into 2D.
* @param {BoundingSphere} [result] The object onto which to store the result.
* @returns {BoundingSphere} The modified result parameter or a new BoundingSphere instance if none was provided.
*/
BoundingSphere.fromRectangle2D = function(rectangle, projection, result) {
return BoundingSphere.fromRectangleWithHeights2D(rectangle, projection, 0.0, 0.0, result);
};
/**
* Computes a bounding sphere from an rectangle projected in 2D. The bounding sphere accounts for the
* object's minimum and maximum heights over the rectangle.
*
* @param {Rectangle} rectangle The rectangle around which to create a bounding sphere.
* @param {Object} [projection=GeographicProjection] The projection used to project the rectangle into 2D.
* @param {Number} [minimumHeight=0.0] The minimum height over the rectangle.
* @param {Number} [maximumHeight=0.0] The maximum height over the rectangle.
* @param {BoundingSphere} [result] The object onto which to store the result.
* @returns {BoundingSphere} The modified result parameter or a new BoundingSphere instance if none was provided.
*/
BoundingSphere.fromRectangleWithHeights2D = function(rectangle, projection, minimumHeight, maximumHeight, result) {
if (!defined(result)) {
result = new BoundingSphere();
}
if (!defined(rectangle)) {
result.center = Cartesian3.clone(Cartesian3.ZERO, result.center);
result.radius = 0.0;
return result;
}
projection = defaultValue(projection, defaultProjection);
Rectangle.southwest(rectangle, fromRectangle2DSouthwest);
fromRectangle2DSouthwest.height = minimumHeight;
Rectangle.northeast(rectangle, fromRectangle2DNortheast);
fromRectangle2DNortheast.height = maximumHeight;
var lowerLeft = projection.project(fromRectangle2DSouthwest, fromRectangle2DLowerLeft);
var upperRight = projection.project(fromRectangle2DNortheast, fromRectangle2DUpperRight);
var width = upperRight.x - lowerLeft.x;
var height = upperRight.y - lowerLeft.y;
var elevation = upperRight.z - lowerLeft.z;
result.radius = Math.sqrt(width * width + height * height + elevation * elevation) * 0.5;
var center = result.center;
center.x = lowerLeft.x + width * 0.5;
center.y = lowerLeft.y + height * 0.5;
center.z = lowerLeft.z + elevation * 0.5;
return result;
};
var fromRectangle3DScratch = [];
/**
* Computes a bounding sphere from an rectangle in 3D. The bounding sphere is created using a subsample of points
* on the ellipsoid and contained in the rectangle. It may not be accurate for all rectangles on all types of ellipsoids.
*
* @param {Rectangle} rectangle The valid rectangle used to create a bounding sphere.
* @param {Ellipsoid} [ellipsoid=Ellipsoid.WGS84] The ellipsoid used to determine positions of the rectangle.
* @param {Number} [surfaceHeight=0.0] The height above the surface of the ellipsoid.
* @param {BoundingSphere} [result] The object onto which to store the result.
* @returns {BoundingSphere} The modified result parameter or a new BoundingSphere instance if none was provided.
*/
BoundingSphere.fromRectangle3D = function(rectangle, ellipsoid, surfaceHeight, result) {
ellipsoid = defaultValue(ellipsoid, Ellipsoid.WGS84);
surfaceHeight = defaultValue(surfaceHeight, 0.0);
var positions;
if (defined(rectangle)) {
positions = Rectangle.subsample(rectangle, ellipsoid, surfaceHeight, fromRectangle3DScratch);
}
return BoundingSphere.fromPoints(positions, result);
};
/**
* Computes a tight-fitting bounding sphere enclosing a list of 3D points, where the points are
* stored in a flat array in X, Y, Z, order. The bounding sphere is computed by running two
* algorithms, a naive algorithm and Ritter's algorithm. The smaller of the two spheres is used to
* ensure a tight fit.
*
* @param {Number[]} positions An array of points that the bounding sphere will enclose. Each point
* is formed from three elements in the array in the order X, Y, Z.
* @param {Cartesian3} [center=Cartesian3.ZERO] The position to which the positions are relative, which need not be the
* origin of the coordinate system. This is useful when the positions are to be used for
* relative-to-center (RTC) rendering.
* @param {Number} [stride=3] The number of array elements per vertex. It must be at least 3, but it may
* be higher. Regardless of the value of this parameter, the X coordinate of the first position
* is at array index 0, the Y coordinate is at array index 1, and the Z coordinate is at array index
* 2. When stride is 3, the X coordinate of the next position then begins at array index 3. If
* the stride is 5, however, two array elements are skipped and the next position begins at array
* index 5.
* @param {BoundingSphere} [result] The object onto which to store the result.
* @returns {BoundingSphere} The modified result parameter or a new BoundingSphere instance if one was not provided.
*
* @example
* // Compute the bounding sphere from 3 positions, each specified relative to a center.
* // In addition to the X, Y, and Z coordinates, the points array contains two additional
* // elements per point which are ignored for the purpose of computing the bounding sphere.
* var center = new Cesium.Cartesian3(1.0, 2.0, 3.0);
* var points = [1.0, 2.0, 3.0, 0.1, 0.2,
* 4.0, 5.0, 6.0, 0.1, 0.2,
* 7.0, 8.0, 9.0, 0.1, 0.2];
* var sphere = Cesium.BoundingSphere.fromVertices(points, center, 5);
*
* @see {@link http://blogs.agi.com/insight3d/index.php/2008/02/04/a-bounding/|Bounding Sphere computation article}
*/
BoundingSphere.fromVertices = function(positions, center, stride, result) {
if (!defined(result)) {
result = new BoundingSphere();
}
if (!defined(positions) || positions.length === 0) {
result.center = Cartesian3.clone(Cartesian3.ZERO, result.center);
result.radius = 0.0;
return result;
}
center = defaultValue(center, Cartesian3.ZERO);
stride = defaultValue(stride, 3);
//>>includeStart('debug', pragmas.debug);
if (stride < 3) {
throw new DeveloperError('stride must be 3 or greater.');
}
//>>includeEnd('debug');
var currentPos = fromPointsCurrentPos;
currentPos.x = positions[0] + center.x;
currentPos.y = positions[1] + center.y;
currentPos.z = positions[2] + center.z;
var xMin = Cartesian3.clone(currentPos, fromPointsXMin);
var yMin = Cartesian3.clone(currentPos, fromPointsYMin);
var zMin = Cartesian3.clone(currentPos, fromPointsZMin);
var xMax = Cartesian3.clone(currentPos, fromPointsXMax);
var yMax = Cartesian3.clone(currentPos, fromPointsYMax);
var zMax = Cartesian3.clone(currentPos, fromPointsZMax);
var numElements = positions.length;
for (var i = 0; i < numElements; i += stride) {
var x = positions[i] + center.x;
var y = positions[i + 1] + center.y;
var z = positions[i + 2] + center.z;
currentPos.x = x;
currentPos.y = y;
currentPos.z = z;
// Store points containing the the smallest and largest components
if (x < xMin.x) {
Cartesian3.clone(currentPos, xMin);
}
if (x > xMax.x) {
Cartesian3.clone(currentPos, xMax);
}
if (y < yMin.y) {
Cartesian3.clone(currentPos, yMin);
}
if (y > yMax.y) {
Cartesian3.clone(currentPos, yMax);
}
if (z < zMin.z) {
Cartesian3.clone(currentPos, zMin);
}
if (z > zMax.z) {
Cartesian3.clone(currentPos, zMax);
}
}
// Compute x-, y-, and z-spans (Squared distances b/n each component's min. and max.).
var xSpan = Cartesian3.magnitudeSquared(Cartesian3.subtract(xMax, xMin, fromPointsScratch));
var ySpan = Cartesian3.magnitudeSquared(Cartesian3.subtract(yMax, yMin, fromPointsScratch));
var zSpan = Cartesian3.magnitudeSquared(Cartesian3.subtract(zMax, zMin, fromPointsScratch));
// Set the diameter endpoints to the largest span.
var diameter1 = xMin;
var diameter2 = xMax;
var maxSpan = xSpan;
if (ySpan > maxSpan) {
maxSpan = ySpan;
diameter1 = yMin;
diameter2 = yMax;
}
if (zSpan > maxSpan) {
maxSpan = zSpan;
diameter1 = zMin;
diameter2 = zMax;
}
// Calculate the center of the initial sphere found by Ritter's algorithm
var ritterCenter = fromPointsRitterCenter;
ritterCenter.x = (diameter1.x + diameter2.x) * 0.5;
ritterCenter.y = (diameter1.y + diameter2.y) * 0.5;
ritterCenter.z = (diameter1.z + diameter2.z) * 0.5;
// Calculate the radius of the initial sphere found by Ritter's algorithm
var radiusSquared = Cartesian3.magnitudeSquared(Cartesian3.subtract(diameter2, ritterCenter, fromPointsScratch));
var ritterRadius = Math.sqrt(radiusSquared);
// Find the center of the sphere found using the Naive method.
var minBoxPt = fromPointsMinBoxPt;
minBoxPt.x = xMin.x;
minBoxPt.y = yMin.y;
minBoxPt.z = zMin.z;
var maxBoxPt = fromPointsMaxBoxPt;
maxBoxPt.x = xMax.x;
maxBoxPt.y = yMax.y;
maxBoxPt.z = zMax.z;
var naiveCenter = Cartesian3.multiplyByScalar(Cartesian3.add(minBoxPt, maxBoxPt, fromPointsScratch), 0.5, fromPointsNaiveCenterScratch);
// Begin 2nd pass to find naive radius and modify the ritter sphere.
var naiveRadius = 0;
for (i = 0; i < numElements; i += stride) {
currentPos.x = positions[i] + center.x;
currentPos.y = positions[i + 1] + center.y;
currentPos.z = positions[i + 2] + center.z;
// Find the furthest point from the naive center to calculate the naive radius.
var r = Cartesian3.magnitude(Cartesian3.subtract(currentPos, naiveCenter, fromPointsScratch));
if (r > naiveRadius) {
naiveRadius = r;
}
// Make adjustments to the Ritter Sphere to include all points.
var oldCenterToPointSquared = Cartesian3.magnitudeSquared(Cartesian3.subtract(currentPos, ritterCenter, fromPointsScratch));
if (oldCenterToPointSquared > radiusSquared) {
var oldCenterToPoint = Math.sqrt(oldCenterToPointSquared);
// Calculate new radius to include the point that lies outside
ritterRadius = (ritterRadius + oldCenterToPoint) * 0.5;
radiusSquared = ritterRadius * ritterRadius;
// Calculate center of new Ritter sphere
var oldToNew = oldCenterToPoint - ritterRadius;
ritterCenter.x = (ritterRadius * ritterCenter.x + oldToNew * currentPos.x) / oldCenterToPoint;
ritterCenter.y = (ritterRadius * ritterCenter.y + oldToNew * currentPos.y) / oldCenterToPoint;
ritterCenter.z = (ritterRadius * ritterCenter.z + oldToNew * currentPos.z) / oldCenterToPoint;
}
}
if (ritterRadius < naiveRadius) {
Cartesian3.clone(ritterCenter, result.center);
result.radius = ritterRadius;
} else {
Cartesian3.clone(naiveCenter, result.center);
result.radius = naiveRadius;
}
return result;
};
/**
* Computes a tight-fitting bounding sphere enclosing a list of {@link EncodedCartesian3}s, where the points are
* stored in parallel flat arrays in X, Y, Z, order. The bounding sphere is computed by running two
* algorithms, a naive algorithm and Ritter's algorithm. The smaller of the two spheres is used to
* ensure a tight fit.
*
* @param {Number[]} positionsHigh An array of high bits of the encoded cartesians that the bounding sphere will enclose. Each point
* is formed from three elements in the array in the order X, Y, Z.
* @param {Number[]} positionsLow An array of low bits of the encoded cartesians that the bounding sphere will enclose. Each point
* is formed from three elements in the array in the order X, Y, Z.
* @param {BoundingSphere} [result] The object onto which to store the result.
* @returns {BoundingSphere} The modified result parameter or a new BoundingSphere instance if one was not provided.
*
* @see {@link http://blogs.agi.com/insight3d/index.php/2008/02/04/a-bounding/|Bounding Sphere computation article}
*/
BoundingSphere.fromEncodedCartesianVertices = function(positionsHigh, positionsLow, result) {
if (!defined(result)) {
result = new BoundingSphere();
}
if (!defined(positionsHigh) || !defined(positionsLow) || positionsHigh.length !== positionsLow.length || positionsHigh.length === 0) {
result.center = Cartesian3.clone(Cartesian3.ZERO, result.center);
result.radius = 0.0;
return result;
}
var currentPos = fromPointsCurrentPos;
currentPos.x = positionsHigh[0] + positionsLow[0];
currentPos.y = positionsHigh[1] + positionsLow[1];
currentPos.z = positionsHigh[2] + positionsLow[2];
var xMin = Cartesian3.clone(currentPos, fromPointsXMin);
var yMin = Cartesian3.clone(currentPos, fromPointsYMin);
var zMin = Cartesian3.clone(currentPos, fromPointsZMin);
var xMax = Cartesian3.clone(currentPos, fromPointsXMax);
var yMax = Cartesian3.clone(currentPos, fromPointsYMax);
var zMax = Cartesian3.clone(currentPos, fromPointsZMax);
var numElements = positionsHigh.length;
for (var i = 0; i < numElements; i += 3) {
var x = positionsHigh[i] + positionsLow[i];
var y = positionsHigh[i + 1] + positionsLow[i + 1];
var z = positionsHigh[i + 2] + positionsLow[i + 2];
currentPos.x = x;
currentPos.y = y;
currentPos.z = z;
// Store points containing the the smallest and largest components
if (x < xMin.x) {
Cartesian3.clone(currentPos, xMin);
}
if (x > xMax.x) {
Cartesian3.clone(currentPos, xMax);
}
if (y < yMin.y) {
Cartesian3.clone(currentPos, yMin);
}
if (y > yMax.y) {
Cartesian3.clone(currentPos, yMax);
}
if (z < zMin.z) {
Cartesian3.clone(currentPos, zMin);
}
if (z > zMax.z) {
Cartesian3.clone(currentPos, zMax);
}
}
// Compute x-, y-, and z-spans (Squared distances b/n each component's min. and max.).
var xSpan = Cartesian3.magnitudeSquared(Cartesian3.subtract(xMax, xMin, fromPointsScratch));
var ySpan = Cartesian3.magnitudeSquared(Cartesian3.subtract(yMax, yMin, fromPointsScratch));
var zSpan = Cartesian3.magnitudeSquared(Cartesian3.subtract(zMax, zMin, fromPointsScratch));
// Set the diameter endpoints to the largest span.
var diameter1 = xMin;
var diameter2 = xMax;
var maxSpan = xSpan;
if (ySpan > maxSpan) {
maxSpan = ySpan;
diameter1 = yMin;
diameter2 = yMax;
}
if (zSpan > maxSpan) {
maxSpan = zSpan;
diameter1 = zMin;
diameter2 = zMax;
}
// Calculate the center of the initial sphere found by Ritter's algorithm
var ritterCenter = fromPointsRitterCenter;
ritterCenter.x = (diameter1.x + diameter2.x) * 0.5;
ritterCenter.y = (diameter1.y + diameter2.y) * 0.5;
ritterCenter.z = (diameter1.z + diameter2.z) * 0.5;
// Calculate the radius of the initial sphere found by Ritter's algorithm
var radiusSquared = Cartesian3.magnitudeSquared(Cartesian3.subtract(diameter2, ritterCenter, fromPointsScratch));
var ritterRadius = Math.sqrt(radiusSquared);
// Find the center of the sphere found using the Naive method.
var minBoxPt = fromPointsMinBoxPt;
minBoxPt.x = xMin.x;
minBoxPt.y = yMin.y;
minBoxPt.z = zMin.z;
var maxBoxPt = fromPointsMaxBoxPt;
maxBoxPt.x = xMax.x;
maxBoxPt.y = yMax.y;
maxBoxPt.z = zMax.z;
var naiveCenter = Cartesian3.multiplyByScalar(Cartesian3.add(minBoxPt, maxBoxPt, fromPointsScratch), 0.5, fromPointsNaiveCenterScratch);
// Begin 2nd pass to find naive radius and modify the ritter sphere.
var naiveRadius = 0;
for (i = 0; i < numElements; i += 3) {
currentPos.x = positionsHigh[i] + positionsLow[i];
currentPos.y = positionsHigh[i + 1] + positionsLow[i + 1];
currentPos.z = positionsHigh[i + 2] + positionsLow[i + 2];
// Find the furthest point from the naive center to calculate the naive radius.
var r = Cartesian3.magnitude(Cartesian3.subtract(currentPos, naiveCenter, fromPointsScratch));
if (r > naiveRadius) {
naiveRadius = r;
}
// Make adjustments to the Ritter Sphere to include all points.
var oldCenterToPointSquared = Cartesian3.magnitudeSquared(Cartesian3.subtract(currentPos, ritterCenter, fromPointsScratch));
if (oldCenterToPointSquared > radiusSquared) {
var oldCenterToPoint = Math.sqrt(oldCenterToPointSquared);
// Calculate new radius to include the point that lies outside
ritterRadius = (ritterRadius + oldCenterToPoint) * 0.5;
radiusSquared = ritterRadius * ritterRadius;
// Calculate center of new Ritter sphere
var oldToNew = oldCenterToPoint - ritterRadius;
ritterCenter.x = (ritterRadius * ritterCenter.x + oldToNew * currentPos.x) / oldCenterToPoint;
ritterCenter.y = (ritterRadius * ritterCenter.y + oldToNew * currentPos.y) / oldCenterToPoint;
ritterCenter.z = (ritterRadius * ritterCenter.z + oldToNew * currentPos.z) / oldCenterToPoint;
}
}
if (ritterRadius < naiveRadius) {
Cartesian3.clone(ritterCenter, result.center);
result.radius = ritterRadius;
} else {
Cartesian3.clone(naiveCenter, result.center);
result.radius = naiveRadius;
}
return result;
};
/**
* Computes a bounding sphere from the corner points of an axis-aligned bounding box. The sphere
* tighly and fully encompases the box.
*
* @param {Cartesian3} [corner] The minimum height over the rectangle.
* @param {Cartesian3} [oppositeCorner] The maximum height over the rectangle.
* @param {BoundingSphere} [result] The object onto which to store the result.
* @returns {BoundingSphere} The modified result parameter or a new BoundingSphere instance if none was provided.
*
* @example
* // Create a bounding sphere around the unit cube
* var sphere = Cesium.BoundingSphere.fromCornerPoints(new Cesium.Cartesian3(-0.5, -0.5, -0.5), new Cesium.Cartesian3(0.5, 0.5, 0.5));
*/
BoundingSphere.fromCornerPoints = function(corner, oppositeCorner, result) {
//>>includeStart('debug', pragmas.debug);
if (!defined(corner) || !defined(oppositeCorner)) {
throw new DeveloperError('corner and oppositeCorner are required.');
}
//>>includeEnd('debug');
if (!defined(result)) {
result = new BoundingSphere();
}
var center = result.center;
Cartesian3.add(corner, oppositeCorner, center);
Cartesian3.multiplyByScalar(center, 0.5, center);
result.radius = Cartesian3.distance(center, oppositeCorner);
return result;
};
/**
* Creates a bounding sphere encompassing an ellipsoid.
*
* @param {Ellipsoid} ellipsoid The ellipsoid around which to create a bounding sphere.
* @param {BoundingSphere} [result] The object onto which to store the result.
* @returns {BoundingSphere} The modified result parameter or a new BoundingSphere instance if none was provided.
*
* @example
* var boundingSphere = Cesium.BoundingSphere.fromEllipsoid(ellipsoid);
*/
BoundingSphere.fromEllipsoid = function(ellipsoid, result) {
//>>includeStart('debug', pragmas.debug);
if (!defined(ellipsoid)) {
throw new DeveloperError('ellipsoid is required.');
}
//>>includeEnd('debug');
if (!defined(result)) {
result = new BoundingSphere();
}
Cartesian3.clone(Cartesian3.ZERO, result.center);
result.radius = ellipsoid.maximumRadius;
return result;
};
var fromBoundingSpheresScratch = new Cartesian3();
/**
* Computes a tight-fitting bounding sphere enclosing the provided array of bounding spheres.
*
* @param {BoundingSphere[]} boundingSpheres The array of bounding spheres.
* @param {BoundingSphere} [result] The object onto which to store the result.
* @returns {BoundingSphere} The modified result parameter or a new BoundingSphere instance if none was provided.
*/
BoundingSphere.fromBoundingSpheres = function(boundingSpheres, result) {
if (!defined(result)) {
result = new BoundingSphere();
}
if (!defined(boundingSpheres) || boundingSpheres.length === 0) {
result.center = Cartesian3.clone(Cartesian3.ZERO, result.center);
result.radius = 0.0;
return result;
}
var length = boundingSpheres.length;
if (length === 1) {
return BoundingSphere.clone(boundingSpheres[0], result);
}
if (length === 2) {
return BoundingSphere.union(boundingSpheres[0], boundingSpheres[1], result);
}
var positions = [];
for (var i = 0; i < length; i++) {
positions.push(boundingSpheres[i].center);
}
result = BoundingSphere.fromPoints(positions, result);
var center = result.center;
var radius = result.radius;
for (i = 0; i < length; i++) {
var tmp = boundingSpheres[i];
radius = Math.max(radius, Cartesian3.distance(center, tmp.center, fromBoundingSpheresScratch) + tmp.radius);
}
result.radius = radius;
return result;
};
var fromOrientedBoundingBoxScratchU = new Cartesian3();
var fromOrientedBoundingBoxScratchV = new Cartesian3();
var fromOrientedBoundingBoxScratchW = new Cartesian3();
/**
* Computes a tight-fitting bounding sphere enclosing the provided oriented bounding box.
*
* @param {OrientedBoundingBox} orientedBoundingBox The oriented bounding box.
* @param {BoundingSphere} [result] The object onto which to store the result.
* @returns {BoundingSphere} The modified result parameter or a new BoundingSphere instance if none was provided.
*/
BoundingSphere.fromOrientedBoundingBox = function(orientedBoundingBox, result) {
if (!defined(result)) {
result = new BoundingSphere();
}
var halfAxes = orientedBoundingBox.halfAxes;
var u = Matrix3.getColumn(halfAxes, 0, fromOrientedBoundingBoxScratchU);
var v = Matrix3.getColumn(halfAxes, 1, fromOrientedBoundingBoxScratchV);
var w = Matrix3.getColumn(halfAxes, 2, fromOrientedBoundingBoxScratchW);
var uHalf = Cartesian3.magnitude(u);
var vHalf = Cartesian3.magnitude(v);
var wHalf = Cartesian3.magnitude(w);
result.center = Cartesian3.clone(orientedBoundingBox.center, result.center);
result.radius = Math.max(uHalf, vHalf, wHalf);
return result;
};
/**
* Duplicates a BoundingSphere instance.
*
* @param {BoundingSphere} sphere The bounding sphere to duplicate.
* @param {BoundingSphere} [result] The object onto which to store the result.
* @returns {BoundingSphere} The modified result parameter or a new BoundingSphere instance if none was provided. (Returns undefined if sphere is undefined)
*/
BoundingSphere.clone = function(sphere, result) {
if (!defined(sphere)) {
return undefined;
}
if (!defined(result)) {
return new BoundingSphere(sphere.center, sphere.radius);
}
result.center = Cartesian3.clone(sphere.center, result.center);
result.radius = sphere.radius;
return result;
};
/**
* The number of elements used to pack the object into an array.
* @type {Number}
*/
BoundingSphere.packedLength = 4;
/**
* Stores the provided instance into the provided array.
*
* @param {BoundingSphere} value The value to pack.
* @param {Number[]} array The array to pack into.
* @param {Number} [startingIndex=0] The index into the array at which to start packing the elements.
*
* @returns {Number[]} The array that was packed into
*/
BoundingSphere.pack = function(value, array, startingIndex) {
//>>includeStart('debug', pragmas.debug);
if (!defined(value)) {
throw new DeveloperError('value is required');
}
if (!defined(array)) {
throw new DeveloperError('array is required');
}
//>>includeEnd('debug');
startingIndex = defaultValue(startingIndex, 0);
var center = value.center;
array[startingIndex++] = center.x;
array[startingIndex++] = center.y;
array[startingIndex++] = center.z;
array[startingIndex] = value.radius;
return array;
};
/**
* Retrieves an instance from a packed array.
*
* @param {Number[]} array The packed array.
* @param {Number} [startingIndex=0] The starting index of the element to be unpacked.
* @param {BoundingSphere} [result] The object into which to store the result.
* @returns {BoundingSphere} The modified result parameter or a new BoundingSphere instance if one was not provided.
*/
BoundingSphere.unpack = function(array, startingIndex, result) {
//>>includeStart('debug', pragmas.debug);
if (!defined(array)) {
throw new DeveloperError('array is required');
}
//>>includeEnd('debug');
startingIndex = defaultValue(startingIndex, 0);
if (!defined(result)) {
result = new BoundingSphere();
}
var center = result.center;
center.x = array[startingIndex++];
center.y = array[startingIndex++];
center.z = array[startingIndex++];
result.radius = array[startingIndex];
return result;
};
var unionScratch = new Cartesian3();
var unionScratchCenter = new Cartesian3();
/**
* Computes a bounding sphere that contains both the left and right bounding spheres.
*
* @param {BoundingSphere} left A sphere to enclose in a bounding sphere.
* @param {BoundingSphere} right A sphere to enclose in a bounding sphere.
* @param {BoundingSphere} [result] The object onto which to store the result.
* @returns {BoundingSphere} The modified result parameter or a new BoundingSphere instance if none was provided.
*/
BoundingSphere.union = function(left, right, result) {
//>>includeStart('debug', pragmas.debug);
if (!defined(left)) {
throw new DeveloperError('left is required.');
}
if (!defined(right)) {
throw new DeveloperError('right is required.');
}
//>>includeEnd('debug');
if (!defined(result)) {
result = new BoundingSphere();
}
var leftCenter = left.center;
var leftRadius = left.radius;
var rightCenter = right.center;
var rightRadius = right.radius;
var toRightCenter = Cartesian3.subtract(rightCenter, leftCenter, unionScratch);
var centerSeparation = Cartesian3.magnitude(toRightCenter);
if (leftRadius >= (centerSeparation + rightRadius)) {
// Left sphere wins.
left.clone(result);
return result;
}
if (rightRadius >= (centerSeparation + leftRadius)) {
// Right sphere wins.
right.clone(result);
return result;
}
// There are two tangent points, one on far side of each sphere.
var halfDistanceBetweenTangentPoints = (leftRadius + centerSeparation + rightRadius) * 0.5;
// Compute the center point halfway between the two tangent points.
var center = Cartesian3.multiplyByScalar(toRightCenter,
(-leftRadius + halfDistanceBetweenTangentPoints) / centerSeparation, unionScratchCenter);
Cartesian3.add(center, leftCenter, center);
Cartesian3.clone(center, result.center);
result.radius = halfDistanceBetweenTangentPoints;
return result;
};
var expandScratch = new Cartesian3();
/**
* Computes a bounding sphere by enlarging the provided sphere to contain the provided point.
*
* @param {BoundingSphere} sphere A sphere to expand.
* @param {Cartesian3} point A point to enclose in a bounding sphere.
* @param {BoundingSphere} [result] The object onto which to store the result.
* @returns {BoundingSphere} The modified result parameter or a new BoundingSphere instance if none was provided.
*/
BoundingSphere.expand = function(sphere, point, result) {
//>>includeStart('debug', pragmas.debug);
if (!defined(sphere)) {
throw new DeveloperError('sphere is required.');
}
if (!defined(point)) {
throw new DeveloperError('point is required.');
}
//>>includeEnd('debug');
result = BoundingSphere.clone(sphere, result);
var radius = Cartesian3.magnitude(Cartesian3.subtract(point, result.center, expandScratch));
if (radius > result.radius) {
result.radius = radius;
}
return result;
};
/**
* Determines which side of a plane a sphere is located.
*
* @param {BoundingSphere} sphere The bounding sphere to test.
* @param {Plane} plane The plane to test against.
* @returns {Intersect} {@link Intersect.INSIDE} if the entire sphere is on the side of the plane
* the normal is pointing, {@link Intersect.OUTSIDE} if the entire sphere is
* on the opposite side, and {@link Intersect.INTERSECTING} if the sphere
* intersects the plane.
*/
BoundingSphere.intersectPlane = function(sphere, plane) {
//>>includeStart('debug', pragmas.debug);
if (!defined(sphere)) {
throw new DeveloperError('sphere is required.');
}
if (!defined(plane)) {
throw new DeveloperError('plane is required.');
}
//>>includeEnd('debug');
var center = sphere.center;
var radius = sphere.radius;
var normal = plane.normal;
var distanceToPlane = Cartesian3.dot(normal, center) + plane.distance;
if (distanceToPlane < -radius) {
// The center point is negative side of the plane normal
return Intersect.OUTSIDE;
} else if (distanceToPlane < radius) {
// The center point is positive side of the plane, but radius extends beyond it; partial overlap
return Intersect.INTERSECTING;
}
return Intersect.INSIDE;
};
/**
* Applies a 4x4 affine transformation matrix to a bounding sphere.
*
* @param {BoundingSphere} sphere The bounding sphere to apply the transformation to.
* @param {Matrix4} transform The transformation matrix to apply to the bounding sphere.
* @param {BoundingSphere} [result] The object onto which to store the result.
* @returns {BoundingSphere} The modified result parameter or a new BoundingSphere instance if none was provided.
*/
BoundingSphere.transform = function(sphere, transform, result) {
//>>includeStart('debug', pragmas.debug);
if (!defined(sphere)) {
throw new DeveloperError('sphere is required.');
}
if (!defined(transform)) {
throw new DeveloperError('transform is required.');
}
//>>includeEnd('debug');
if (!defined(result)) {
result = new BoundingSphere();
}
result.center = Matrix4.multiplyByPoint(transform, sphere.center, result.center);
result.radius = Matrix4.getMaximumScale(transform) * sphere.radius;
return result;
};
var distanceSquaredToScratch = new Cartesian3();
/**
* Computes the estimated distance squared from the closest point on a bounding sphere to a point.
*
* @param {BoundingSphere} sphere The sphere.
* @param {Cartesian3} cartesian The point
* @returns {Number} The estimated distance squared from the bounding sphere to the point.
*
* @example
* // Sort bounding spheres from back to front
* spheres.sort(function(a, b) {
* return Cesium.BoundingSphere.distanceSquaredTo(b, camera.positionWC) - Cesium.BoundingSphere.distanceSquaredTo(a, camera.positionWC);
* });
*/
BoundingSphere.distanceSquaredTo = function(sphere, cartesian) {
//>>includeStart('debug', pragmas.debug);
if (!defined(sphere)) {
throw new DeveloperError('sphere is required.');
}
if (!defined(cartesian)) {
throw new DeveloperError('cartesian is required.');
}
//>>includeEnd('debug');
var diff = Cartesian3.subtract(sphere.center, cartesian, distanceSquaredToScratch);
return Cartesian3.magnitudeSquared(diff) - sphere.radius * sphere.radius;
};
/**
* Applies a 4x4 affine transformation matrix to a bounding sphere where there is no scale
* The transformation matrix is not verified to have a uniform scale of 1.
* This method is faster than computing the general bounding sphere transform using {@link BoundingSphere.transform}.
*
* @param {BoundingSphere} sphere The bounding sphere to apply the transformation to.
* @param {Matrix4} transform The transformation matrix to apply to the bounding sphere.
* @param {BoundingSphere} [result] The object onto which to store the result.
* @returns {BoundingSphere} The modified result parameter or a new BoundingSphere instance if none was provided.
*
* @example
* var modelMatrix = Cesium.Transforms.eastNorthUpToFixedFrame(positionOnEllipsoid);
* var boundingSphere = new Cesium.BoundingSphere();
* var newBoundingSphere = Cesium.BoundingSphere.transformWithoutScale(boundingSphere, modelMatrix);
*/
BoundingSphere.transformWithoutScale = function(sphere, transform, result) {
//>>includeStart('debug', pragmas.debug);
if (!defined(sphere)) {
throw new DeveloperError('sphere is required.');
}
if (!defined(transform)) {
throw new DeveloperError('transform is required.');
}
//>>includeEnd('debug');
if (!defined(result)) {
result = new BoundingSphere();
}
result.center = Matrix4.multiplyByPoint(transform, sphere.center, result.center);
result.radius = sphere.radius;
return result;
};
var scratchCartesian3 = new Cartesian3();
/**
* The distances calculated by the vector from the center of the bounding sphere to position projected onto direction
* plus/minus the radius of the bounding sphere.
* <br>
* If you imagine the infinite number of planes with normal direction, this computes the smallest distance to the
* closest and farthest planes from position that intersect the bounding sphere.
*
* @param {BoundingSphere} sphere The bounding sphere to calculate the distance to.
* @param {Cartesian3} position The position to calculate the distance from.
* @param {Cartesian3} direction The direction from position.
* @param {Interval} [result] A Interval to store the nearest and farthest distances.
* @returns {Interval} The nearest and farthest distances on the bounding sphere from position in direction.
*/
BoundingSphere.computePlaneDistances = function(sphere, position, direction, result) {
//>>includeStart('debug', pragmas.debug);
if (!defined(sphere)) {
throw new DeveloperError('sphere is required.');
}
if (!defined(position)) {
throw new DeveloperError('position is required.');
}
if (!defined(direction)) {
throw new DeveloperError('direction is required.');
}
//>>includeEnd('debug');
if (!defined(result)) {
result = new Interval();
}
var toCenter = Cartesian3.subtract(sphere.center, position, scratchCartesian3);
var mag = Cartesian3.dot(direction, toCenter);
result.start = mag - sphere.radius;
result.stop = mag + sphere.radius;
return result;
};
var projectTo2DNormalScratch = new Cartesian3();
var projectTo2DEastScratch = new Cartesian3();
var projectTo2DNorthScratch = new Cartesian3();
var projectTo2DWestScratch = new Cartesian3();
var projectTo2DSouthScratch = new Cartesian3();
var projectTo2DCartographicScratch = new Cartographic();
var projectTo2DPositionsScratch = new Array(8);
for (var n = 0; n < 8; ++n) {
projectTo2DPositionsScratch[n] = new Cartesian3();
}
var projectTo2DProjection = new GeographicProjection();
/**
* Creates a bounding sphere in 2D from a bounding sphere in 3D world coordinates.
*
* @param {BoundingSphere} sphere The bounding sphere to transform to 2D.
* @param {Object} [projection=GeographicProjection] The projection to 2D.
* @param {BoundingSphere} [result] The object onto which to store the result.
* @returns {BoundingSphere} The modified result parameter or a new BoundingSphere instance if none was provided.
*/
BoundingSphere.projectTo2D = function(sphere, projection, result) {
//>>includeStart('debug', pragmas.debug);
if (!defined(sphere)) {
throw new DeveloperError('sphere is required.');
}
//>>includeEnd('debug');
projection = defaultValue(projection, projectTo2DProjection);
var ellipsoid = projection.ellipsoid;
var center = sphere.center;
var radius = sphere.radius;
var normal = ellipsoid.geodeticSurfaceNormal(center, projectTo2DNormalScratch);
var east = Cartesian3.cross(Cartesian3.UNIT_Z, normal, projectTo2DEastScratch);
Cartesian3.normalize(east, east);
var north = Cartesian3.cross(normal, east, projectTo2DNorthScratch);
Cartesian3.normalize(north, north);
Cartesian3.multiplyByScalar(normal, radius, normal);
Cartesian3.multiplyByScalar(north, radius, north);
Cartesian3.multiplyByScalar(east, radius, east);
var south = Cartesian3.negate(north, projectTo2DSouthScratch);
var west = Cartesian3.negate(east, projectTo2DWestScratch);
var positions = projectTo2DPositionsScratch;
// top NE corner
var corner = positions[0];
Cartesian3.add(normal, north, corner);
Cartesian3.add(corner, east, corner);
// top NW corner
corner = positions[1];
Cartesian3.add(normal, north, corner);
Cartesian3.add(corner, west, corner);
// top SW corner
corner = positions[2];
Cartesian3.add(normal, south, corner);
Cartesian3.add(corner, west, corner);
// top SE corner
corner = positions[3];
Cartesian3.add(normal, south, corner);
Cartesian3.add(corner, east, corner);
Cartesian3.negate(normal, normal);
// bottom NE corner
corner = positions[4];
Cartesian3.add(normal, north, corner);
Cartesian3.add(corner, east, corner);
// bottom NW corner
corner = positions[5];
Cartesian3.add(normal, north, corner);
Cartesian3.add(corner, west, corner);
// bottom SW corner
corner = positions[6];
Cartesian3.add(normal, south, corner);
Cartesian3.add(corner, west, corner);
// bottom SE corner
corner = positions[7];
Cartesian3.add(normal, south, corner);
Cartesian3.add(corner, east, corner);
var length = positions.length;
for (var i = 0; i < length; ++i) {
var position = positions[i];
Cartesian3.add(center, position, position);
var cartographic = ellipsoid.cartesianToCartographic(position, projectTo2DCartographicScratch);
projection.project(cartographic, position);
}
result = BoundingSphere.fromPoints(positions, result);
// swizzle center components
center = result.center;
var x = center.x;
var y = center.y;
var z = center.z;
center.x = z;
center.y = x;
center.z = y;
return result;
};
/**
* Determines whether or not a sphere is hidden from view by the occluder.
*
* @param {BoundingSphere} sphere The bounding sphere surrounding the occludee object.
* @param {Occluder} occluder The occluder.
* @returns {Boolean} <code>true</code> if the sphere is not visible; otherwise <code>false</code>.
*/
BoundingSphere.isOccluded = function(sphere, occluder) {
//>>includeStart('debug', pragmas.debug);
if (!defined(sphere)) {
throw new DeveloperError('sphere is required.');
}
if (!defined(occluder)) {
throw new DeveloperError('occluder is required.');
}
//>>includeEnd('debug');
return !occluder.isBoundingSphereVisible(sphere);
};
/**
* Compares the provided BoundingSphere componentwise and returns
* <code>true</code> if they are equal, <code>false</code> otherwise.
*
* @param {BoundingSphere} [left] The first BoundingSphere.
* @param {BoundingSphere} [right] The second BoundingSphere.
* @returns {Boolean} <code>true</code> if left and right are equal, <code>false</code> otherwise.
*/
BoundingSphere.equals = function(left, right) {
return (left === right) ||
((defined(left)) &&
(defined(right)) &&
Cartesian3.equals(left.center, right.center) &&
left.radius === right.radius);
};
/**
* Determines which side of a plane the sphere is located.
*
* @param {Plane} plane The plane to test against.
* @returns {Intersect} {@link Intersect.INSIDE} if the entire sphere is on the side of the plane
* the normal is pointing, {@link Intersect.OUTSIDE} if the entire sphere is
* on the opposite side, and {@link Intersect.INTERSECTING} if the sphere
* intersects the plane.
*/
BoundingSphere.prototype.intersectPlane = function(plane) {
return BoundingSphere.intersectPlane(this, plane);
};
/**
* Computes the estimated distance squared from the closest point on a bounding sphere to a point.
*
* @param {Cartesian3} cartesian The point
* @returns {Number} The estimated distance squared from the bounding sphere to the point.
*
* @example
* // Sort bounding spheres from back to front
* spheres.sort(function(a, b) {
* return b.distanceSquaredTo(camera.positionWC) - a.distanceSquaredTo(camera.positionWC);
* });
*/
BoundingSphere.prototype.distanceSquaredTo = function(cartesian) {
return BoundingSphere.distanceSquaredTo(this, cartesian);
};
/**
* The distances calculated by the vector from the center of the bounding sphere to position projected onto direction
* plus/minus the radius of the bounding sphere.
* <br>
* If you imagine the infinite number of planes with normal direction, this computes the smallest distance to the
* closest and farthest planes from position that intersect the bounding sphere.
*
* @param {Cartesian3} position The position to calculate the distance from.
* @param {Cartesian3} direction The direction from position.
* @param {Interval} [result] A Interval to store the nearest and farthest distances.
* @returns {Interval} The nearest and farthest distances on the bounding sphere from position in direction.
*/
BoundingSphere.prototype.computePlaneDistances = function(position, direction, result) {
return BoundingSphere.computePlaneDistances(this, position, direction, result);
};
/**
* Determines whether or not a sphere is hidden from view by the occluder.
*
* @param {Occluder} occluder The occluder.
* @returns {Boolean} <code>true</code> if the sphere is not visible; otherwise <code>false</code>.
*/
BoundingSphere.prototype.isOccluded = function(occluder) {
return BoundingSphere.isOccluded(this, occluder);
};
/**
* Compares this BoundingSphere against the provided BoundingSphere componentwise and returns
* <code>true</code> if they are equal, <code>false</code> otherwise.
*
* @param {BoundingSphere} [right] The right hand side BoundingSphere.
* @returns {Boolean} <code>true</code> if they are equal, <code>false</code> otherwise.
*/
BoundingSphere.prototype.equals = function(right) {
return BoundingSphere.equals(this, right);
};
/**
* Duplicates this BoundingSphere instance.
*
* @param {BoundingSphere} [result] The object onto which to store the result.
* @returns {BoundingSphere} The modified result parameter or a new BoundingSphere instance if none was provided.
*/
BoundingSphere.prototype.clone = function(result) {
return BoundingSphere.clone(this, result);
};
return BoundingSphere;
});