import BoundingSphere from "./BoundingSphere.js";
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import Cartesian3 from "./Cartesian3.js";
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import defaultValue from "./defaultValue.js";
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import defined from "./defined.js";
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import DeveloperError from "./DeveloperError.js";
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import Ellipsoid from "./Ellipsoid.js";
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import CesiumMath from "./Math.js";
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import Rectangle from "./Rectangle.js";
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import Visibility from "./Visibility.js";
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/**
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* Creates an Occluder derived from an object's position and radius, as well as the camera position.
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* The occluder can be used to determine whether or not other objects are visible or hidden behind the
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* visible horizon defined by the occluder and camera position.
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*
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* @alias Occluder
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*
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* @param {BoundingSphere} occluderBoundingSphere The bounding sphere surrounding the occluder.
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* @param {Cartesian3} cameraPosition The coordinate of the viewer/camera.
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*
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* @constructor
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*
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* @example
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* // Construct an occluder one unit away from the origin with a radius of one.
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* var cameraPosition = Cesium.Cartesian3.ZERO;
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* var occluderBoundingSphere = new Cesium.BoundingSphere(new Cesium.Cartesian3(0, 0, -1), 1);
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* var occluder = new Cesium.Occluder(occluderBoundingSphere, cameraPosition);
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*/
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function Occluder(occluderBoundingSphere, cameraPosition) {
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//>>includeStart('debug', pragmas.debug);
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if (!defined(occluderBoundingSphere)) {
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throw new DeveloperError("occluderBoundingSphere is required.");
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}
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if (!defined(cameraPosition)) {
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throw new DeveloperError("camera position is required.");
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}
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//>>includeEnd('debug');
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this._occluderPosition = Cartesian3.clone(occluderBoundingSphere.center);
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this._occluderRadius = occluderBoundingSphere.radius;
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this._horizonDistance = 0.0;
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this._horizonPlaneNormal = undefined;
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this._horizonPlanePosition = undefined;
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this._cameraPosition = undefined;
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// cameraPosition fills in the above values
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this.cameraPosition = cameraPosition;
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}
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var scratchCartesian3 = new Cartesian3();
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Object.defineProperties(Occluder.prototype, {
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/**
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* The position of the occluder.
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* @memberof Occluder.prototype
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* @type {Cartesian3}
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*/
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position: {
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get: function () {
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return this._occluderPosition;
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},
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},
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/**
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* The radius of the occluder.
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* @memberof Occluder.prototype
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* @type {Number}
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*/
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radius: {
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get: function () {
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return this._occluderRadius;
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},
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},
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/**
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* The position of the camera.
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* @memberof Occluder.prototype
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* @type {Cartesian3}
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*/
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cameraPosition: {
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set: function (cameraPosition) {
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//>>includeStart('debug', pragmas.debug);
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if (!defined(cameraPosition)) {
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throw new DeveloperError("cameraPosition is required.");
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}
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//>>includeEnd('debug');
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cameraPosition = Cartesian3.clone(cameraPosition, this._cameraPosition);
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var cameraToOccluderVec = Cartesian3.subtract(
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this._occluderPosition,
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cameraPosition,
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scratchCartesian3
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);
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var invCameraToOccluderDistance = Cartesian3.magnitudeSquared(
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cameraToOccluderVec
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);
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var occluderRadiusSqrd = this._occluderRadius * this._occluderRadius;
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var horizonDistance;
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var horizonPlaneNormal;
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var horizonPlanePosition;
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if (invCameraToOccluderDistance > occluderRadiusSqrd) {
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horizonDistance = Math.sqrt(
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invCameraToOccluderDistance - occluderRadiusSqrd
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);
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invCameraToOccluderDistance =
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1.0 / Math.sqrt(invCameraToOccluderDistance);
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horizonPlaneNormal = Cartesian3.multiplyByScalar(
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cameraToOccluderVec,
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invCameraToOccluderDistance,
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scratchCartesian3
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);
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var nearPlaneDistance =
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horizonDistance * horizonDistance * invCameraToOccluderDistance;
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horizonPlanePosition = Cartesian3.add(
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cameraPosition,
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Cartesian3.multiplyByScalar(
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horizonPlaneNormal,
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nearPlaneDistance,
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scratchCartesian3
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),
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scratchCartesian3
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);
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} else {
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horizonDistance = Number.MAX_VALUE;
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}
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this._horizonDistance = horizonDistance;
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this._horizonPlaneNormal = horizonPlaneNormal;
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this._horizonPlanePosition = horizonPlanePosition;
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this._cameraPosition = cameraPosition;
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},
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},
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});
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/**
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* Creates an occluder from a bounding sphere and the camera position.
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*
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* @param {BoundingSphere} occluderBoundingSphere The bounding sphere surrounding the occluder.
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* @param {Cartesian3} cameraPosition The coordinate of the viewer/camera.
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* @param {Occluder} [result] The object onto which to store the result.
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* @returns {Occluder} The occluder derived from an object's position and radius, as well as the camera position.
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*/
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Occluder.fromBoundingSphere = function (
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occluderBoundingSphere,
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cameraPosition,
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result
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) {
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//>>includeStart('debug', pragmas.debug);
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if (!defined(occluderBoundingSphere)) {
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throw new DeveloperError("occluderBoundingSphere is required.");
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}
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if (!defined(cameraPosition)) {
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throw new DeveloperError("camera position is required.");
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}
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//>>includeEnd('debug');
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if (!defined(result)) {
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return new Occluder(occluderBoundingSphere, cameraPosition);
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}
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Cartesian3.clone(occluderBoundingSphere.center, result._occluderPosition);
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result._occluderRadius = occluderBoundingSphere.radius;
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result.cameraPosition = cameraPosition;
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return result;
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};
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var tempVecScratch = new Cartesian3();
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/**
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* Determines whether or not a point, the <code>occludee</code>, is hidden from view by the occluder.
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*
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* @param {Cartesian3} occludee The point surrounding the occludee object.
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* @returns {Boolean} <code>true</code> if the occludee is visible; otherwise <code>false</code>.
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*
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*
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* @example
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* var cameraPosition = new Cesium.Cartesian3(0, 0, 0);
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* var littleSphere = new Cesium.BoundingSphere(new Cesium.Cartesian3(0, 0, -1), 0.25);
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* var occluder = new Cesium.Occluder(littleSphere, cameraPosition);
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* var point = new Cesium.Cartesian3(0, 0, -3);
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* occluder.isPointVisible(point); //returns true
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*
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* @see Occluder#computeVisibility
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*/
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Occluder.prototype.isPointVisible = function (occludee) {
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if (this._horizonDistance !== Number.MAX_VALUE) {
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var tempVec = Cartesian3.subtract(
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occludee,
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this._occluderPosition,
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tempVecScratch
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);
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var temp = this._occluderRadius;
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temp = Cartesian3.magnitudeSquared(tempVec) - temp * temp;
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if (temp > 0.0) {
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temp = Math.sqrt(temp) + this._horizonDistance;
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tempVec = Cartesian3.subtract(occludee, this._cameraPosition, tempVec);
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return temp * temp > Cartesian3.magnitudeSquared(tempVec);
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}
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}
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return false;
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};
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var occludeePositionScratch = new Cartesian3();
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/**
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* Determines whether or not a sphere, the <code>occludee</code>, is hidden from view by the occluder.
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*
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* @param {BoundingSphere} occludee The bounding sphere surrounding the occludee object.
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* @returns {Boolean} <code>true</code> if the occludee is visible; otherwise <code>false</code>.
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*
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*
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* @example
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* var cameraPosition = new Cesium.Cartesian3(0, 0, 0);
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* var littleSphere = new Cesium.BoundingSphere(new Cesium.Cartesian3(0, 0, -1), 0.25);
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* var occluder = new Cesium.Occluder(littleSphere, cameraPosition);
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* var bigSphere = new Cesium.BoundingSphere(new Cesium.Cartesian3(0, 0, -3), 1);
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* occluder.isBoundingSphereVisible(bigSphere); //returns true
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*
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* @see Occluder#computeVisibility
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*/
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Occluder.prototype.isBoundingSphereVisible = function (occludee) {
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var occludeePosition = Cartesian3.clone(
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occludee.center,
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occludeePositionScratch
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);
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var occludeeRadius = occludee.radius;
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if (this._horizonDistance !== Number.MAX_VALUE) {
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var tempVec = Cartesian3.subtract(
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occludeePosition,
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this._occluderPosition,
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tempVecScratch
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);
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var temp = this._occluderRadius - occludeeRadius;
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temp = Cartesian3.magnitudeSquared(tempVec) - temp * temp;
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if (occludeeRadius < this._occluderRadius) {
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if (temp > 0.0) {
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temp = Math.sqrt(temp) + this._horizonDistance;
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tempVec = Cartesian3.subtract(
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occludeePosition,
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this._cameraPosition,
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tempVec
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);
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return (
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temp * temp + occludeeRadius * occludeeRadius >
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Cartesian3.magnitudeSquared(tempVec)
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);
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}
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return false;
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}
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// Prevent against the case where the occludee radius is larger than the occluder's; since this is
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// an uncommon case, the following code should rarely execute.
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if (temp > 0.0) {
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tempVec = Cartesian3.subtract(
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occludeePosition,
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this._cameraPosition,
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tempVec
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);
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var tempVecMagnitudeSquared = Cartesian3.magnitudeSquared(tempVec);
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var occluderRadiusSquared = this._occluderRadius * this._occluderRadius;
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var occludeeRadiusSquared = occludeeRadius * occludeeRadius;
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if (
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(this._horizonDistance * this._horizonDistance +
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occluderRadiusSquared) *
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occludeeRadiusSquared >
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tempVecMagnitudeSquared * occluderRadiusSquared
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) {
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// The occludee is close enough that the occluder cannot possible occlude the occludee
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return true;
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}
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temp = Math.sqrt(temp) + this._horizonDistance;
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return temp * temp + occludeeRadiusSquared > tempVecMagnitudeSquared;
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}
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// The occludee completely encompasses the occluder
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return true;
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}
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return false;
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};
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var tempScratch = new Cartesian3();
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/**
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* Determine to what extent an occludee is visible (not visible, partially visible, or fully visible).
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*
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* @param {BoundingSphere} occludeeBS The bounding sphere of the occludee.
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* @returns {Visibility} Visibility.NONE if the occludee is not visible,
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* Visibility.PARTIAL if the occludee is partially visible, or
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* Visibility.FULL if the occludee is fully visible.
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*
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*
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* @example
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* var sphere1 = new Cesium.BoundingSphere(new Cesium.Cartesian3(0, 0, -1.5), 0.5);
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* var sphere2 = new Cesium.BoundingSphere(new Cesium.Cartesian3(0, 0, -2.5), 0.5);
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* var cameraPosition = new Cesium.Cartesian3(0, 0, 0);
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* var occluder = new Cesium.Occluder(sphere1, cameraPosition);
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* occluder.computeVisibility(sphere2); //returns Visibility.NONE
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*
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* @see Occluder#isVisible
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*/
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Occluder.prototype.computeVisibility = function (occludeeBS) {
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//>>includeStart('debug', pragmas.debug);
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if (!defined(occludeeBS)) {
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throw new DeveloperError("occludeeBS is required.");
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}
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//>>includeEnd('debug');
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// If the occludee radius is larger than the occluders, this will return that
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// the entire ocludee is visible, even though that may not be the case, though this should
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// not occur too often.
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var occludeePosition = Cartesian3.clone(occludeeBS.center);
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var occludeeRadius = occludeeBS.radius;
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if (occludeeRadius > this._occluderRadius) {
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return Visibility.FULL;
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}
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if (this._horizonDistance !== Number.MAX_VALUE) {
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// The camera is outside the occluder
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var tempVec = Cartesian3.subtract(
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occludeePosition,
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this._occluderPosition,
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tempScratch
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);
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var temp = this._occluderRadius - occludeeRadius;
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var occluderToOccludeeDistSqrd = Cartesian3.magnitudeSquared(tempVec);
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temp = occluderToOccludeeDistSqrd - temp * temp;
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if (temp > 0.0) {
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// The occludee is not completely inside the occluder
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// Check to see if the occluder completely hides the occludee
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temp = Math.sqrt(temp) + this._horizonDistance;
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tempVec = Cartesian3.subtract(
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occludeePosition,
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this._cameraPosition,
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tempVec
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);
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var cameraToOccludeeDistSqrd = Cartesian3.magnitudeSquared(tempVec);
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if (
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temp * temp + occludeeRadius * occludeeRadius <
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cameraToOccludeeDistSqrd
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) {
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return Visibility.NONE;
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}
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// Check to see whether the occluder is fully or partially visible
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// when the occludee does not intersect the occluder
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temp = this._occluderRadius + occludeeRadius;
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temp = occluderToOccludeeDistSqrd - temp * temp;
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if (temp > 0.0) {
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// The occludee does not intersect the occluder.
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temp = Math.sqrt(temp) + this._horizonDistance;
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return cameraToOccludeeDistSqrd <
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temp * temp + occludeeRadius * occludeeRadius
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? Visibility.FULL
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: Visibility.PARTIAL;
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}
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//Check to see if the occluder is fully or partially visible when the occludee DOES
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//intersect the occluder
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tempVec = Cartesian3.subtract(
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occludeePosition,
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this._horizonPlanePosition,
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tempVec
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);
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return Cartesian3.dot(tempVec, this._horizonPlaneNormal) > -occludeeRadius
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? Visibility.PARTIAL
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: Visibility.FULL;
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}
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}
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return Visibility.NONE;
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};
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var occludeePointScratch = new Cartesian3();
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/**
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* Computes a point that can be used as the occludee position to the visibility functions.
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* Use a radius of zero for the occludee radius. Typically, a user computes a bounding sphere around
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* an object that is used for visibility; however it is also possible to compute a point that if
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* seen/not seen would also indicate if an object is visible/not visible. This function is better
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* called for objects that do not move relative to the occluder and is large, such as a chunk of
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* terrain. You are better off not calling this and using the object's bounding sphere for objects
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* such as a satellite or ground vehicle.
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*
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* @param {BoundingSphere} occluderBoundingSphere The bounding sphere surrounding the occluder.
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* @param {Cartesian3} occludeePosition The point where the occludee (bounding sphere of radius 0) is located.
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* @param {Cartesian3[]} positions List of altitude points on the horizon near the surface of the occluder.
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* @returns {Object} An object containing two attributes: <code>occludeePoint</code> and <code>valid</code>
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* which is a boolean value.
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*
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* @exception {DeveloperError} <code>positions</code> must contain at least one element.
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* @exception {DeveloperError} <code>occludeePosition</code> must have a value other than <code>occluderBoundingSphere.center</code>.
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*
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* @example
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* var cameraPosition = new Cesium.Cartesian3(0, 0, 0);
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* var occluderBoundingSphere = new Cesium.BoundingSphere(new Cesium.Cartesian3(0, 0, -8), 2);
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* var occluder = new Cesium.Occluder(occluderBoundingSphere, cameraPosition);
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* var positions = [new Cesium.Cartesian3(-0.25, 0, -5.3), new Cesium.Cartesian3(0.25, 0, -5.3)];
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* var tileOccluderSphere = Cesium.BoundingSphere.fromPoints(positions);
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* var occludeePosition = tileOccluderSphere.center;
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* var occludeePt = Cesium.Occluder.computeOccludeePoint(occluderBoundingSphere, occludeePosition, positions);
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*/
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Occluder.computeOccludeePoint = function (
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occluderBoundingSphere,
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occludeePosition,
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positions
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) {
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//>>includeStart('debug', pragmas.debug);
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if (!defined(occluderBoundingSphere)) {
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throw new DeveloperError("occluderBoundingSphere is required.");
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}
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if (!defined(positions)) {
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throw new DeveloperError("positions is required.");
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}
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if (positions.length === 0) {
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throw new DeveloperError("positions must contain at least one element");
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}
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//>>includeEnd('debug');
|
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var occludeePos = Cartesian3.clone(occludeePosition);
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var occluderPosition = Cartesian3.clone(occluderBoundingSphere.center);
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var occluderRadius = occluderBoundingSphere.radius;
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var numPositions = positions.length;
|
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//>>includeStart('debug', pragmas.debug);
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if (Cartesian3.equals(occluderPosition, occludeePosition)) {
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throw new DeveloperError(
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"occludeePosition must be different than occluderBoundingSphere.center"
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);
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}
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//>>includeEnd('debug');
|
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// Compute a plane with a normal from the occluder to the occludee position.
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var occluderPlaneNormal = Cartesian3.normalize(
|
Cartesian3.subtract(occludeePos, occluderPosition, occludeePointScratch),
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occludeePointScratch
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);
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var occluderPlaneD = -Cartesian3.dot(occluderPlaneNormal, occluderPosition);
|
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//For each position, determine the horizon intersection. Choose the position and intersection
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//that results in the greatest angle with the occcluder plane.
|
var aRotationVector = Occluder._anyRotationVector(
|
occluderPosition,
|
occluderPlaneNormal,
|
occluderPlaneD
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);
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var dot = Occluder._horizonToPlaneNormalDotProduct(
|
occluderBoundingSphere,
|
occluderPlaneNormal,
|
occluderPlaneD,
|
aRotationVector,
|
positions[0]
|
);
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if (!dot) {
|
//The position is inside the mimimum radius, which is invalid
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return undefined;
|
}
|
var tempDot;
|
for (var i = 1; i < numPositions; ++i) {
|
tempDot = Occluder._horizonToPlaneNormalDotProduct(
|
occluderBoundingSphere,
|
occluderPlaneNormal,
|
occluderPlaneD,
|
aRotationVector,
|
positions[i]
|
);
|
if (!tempDot) {
|
//The position is inside the minimum radius, which is invalid
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return undefined;
|
}
|
if (tempDot < dot) {
|
dot = tempDot;
|
}
|
}
|
//Verify that the dot is not near 90 degress
|
if (dot < 0.00174532836589830883577820272085) {
|
return undefined;
|
}
|
|
var distance = occluderRadius / dot;
|
return Cartesian3.add(
|
occluderPosition,
|
Cartesian3.multiplyByScalar(
|
occluderPlaneNormal,
|
distance,
|
occludeePointScratch
|
),
|
occludeePointScratch
|
);
|
};
|
|
var computeOccludeePointFromRectangleScratch = [];
|
/**
|
* Computes a point that can be used as the occludee position to the visibility functions from a rectangle.
|
*
|
* @param {Rectangle} rectangle The rectangle used to create a bounding sphere.
|
* @param {Ellipsoid} [ellipsoid=Ellipsoid.WGS84] The ellipsoid used to determine positions of the rectangle.
|
* @returns {Object} An object containing two attributes: <code>occludeePoint</code> and <code>valid</code>
|
* which is a boolean value.
|
*/
|
Occluder.computeOccludeePointFromRectangle = function (rectangle, ellipsoid) {
|
//>>includeStart('debug', pragmas.debug);
|
if (!defined(rectangle)) {
|
throw new DeveloperError("rectangle is required.");
|
}
|
//>>includeEnd('debug');
|
|
ellipsoid = defaultValue(ellipsoid, Ellipsoid.WGS84);
|
var positions = Rectangle.subsample(
|
rectangle,
|
ellipsoid,
|
0.0,
|
computeOccludeePointFromRectangleScratch
|
);
|
var bs = BoundingSphere.fromPoints(positions);
|
|
// TODO: get correct ellipsoid center
|
var ellipsoidCenter = Cartesian3.ZERO;
|
if (!Cartesian3.equals(ellipsoidCenter, bs.center)) {
|
return Occluder.computeOccludeePoint(
|
new BoundingSphere(ellipsoidCenter, ellipsoid.minimumRadius),
|
bs.center,
|
positions
|
);
|
}
|
|
return undefined;
|
};
|
|
var tempVec0Scratch = new Cartesian3();
|
Occluder._anyRotationVector = function (
|
occluderPosition,
|
occluderPlaneNormal,
|
occluderPlaneD
|
) {
|
var tempVec0 = Cartesian3.abs(occluderPlaneNormal, tempVec0Scratch);
|
var majorAxis = tempVec0.x > tempVec0.y ? 0 : 1;
|
if (
|
(majorAxis === 0 && tempVec0.z > tempVec0.x) ||
|
(majorAxis === 1 && tempVec0.z > tempVec0.y)
|
) {
|
majorAxis = 2;
|
}
|
var tempVec = new Cartesian3();
|
var tempVec1;
|
if (majorAxis === 0) {
|
tempVec0.x = occluderPosition.x;
|
tempVec0.y = occluderPosition.y + 1.0;
|
tempVec0.z = occluderPosition.z + 1.0;
|
tempVec1 = Cartesian3.UNIT_X;
|
} else if (majorAxis === 1) {
|
tempVec0.x = occluderPosition.x + 1.0;
|
tempVec0.y = occluderPosition.y;
|
tempVec0.z = occluderPosition.z + 1.0;
|
tempVec1 = Cartesian3.UNIT_Y;
|
} else {
|
tempVec0.x = occluderPosition.x + 1.0;
|
tempVec0.y = occluderPosition.y + 1.0;
|
tempVec0.z = occluderPosition.z;
|
tempVec1 = Cartesian3.UNIT_Z;
|
}
|
var u =
|
(Cartesian3.dot(occluderPlaneNormal, tempVec0) + occluderPlaneD) /
|
-Cartesian3.dot(occluderPlaneNormal, tempVec1);
|
return Cartesian3.normalize(
|
Cartesian3.subtract(
|
Cartesian3.add(
|
tempVec0,
|
Cartesian3.multiplyByScalar(tempVec1, u, tempVec),
|
tempVec0
|
),
|
occluderPosition,
|
tempVec0
|
),
|
tempVec0
|
);
|
};
|
|
var posDirectionScratch = new Cartesian3();
|
Occluder._rotationVector = function (
|
occluderPosition,
|
occluderPlaneNormal,
|
occluderPlaneD,
|
position,
|
anyRotationVector
|
) {
|
//Determine the angle between the occluder plane normal and the position direction
|
var positionDirection = Cartesian3.subtract(
|
position,
|
occluderPosition,
|
posDirectionScratch
|
);
|
positionDirection = Cartesian3.normalize(
|
positionDirection,
|
positionDirection
|
);
|
if (
|
Cartesian3.dot(occluderPlaneNormal, positionDirection) <
|
0.99999998476912904932780850903444
|
) {
|
var crossProduct = Cartesian3.cross(
|
occluderPlaneNormal,
|
positionDirection,
|
positionDirection
|
);
|
var length = Cartesian3.magnitude(crossProduct);
|
if (length > CesiumMath.EPSILON13) {
|
return Cartesian3.normalize(crossProduct, new Cartesian3());
|
}
|
}
|
//The occluder plane normal and the position direction are colinear. Use any
|
//vector in the occluder plane as the rotation vector
|
return anyRotationVector;
|
};
|
|
var posScratch1 = new Cartesian3();
|
var occluerPosScratch = new Cartesian3();
|
var posScratch2 = new Cartesian3();
|
var horizonPlanePosScratch = new Cartesian3();
|
Occluder._horizonToPlaneNormalDotProduct = function (
|
occluderBS,
|
occluderPlaneNormal,
|
occluderPlaneD,
|
anyRotationVector,
|
position
|
) {
|
var pos = Cartesian3.clone(position, posScratch1);
|
var occluderPosition = Cartesian3.clone(occluderBS.center, occluerPosScratch);
|
var occluderRadius = occluderBS.radius;
|
|
//Verify that the position is outside the occluder
|
var positionToOccluder = Cartesian3.subtract(
|
occluderPosition,
|
pos,
|
posScratch2
|
);
|
var occluderToPositionDistanceSquared = Cartesian3.magnitudeSquared(
|
positionToOccluder
|
);
|
var occluderRadiusSquared = occluderRadius * occluderRadius;
|
if (occluderToPositionDistanceSquared < occluderRadiusSquared) {
|
return false;
|
}
|
|
//Horizon parameters
|
var horizonDistanceSquared =
|
occluderToPositionDistanceSquared - occluderRadiusSquared;
|
var horizonDistance = Math.sqrt(horizonDistanceSquared);
|
var occluderToPositionDistance = Math.sqrt(occluderToPositionDistanceSquared);
|
var invOccluderToPositionDistance = 1.0 / occluderToPositionDistance;
|
var cosTheta = horizonDistance * invOccluderToPositionDistance;
|
var horizonPlaneDistance = cosTheta * horizonDistance;
|
positionToOccluder = Cartesian3.normalize(
|
positionToOccluder,
|
positionToOccluder
|
);
|
var horizonPlanePosition = Cartesian3.add(
|
pos,
|
Cartesian3.multiplyByScalar(
|
positionToOccluder,
|
horizonPlaneDistance,
|
horizonPlanePosScratch
|
),
|
horizonPlanePosScratch
|
);
|
var horizonCrossDistance = Math.sqrt(
|
horizonDistanceSquared - horizonPlaneDistance * horizonPlaneDistance
|
);
|
|
//Rotate the position to occluder vector 90 degrees
|
var tempVec = this._rotationVector(
|
occluderPosition,
|
occluderPlaneNormal,
|
occluderPlaneD,
|
pos,
|
anyRotationVector
|
);
|
var horizonCrossDirection = Cartesian3.fromElements(
|
tempVec.x * tempVec.x * positionToOccluder.x +
|
(tempVec.x * tempVec.y - tempVec.z) * positionToOccluder.y +
|
(tempVec.x * tempVec.z + tempVec.y) * positionToOccluder.z,
|
(tempVec.x * tempVec.y + tempVec.z) * positionToOccluder.x +
|
tempVec.y * tempVec.y * positionToOccluder.y +
|
(tempVec.y * tempVec.z - tempVec.x) * positionToOccluder.z,
|
(tempVec.x * tempVec.z - tempVec.y) * positionToOccluder.x +
|
(tempVec.y * tempVec.z + tempVec.x) * positionToOccluder.y +
|
tempVec.z * tempVec.z * positionToOccluder.z,
|
posScratch1
|
);
|
horizonCrossDirection = Cartesian3.normalize(
|
horizonCrossDirection,
|
horizonCrossDirection
|
);
|
|
//Horizon positions
|
var offset = Cartesian3.multiplyByScalar(
|
horizonCrossDirection,
|
horizonCrossDistance,
|
posScratch1
|
);
|
tempVec = Cartesian3.normalize(
|
Cartesian3.subtract(
|
Cartesian3.add(horizonPlanePosition, offset, posScratch2),
|
occluderPosition,
|
posScratch2
|
),
|
posScratch2
|
);
|
var dot0 = Cartesian3.dot(occluderPlaneNormal, tempVec);
|
tempVec = Cartesian3.normalize(
|
Cartesian3.subtract(
|
Cartesian3.subtract(horizonPlanePosition, offset, tempVec),
|
occluderPosition,
|
tempVec
|
),
|
tempVec
|
);
|
var dot1 = Cartesian3.dot(occluderPlaneNormal, tempVec);
|
return dot0 < dot1 ? dot0 : dot1;
|
};
|
export default Occluder;
|
