Entity.js

import Cartesian3 from "../Core/Cartesian3.js";
import Cartographic from "../Core/Cartographic.js";
import Check from "../Core/Check.js";
import createGuid from "../Core/createGuid.js";
import defaultValue from "../Core/defaultValue.js";
import defined from "../Core/defined.js";
import DeveloperError from "../Core/DeveloperError.js";
import Event from "../Core/Event.js";
import CesiumMath from "../Core/Math.js";
import Matrix3 from "../Core/Matrix3.js";
import Matrix4 from "../Core/Matrix4.js";
import Quaternion from "../Core/Quaternion.js";
import Transforms from "../Core/Transforms.js";
import GroundPolylinePrimitive from "../Scene/GroundPolylinePrimitive.js";
import GroundPrimitive from "../Scene/GroundPrimitive.js";
import HeightReference from "../Scene/HeightReference.js";
import BillboardGraphics from "./BillboardGraphics.js";
import BoxGraphics from "./BoxGraphics.js";
import ConstantPositionProperty from "./ConstantPositionProperty.js";
import CorridorGraphics from "./CorridorGraphics.js";
import createPropertyDescriptor from "./createPropertyDescriptor.js";
import createRawPropertyDescriptor from "./createRawPropertyDescriptor.js";
import CylinderGraphics from "./CylinderGraphics.js";
import EllipseGraphics from "./EllipseGraphics.js";
import EllipsoidGraphics from "./EllipsoidGraphics.js";
import LabelGraphics from "./LabelGraphics.js";
import ModelGraphics from "./ModelGraphics.js";
import Cesium3DTilesetGraphics from "./Cesium3DTilesetGraphics.js";
import PathGraphics from "./PathGraphics.js";
import PlaneGraphics from "./PlaneGraphics.js";
import PointGraphics from "./PointGraphics.js";
import PolygonGraphics from "./PolygonGraphics.js";
import PolylineGraphics from "./PolylineGraphics.js";
import PolylineVolumeGraphics from "./PolylineVolumeGraphics.js";
import Property from "./Property.js";
import PropertyBag from "./PropertyBag.js";
import RectangleGraphics from "./RectangleGraphics.js";
import WallGraphics from "./WallGraphics.js";

const cartoScratch = new Cartographic();

function createConstantPositionProperty(value) {
  return new ConstantPositionProperty(value);
}

function createPositionPropertyDescriptor(name) {
  return createPropertyDescriptor(
    name,
    undefined,
    createConstantPositionProperty
  );
}

function createPropertyTypeDescriptor(name, Type) {
  return createPropertyDescriptor(name, undefined, function (value) {
    if (value instanceof Type) {
      return value;
    }
    return new Type(value);
  });
}

/**
 * @typedef {Object} Entity.ConstructorOptions
 *
 * Initialization options for the Entity constructor
 *
 * @property {String} [id] A unique identifier for this object. If none is provided, a GUID is generated.
 * @property {String} [name] A human readable name to display to users. It does not have to be unique.
 * @property {TimeIntervalCollection} [availability] The availability, if any, associated with this object.
 * @property {Boolean} [show] A boolean value indicating if the entity and its children are displayed.
 * @property {Property | string} [description] A string Property specifying an HTML description for this entity.
 * @property {PositionProperty | Cartesian3} [position] A Property specifying the entity position.
 * @property {Property} [orientation] A Property specifying the entity orientation.
 * @property {Property} [viewFrom] A suggested initial offset for viewing this object.
 * @property {Entity} [parent] A parent entity to associate with this entity.
 * @property {BillboardGraphics | BillboardGraphics.ConstructorOptions} [billboard] A billboard to associate with this entity.
 * @property {BoxGraphics | BoxGraphics.ConstructorOptions} [box] A box to associate with this entity.
 * @property {CorridorGraphics | CorridorGraphics.ConstructorOptions} [corridor] A corridor to associate with this entity.
 * @property {CylinderGraphics | CylinderGraphics.ConstructorOptions} [cylinder] A cylinder to associate with this entity.
 * @property {EllipseGraphics | EllipseGraphics.ConstructorOptions} [ellipse] A ellipse to associate with this entity.
 * @property {EllipsoidGraphics | EllipsoidGraphics.ConstructorOptions} [ellipsoid] A ellipsoid to associate with this entity.
 * @property {LabelGraphics | LabelGraphics.ConstructorOptions} [label] A options.label to associate with this entity.
 * @property {ModelGraphics | ModelGraphics.ConstructorOptions} [model] A model to associate with this entity.
 * @property {Cesium3DTilesetGraphics | Cesium3DTilesetGraphics.ConstructorOptions} [tileset] A 3D Tiles tileset to associate with this entity.
 * @property {PathGraphics | PathGraphics.ConstructorOptions} [path] A path to associate with this entity.
 * @property {PlaneGraphics | PlaneGraphics.ConstructorOptions} [plane] A plane to associate with this entity.
 * @property {PointGraphics | PointGraphics.ConstructorOptions} [point] A point to associate with this entity.
 * @property {PolygonGraphics | PolygonGraphics.ConstructorOptions} [polygon] A polygon to associate with this entity.
 * @property {PolylineGraphics | PolylineGraphics.ConstructorOptions} [polyline] A polyline to associate with this entity.
 * @property {PropertyBag | Object.<string,*>} [properties] Arbitrary properties to associate with this entity.
 * @property {PolylineVolumeGraphics | PolylineVolumeGraphics.ConstructorOptions} [polylineVolume] A polylineVolume to associate with this entity.
 * @property {RectangleGraphics | RectangleGraphics.ConstructorOptions} [rectangle] A rectangle to associate with this entity.
 * @property {WallGraphics | WallGraphics.ConstructorOptions} [wall] A wall to associate with this entity.
 */

/**
 * Entity instances aggregate multiple forms of visualization into a single high-level object.
 * They can be created manually and added to {@link Viewer#entities} or be produced by
 * data sources, such as {@link CzmlDataSource} and {@link GeoJsonDataSource}.
 * @alias Entity
 * @constructor
 *
 * @param {Entity.ConstructorOptions} [options] Object describing initialization options
 *
 * @see {@link https://cesium.com/learn/cesiumjs-learn/cesiumjs-creating-entities/|Creating Entities}
 */
function Entity(options) {
  options = defaultValue(options, defaultValue.EMPTY_OBJECT);

  let id = options.id;
  if (!defined(id)) {
    id = createGuid();
  }

  this._availability = undefined;
  this._id = id;
  this._definitionChanged = new Event();
  this._name = options.name;
  this._show = defaultValue(options.show, true);
  this._parent = undefined;
  this._propertyNames = [
    "billboard",
    "box",
    "corridor",
    "cylinder",
    "description",
    "ellipse", //
    "ellipsoid",
    "label",
    "model",
    "tileset",
    "orientation",
    "path",
    "plane",
    "point",
    "polygon", //
    "polyline",
    "polylineVolume",
    "position",
    "properties",
    "rectangle",
    "viewFrom",
    "wall",
  ];

  this._billboard = undefined;
  this._billboardSubscription = undefined;
  this._box = undefined;
  this._boxSubscription = undefined;
  this._corridor = undefined;
  this._corridorSubscription = undefined;
  this._cylinder = undefined;
  this._cylinderSubscription = undefined;
  this._description = undefined;
  this._descriptionSubscription = undefined;
  this._ellipse = undefined;
  this._ellipseSubscription = undefined;
  this._ellipsoid = undefined;
  this._ellipsoidSubscription = undefined;
  this._label = undefined;
  this._labelSubscription = undefined;
  this._model = undefined;
  this._modelSubscription = undefined;
  this._tileset = undefined;
  this._tilesetSubscription = undefined;
  this._orientation = undefined;
  this._orientationSubscription = undefined;
  this._path = undefined;
  this._pathSubscription = undefined;
  this._plane = undefined;
  this._planeSubscription = undefined;
  this._point = undefined;
  this._pointSubscription = undefined;
  this._polygon = undefined;
  this._polygonSubscription = undefined;
  this._polyline = undefined;
  this._polylineSubscription = undefined;
  this._polylineVolume = undefined;
  this._polylineVolumeSubscription = undefined;
  this._position = undefined;
  this._positionSubscription = undefined;
  this._properties = undefined;
  this._propertiesSubscription = undefined;
  this._rectangle = undefined;
  this._rectangleSubscription = undefined;
  this._viewFrom = undefined;
  this._viewFromSubscription = undefined;
  this._wall = undefined;
  this._wallSubscription = undefined;
  this._children = [];

  /**
   * Gets or sets the entity collection that this entity belongs to.
   * @type {EntityCollection}
   */
  this.entityCollection = undefined;

  this.parent = options.parent;
  this.merge(options);
}

function updateShow(entity, children, isShowing) {
  const length = children.length;
  for (let i = 0; i < length; i++) {
    const child = children[i];
    const childShow = child._show;
    const oldValue = !isShowing && childShow;
    const newValue = isShowing && childShow;
    if (oldValue !== newValue) {
      updateShow(child, child._children, isShowing);
    }
  }
  entity._definitionChanged.raiseEvent(
    entity,
    "isShowing",
    isShowing,
    !isShowing
  );
}

Object.defineProperties(Entity.prototype, {
  /**
   * The availability, if any, associated with this object.
   * If availability is undefined, it is assumed that this object's
   * other properties will return valid data for any provided time.
   * If availability exists, the objects other properties will only
   * provide valid data if queried within the given interval.
   * @memberof Entity.prototype
   * @type {TimeIntervalCollection|undefined}
   */
  availability: createRawPropertyDescriptor("availability"),
  /**
   * Gets the unique ID associated with this object.
   * @memberof Entity.prototype
   * @type {String}
   */
  id: {
    get: function () {
      return this._id;
    },
  },
  /**
   * Gets the event that is raised whenever a property or sub-property is changed or modified.
   * @memberof Entity.prototype
   *
   * @type {Event}
   * @readonly
   */
  definitionChanged: {
    get: function () {
      return this._definitionChanged;
    },
  },
  /**
   * Gets or sets the name of the object.  The name is intended for end-user
   * consumption and does not need to be unique.
   * @memberof Entity.prototype
   * @type {String|undefined}
   */
  name: createRawPropertyDescriptor("name"),
  /**
   * Gets or sets whether this entity should be displayed. When set to true,
   * the entity is only displayed if the parent entity's show property is also true.
   * @memberof Entity.prototype
   * @type {Boolean}
   */
  show: {
    get: function () {
      return this._show;
    },
    set: function (value) {
      //>>includeStart('debug', pragmas.debug);
      if (!defined(value)) {
        throw new DeveloperError("value is required.");
      }
      //>>includeEnd('debug');

      if (value === this._show) {
        return;
      }

      const wasShowing = this.isShowing;
      this._show = value;
      const isShowing = this.isShowing;

      if (wasShowing !== isShowing) {
        updateShow(this, this._children, isShowing);
      }

      this._definitionChanged.raiseEvent(this, "show", value, !value);
    },
  },
  /**
   * Gets whether this entity is being displayed, taking into account
   * the visibility of any ancestor entities.
   * @memberof Entity.prototype
   * @type {Boolean}
   */
  isShowing: {
    get: function () {
      return (
        this._show &&
        (!defined(this.entityCollection) || this.entityCollection.show) &&
        (!defined(this._parent) || this._parent.isShowing)
      );
    },
  },
  /**
   * Gets or sets the parent object.
   * @memberof Entity.prototype
   * @type {Entity|undefined}
   */
  parent: {
    get: function () {
      return this._parent;
    },
    set: function (value) {
      const oldValue = this._parent;

      if (oldValue === value) {
        return;
      }

      const wasShowing = this.isShowing;
      if (defined(oldValue)) {
        const index = oldValue._children.indexOf(this);
        oldValue._children.splice(index, 1);
      }

      this._parent = value;
      if (defined(value)) {
        value._children.push(this);
      }

      const isShowing = this.isShowing;

      if (wasShowing !== isShowing) {
        updateShow(this, this._children, isShowing);
      }

      this._definitionChanged.raiseEvent(this, "parent", value, oldValue);
    },
  },
  /**
   * Gets the names of all properties registered on this instance.
   * @memberof Entity.prototype
   * @type {string[]}
   */
  propertyNames: {
    get: function () {
      return this._propertyNames;
    },
  },
  /**
   * Gets or sets the billboard.
   * @memberof Entity.prototype
   * @type {BillboardGraphics|undefined}
   */
  billboard: createPropertyTypeDescriptor("billboard", BillboardGraphics),
  /**
   * Gets or sets the box.
   * @memberof Entity.prototype
   * @type {BoxGraphics|undefined}
   */
  box: createPropertyTypeDescriptor("box", BoxGraphics),
  /**
   * Gets or sets the corridor.
   * @memberof Entity.prototype
   * @type {CorridorGraphics|undefined}
   */
  corridor: createPropertyTypeDescriptor("corridor", CorridorGraphics),
  /**
   * Gets or sets the cylinder.
   * @memberof Entity.prototype
   * @type {CylinderGraphics|undefined}
   */
  cylinder: createPropertyTypeDescriptor("cylinder", CylinderGraphics),
  /**
   * Gets or sets the description.
   * @memberof Entity.prototype
   * @type {Property|undefined}
   */
  description: createPropertyDescriptor("description"),
  /**
   * Gets or sets the ellipse.
   * @memberof Entity.prototype
   * @type {EllipseGraphics|undefined}
   */
  ellipse: createPropertyTypeDescriptor("ellipse", EllipseGraphics),
  /**
   * Gets or sets the ellipsoid.
   * @memberof Entity.prototype
   * @type {EllipsoidGraphics|undefined}
   */
  ellipsoid: createPropertyTypeDescriptor("ellipsoid", EllipsoidGraphics),
  /**
   * Gets or sets the label.
   * @memberof Entity.prototype
   * @type {LabelGraphics|undefined}
   */
  label: createPropertyTypeDescriptor("label", LabelGraphics),
  /**
   * Gets or sets the model.
   * @memberof Entity.prototype
   * @type {ModelGraphics|undefined}
   */
  model: createPropertyTypeDescriptor("model", ModelGraphics),
  /**
   * Gets or sets the tileset.
   * @memberof Entity.prototype
   * @type {Cesium3DTilesetGraphics|undefined}
   */
  tileset: createPropertyTypeDescriptor("tileset", Cesium3DTilesetGraphics),
  /**
   * Gets or sets the orientation.
   * @memberof Entity.prototype
   * @type {Property|undefined}
   */
  orientation: createPropertyDescriptor("orientation"),
  /**
   * Gets or sets the path.
   * @memberof Entity.prototype
   * @type {PathGraphics|undefined}
   */
  path: createPropertyTypeDescriptor("path", PathGraphics),
  /**
   * Gets or sets the plane.
   * @memberof Entity.prototype
   * @type {PlaneGraphics|undefined}
   */
  plane: createPropertyTypeDescriptor("plane", PlaneGraphics),
  /**
   * Gets or sets the point graphic.
   * @memberof Entity.prototype
   * @type {PointGraphics|undefined}
   */
  point: createPropertyTypeDescriptor("point", PointGraphics),
  /**
   * Gets or sets the polygon.
   * @memberof Entity.prototype
   * @type {PolygonGraphics|undefined}
   */
  polygon: createPropertyTypeDescriptor("polygon", PolygonGraphics),
  /**
   * Gets or sets the polyline.
   * @memberof Entity.prototype
   * @type {PolylineGraphics|undefined}
   */
  polyline: createPropertyTypeDescriptor("polyline", PolylineGraphics),
  /**
   * Gets or sets the polyline volume.
   * @memberof Entity.prototype
   * @type {PolylineVolumeGraphics|undefined}
   */
  polylineVolume: createPropertyTypeDescriptor(
    "polylineVolume",
    PolylineVolumeGraphics
  ),
  /**
   * Gets or sets the bag of arbitrary properties associated with this entity.
   * @memberof Entity.prototype
   * @type {PropertyBag|undefined}
   */
  properties: createPropertyTypeDescriptor("properties", PropertyBag),
  /**
   * Gets or sets the position.
   * @memberof Entity.prototype
   * @type {PositionProperty|undefined}
   */
  position: createPositionPropertyDescriptor("position"),
  /**
   * Gets or sets the rectangle.
   * @memberof Entity.prototype
   * @type {RectangleGraphics|undefined}
   */
  rectangle: createPropertyTypeDescriptor("rectangle", RectangleGraphics),
  /**
   * Gets or sets the suggested initial offset when tracking this object.
   * The offset is typically defined in the east-north-up reference frame,
   * but may be another frame depending on the object's velocity.
   * @memberof Entity.prototype
   * @type {Property|undefined}
   */
  viewFrom: createPropertyDescriptor("viewFrom"),
  /**
   * Gets or sets the wall.
   * @memberof Entity.prototype
   * @type {WallGraphics|undefined}
   */
  wall: createPropertyTypeDescriptor("wall", WallGraphics),
});

/**
 * Given a time, returns true if this object should have data during that time.
 *
 * @param {JulianDate} time The time to check availability for.
 * @returns {Boolean} true if the object should have data during the provided time, false otherwise.
 */
Entity.prototype.isAvailable = function (time) {
  //>>includeStart('debug', pragmas.debug);
  if (!defined(time)) {
    throw new DeveloperError("time is required.");
  }
  //>>includeEnd('debug');

  const availability = this._availability;
  return !defined(availability) || availability.contains(time);
};

/**
 * Adds a property to this object.  Once a property is added, it can be
 * observed with {@link Entity#definitionChanged} and composited
 * with {@link CompositeEntityCollection}
 *
 * @param {String} propertyName The name of the property to add.
 *
 * @exception {DeveloperError} "propertyName" is a reserved property name.
 * @exception {DeveloperError} "propertyName" is already a registered property.
 */
Entity.prototype.addProperty = function (propertyName) {
  const propertyNames = this._propertyNames;

  //>>includeStart('debug', pragmas.debug);
  if (!defined(propertyName)) {
    throw new DeveloperError("propertyName is required.");
  }
  if (propertyNames.indexOf(propertyName) !== -1) {
    throw new DeveloperError(
      `${propertyName} is already a registered property.`
    );
  }
  if (propertyName in this) {
    throw new DeveloperError(`${propertyName} is a reserved property name.`);
  }
  //>>includeEnd('debug');

  propertyNames.push(propertyName);
  Object.defineProperty(
    this,
    propertyName,
    createRawPropertyDescriptor(propertyName, true)
  );
};

/**
 * Removed a property previously added with addProperty.
 *
 * @param {String} propertyName The name of the property to remove.
 *
 * @exception {DeveloperError} "propertyName" is a reserved property name.
 * @exception {DeveloperError} "propertyName" is not a registered property.
 */
Entity.prototype.removeProperty = function (propertyName) {
  const propertyNames = this._propertyNames;
  const index = propertyNames.indexOf(propertyName);

  //>>includeStart('debug', pragmas.debug);
  if (!defined(propertyName)) {
    throw new DeveloperError("propertyName is required.");
  }
  if (index === -1) {
    throw new DeveloperError(`${propertyName} is not a registered property.`);
  }
  //>>includeEnd('debug');

  this._propertyNames.splice(index, 1);
  delete this[propertyName];
};

/**
 * Assigns each unassigned property on this object to the value
 * of the same property on the provided source object.
 *
 * @param {Entity} source The object to be merged into this object.
 */
Entity.prototype.merge = function (source) {
  //>>includeStart('debug', pragmas.debug);
  if (!defined(source)) {
    throw new DeveloperError("source is required.");
  }
  //>>includeEnd('debug');

  //Name, show, and availability are not Property objects and are currently handled differently.
  //source.show is intentionally ignored because this.show always has a value.
  this.name = defaultValue(this.name, source.name);
  this.availability = defaultValue(this.availability, source.availability);

  const propertyNames = this._propertyNames;
  const sourcePropertyNames = defined(source._propertyNames)
    ? source._propertyNames
    : Object.keys(source);
  const propertyNamesLength = sourcePropertyNames.length;
  for (let i = 0; i < propertyNamesLength; i++) {
    const name = sourcePropertyNames[i];

    //While source is required by the API to be an Entity, we internally call this method from the
    //constructor with an options object to configure initial custom properties.
    //So we need to ignore reserved-non-property.
    if (name === "parent" || name === "name" || name === "availability") {
      continue;
    }

    const targetProperty = this[name];
    const sourceProperty = source[name];

    //Custom properties that are registered on the source entity must also
    //get registered on this entity.
    if (!defined(targetProperty) && propertyNames.indexOf(name) === -1) {
      this.addProperty(name);
    }

    if (defined(sourceProperty)) {
      if (defined(targetProperty)) {
        if (defined(targetProperty.merge)) {
          targetProperty.merge(sourceProperty);
        }
      } else if (
        defined(sourceProperty.merge) &&
        defined(sourceProperty.clone)
      ) {
        this[name] = sourceProperty.clone();
      } else {
        this[name] = sourceProperty;
      }
    }
  }
};

const matrix3Scratch = new Matrix3();
const positionScratch = new Cartesian3();
const orientationScratch = new Quaternion();

/**
 * Computes the model matrix for the entity's transform at specified time. Returns undefined if orientation or position
 * are undefined.
 *
 * @param {JulianDate} time The time to retrieve model matrix for.
 * @param {Matrix4} [result] The object onto which to store the result.
 *
 * @returns {Matrix4} The modified result parameter or a new Matrix4 instance if one was not provided. Result is undefined if position or orientation are undefined.
 */
Entity.prototype.computeModelMatrix = function (time, result) {
  //>>includeStart('debug', pragmas.debug);
  Check.typeOf.object("time", time);
  //>>includeEnd('debug');
  const position = Property.getValueOrUndefined(
    this._position,
    time,
    positionScratch
  );
  if (!defined(position)) {
    return undefined;
  }

  const orientation = Property.getValueOrUndefined(
    this._orientation,
    time,
    orientationScratch
  );
  if (!defined(orientation)) {
    result = Transforms.eastNorthUpToFixedFrame(position, undefined, result);
  } else {
    result = Matrix4.fromRotationTranslation(
      Matrix3.fromQuaternion(orientation, matrix3Scratch),
      position,
      result
    );
  }
  return result;
};

/**
 * @private
 */
Entity.prototype.computeModelMatrixForHeightReference = function (
  time,
  heightReferenceProperty,
  heightOffset,
  ellipsoid,
  result
) {
  //>>includeStart('debug', pragmas.debug);
  Check.typeOf.object("time", time);
  //>>includeEnd('debug');
  const heightReference = Property.getValueOrDefault(
    heightReferenceProperty,
    time,
    HeightReference.NONE
  );
  let position = Property.getValueOrUndefined(
    this._position,
    time,
    positionScratch
  );
  if (
    heightReference === HeightReference.NONE ||
    !defined(position) ||
    Cartesian3.equalsEpsilon(position, Cartesian3.ZERO, CesiumMath.EPSILON8)
  ) {
    return this.computeModelMatrix(time, result);
  }

  const carto = ellipsoid.cartesianToCartographic(position, cartoScratch);
  if (heightReference === HeightReference.CLAMP_TO_GROUND) {
    carto.height = heightOffset;
  } else {
    carto.height += heightOffset;
  }
  position = ellipsoid.cartographicToCartesian(carto, position);

  const orientation = Property.getValueOrUndefined(
    this._orientation,
    time,
    orientationScratch
  );
  if (!defined(orientation)) {
    result = Transforms.eastNorthUpToFixedFrame(position, undefined, result);
  } else {
    result = Matrix4.fromRotationTranslation(
      Matrix3.fromQuaternion(orientation, matrix3Scratch),
      position,
      result
    );
  }
  return result;
};

/**
 * Checks if the given Scene supports materials besides Color on Entities draped on terrain or 3D Tiles.
 * If this feature is not supported, Entities with non-color materials but no `height` will
 * instead be rendered as if height is 0.
 *
 * @param {Scene} scene The current scene.
 * @returns {Boolean} Whether or not the current scene supports materials for entities on terrain.
 */
Entity.supportsMaterialsforEntitiesOnTerrain = function (scene) {
  return GroundPrimitive.supportsMaterials(scene);
};

/**
 * Checks if the given Scene supports polylines clamped to terrain or 3D Tiles.
 * If this feature is not supported, Entities with PolylineGraphics will be rendered with vertices at
 * the provided heights and using the `arcType` parameter instead of clamped to the ground.
 *
 * @param {Scene} scene The current scene.
 * @returns {Boolean} Whether or not the current scene supports polylines on terrain or 3D TIles.
 */
Entity.supportsPolylinesOnTerrain = function (scene) {
  return GroundPolylinePrimitive.isSupported(scene);
};
export default Entity;