cesium/Source/DataSources/DataSourceDisplay.js

CesiumJS is a JavaScript library for creating 3D globes and 2D maps in a web browser without a plugin.

define([
        '../Core/BoundingSphere',
        '../Core/Check',
        '../Core/defaultValue',
        '../Core/defined',
        '../Core/defineProperties',
        '../Core/destroyObject',
        '../Core/EventHelper',
        '../Scene/GroundPrimitive',
        '../Scene/OrderedGroundPrimitiveCollection',
        '../Scene/PrimitiveCollection',
        './BillboardVisualizer',
        './BoundingSphereState',
        './CustomDataSource',
        './GeometryVisualizer',
        './LabelVisualizer',
        './ModelVisualizer',
        './PathVisualizer',
        './PointVisualizer',
        './PolylineVisualizer'
    ], function(
        BoundingSphere,
        Check,
        defaultValue,
        defined,
        defineProperties,
        destroyObject,
        EventHelper,
        GroundPrimitive,
        OrderedGroundPrimitiveCollection,
        PrimitiveCollection,
        BillboardVisualizer,
        BoundingSphereState,
        CustomDataSource,
        GeometryVisualizer,
        LabelVisualizer,
        ModelVisualizer,
        PathVisualizer,
        PointVisualizer,
        PolylineVisualizer) {
    'use strict';

    /**
     * Visualizes a collection of {@link DataSource} instances.
     * @alias DataSourceDisplay
     * @constructor
     *
     * @param {Object} options Object with the following properties:
     * @param {Scene} options.scene The scene in which to display the data.
     * @param {DataSourceCollection} options.dataSourceCollection The data sources to display.
     * @param {DataSourceDisplay~VisualizersCallback} [options.visualizersCallback=DataSourceDisplay.defaultVisualizersCallback]
     *        A function which creates an array of visualizers used for visualization.
     *        If undefined, all standard visualizers are used.
     */
    function DataSourceDisplay(options) {
        //>>includeStart('debug', pragmas.debug);
        Check.typeOf.object('options', options);
        Check.typeOf.object('options.scene', options.scene);
        Check.typeOf.object('options.dataSourceCollection', options.dataSourceCollection);
        //>>includeEnd('debug');

        GroundPrimitive.initializeTerrainHeights();

        var scene = options.scene;
        var dataSourceCollection = options.dataSourceCollection;

        this._eventHelper = new EventHelper();
        this._eventHelper.add(dataSourceCollection.dataSourceAdded, this._onDataSourceAdded, this);
        this._eventHelper.add(dataSourceCollection.dataSourceRemoved, this._onDataSourceRemoved, this);
        this._eventHelper.add(dataSourceCollection.dataSourceMoved, this._onDataSourceMoved, this);

        this._dataSourceCollection = dataSourceCollection;
        this._scene = scene;
        this._visualizersCallback = defaultValue(options.visualizersCallback, DataSourceDisplay.defaultVisualizersCallback);

        var primitivesAdded = false;
        var primitives = new PrimitiveCollection();
        var groundPrimitives = new PrimitiveCollection();

        if (dataSourceCollection.length > 0) {
            scene.primitives.add(primitives);
            scene.groundPrimitives.add(groundPrimitives);
            primitivesAdded = true;
        }

        this._primitives = primitives;
        this._groundPrimitives = groundPrimitives;

        for (var i = 0, len = dataSourceCollection.length; i < len; i++) {
            this._onDataSourceAdded(dataSourceCollection, dataSourceCollection.get(i));
        }

        var defaultDataSource = new CustomDataSource();
        this._onDataSourceAdded(undefined, defaultDataSource);
        this._defaultDataSource = defaultDataSource;

        var removeDefaultDataSoureListener;
        var removeDataSourceCollectionListener;
        if (!primitivesAdded) {
            var that = this;
            var addPrimitives = function() {
                scene.primitives.add(primitives);
                scene.groundPrimitives.add(groundPrimitives);
                removeDefaultDataSoureListener();
                removeDataSourceCollectionListener();
                that._removeDefaultDataSoureListener = undefined;
                that._removeDataSourceCollectionListener = undefined;
            };
            removeDefaultDataSoureListener = defaultDataSource.entities.collectionChanged.addEventListener(addPrimitives);
            removeDataSourceCollectionListener = dataSourceCollection.dataSourceAdded.addEventListener(addPrimitives);
        }

        this._removeDefaultDataSoureListener = removeDefaultDataSoureListener;
        this._removeDataSourceCollectionListener = removeDataSourceCollectionListener;

        this._ready = false;
    }

    /**
     * Gets or sets the default function which creates an array of visualizers used for visualization.
     * By default, this function uses all standard visualizers.
     *
     * @type {DataSourceDisplay~VisualizersCallback}
     */
    DataSourceDisplay.defaultVisualizersCallback = function(scene, entityCluster, dataSource) {
        var entities = dataSource.entities;
        return [new BillboardVisualizer(entityCluster, entities),
                new GeometryVisualizer(scene, entities, dataSource._primitives, dataSource._groundPrimitives),
                new LabelVisualizer(entityCluster, entities),
                new ModelVisualizer(scene, entities),
                new PointVisualizer(entityCluster, entities),
                new PathVisualizer(scene, entities),
                new PolylineVisualizer(scene, entities)];
    };

    defineProperties(DataSourceDisplay.prototype, {
        /**
         * Gets the scene associated with this display.
         * @memberof DataSourceDisplay.prototype
         * @type {Scene}
         */
        scene : {
            get : function() {
                return this._scene;
            }
        },
        /**
         * Gets the collection of data sources to display.
         * @memberof DataSourceDisplay.prototype
         * @type {DataSourceCollection}
         */
        dataSources : {
            get : function() {
                return this._dataSourceCollection;
            }
        },
        /**
         * Gets the default data source instance which can be used to
         * manually create and visualize entities not tied to
         * a specific data source. This instance is always available
         * and does not appear in the list dataSources collection.
         * @memberof DataSourceDisplay.prototype
         * @type {CustomDataSource}
         */
        defaultDataSource : {
            get : function() {
                return this._defaultDataSource;
            }
        },

        /**
         * Gets a value indicating whether or not all entities in the data source are ready
         * @memberof DataSourceDisplay.prototype
         * @type {Boolean}
         * @readonly
         */
        ready : {
            get : function() {
                return this._ready;
            }
        }
    });

    /**
     * Returns true if this object was destroyed; otherwise, false.
     * <br /><br />
     * If this object was destroyed, it should not be used; calling any function other than
     * <code>isDestroyed</code> will result in a {@link DeveloperError} exception.
     *
     * @returns {Boolean} True if this object was destroyed; otherwise, false.
     *
     * @see DataSourceDisplay#destroy
     */
    DataSourceDisplay.prototype.isDestroyed = function() {
        return false;
    };

    /**
     * Destroys the WebGL resources held by this object.  Destroying an object allows for deterministic
     * release of WebGL resources, instead of relying on the garbage collector to destroy this object.
     * <br /><br />
     * Once an object is destroyed, it should not be used; calling any function other than
     * <code>isDestroyed</code> will result in a {@link DeveloperError} exception.  Therefore,
     * assign the return value (<code>undefined</code>) to the object as done in the example.
     *
     * @exception {DeveloperError} This object was destroyed, i.e., destroy() was called.
     *
     *
     * @example
     * dataSourceDisplay = dataSourceDisplay.destroy();
     *
     * @see DataSourceDisplay#isDestroyed
     */
    DataSourceDisplay.prototype.destroy = function() {
        this._eventHelper.removeAll();

        var dataSourceCollection = this._dataSourceCollection;
        for (var i = 0, length = dataSourceCollection.length; i < length; ++i) {
            this._onDataSourceRemoved(this._dataSourceCollection, dataSourceCollection.get(i));
        }
        this._onDataSourceRemoved(undefined, this._defaultDataSource);

        if (defined(this._removeDefaultDataSoureListener)) {
            this._removeDefaultDataSoureListener();
            this._removeDataSourceCollectionListener();
        } else {
            this._scene.primitives.remove(this._primitives);
            this._scene.groundPrimitives.remove(this._groundPrimitives);
        }

        return destroyObject(this);
    };

    /**
     * Updates the display to the provided time.
     *
     * @param {JulianDate} time The simulation time.
     * @returns {Boolean} True if all data sources are ready to be displayed, false otherwise.
     */
    DataSourceDisplay.prototype.update = function(time) {
        //>>includeStart('debug', pragmas.debug);
        Check.defined('time', time);
        //>>includeEnd('debug');

        if (!GroundPrimitive._initialized) {
            this._ready = false;
            return false;
        }

        var result = true;

        var i;
        var x;
        var visualizers;
        var vLength;
        var dataSources = this._dataSourceCollection;
        var length = dataSources.length;
        for (i = 0; i < length; i++) {
            var dataSource = dataSources.get(i);
            if (defined(dataSource.update)) {
                result = dataSource.update(time) && result;
            }

            visualizers = dataSource._visualizers;
            vLength = visualizers.length;
            for (x = 0; x < vLength; x++) {
                result = visualizers[x].update(time) && result;
            }
        }

        visualizers = this._defaultDataSource._visualizers;
        vLength = visualizers.length;
        for (x = 0; x < vLength; x++) {
            result = visualizers[x].update(time) && result;
        }

        this._ready = result;

        return result;
    };

    var getBoundingSphereArrayScratch = [];
    var getBoundingSphereBoundingSphereScratch = new BoundingSphere();

    /**
     * Computes a bounding sphere which encloses the visualization produced for the specified entity.
     * The bounding sphere is in the fixed frame of the scene's globe.
     *
     * @param {Entity} entity The entity whose bounding sphere to compute.
     * @param {Boolean} allowPartial If true, pending bounding spheres are ignored and an answer will be returned from the currently available data.
     *                               If false, the the function will halt and return pending if any of the bounding spheres are pending.
     * @param {BoundingSphere} result The bounding sphere onto which to store the result.
     * @returns {BoundingSphereState} BoundingSphereState.DONE if the result contains the bounding sphere,
     *                       BoundingSphereState.PENDING if the result is still being computed, or
     *                       BoundingSphereState.FAILED if the entity has no visualization in the current scene.
     * @private
     */
    DataSourceDisplay.prototype.getBoundingSphere = function(entity, allowPartial, result) {
        //>>includeStart('debug', pragmas.debug);
        Check.defined('entity', entity);
        Check.typeOf.bool('allowPartial', allowPartial);
        Check.defined('result', result);
        //>>includeEnd('debug');

        if (!this._ready) {
            return BoundingSphereState.PENDING;
        }

        var i;
        var length;
        var dataSource = this._defaultDataSource;
        if (!dataSource.entities.contains(entity)) {
            dataSource = undefined;

            var dataSources = this._dataSourceCollection;
            length = dataSources.length;
            for (i = 0; i < length; i++) {
                var d = dataSources.get(i);
                if (d.entities.contains(entity)) {
                    dataSource = d;
                    break;
                }
            }
        }

        if (!defined(dataSource)) {
            return BoundingSphereState.FAILED;
        }

        var boundingSpheres = getBoundingSphereArrayScratch;
        var tmp = getBoundingSphereBoundingSphereScratch;

        var count = 0;
        var state = BoundingSphereState.DONE;
        var visualizers = dataSource._visualizers;
        var visualizersLength = visualizers.length;

        for (i = 0; i < visualizersLength; i++) {
            var visualizer = visualizers[i];
            if (defined(visualizer.getBoundingSphere)) {
                state = visualizers[i].getBoundingSphere(entity, tmp);
                if (!allowPartial && state === BoundingSphereState.PENDING) {
                    return BoundingSphereState.PENDING;
                } else if (state === BoundingSphereState.DONE) {
                    boundingSpheres[count] = BoundingSphere.clone(tmp, boundingSpheres[count]);
                    count++;
                }
            }
        }

        if (count === 0) {
            return BoundingSphereState.FAILED;
        }

        boundingSpheres.length = count;
        BoundingSphere.fromBoundingSpheres(boundingSpheres, result);
        return BoundingSphereState.DONE;
    };

    DataSourceDisplay.prototype._onDataSourceAdded = function(dataSourceCollection, dataSource) {
        var scene = this._scene;

        var displayPrimitives = this._primitives;
        var displayGroundPrimitives = this._groundPrimitives;

        var primitives = displayPrimitives.add(new PrimitiveCollection());
        var groundPrimitives = displayGroundPrimitives.add(new OrderedGroundPrimitiveCollection());

        dataSource._primitives = primitives;
        dataSource._groundPrimitives = groundPrimitives;

        var entityCluster = dataSource.clustering;
        entityCluster._initialize(scene);

        primitives.add(entityCluster);

        dataSource._visualizers = this._visualizersCallback(scene, entityCluster, dataSource);
    };

    DataSourceDisplay.prototype._onDataSourceRemoved = function(dataSourceCollection, dataSource) {
        var displayPrimitives = this._primitives;
        var displayGroundPrimitives = this._groundPrimitives;

        var primitives = dataSource._primitives;
        var groundPrimitives = dataSource._groundPrimitives;

        var entityCluster = dataSource.clustering;
        primitives.remove(entityCluster);

        var visualizers = dataSource._visualizers;
        var length = visualizers.length;
        for (var i = 0; i < length; i++) {
            visualizers[i].destroy();
        }

        displayPrimitives.remove(primitives);
        displayGroundPrimitives.remove(groundPrimitives);

        dataSource._visualizers = undefined;
    };

    DataSourceDisplay.prototype._onDataSourceMoved = function(dataSource, newIndex, oldIndex) {
        var displayPrimitives = this._primitives;
        var displayGroundPrimitives = this._groundPrimitives;

        var primitives = dataSource._primitives;
        var groundPrimitives = dataSource._groundPrimitives;

        if (newIndex === oldIndex + 1) {
            displayPrimitives.raise(primitives);
            displayGroundPrimitives.raise(groundPrimitives);
        } else if (newIndex === oldIndex - 1) {
            displayPrimitives.lower(primitives);
            displayGroundPrimitives.lower(groundPrimitives);
        } else if (newIndex === 0) {
            displayPrimitives.lowerToBottom(primitives);
            displayGroundPrimitives.lowerToBottom(groundPrimitives);
            displayPrimitives.raise(primitives); // keep defaultDataSource primitives at index 0 since it's not in the collection
            displayGroundPrimitives.raise(groundPrimitives);
        } else {
            displayPrimitives.raiseToTop(primitives);
            displayGroundPrimitives.raiseToTop(groundPrimitives);
        }
    };

    /**
     * A function which creates an array of visualizers used for visualization.
     * @callback DataSourceDisplay~VisualizersCallback
     *
     * @param {Scene} scene The scene to create visualizers for.
     * @param {DataSource} dataSource The data source to create visualizers for.
     * @returns {Visualizer[]} An array of visualizers used for visualization.
     *
     * @example
     * function createVisualizers(scene, dataSource) {
     *     return [new Cesium.BillboardVisualizer(scene, dataSource.entities)];
     * }
     */

    return DataSourceDisplay;
});