Cesium-Prequel/Source/Scene/OrderedGroundPrimitiveCollection.js

import Check from "../Core/Check.js";
import defaultValue from "../Core/defaultValue.js";
import defined from "../Core/defined.js";
import destroyObject from "../Core/destroyObject.js";
import PrimitiveCollection from "./PrimitiveCollection.js";

/**
 * A primitive collection for helping maintain the order or ground primitives based on a z-index
 *
 * @private
 */
function OrderedGroundPrimitiveCollection() {
  this._length = 0;
  this._collections = {};
  this._collectionsArray = [];

  this.show = true;
}

Object.defineProperties(OrderedGroundPrimitiveCollection.prototype, {
  /**
   * Gets the number of primitives in the collection.
   *
   * @memberof OrderedGroundPrimitiveCollection.prototype
   *
   * @type {Number}
   * @readonly
   */
  length: {
    get: function () {
      return this._length;
    },
  },
});

/**
 * Adds a primitive to the collection.
 *
 * @param {GroundPrimitive} primitive The primitive to add.
 * @param {Number} [zIndex = 0] The index of the primitive
 * @returns {GroundPrimitive} The primitive added to the collection.
 */
OrderedGroundPrimitiveCollection.prototype.add = function (primitive, zIndex) {
  //>>includeStart('debug', pragmas.debug);
  Check.defined("primitive", primitive);
  if (defined(zIndex)) {
    Check.typeOf.number("zIndex", zIndex);
  }
  //>>includeEnd('debug');

  zIndex = defaultValue(zIndex, 0);
  var collection = this._collections[zIndex];
  if (!defined(collection)) {
    collection = new PrimitiveCollection({ destroyPrimitives: false });
    collection._zIndex = zIndex;
    this._collections[zIndex] = collection;
    var array = this._collectionsArray;
    var i = 0;
    while (i < array.length && array[i]._zIndex < zIndex) {
      i++;
    }
    array.splice(i, 0, collection);
  }

  collection.add(primitive);
  this._length++;
  primitive._zIndex = zIndex;

  return primitive;
};

/**
 * Adjusts the z-index
 * @param {GroundPrimitive} primitive
 * @param {Number} zIndex
 */
OrderedGroundPrimitiveCollection.prototype.set = function (primitive, zIndex) {
  //>>includeStart('debug', pragmas.debug);
  Check.defined("primitive", primitive);
  Check.typeOf.number("zIndex", zIndex);
  //>>includeEnd('debug');

  if (zIndex === primitive._zIndex) {
    return primitive;
  }

  this.remove(primitive, true);
  this.add(primitive, zIndex);

  return primitive;
};

/**
 * Removes a primitive from the collection.
 *
 * @param {Object} primitive The primitive to remove.
 * @param {Boolean} [doNotDestroy = false]
 * @returns {Boolean} <code>true</code> if the primitive was removed; <code>false</code> if the primitive is <code>undefined</code> or was not found in the collection.
 */
OrderedGroundPrimitiveCollection.prototype.remove = function (
  primitive,
  doNotDestroy
) {
  if (this.contains(primitive)) {
    var index = primitive._zIndex;
    var collection = this._collections[index];
    var result;
    if (doNotDestroy) {
      result = collection.remove(primitive);
    } else {
      result = collection.removeAndDestroy(primitive);
    }

    if (result) {
      this._length--;
    }

    if (collection.length === 0) {
      this._collectionsArray.splice(
        this._collectionsArray.indexOf(collection),
        1
      );
      this._collections[index] = undefined;
      collection.destroy();
    }

    return result;
  }

  return false;
};

/**
 * Removes all primitives in the collection.
 *
 * @exception {DeveloperError} This object was destroyed, i.e., destroy() was called.
 *
 * @see OrderedGroundPrimitiveCollection#destroyPrimitives
 */
OrderedGroundPrimitiveCollection.prototype.removeAll = function () {
  var collections = this._collectionsArray;
  for (var i = 0; i < collections.length; i++) {
    var collection = collections[i];
    collection.destroyPrimitives = true;
    collection.destroy();
  }

  this._collections = {};
  this._collectionsArray = [];
  this._length = 0;
};

/**
 * Determines if this collection contains a primitive.
 *
 * @param {Object} primitive The primitive to check for.
 * @returns {Boolean} <code>true</code> if the primitive is in the collection; <code>false</code> if the primitive is <code>undefined</code> or was not found in the collection.
 */
OrderedGroundPrimitiveCollection.prototype.contains = function (primitive) {
  if (!defined(primitive)) {
    return false;
  }
  var collection = this._collections[primitive._zIndex];
  return defined(collection) && collection.contains(primitive);
};

/**
 * @private
 */
OrderedGroundPrimitiveCollection.prototype.update = function (frameState) {
  if (!this.show) {
    return;
  }

  var collections = this._collectionsArray;
  for (var i = 0; i < collections.length; i++) {
    collections[i].update(frameState);
  }
};

/**
 * 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 OrderedGroundPrimitiveCollection#destroy
 */
OrderedGroundPrimitiveCollection.prototype.isDestroyed = function () {
  return false;
};

/**
 * Destroys the WebGL resources held by each primitive in this collection.  Explicitly destroying this
 * collection allows for deterministic release of WebGL resources, instead of relying on the garbage
 * collector to destroy this collection.
 * <br /><br />
 * Since destroying a collection destroys all the contained primitives, only destroy a collection
 * when you are sure no other code is still using any of the contained primitives.
 * <br /><br />
 * Once this collection 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
 * primitives = primitives && primitives.destroy();
 *
 * @see OrderedGroundPrimitiveCollection#isDestroyed
 */
OrderedGroundPrimitiveCollection.prototype.destroy = function () {
  this.removeAll();
  return destroyObject(this);
};
export default OrderedGroundPrimitiveCollection;