import Check from "../Core/Check.js";
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import clone from "../Core/clone.js";
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import defined from "../Core/defined.js";
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import Resource from "../Core/Resource.js";
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import RuntimeError from "../Core/RuntimeError.js";
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import hasExtension from "./hasExtension.js";
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import ImplicitSubdivisionScheme from "./ImplicitSubdivisionScheme.js";
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/**
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* An ImplicitTileset is a simple struct that stores information about the
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* structure of a single implicit tileset. This includes template URIs for
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* locating resources, details from the implicit root tile (bounding volume,
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* geometricError, etc.), and details about the subtrees (e.g. subtreeLevels,
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* subdivisionScheme).
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*
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* @alias ImplicitTileset
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* @constructor
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*
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* @param {Resource} baseResource The base resource for the tileset
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* @param {Object} tileJson The JSON header of the tile with the 3DTILES_implicit_tiling extension.
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* @param {MetadataSchema} [metadataSchema] The metadata schema containing the implicit tile metadata class.
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* @private
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* @experimental This feature is using part of the 3D Tiles spec that is not final and is subject to change without Cesium's standard deprecation policy.
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*/
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export default function ImplicitTileset(
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baseResource,
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tileJson,
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metadataSchema
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) {
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var extension = tileJson.extensions["3DTILES_implicit_tiling"];
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//>>includeStart('debug', pragmas.debug);
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Check.typeOf.object(
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'tileJson.extensions["3DTILES_implicit_tiling"]',
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extension
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);
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//>>includeEnd('debug');
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/**
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* The base resource for the tileset. This is stored here as it is needed
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* later when expanding Implicit3DTileContents so tile URLs are relative
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* to the tileset, not the subtree file.
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*
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* @type {Resource}
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* @readonly
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* @private
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*/
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this.baseResource = baseResource;
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/**
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* The geometric error of the root tile
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*
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* @type {Number}
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* @readonly
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* @private
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*/
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this.geometricError = tileJson.geometricError;
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/**
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* The metadata schema containing the implicit tile metadata class.
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*
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* @type {MetadataSchema|undefined}
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* @readonly
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* @private
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*/
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this.metadataSchema = metadataSchema;
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if (
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!defined(tileJson.boundingVolume.box) &&
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!defined(tileJson.boundingVolume.region) &&
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!hasExtension(tileJson.boundingVolume, "3DTILES_bounding_volume_S2")
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) {
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throw new RuntimeError(
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"Only box, region and 3DTILES_bounding_volume_S2 are supported for implicit tiling"
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);
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}
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/**
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* The JSON representation of a bounding volume. This is either a box or a
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* region.
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*
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* @type {Object}
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* @readonly
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* @private
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*/
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this.boundingVolume = tileJson.boundingVolume;
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/**
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* The refine strategy as a string, either 'ADD' or 'REPLACE'
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*
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* @type {String}
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* @readonly
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* @private
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*/
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this.refine = tileJson.refine;
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/**
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* Template URI for the subtree resources, e.g.
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* <code>https://example.com/{level}/{x}/{y}.subtree</code>
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*
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* @type {Resource}
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* @readonly
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* @private
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*/
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this.subtreeUriTemplate = new Resource({ url: extension.subtrees.uri });
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/**
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* Template URIs for locating content resources, e.g.
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* <code>https://example.com/{level}/{x}/{y}.b3dm</code>.
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* <p>
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* This is an array to support <code>3DTILES_multiple_contents</code>
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* </p>
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*
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* @type {Resource[]}
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* @readonly
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* @private
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*/
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this.contentUriTemplates = [];
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/**
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* Store a copy of the content headers, so properties such as
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* <code>extras</code> or <code>extensions</code> are preserved when
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* {@link Cesium3DTile}s are created for each tile.
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* <p>
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* This is an array to support <code>3DTILES_multiple_contents</code>
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* </p>
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*
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* @type {Object[]}
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* @readonly
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* @private
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*/
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this.contentHeaders = [];
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var contentHeaders = gatherContentHeaders(tileJson);
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for (var i = 0; i < contentHeaders.length; i++) {
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var contentHeader = contentHeaders[i];
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this.contentHeaders.push(clone(contentHeader, true));
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var contentResource = new Resource({ url: contentHeader.uri });
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this.contentUriTemplates.push(contentResource);
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}
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/**
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* The maximum number of contents as well as content availability bitstreams.
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* This is used for loop bounds when checking content availability.
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*
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* @type {Number}
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* @readonly
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* @private
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*/
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this.contentCount = this.contentHeaders.length;
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/**
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* Stores a copy of the root implicit tile's JSON header. This is used
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* as a template for creating {@link Cesium3DTile}s. The following properties
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* are removed:
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*
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* <ul>
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* <li><code>tile.extensions["3DTILES_implicit_tiling"]</code> to prevent infinite loops of implicit tiling</li>
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* <li><code>tile.content</code> since this is handled separately</li>
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* <li><code>tile.extensions["3DTILES_multiple_contents"]</code>, again
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* because contents are handled separately</li>
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* </ul>
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*
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* @type {Object}
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* @readonly
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* @private
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*/
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this.tileHeader = makeTileHeaderTemplate(tileJson);
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/**
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* The subdivision scheme for this implicit tileset; either OCTREE or QUADTREE
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*
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* @type {ImplicitSubdivisionScheme}
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* @readonly
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* @private
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*/
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this.subdivisionScheme =
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ImplicitSubdivisionScheme[extension.subdivisionScheme];
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/**
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* The branching factor for this tileset. Either 4 for quadtrees or 8 for
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* octrees.
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*
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* @type {Number}
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* @readonly
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* @private
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*/
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this.branchingFactor = ImplicitSubdivisionScheme.getBranchingFactor(
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this.subdivisionScheme
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);
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/**
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* How many distinct levels within each subtree. For example, a quadtree
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* with subtreeLevels = 2 will have 5 nodes per quadtree (1 root + 4 children)
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*
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* @type {Number}
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* @readonly
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* @private
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*/
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this.subtreeLevels = extension.subtreeLevels;
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/**
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* The deepest level of any available tile in the entire tileset.
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*
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* @type {Number}
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* @readonly
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* @private
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*/
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this.maximumLevel = extension.maximumLevel;
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}
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/**
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* Gather JSON headers for all contents in the tile.
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* This handles both regular tiles and tiles with the
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* `3DTILES_multiple_contents` extension
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*
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* @param {Object} tileJson The JSON header of the tile with the 3DTILES_implicit_tiling extension.
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* @return {Object[]} An array of JSON headers for the contents of each tile
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* @private
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*/
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function gatherContentHeaders(tileJson) {
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if (hasExtension(tileJson, "3DTILES_multiple_contents")) {
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return tileJson.extensions["3DTILES_multiple_contents"].content;
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}
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if (defined(tileJson.content)) {
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return [tileJson.content];
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}
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return [];
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}
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function makeTileHeaderTemplate(tileJson) {
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var template = clone(tileJson, true);
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// remove the implicit tiling extension to prevent infinite loops
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delete template.extensions["3DTILES_implicit_tiling"];
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// content is handled separately, so remove content-related properties
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delete template.content;
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delete template.extensions["3DTILES_multiple_contents"];
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// if there are no other extensions, remove the extensions property to
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// keep each tile simple
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if (Object.keys(template.extensions).length === 0) {
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delete template.extensions;
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}
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return template;
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}
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