/
VRTheWorldTerrainProvider.js
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/
VRTheWorldTerrainProvider.js
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define([
'../ThirdParty/when',
'./Credit',
'./defaultValue',
'./defined',
'./defineProperties',
'./DeveloperError',
'./Ellipsoid',
'./Event',
'./GeographicTilingScheme',
'./getImagePixels',
'./HeightmapTerrainData',
'./Math',
'./Rectangle',
'./Resource',
'./TerrainProvider',
'./TileProviderError'
], function(
when,
Credit,
defaultValue,
defined,
defineProperties,
DeveloperError,
Ellipsoid,
Event,
GeographicTilingScheme,
getImagePixels,
HeightmapTerrainData,
CesiumMath,
Rectangle,
Resource,
TerrainProvider,
TileProviderError) {
'use strict';
function DataRectangle(rectangle, maxLevel) {
this.rectangle = rectangle;
this.maxLevel = maxLevel;
}
/**
* A {@link TerrainProvider} that produces terrain geometry by tessellating height maps
* retrieved from a {@link http://vr-theworld.com/|VT MÄK VR-TheWorld server}.
*
* @alias VRTheWorldTerrainProvider
* @constructor
*
* @param {Object} options Object with the following properties:
* @param {Resource|String} options.url The URL of the VR-TheWorld TileMap.
* @param {Ellipsoid} [options.ellipsoid=Ellipsoid.WGS84] The ellipsoid. If this parameter is not
* specified, the WGS84 ellipsoid is used.
* @param {Credit|String} [options.credit] A credit for the data source, which is displayed on the canvas.
*
*
* @example
* var terrainProvider = new Cesium.VRTheWorldTerrainProvider({
* url : 'https://www.vr-theworld.com/vr-theworld/tiles1.0.0/73/'
* });
* viewer.terrainProvider = terrainProvider;
*
* @see TerrainProvider
*/
function VRTheWorldTerrainProvider(options) {
options = defaultValue(options, defaultValue.EMPTY_OBJECT);
//>>includeStart('debug', pragmas.debug);
if (!defined(options.url)) {
throw new DeveloperError('options.url is required.');
}
//>>includeEnd('debug');
var resource = Resource.createIfNeeded(options.url);
this._resource = resource;
this._errorEvent = new Event();
this._ready = false;
this._readyPromise = when.defer();
this._terrainDataStructure = {
heightScale : 1.0 / 1000.0,
heightOffset : -1000.0,
elementsPerHeight : 3,
stride : 4,
elementMultiplier : 256.0,
isBigEndian : true,
lowestEncodedHeight : 0,
highestEncodedHeight : 256 * 256 * 256 - 1
};
var credit = options.credit;
if (typeof credit === 'string') {
credit = new Credit(credit);
}
this._credit = credit;
this._tilingScheme = undefined;
this._rectangles = [];
var that = this;
var metadataError;
var ellipsoid = defaultValue(options.ellipsoid, Ellipsoid.WGS84);
function metadataSuccess(xml) {
var srs = xml.getElementsByTagName('SRS')[0].textContent;
if (srs === 'EPSG:4326') {
that._tilingScheme = new GeographicTilingScheme({ellipsoid : ellipsoid});
} else {
metadataFailure('SRS ' + srs + ' is not supported.');
return;
}
var tileFormat = xml.getElementsByTagName('TileFormat')[0];
that._heightmapWidth = parseInt(tileFormat.getAttribute('width'), 10);
that._heightmapHeight = parseInt(tileFormat.getAttribute('height'), 10);
that._levelZeroMaximumGeometricError = TerrainProvider.getEstimatedLevelZeroGeometricErrorForAHeightmap(ellipsoid, Math.min(that._heightmapWidth, that._heightmapHeight), that._tilingScheme.getNumberOfXTilesAtLevel(0));
var dataRectangles = xml.getElementsByTagName('DataExtent');
for (var i = 0; i < dataRectangles.length; ++i) {
var dataRectangle = dataRectangles[i];
var west = CesiumMath.toRadians(parseFloat(dataRectangle.getAttribute('minx')));
var south = CesiumMath.toRadians(parseFloat(dataRectangle.getAttribute('miny')));
var east = CesiumMath.toRadians(parseFloat(dataRectangle.getAttribute('maxx')));
var north = CesiumMath.toRadians(parseFloat(dataRectangle.getAttribute('maxy')));
var maxLevel = parseInt(dataRectangle.getAttribute('maxlevel'), 10);
that._rectangles.push(new DataRectangle(new Rectangle(west, south, east, north), maxLevel));
}
that._ready = true;
that._readyPromise.resolve(true);
}
function metadataFailure(e) {
var message = defaultValue(e, 'An error occurred while accessing ' + that._resource.url + '.');
metadataError = TileProviderError.handleError(metadataError, that, that._errorEvent, message, undefined, undefined, undefined, requestMetadata);
}
function requestMetadata() {
when(that._resource.fetchXML(), metadataSuccess, metadataFailure);
}
requestMetadata();
}
defineProperties(VRTheWorldTerrainProvider.prototype, {
/**
* Gets an event that is raised when the terrain provider encounters an asynchronous error. By subscribing
* to the event, you will be notified of the error and can potentially recover from it. Event listeners
* are passed an instance of {@link TileProviderError}.
* @memberof VRTheWorldTerrainProvider.prototype
* @type {Event}
*/
errorEvent : {
get : function() {
return this._errorEvent;
}
},
/**
* Gets the credit to display when this terrain provider is active. Typically this is used to credit
* the source of the terrain. This function should not be called before {@link VRTheWorldTerrainProvider#ready} returns true.
* @memberof VRTheWorldTerrainProvider.prototype
* @type {Credit}
*/
credit : {
get : function() {
return this._credit;
}
},
/**
* Gets the tiling scheme used by this provider. This function should
* not be called before {@link VRTheWorldTerrainProvider#ready} returns true.
* @memberof VRTheWorldTerrainProvider.prototype
* @type {GeographicTilingScheme}
*/
tilingScheme : {
get : function() {
//>>includeStart('debug', pragmas.debug);
if (!this.ready) {
throw new DeveloperError('requestTileGeometry must not be called before ready returns true.');
}
//>>includeEnd('debug');
return this._tilingScheme;
}
},
/**
* Gets a value indicating whether or not the provider is ready for use.
* @memberof VRTheWorldTerrainProvider.prototype
* @type {Boolean}
*/
ready : {
get : function() {
return this._ready;
}
},
/**
* Gets a promise that resolves to true when the provider is ready for use.
* @memberof VRTheWorldTerrainProvider.prototype
* @type {Promise.<Boolean>}
* @readonly
*/
readyPromise : {
get : function() {
return this._readyPromise.promise;
}
},
/**
* Gets a value indicating whether or not the provider includes a water mask. The water mask
* indicates which areas of the globe are water rather than land, so they can be rendered
* as a reflective surface with animated waves. This function should not be
* called before {@link VRTheWorldTerrainProvider#ready} returns true.
* @memberof VRTheWorldTerrainProvider.prototype
* @type {Boolean}
*/
hasWaterMask : {
get : function() {
return false;
}
},
/**
* Gets a value indicating whether or not the requested tiles include vertex normals.
* This function should not be called before {@link VRTheWorldTerrainProvider#ready} returns true.
* @memberof VRTheWorldTerrainProvider.prototype
* @type {Boolean}
*/
hasVertexNormals : {
get : function() {
return false;
}
}
});
/**
* Requests the geometry for a given tile. This function should not be called before
* {@link VRTheWorldTerrainProvider#ready} returns true. The result includes terrain
* data and indicates that all child tiles are available.
*
* @param {Number} x The X coordinate of the tile for which to request geometry.
* @param {Number} y The Y coordinate of the tile for which to request geometry.
* @param {Number} level The level of the tile for which to request geometry.
* @param {Request} [request] The request object. Intended for internal use only.
* @returns {Promise.<TerrainData>|undefined} A promise for the requested geometry. If this method
* returns undefined instead of a promise, it is an indication that too many requests are already
* pending and the request will be retried later.
*/
VRTheWorldTerrainProvider.prototype.requestTileGeometry = function(x, y, level, request) {
//>>includeStart('debug', pragmas.debug);
if (!this.ready) {
throw new DeveloperError('requestTileGeometry must not be called before ready returns true.');
}
//>>includeEnd('debug');
var yTiles = this._tilingScheme.getNumberOfYTilesAtLevel(level);
var resource = this._resource.getDerivedResource({
url : level + '/' + x + '/' + (yTiles - y - 1) + '.tif',
queryParameters : {
cesium : true
},
request : request
});
var promise = resource.fetchImage({
preferImageBitmap: true
});
if (!defined(promise)) {
return undefined;
}
var that = this;
return when(promise)
.then(function(image) {
return new HeightmapTerrainData({
buffer : getImagePixels(image),
width : that._heightmapWidth,
height : that._heightmapHeight,
childTileMask : getChildMask(that, x, y, level),
structure : that._terrainDataStructure
});
});
};
/**
* Gets the maximum geometric error allowed in a tile at a given level.
*
* @param {Number} level The tile level for which to get the maximum geometric error.
* @returns {Number} The maximum geometric error.
*/
VRTheWorldTerrainProvider.prototype.getLevelMaximumGeometricError = function(level) {
//>>includeStart('debug', pragmas.debug);
if (!this.ready) {
throw new DeveloperError('requestTileGeometry must not be called before ready returns true.');
}
//>>includeEnd('debug');
return this._levelZeroMaximumGeometricError / (1 << level);
};
var rectangleScratch = new Rectangle();
function getChildMask(provider, x, y, level) {
var tilingScheme = provider._tilingScheme;
var rectangles = provider._rectangles;
var parentRectangle = tilingScheme.tileXYToRectangle(x, y, level);
var childMask = 0;
for (var i = 0; i < rectangles.length && childMask !== 15; ++i) {
var rectangle = rectangles[i];
if (rectangle.maxLevel <= level) {
continue;
}
var testRectangle = rectangle.rectangle;
var intersection = Rectangle.intersection(testRectangle, parentRectangle, rectangleScratch);
if (defined(intersection)) {
// Parent tile is inside this rectangle, so at least one child is, too.
if (isTileInRectangle(tilingScheme, testRectangle, x * 2, y * 2, level + 1)) {
childMask |= 4; // northwest
}
if (isTileInRectangle(tilingScheme, testRectangle, x * 2 + 1, y * 2, level + 1)) {
childMask |= 8; // northeast
}
if (isTileInRectangle(tilingScheme, testRectangle, x * 2, y * 2 + 1, level + 1)) {
childMask |= 1; // southwest
}
if (isTileInRectangle(tilingScheme, testRectangle, x * 2 + 1, y * 2 + 1, level + 1)) {
childMask |= 2; // southeast
}
}
}
return childMask;
}
function isTileInRectangle(tilingScheme, rectangle, x, y, level) {
var tileRectangle = tilingScheme.tileXYToRectangle(x, y, level);
return defined(Rectangle.intersection(tileRectangle, rectangle, rectangleScratch));
}
/**
* Determines whether data for a tile is available to be loaded.
*
* @param {Number} x The X coordinate of the tile for which to request geometry.
* @param {Number} y The Y coordinate of the tile for which to request geometry.
* @param {Number} level The level of the tile for which to request geometry.
* @returns {Boolean} Undefined if not supported, otherwise true or false.
*/
VRTheWorldTerrainProvider.prototype.getTileDataAvailable = function(x, y, level) {
return undefined;
};
/**
* Makes sure we load availability data for a tile
*
* @param {Number} x The X coordinate of the tile for which to request geometry.
* @param {Number} y The Y coordinate of the tile for which to request geometry.
* @param {Number} level The level of the tile for which to request geometry.
* @returns {undefined|Promise} Undefined if nothing need to be loaded or a Promise that resolves when all required tiles are loaded
*/
VRTheWorldTerrainProvider.prototype.loadTileDataAvailability = function(x, y, level) {
return undefined;
};
return VRTheWorldTerrainProvider;
});