/*global define*/
define([
'../Core/defined',
'../Core/defineProperties',
'../Core/DeveloperError',
'../Core/loadImage',
'../Core/loadImageViaBlob',
'../Core/throttleRequestByServer'
], function(
defined,
defineProperties,
DeveloperError,
loadImage,
loadImageViaBlob,
throttleRequestByServer) {
'use strict';
/**
* Provides imagery to be displayed on the surface of an ellipsoid. This type describes an
* interface and is not intended to be instantiated directly.
*
* @alias ImageryProvider
* @constructor
*
* @see ArcGisMapServerImageryProvider
* @see SingleTileImageryProvider
* @see BingMapsImageryProvider
* @see GoogleEarthImageryProvider
* @see MapboxImageryProvider
* @see createOpenStreetMapImageryProvider
* @see WebMapTileServiceImageryProvider
* @see WebMapServiceImageryProvider
*
* @demo {@link http://cesiumjs.org/Cesium/Apps/Sandcastle/index.html?src=Imagery%20Layers.html|Cesium Sandcastle Imagery Layers Demo}
* @demo {@link http://cesiumjs.org/Cesium/Apps/Sandcastle/index.html?src=Imagery%20Layers%20Manipulation.html|Cesium Sandcastle Imagery Manipulation Demo}
*/
function ImageryProvider() {
/**
* The default alpha blending value of this provider, with 0.0 representing fully transparent and
* 1.0 representing fully opaque.
*
* @type {Number}
* @default undefined
*/
this.defaultAlpha = undefined;
/**
* The default brightness of this provider. 1.0 uses the unmodified imagery color. Less than 1.0
* makes the imagery darker while greater than 1.0 makes it brighter.
*
* @type {Number}
* @default undefined
*/
this.defaultBrightness = undefined;
/**
* The default contrast of this provider. 1.0 uses the unmodified imagery color. Less than 1.0 reduces
* the contrast while greater than 1.0 increases it.
*
* @type {Number}
* @default undefined
*/
this.defaultContrast = undefined;
/**
* The default hue of this provider in radians. 0.0 uses the unmodified imagery color.
*
* @type {Number}
* @default undefined
*/
this.defaultHue = undefined;
/**
* The default saturation of this provider. 1.0 uses the unmodified imagery color. Less than 1.0 reduces the
* saturation while greater than 1.0 increases it.
*
* @type {Number}
* @default undefined
*/
this.defaultSaturation = undefined;
/**
* The default gamma correction to apply to this provider. 1.0 uses the unmodified imagery color.
*
* @type {Number}
* @default undefined
*/
this.defaultGamma = undefined;
DeveloperError.throwInstantiationError();
}
defineProperties(ImageryProvider.prototype, {
/**
* Gets a value indicating whether or not the provider is ready for use.
* @memberof ImageryProvider.prototype
* @type {Boolean}
* @readonly
*/
ready : {
get : DeveloperError.throwInstantiationError
},
/**
* Gets a promise that resolves to true when the provider is ready for use.
* @memberof ImageryProvider.prototype
* @type {Promise.<Boolean>}
* @readonly
*/
readyPromise : {
get : DeveloperError.throwInstantiationError
},
/**
* Gets the rectangle, in radians, of the imagery provided by the instance. This function should
* not be called before {@link ImageryProvider#ready} returns true.
* @memberof ImageryProvider.prototype
* @type {Rectangle}
* @readonly
*/
rectangle: {
get : DeveloperError.throwInstantiationError
},
/**
* Gets the width of each tile, in pixels. This function should
* not be called before {@link ImageryProvider#ready} returns true.
* @memberof ImageryProvider.prototype
* @type {Number}
* @readonly
*/
tileWidth : {
get : DeveloperError.throwInstantiationError
},
/**
* Gets the height of each tile, in pixels. This function should
* not be called before {@link ImageryProvider#ready} returns true.
* @memberof ImageryProvider.prototype
* @type {Number}
* @readonly
*/
tileHeight : {
get : DeveloperError.throwInstantiationError
},
/**
* Gets the maximum level-of-detail that can be requested. This function should
* not be called before {@link ImageryProvider#ready} returns true.
* @memberof ImageryProvider.prototype
* @type {Number}
* @readonly
*/
maximumLevel : {
get : DeveloperError.throwInstantiationError
},
/**
* Gets the minimum level-of-detail that can be requested. This function should
* not be called before {@link ImageryProvider#ready} returns true. Generally,
* a minimum level should only be used when the rectangle of the imagery is small
* enough that the number of tiles at the minimum level is small. An imagery
* provider with more than a few tiles at the minimum level will lead to
* rendering problems.
* @memberof ImageryProvider.prototype
* @type {Number}
* @readonly
*/
minimumLevel : {
get : DeveloperError.throwInstantiationError
},
/**
* Gets the tiling scheme used by the provider. This function should
* not be called before {@link ImageryProvider#ready} returns true.
* @memberof ImageryProvider.prototype
* @type {TilingScheme}
* @readonly
*/
tilingScheme : {
get : DeveloperError.throwInstantiationError
},
/**
* Gets the tile discard policy. If not undefined, the discard policy is responsible
* for filtering out "missing" tiles via its shouldDiscardImage function. If this function
* returns undefined, no tiles are filtered. This function should
* not be called before {@link ImageryProvider#ready} returns true.
* @memberof ImageryProvider.prototype
* @type {TileDiscardPolicy}
* @readonly
*/
tileDiscardPolicy : {
get : DeveloperError.throwInstantiationError
},
/**
* Gets an event that is raised when the imagery 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 ImageryProvider.prototype
* @type {Event}
* @readonly
*/
errorEvent : {
get : DeveloperError.throwInstantiationError
},
/**
* Gets the credit to display when this imagery provider is active. Typically this is used to credit
* the source of the imagery. This function should
* not be called before {@link ImageryProvider#ready} returns true.
* @memberof ImageryProvider.prototype
* @type {Credit}
* @readonly
*/
credit : {
get : DeveloperError.throwInstantiationError
},
/**
* Gets the proxy used by this provider.
* @memberof ImageryProvider.prototype
* @type {Proxy}
* @readonly
*/
proxy : {
get : DeveloperError.throwInstantiationError
},
/**
* Gets a value indicating whether or not the images provided by this imagery provider
* include an alpha channel. If this property is false, an alpha channel, if present, will
* be ignored. If this property is true, any images without an alpha channel will be treated
* as if their alpha is 1.0 everywhere. When this property is false, memory usage
* and texture upload time are reduced.
* @memberof ImageryProvider.prototype
* @type {Boolean}
* @readonly
*/
hasAlphaChannel : {
get : DeveloperError.throwInstantiationError
}
});
/**
* Gets the credits to be displayed when a given tile is displayed.
* @function
*
* @param {Number} x The tile X coordinate.
* @param {Number} y The tile Y coordinate.
* @param {Number} level The tile level;
* @returns {Credit[]} The credits to be displayed when the tile is displayed.
*
* @exception {DeveloperError} <code>getTileCredits</code> must not be called before the imagery provider is ready.
*/
ImageryProvider.prototype.getTileCredits = DeveloperError.throwInstantiationError;
/**
* Requests the image for a given tile. This function should
* not be called before {@link ImageryProvider#ready} returns true.
* @function
*
* @param {Number} x The tile X coordinate.
* @param {Number} y The tile Y coordinate.
* @param {Number} level The tile level.
* @returns {Promise.<Image|Canvas>|undefined} A promise for the image that will resolve when the image is available, or
* undefined if there are too many active requests to the server, and the request
* should be retried later. The resolved image may be either an
* Image or a Canvas DOM object.
*
* @exception {DeveloperError} <code>requestImage</code> must not be called before the imagery provider is ready.
*/
ImageryProvider.prototype.requestImage = DeveloperError.throwInstantiationError;
/**
* Asynchronously determines what features, if any, are located at a given longitude and latitude within
* a tile. This function should not be called before {@link ImageryProvider#ready} returns true.
* This function is optional, so it may not exist on all ImageryProviders.
*
* @function
*
* @param {Number} x The tile X coordinate.
* @param {Number} y The tile Y coordinate.
* @param {Number} level The tile level.
* @param {Number} longitude The longitude at which to pick features.
* @param {Number} latitude The latitude at which to pick features.
* @return {Promise.<ImageryLayerFeatureInfo[]>|undefined} A promise for the picked features that will resolve when the asynchronous
* picking completes. The resolved value is an array of {@link ImageryLayerFeatureInfo}
* instances. The array may be empty if no features are found at the given location.
* It may also be undefined if picking is not supported.
*
* @exception {DeveloperError} <code>pickFeatures</code> must not be called before the imagery provider is ready.
*/
ImageryProvider.prototype.pickFeatures = DeveloperError.throwInstantiationError;
/**
* Loads an image from a given URL. If the server referenced by the URL already has
* too many requests pending, this function will instead return undefined, indicating
* that the request should be retried later.
*
* @param {String} url The URL of the image.
* @returns {Promise.<Image|Canvas>|undefined} A promise for the image that will resolve when the image is available, or
* undefined if there are too many active requests to the server, and the request
* should be retried later. The resolved image may be either an
* Image or a Canvas DOM object.
*/
ImageryProvider.loadImage = function(imageryProvider, url) {
if (defined(imageryProvider.tileDiscardPolicy)) {
return throttleRequestByServer(url, loadImageViaBlob);
}
return throttleRequestByServer(url, loadImage);
};
return ImageryProvider;
});