/
ImageryProvider.js
267 lines (246 loc) · 8.6 KB
/
ImageryProvider.js
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
import Check from "../Core/Check.js";
import defined from "../Core/defined.js";
import DeveloperError from "../Core/DeveloperError.js";
import loadKTX2 from "../Core/loadKTX2.js";
import Resource from "../Core/Resource.js";
/**
* @typedef {HTMLImageElement|HTMLCanvasElement|ImageBitmap} ImageryTypes
*
* The format in which {@link ImageryProvider} methods return an image may
* vary by provider, configuration, or server settings. Most common are
* <code>HTMLImageElement</code>, <code>HTMLCanvasElement</code>, or on supported
* browsers, <code>ImageBitmap</code>.
*
* See the documentation for each ImageryProvider class for more information about how they return images.
*/
/**
* 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
* @abstract
*
* @see ArcGisMapServerImageryProvider
* @see BingMapsImageryProvider
* @see OpenStreetMapImageryProvider
* @see TileMapServiceImageryProvider
* @see GoogleEarthEnterpriseImageryProvider
* @see GoogleEarthEnterpriseMapsProvider
* @see GridImageryProvider
* @see IonImageryProvider
* @see MapboxImageryProvider
* @see MapboxStyleImageryProvider
* @see SingleTileImageryProvider
* @see TileCoordinatesImageryProvider
* @see UrlTemplateImageryProvider
* @see WebMapServiceImageryProvider
* @see WebMapTileServiceImageryProvider
*
* @demo {@link https://sandcastle.cesium.com/index.html?src=Imagery%20Layers.html|Cesium Sandcastle Imagery Layers Demo}
* @demo {@link https://sandcastle.cesium.com/index.html?src=Imagery%20Layers%20Manipulation.html|Cesium Sandcastle Imagery Manipulation Demo}
*/
function ImageryProvider() {
DeveloperError.throwInstantiationError();
}
Object.defineProperties(ImageryProvider.prototype, {
/**
* Gets the rectangle, in radians, of the imagery provided by the instance.
* @memberof ImageryProvider.prototype
* @type {Rectangle}
* @readonly
*/
rectangle: {
get: DeveloperError.throwInstantiationError,
},
/**
* Gets the width of each tile, in pixels.
* @memberof ImageryProvider.prototype
* @type {number}
* @readonly
*/
tileWidth: {
get: DeveloperError.throwInstantiationError,
},
/**
* Gets the height of each tile, in pixels.
* @memberof ImageryProvider.prototype
* @type {number}
* @readonly
*/
tileHeight: {
get: DeveloperError.throwInstantiationError,
},
/**
* Gets the maximum level-of-detail that can be requested.
* @memberof ImageryProvider.prototype
* @type {number|undefined}
* @readonly
*/
maximumLevel: {
get: DeveloperError.throwInstantiationError,
},
/**
* Gets the minimum level-of-detail that can be requested. 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.
* @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.
* @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.
* @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.
*
* @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.
*/
ImageryProvider.prototype.getTileCredits = function (x, y, level) {
DeveloperError.throwInstantiationError();
};
/**
* Requests the image for a given tile.
*
* @param {number} x The tile X coordinate.
* @param {number} y The tile Y coordinate.
* @param {number} level The tile level.
* @param {Request} [request] The request object. Intended for internal use only.
* @returns {Promise<ImageryTypes>|undefined} Returns 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.
*/
ImageryProvider.prototype.requestImage = function (x, y, level, request) {
DeveloperError.throwInstantiationError();
};
/**
* Asynchronously determines what features, if any, are located at a given longitude and latitude within
* a tile.
* 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.
*
*/
ImageryProvider.prototype.pickFeatures = function (
x,
y,
level,
longitude,
latitude
) {
DeveloperError.throwInstantiationError();
};
const ktx2Regex = /\.ktx2$/i;
/**
* 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 {ImageryProvider} imageryProvider The imagery provider for the URL.
* @param {Resource|string} url The URL of the image.
* @returns {Promise<ImageryTypes|CompressedTextureBuffer>|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.
*/
ImageryProvider.loadImage = function (imageryProvider, url) {
//>>includeStart('debug', pragmas.debug);
Check.defined("url", url);
//>>includeEnd('debug');
const resource = Resource.createIfNeeded(url);
if (ktx2Regex.test(resource.url)) {
// Resolves with `CompressedTextureBuffer`
return loadKTX2(resource);
} else if (
defined(imageryProvider) &&
defined(imageryProvider.tileDiscardPolicy)
) {
// Resolves with `HTMLImageElement` or `ImageBitmap`
return resource.fetchImage({
preferBlob: true,
preferImageBitmap: true,
flipY: true,
});
}
return resource.fetchImage({
preferImageBitmap: true,
flipY: true,
});
};
export default ImageryProvider;