# GridImageryProvider

#### new Cesium.GridImageryProvider(options)
Scene/GridImageryProvider.js 40

An `ImageryProvider` that draws a wireframe grid on every tile with controllable background and glow. May be useful for custom rendering effects or debugging terrain.

Name | Type | Description
--- | --- | ---
`options` | GridImageryProvider.ConstructorOptions | Object describing initialization options

### Members

#### readonly credit : Credit
Scene/GridImageryProvider.js 306

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 `GridImageryProvider#ready` returns true.

#### defaultAlpha : Number|undefined
Scene/GridImageryProvider.js 50

The default alpha blending value of this provider, with 0.0 representing fully transparent and 1.0 representing fully opaque.

Default Value: `undefined`

#### defaultBrightness : Number|undefined
Scene/GridImageryProvider.js 77

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.

Default Value: `undefined`

#### defaultContrast : Number|undefined
Scene/GridImageryProvider.js 86

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.

Default Value: `undefined`

#### defaultDayAlpha : Number|undefined
Scene/GridImageryProvider.js 68

The default alpha blending value on the day side of the globe of this provider, with 0.0 representing fully transparent and 1.0 representing fully opaque.

Default Value: `undefined`

#### defaultGamma : Number|undefined
Scene/GridImageryProvider.js 111

The default gamma correction to apply to this provider. 1.0 uses the unmodified imagery color.

Default Value: `undefined`

#### defaultHue : Number|undefined
Scene/GridImageryProvider.js 94

The default hue of this provider in radians. 0.0 uses the unmodified imagery color.

Default Value: `undefined`

#### defaultMagnificationFilter : TextureMagnificationFilter
Scene/GridImageryProvider.js 127

The default texture magnification filter to apply to this provider.

Default Value: `undefined`

#### defaultMinificationFilter : TextureMinificationFilter
Scene/GridImageryProvider.js 119

The default texture minification filter to apply to this provider.

Default Value: `undefined`

#### defaultNightAlpha : Number|undefined
Scene/GridImageryProvider.js 59

The default alpha blending value on the night side of the globe of this provider, with 0.0 representing fully transparent and 1.0 representing fully opaque.

Default Value: `undefined`

#### defaultSaturation : Number|undefined
Scene/GridImageryProvider.js 103

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.

Default Value: `undefined`

#### readonly errorEvent : Event
Scene/GridImageryProvider.js 269

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 `TileProviderError`.

#### readonly hasAlphaChannel : Boolean
Scene/GridImageryProvider.js 322

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.

#### readonly maximumLevel : Number|undefined
Scene/GridImageryProvider.js 201

Gets the maximum level-of-detail that can be requested. This function should not be called before `GridImageryProvider#ready` returns true.

#### readonly minimumLevel : Number
Scene/GridImageryProvider.js 214

Gets the minimum level-of-detail that can be requested. This function should not be called before `GridImageryProvider#ready` returns true.

#### readonly proxy : Proxy
Scene/GridImageryProvider.js 162

Gets the proxy used by this provider.

#### readonly ready : Boolean
Scene/GridImageryProvider.js 281

Gets a value indicating whether or not the provider is ready for use.

#### readonly readyPromise : Promise.<Boolean>
Scene/GridImageryProvider.js 293

Gets a promise that resolves to true when the provider is ready for use.

#### readonly rectangle : Rectangle
Scene/GridImageryProvider.js 240

Gets the rectangle, in radians, of the imagery provided by this instance. This function should not be called before `GridImageryProvider#ready` returns true.

#### readonly tileDiscardPolicy : TileDiscardPolicy
Scene/GridImageryProvider.js 255

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 `GridImageryProvider#ready` returns true.

#### readonly tileHeight : Number
Scene/GridImageryProvider.js 188

Gets the height of each tile, in pixels. This function should not be called before `GridImageryProvider#ready` returns true.

#### readonly tileWidth : Number
Scene/GridImageryProvider.js 175

Gets the width of each tile, in pixels. This function should not be called before `GridImageryProvider#ready` returns true.

#### readonly tilingScheme : TilingScheme
Scene/GridImageryProvider.js 227

Gets the tiling scheme used by this provider. This function should not be called before `GridImageryProvider#ready` returns true.

### Methods

#### _createGridCanvas()
Scene/GridImageryProvider.js 350

Render a grid into a canvas with background and glow

#### _drawGrid()
Scene/GridImageryProvider.js 332

Draws a grid of lines into a canvas.

#### getTileCredits(x, y, level) → Array.<Credit>
Scene/GridImageryProvider.js 399

Gets the credits to be displayed when a given tile is displayed.

Name | Type | Description
--- | --- | ---
`x` | Number | The tile X coordinate.
`y` | Number | The tile Y coordinate.
`level` | Number | The tile level;

##### Returns:

The credits to be displayed when the tile is displayed.

##### Throws:

- DeveloperError : `getTileCredits` must not be called before the imagery provider is ready.

#### pickFeatures(x, y, level, longitude, latitude) → Promise.<Array.<ImageryLayerFeatureInfo>>|undefined
Scene/GridImageryProvider.js 434

Picking features is not currently supported by this imagery provider, so this function simply returns undefined.

Name | Type | Description
--- | --- | ---
`x` | Number | The tile X coordinate.
`y` | Number | The tile Y coordinate.
`level` | Number | The tile level.
`longitude` | Number | The longitude at which to pick features.
`latitude` | Number | The latitude at which to pick features.

##### Returns:

A promise for the picked features that will resolve when the asynchronous picking completes. The resolved value is an array of `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.

#### requestImage(x, y, level, request) → Promise.<(HTMLImageElement|HTMLCanvasElement)>|undefined
Scene/GridImageryProvider.js 416

Requests the image for a given tile. This function should not be called before `GridImageryProvider#ready` returns true.

Name | Type | Description
--- | --- | ---
`x` | Number | The tile X coordinate.
`y` | Number | The tile Y coordinate.
`level` | Number | The tile level.
`request` | Request | optional The request object. Intended for internal use only.

##### 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. The resolved image may be either an Image or a Canvas DOM object.

### Type Definitions

#### Cesium.GridImageryProvider.ConstructorOptions
Scene/GridImageryProvider.js 12

Initialization options for the GridImageryProvider constructor

##### Properties:

Name | Type | Attributes | Default | Description
--- | --- | --- | --- | ---
`tilingScheme` | TilingScheme | <optional> | new GeographicTilingScheme() | The tiling scheme for which to draw tiles.
`ellipsoid` | Ellipsoid | <optional> |  | The ellipsoid. If the tilingScheme is specified, this parameter is ignored and the tiling scheme's ellipsoid is used instead. If neither parameter is specified, the WGS84 ellipsoid is used.
`cells` | Number | <optional> | 8 | The number of grids cells.
`color` | Color | <optional> | Color(1.0, 1.0, 1.0, 0.4) | The color to draw grid lines.
`glowColor` | Color | <optional> | Color(0.0, 1.0, 0.0, 0.05) | The color to draw glow for grid lines.
`glowWidth` | Number | <optional> | 6 | The width of lines used for rendering the line glow effect.
`backgroundColor` | Color | <optional> | Color(0.0, 0.5, 0.0, 0.2) | Background fill color.
`tileWidth` | Number | <optional> | 256 | The width of the tile for level-of-detail selection purposes.
`tileHeight` | Number | <optional> | 256 | The height of the tile for level-of-detail selection purposes.
`canvasSize` | Number | <optional> | 256 | The size of the canvas used for rendering.