ImageryLayer

Members

alpha :Number

The alpha blending value of this layer, usually from 0.0 to 1.0. This can either be a simple number or a function with the signature function(frameState, layer, x, y, level). The function is passed the current FrameState, this layer, and the x, y, and level coordinates of the imagery tile for which the alpha is required, and it is expected to return the alpha value to use for the tile. The function is executed for every frame and for every tile, so it must be fast.

brightness :Number

The brightness of this layer. 1.0 uses the unmodified imagery color. Less than 1.0 makes the imagery darker while greater than 1.0 makes it brighter. This can either be a simple number or a function with the signature function(frameState, layer, x, y, level). The function is passed the current FrameState, this layer, and the x, y, and level coordinates of the imagery tile for which the brightness is required, and it is expected to return the brightness value to use for the tile. The function is executed for every frame and for every tile, so it must be fast.

contrast :Number

The contrast of this layer. 1.0 uses the unmodified imagery color. Less than 1.0 reduces the contrast while greater than 1.0 increases it. This can either be a simple number or a function with the signature function(frameState, layer, x, y, level). The function is passed the current FrameState, this layer, and the x, y, and level coordinates of the imagery tile for which the contrast is required, and it is expected to return the contrast value to use for the tile. The function is executed for every frame and for every tile, so it must be fast.

gamma :Number

The gamma correction to apply to this layer. 1.0 uses the unmodified imagery color. This can either be a simple number or a function with the signature function(frameState, layer, x, y, level). The function is passed the current FrameState, this layer, and the x, y, and level coordinates of the imagery tile for which the gamma is required, and it is expected to return the gamma value to use for the tile. The function is executed for every frame and for every tile, so it must be fast.

hue :Number

The hue of this layer in radians. 0.0 uses the unmodified imagery color. This can either be a simple number or a function with the signature function(frameState, layer, x, y, level). The function is passed the current FrameState, this layer, and the x, y, and level coordinates of the imagery tile for which the hue is required, and it is expected to return the hue value to use for the tile. The function is executed for every frame and for every tile, so it must be fast.

saturation :Number

The saturation of this layer. 1.0 uses the unmodified imagery color. Less than 1.0 reduces the saturation while greater than 1.0 increases it. This can either be a simple number or a function with the signature function(frameState, layer, x, y, level). The function is passed the current FrameState, this layer, and the x, y, and level coordinates of the imagery tile for which the saturation is required, and it is expected to return the saturation value to use for the tile. The function is executed for every frame and for every tile, so it must be fast.

show :Boolean

Determines if this layer is shown.

<static> DEFAULT_BRIGHTNESS :number

This value is used as the default brightness for the imagery layer if one is not provided during construction or by the imagery provider. This value does not modify the brightness of the imagery.

<static> DEFAULT_CONTRAST :number

This value is used as the default contrast for the imagery layer if one is not provided during construction or by the imagery provider. This value does not modify the contrast of the imagery.

<static> DEFAULT_GAMMA :number

This value is used as the default gamma for the imagery layer if one is not provided during construction or by the imagery provider. This value does not modify the gamma of the imagery.

<static> DEFAULT_HUE :number

This value is used as the default hue for the imagery layer if one is not provided during construction or by the imagery provider. This value does not modify the hue of the imagery.

<static> DEFAULT_SATURATION :number

This value is used as the default saturation for the imagery layer if one is not provided during construction or by the imagery provider. This value does not modify the saturation of the imagery.

Methods

destroy

Destroys the WebGL resources held by this object. Destroying an object allows for deterministic release of WebGL resources, instead of relying on the garbage collector to destroy this object.

Once an object is destroyed, it should not be used; calling any function other than isDestroyed will result in a DeveloperError exception. Therefore, assign the return value (undefined) to the object as done in the example.

Throws:

DeveloperError : This object was destroyed, i.e., destroy() was called.

Returns:

Example

imageryLayer = imageryLayer && imageryLayer.destroy();

See:

• ImageryLayer#isDestroyed

getExtent

Gets the extent of this layer. If this extent is smaller than the extent of the ImageryProvider, only a portion of the imagery provider is shown.

Returns:

Extent The extent.

getImageryProvider

Gets the imagery provider for this layer.

Returns:

ImageryProvider The imagery provider.

isBaseLayer

Gets a value indicating whether this layer is the base layer in the ImageryLayerCollection. The base layer is the one that underlies all others. It is special in that it is treated as if it has global extent, even if it actually does not, by stretching the texels at the edges over the entire globe.

Returns:

Boolean true if this is the base layer; otherwise, false.

isDestroyed

Returns true if this object was destroyed; otherwise, false.

If this object was destroyed, it should not be used; calling any function other than isDestroyed will result in a DeveloperError exception.

Returns:

Boolean True if this object was destroyed; otherwise, false.

See:

• ImageryLayer#destroy