spark.filters.DisplacementMapFilter - Adobe® Flex® 4 Language Reference (Flex 4)

Package	spark.filters
Class	public class DisplacementMapFilter
Inheritance	DisplacementMapFilter BaseFilter EventDispatcher Object
Implements	IBitmapFilter

Language Version:

ActionScript 3.0

Product Version:

Flex 4

Runtime Versions:

Flash Player 10, AIR 1.5

The DisplacementMapFilter class uses the pixel values from the specified BitmapData object (called the displacement map image) to perform a displacement of an object. You can use this filter to apply a warped or mottled effect to any object that inherits from the DisplayObject class, such as MovieClip, SimpleButton, TextField, and Video objects, as well as to BitmapData objects.

The use of filters depends on the object to which you apply the filter:

To apply filters to a display object, use the filters property of the display object. Setting the filters property of an object does not modify the object, and you can remove the filter by clearing the filters property.
To apply filters to BitmapData objects, use the BitmapData.applyFilter() method. Calling applyFilter() on a BitmapData object takes the source BitmapData object and the filter object and generates a filtered image.

If you apply a filter to a display object, the value of the cacheAsBitmap property of the display object is set to true. If you clear all filters, the original value of cacheAsBitmap is restored.

The filter uses the following formula:

dstPixel[x, y] = srcPixel[x + ((componentX(x, y) - 128) * scaleX) / 256, y + ((componentY(x, y) - 128) *scaleY) / 256)

where componentX(x, y) gets the componentX property color value from the mapBitmap property at (x - mapPoint.x ,y - mapPoint.y).

The map image used by the filter is scaled to match the Stage scaling. It is not scaled when the object itself is scaled.

This filter supports Stage scaling. However, general scaling, rotation, and skewing are not supported. If the object itself is scaled (if the scaleX and scaleY properties are set to a value other than 1.0), the filter effect is not scaled. It is scaled only when the user zooms in on the Stage.

MXML Syntax expanded

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The <s:DisplacementMapFilter> tag inherits all of the tag attributes of its superclass and adds the following tag attributes:

 <s:DisplacementMapFilter 
   Properties
   alpha="0"
   color="0x000000"
   componentX="0"
   componentY="0"
   mapBitmap="null"
   mapPoint="null"
   mode="wrap"
   scaleX="0"
   scaleY="0"
 />

Public Properties

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	Property		Defined By
		alpha : Number Specifies the alpha transparency value to use for out-of-bounds displacements.	DisplacementMapFilter
		color : uint Specifies what color to use for out-of-bounds displacements.	DisplacementMapFilter
		componentX : uint Describes which color channel to use in the map image to displace the x result.	DisplacementMapFilter
		componentY : uint Describes which color channel to use in the map image to displace the y result.	DisplacementMapFilter
		constructor : Object A reference to the class object or constructor function for a given object instance.	Object
		mapBitmap : BitmapData A BitmapData object containing the displacement map data.	DisplacementMapFilter
		mapPoint : Point A value that contains the offset of the upper-left corner of the target display object from the upper-left corner of the map image.	DisplacementMapFilter
		mode : String The mode for the filter.	DisplacementMapFilter
		prototype : Object [static] A reference to the prototype object of a class or function object.	Object
		scaleX : Number The multiplier to use to scale the x displacement result from the map calculation.	DisplacementMapFilter
		scaleY : Number The multiplier to use to scale the y displacement result from the map calculation.	DisplacementMapFilter

Public Methods

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	Method		Defined By
		DisplacementMapFilter(mapBitmap:BitmapData = null, mapPoint:Point = null, componentX:uint = 0, componentY:uint = 0, scaleX:Number = 0.0, scaleY:Number = 0.0, mode:String = "wrap", color:uint = 0, alpha:Number = 0.0) Constructor.	DisplacementMapFilter
		addEventListener(type:String, listener:Function, useCapture:Boolean = false, priority:int = 0, useWeakReference:Boolean = false):void Registers an event listener object with an EventDispatcher object so that the listener receives notification of an event.	EventDispatcher
		clone():BitmapFilter Returns a copy of this filter object.	DisplacementMapFilter
		dispatchEvent(event:Event):Boolean Dispatches an event into the event flow.	EventDispatcher
		hasEventListener(type:String):Boolean Checks whether the EventDispatcher object has any listeners registered for a specific type of event.	EventDispatcher
		hasOwnProperty(name:String):Boolean Indicates whether an object has a specified property defined.	Object
		isPrototypeOf(theClass:Object):Boolean Indicates whether an instance of the Object class is in the prototype chain of the object specified as the parameter.	Object
		notifyFilterChanged():void	BaseFilter
		propertyIsEnumerable(name:String):Boolean Indicates whether the specified property exists and is enumerable.	Object
		removeEventListener(type:String, listener:Function, useCapture:Boolean = false):void Removes a listener from the EventDispatcher object.	EventDispatcher
		setPropertyIsEnumerable(name:String, isEnum:Boolean = true):void Sets the availability of a dynamic property for loop operations.	Object
		toLocaleString():String Returns the string representation of this object, formatted according to locale-specific conventions.	Object
		toString():String Returns the string representation of the specified object.	Object
		valueOf():Object Returns the primitive value of the specified object.	Object
		willTrigger(type:String):Boolean Checks whether an event listener is registered with this EventDispatcher object or any of its ancestors for the specified event type.	EventDispatcher

Events

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	Event		Summary	Defined By
		activate	[broadcast event] Dispatched when the Flash Player or AIR application gains operating system focus and becomes active.	EventDispatcher
		deactivate	[broadcast event] Dispatched when the Flash Player or AIR application operating loses system focus and is becoming inactive.	EventDispatcher

Public Constants

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	Constant		Defined By
		CHANGE : String = "change" [static]	BaseFilter

Property Detail

alpha

property

alpha:Number

Language Version:

ActionScript 3.0

Product Version:

Flex 4

Runtime Versions:

Flash Player 10, AIR 1.5

Specifies the alpha transparency value to use for out-of-bounds displacements. It is specified as a normalized value from 0.0 to 1.0. For example, .25 sets a transparency value of 25%. The default value is 0. Use this property if the mode property is set to DisplacementMapFilterMode.COLOR.

The default value is 0.

Implementation
public function get alpha():Number
public function set alpha(value:Number):void

color

property

color:uint

Language Version:

ActionScript 3.0

Product Version:

Flex 4

Runtime Versions:

Flash Player 10, AIR 1.5

Specifies what color to use for out-of-bounds displacements. The valid range of displacements is 0.0 to 1.0. Values are in hexadecimal format. The default value for color is 0. Use this property if the mode property is set to DisplacementMapFilterMode.COLOR.

The default value is 0x000000.

Implementation
public function get color():uint
public function set color(value:uint):void

componentX

property

componentX:uint

Language Version:

ActionScript 3.0

Product Version:

Flex 4

Runtime Versions:

Flash Player 10, AIR 1.5

Describes which color channel to use in the map image to displace the x result. Possible values are BitmapDataChannel constants:

BitmapDataChannel.ALPHA
BitmapDataChannel.BLUE
BitmapDataChannel.GREEN
BitmapDataChannel.RED

The default value is 0, meaning no channel..

Implementation
public function get componentX():uint
public function set componentX(value:uint):void

componentY

property

componentY:uint

Language Version:

ActionScript 3.0

Product Version:

Flex 4

Runtime Versions:

Flash Player 10, AIR 1.5

Describes which color channel to use in the map image to displace the y result. Possible values are BitmapDataChannel constants:

BitmapDataChannel.ALPHA
BitmapDataChannel.BLUE
BitmapDataChannel.GREEN
BitmapDataChannel.RED

The default value is 0, meaning no channel..

Implementation
public function get componentY():uint
public function set componentY(value:uint):void

mapBitmap

property

mapBitmap:BitmapData

Language Version:

ActionScript 3.0

Product Version:

Flex 4

Runtime Versions:

Flash Player 10, AIR 1.5

A BitmapData object containing the displacement map data.

The default value is null.

Implementation
public function get mapBitmap():BitmapData
public function set mapBitmap(value:BitmapData):void

mapPoint

property

mapPoint:Point

Language Version:

ActionScript 3.0

Product Version:

Flex 4

Runtime Versions:

Flash Player 10, AIR 1.5

A value that contains the offset of the upper-left corner of the target display object from the upper-left corner of the map image.

The default value is null.

Implementation
public function get mapPoint():Point
public function set mapPoint(value:Point):void

mode

property

mode:String

Language Version:

ActionScript 3.0

Product Version:

Flex 4

Runtime Versions:

Flash Player 10, AIR 1.5

The mode for the filter. Possible values are DisplacementMapFilterMode constants:

DisplacementMapFilterMode.WRAP - Wraps the displacement value to the other side of the source image.
DisplacementMapFilterMode.CLAMP - Clamps the displacement value to the edge of the source image.
DisplacementMapFilterMode.IGNORE - If the displacement value is out of range, ignores the displacement and uses the source pixel.
DisplacementMapFilterMode.COLOR - If the displacement value is outside the image, substitutes the values in the color and alpha properties.

The default value is DisplacementMapFilterMode.WRAP.

Implementation
public function get mode():String
public function set mode(value:String):void

scaleX

property

scaleX:Number

Language Version:

ActionScript 3.0

Product Version:

Flex 4

Runtime Versions:

Flash Player 10, AIR 1.5

The multiplier to use to scale the x displacement result from the map calculation.

The default value is 0.

Implementation
public function get scaleX():Number
public function set scaleX(value:Number):void

scaleY

property

scaleY:Number

Language Version:

ActionScript 3.0

Product Version:

Flex 4

Runtime Versions:

Flash Player 10, AIR 1.5

The multiplier to use to scale the y displacement result from the map calculation.

The default value is 0.

Implementation
public function get scaleY():Number
public function set scaleY(value:Number):void

Constructor Detail

DisplacementMapFilter

()

Constructor

public function DisplacementMapFilter(mapBitmap:BitmapData = null, mapPoint:Point = null, componentX:uint = 0, componentY:uint = 0, scaleX:Number = 0.0, scaleY:Number = 0.0, mode:String = "wrap", color:uint = 0, alpha:Number = 0.0)

Language Version:

ActionScript 3.0

Product Version:

Flex 4

Runtime Versions:

Flash Player 10, AIR 1.5

Constructor.

Parameters

	`mapBitmap:BitmapData` (default = `null`) — A BitmapData object containing the displacement map data.

	`mapPoint:Point` (default = `null`) — A value that contains the offset of the upper-left corner of the target display object from the upper-left corner of the map image.

	`componentX:uint` (default = `0`) — Describes which color channel to use in the map image to displace the x result. Possible values are the BitmapDataChannel constants.

	`componentY:uint` (default = `0`) — Describes which color channel to use in the map image to displace the y result. Possible values are the BitmapDataChannel constants.

	`scaleX:Number` (default = `0.0`) — The multiplier to use to scale the x displacement result from the map calculation.

	`scaleY:Number` (default = `0.0`) — The multiplier to use to scale the y displacement result from the map calculation.

	`mode:String` (default = "`wrap`") — The mode of the filter. Possible values are the DisplacementMapFilterMode constants.

	`color:uint` (default = `0`) — Specifies the color to use for out-of-bounds displacements. The valid range of displacements is 0.0 to 1.0. Use this parameter if `mode` is set to `DisplacementMapFilterMode.COLOR`.

	`alpha:Number` (default = `0.0`) — Specifies what alpha value to use for out-of-bounds displacements. It is specified as a normalized value from 0.0 to 1.0. For example, .25 sets a transparency value of 25%. Use this parameter if `mode` is set to `DisplacementMapFilterMode.COLOR`.

clone

()

method

public function clone():BitmapFilter

Language Version:

ActionScript 3.0

Product Version:

Flex 4

Runtime Versions:

Flash Player 10, AIR 1.5

Returns a copy of this filter object.

Returns

BitmapFilter — A new DisplacementMapFilter instance with all the same properties as the original one.