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.

Constructor

new (?mapBitmap:BitmapData, ?mapPoint:Point, componentX:Int = 0, componentY:Int = 0, scaleX:Float = 0.0, scaleY:Float = 0.0, mode:DisplacementMapFilterMode = WRAP, color:Int = 0, alpha:Float = 0.0)

Initializes a DisplacementMapFilter instance with the specified parameters.

Parameters:

mapBitmap

A BitmapData object containing the displacement map data.

mapPoint

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

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

componentY

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

scaleX

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

scaleY

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

mode

The mode of the filter. Possible values are the DisplacementMapFilterMode constants.

color

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

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.

Variables

alpha:Float

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.

color:Int

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.

componentX:Int

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

componentY:Int

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

mapBitmap:BitmapData

A BitmapData object containing the displacement map data.

Throws:

TypeError

The BitmapData is null when being set

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.

Throws:

TypeError

The Point is null when being set

mode:DisplacementMapFilterMode

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.

Throws:

ArgumentError

The mode string is not one of the valid types

TypeError

The String is null when being set

scaleX:Float

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

scaleY:Float

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

Methods

Inherited Variables

Inherited Methods