| Package | flash.filters |
| Class | public final class DisplacementMapFilter |
| Inheritance | DisplacementMapFilter BitmapFilter Object |
| Language Version: | ActionScript 3.0 |
| Runtime Versions: | AIR 1.0, Flash Player 9 |
The use of filters depends on the object to which you apply the filter:
- To apply filters to a display object, use the
filtersproperty of the display object. Setting thefiltersproperty of an object does not modify the object, and you can remove the filter by clearing thefiltersproperty. - To apply filters to BitmapData objects, use the
BitmapData.applyFilter()method. CallingapplyFilter()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.
Related API Elements
flash.display.DisplayObject.filters
flash.display.DisplayObject.cacheAsBitmap
| 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 | ||
| 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)
Initializes a DisplacementMapFilter instance with the specified parameters. | DisplacementMapFilter | ||
[override]
Returns a copy of this filter object. | DisplacementMapFilter | ||
![]() |
Indicates whether an object has a specified property defined. | Object | |
![]() |
Indicates whether an instance of the Object class is in the prototype chain of the object specified
as the parameter. | Object | |
![]() |
Indicates whether the specified property exists and is enumerable. | Object | |
![]() |
Sets the availability of a dynamic property for loop operations. | Object | |
![]() |
Returns the string representation of this object, formatted according to locale-specific conventions. | Object | |
![]() |
Returns the string representation of the specified object. | Object | |
![]() |
Returns the primitive value of the specified object. | Object | |
alpha | property |
alpha:Number| Language Version: | ActionScript 3.0 |
| Runtime Versions: | AIR 1.0, Flash Player 9 |
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.
Implementation
public function get alpha():Number public function set alpha(value:Number):voidcolor | property |
color:uint| Language Version: | ActionScript 3.0 |
| Runtime Versions: | AIR 1.0, Flash Player 9 |
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.
Implementation
public function get color():uint public function set color(value:uint):voidcomponentX | property |
componentX:uint| Language Version: | ActionScript 3.0 |
| Runtime Versions: | AIR 1.0, Flash Player 9 |
Describes which color channel to use in the map image to displace the x result. Possible values are BitmapDataChannel constants:
BitmapDataChannel.ALPHABitmapDataChannel.BLUEBitmapDataChannel.GREENBitmapDataChannel.RED
Implementation
public function get componentX():uint public function set componentX(value:uint):voidRelated API Elements
componentY | property |
componentY:uint| Language Version: | ActionScript 3.0 |
| Runtime Versions: | AIR 1.0, Flash Player 9 |
Describes which color channel to use in the map image to displace the y result. Possible values are BitmapDataChannel constants:
BitmapDataChannel.ALPHABitmapDataChannel.BLUEBitmapDataChannel.GREENBitmapDataChannel.RED
Implementation
public function get componentY():uint public function set componentY(value:uint):voidRelated API Elements
mapBitmap | property |
mapBitmap:BitmapData| Language Version: | ActionScript 3.0 |
| Runtime Versions: | AIR 1.0, Flash Player 9 |
A BitmapData object containing the displacement map data.
Implementation
public function get mapBitmap():BitmapData public function set mapBitmap(value:BitmapData):voidThrows
TypeError — The BitmapData is null when being set
|
Related API Elements
mapPoint | property |
mapPoint:Point| Language Version: | ActionScript 3.0 |
| Runtime Versions: | AIR 1.0, Flash Player 9 |
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.
Implementation
public function get mapPoint():Point public function set mapPoint(value:Point):voidThrows
TypeError — The Point is null when being set
|
Related API Elements
mode | property |
mode:String| Language Version: | ActionScript 3.0 |
| Runtime Versions: | AIR 1.0, Flash Player 9 |
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 thecolorandalphaproperties.
Implementation
public function get mode():String public function set mode(value:String):voidThrows
TypeError — The String is null when being set
| |
ArgumentError — The mode string is not one of the valid types
|
Related API Elements
scaleX | property |
scaleY | property |
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 |
| Runtime Versions: | AIR 1.0, Flash Player 9 |
Initializes a DisplacementMapFilter instance with the specified parameters.
ParametersmapBitmap: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.
|
Related API Elements
clone | () | method |
override public function clone():BitmapFilter| Language Version: | ActionScript 3.0 |
| Runtime Versions: | AIR 1.0, Flash Player 9 |
Returns a copy of this filter object.
ReturnsBitmapFilter — A new DisplacementMapFilter instance with all the same properties as the
original one.
|
- The class defines variables for the background color, for the text field label, and for the size and offset that will be used in various functions.
- The constructor function calls the
draw()method, which uses the methods of the Graphics class to draw a square with a radial gradient fill. Note thatgraphicsis a property of the DisplacementMapFilterExample object, which extends Sprite. - The constructor function calls the
createLabel()method, which creates a text field displaying the value oflabelTextand adds it to the display list. - The constructor function calls the
createFilter()method, which does the following:- Creates a variable named
filterfor the filter object. - Calls the
getDisplacementMapFilter()method and assigns its return value to thefiltervariable. - Passes
filterto thefiltersproperty of the DisplacementFilterExample object (the main class).
- Creates a variable named
- The
getBitmapFilter()method creates a BitmapData object namedmapBitmapand assigns it the results of thecreateBitmapData()method. ThemapBitmapobject, along with other variables, defines a new displacement map filter. - The
createBitmapData()method creates a new BitmapData object that is based on the current contents of the DisplacementMapFilterExample object. It creates a new bitmap based onbitmapDataand adds the bitmap to the Stage.
package {
import flash.display.Bitmap;
import flash.display.BitmapData;
import flash.display.BitmapDataChannel;
import flash.display.GradientType;
import flash.display.SpreadMethod;
import flash.display.Sprite;
import flash.filters.BitmapFilter;
import flash.filters.DisplacementMapFilter;
import flash.filters.DisplacementMapFilterMode;
import flash.geom.Matrix;
import flash.geom.Point;
import flash.text.TextField;
public class DisplacementMapFilterExample extends Sprite {
private var bgColor:uint = 0xFFCC00;
private var size:uint = 200;
private var offset:uint = 90;
private var labelText:String = "Watch the text bend with the displacement map";
public function DisplacementMapFilterExample() {
draw();
createLabel();
createFilter();
}
private function createFilter():void {
var filter:BitmapFilter = getBitmapFilter();
filters = new Array(filter);
}
private function getBitmapFilter():BitmapFilter {
var mapBitmap:BitmapData = createBitmapData();
var mapPoint:Point = new Point(0, 0);
var channels:uint = BitmapDataChannel.RED;
var componentX:uint = channels;
var componentY:uint = channels;
var scaleX:Number = 0.5;
var scaleY:Number = -30;
var mode:String = DisplacementMapFilterMode.CLAMP;
var color:uint = 0;
var alpha:Number = 0;
return new DisplacementMapFilter(mapBitmap,
mapPoint,
componentX,
componentY,
scaleX,
scaleY,
mode,
color,
alpha);
}
private function draw():void {
var matrix:Matrix = new Matrix();
matrix.createGradientBox(size, size);
graphics.beginGradientFill(GradientType.RADIAL,
[0xFF0000, 0x0000FF],
[100, 100],
[55, 200],
matrix,
SpreadMethod.PAD);
graphics.drawRect(0, 0, size, size);
}
private function createBitmapData():BitmapData {
var bitmapData:BitmapData = new BitmapData(size, size, true, bgColor);
bitmapData.draw(this, new Matrix());
var bitmap:Bitmap = new Bitmap(bitmapData);
bitmap.x = size;
addChild(bitmap);
return bitmapData;
}
private function createLabel():void {
var tf:TextField = new TextField();
tf.text = labelText;
tf.y = offset;
tf.width = size;
addChild(tf);
}
}
}
Mon Nov 28 2011, 06:48 AM -08:00
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