ActionScript® 3.0 Reference for the Adobe® Flash® Platform
Home  |  Show Packages and Classes List |  Packages  |  Classes  |  What's New  |  Index  |  Appendixes
fl.motion 

BezierEase  - AS3 Flash

Packagefl.motion
Classpublic class BezierEase
InheritanceBezierEase Inheritance Object
Implements ITween

Language Version: ActionScript 3.0
Product Version: Flash CS3
Runtime Versions: Flash Player 9.0.28.0, AIR 1.0

The BezierEase class provides precise easing control for a motion tween between two keyframes. You can apply an instance of this class to all properties of a keyframe at once, or you can define different curves for different properties.

Both this class and the CustomEase class use one or more cubic Bezier curves to define the interpolation. However, the BezierEase class defines its coordinates slightly differently than the CustomEase class.

The BezierEase class uses literal values for the y coordinates of the curve, rather than normalized values between 0 and 1. This allows you to create curves that cannot be created with custom easing. For example, you can create a curve where the start and end values are identical, but the curve rises and falls in between those values. Also, depending on the context, you may want to define the easing curve with literal values instead of percentages.

Default MXML Propertypoints

Related API Elements



Public Properties
 PropertyDefined By
 Inheritedconstructor : Object
A reference to the class object or constructor function for a given object instance.
Object
  points : Array
An ordered collection of points in the custom easing curve.
BezierEase
  target : String
The name of the animation property to target.
BezierEase
Public Methods
 MethodDefined By
  
BezierEase(xml:XML = null)
Constructor for BezierEase instances.
BezierEase
  
getValue(time:Number, begin:Number, change:Number, duration:Number):Number
Calculates an interpolated value for a numerical property of animation, using a Bezier easing curve.
BezierEase
 Inherited
Indicates whether an object has a specified property defined.
Object
 Inherited
Indicates whether an instance of the Object class is in the prototype chain of the object specified as the parameter.
Object
 Inherited
Indicates whether the specified property exists and is enumerable.
Object
 Inherited
Sets the availability of a dynamic property for loop operations.
Object
 Inherited
Returns the string representation of this object, formatted according to locale-specific conventions.
Object
 Inherited
Returns the string representation of the specified object.
Object
 Inherited
Returns the primitive value of the specified object.
Object
Property Detail

points

property
public var points:Array

Language Version: ActionScript 3.0
Product Version: Flash CS3
Runtime Versions: Flash Player 9.0.28.0, AIR 1.0

An ordered collection of points in the custom easing curve. Each item in the array is a flash.geom.Point instance, with x and y properties.

The x coordinate of each point represents the time coordinate of the ease, as a percentage. The x value is normalized to fall between 0 and 1, where 0 is the beginning of the tween and 1 is the end of the tween. The y coordinate of each point contains the literal value of the animation property at that point in the ease. The y value is not normalized to fall between 0 and 1.

The first and last points of the curve are not included in the array, because the first point is locked to the starting value, defined by the current keyframe, and the last point is locked to the ending value, defined by the next keyframe.

Related API Elements

target

property 
target:String

Language Version: ActionScript 3.0
Product Version: Flash CS3
Runtime Versions: Flash Player 9.0.28.0, AIR 1.0

The name of the animation property to target.

The default value is "".



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

Related API Elements

Constructor Detail

BezierEase

()Constructor
public function BezierEase(xml:XML = null)

Language Version: ActionScript 3.0
Product Version: Flash CS3
Runtime Versions: Flash Player 9.0.28.0, AIR 1.0

Constructor for BezierEase instances.

Parameters
xml:XML (default = null) — Optional E4X XML object defining a BezierEase in Motion XML format.
Method Detail

getValue

()method
public function getValue(time:Number, begin:Number, change:Number, duration:Number):Number

Language Version: ActionScript 3.0
Product Version: Flash CS3
Runtime Versions: Flash Player 9.0.28.0, AIR 1.0

Calculates an interpolated value for a numerical property of animation, using a Bezier easing curve. The percent value is read from the BezierEase instance's points property, rather than being passed into the method. Using the points property value allows the function signature to match the ITween interface.

Parameters

time:Number — The time value, which must be between 0 and duration, inclusive. The unit can be freely chosen (for example, frames, seconds, milliseconds), but must match the duration unit.
 
begin:Number — The value of the animation property at the start of the tween, when time is 0.
 
change:Number — The change in the value of the animation property over the course of the tween. This value can be positive or negative. For example, if an object rotates from 90 to 60 degrees, the change is -30.
 
duration:Number — The length of time for the tween. This value must be greater than zero. The unit can be freely chosen (for example, frames, seconds, milliseconds), but must match the time unit.

Returns
Number — The interpolated value at the specified time.

Related API Elements