Module javafx.graphics
Package javafx.animation

Class Interpolator

java.lang.Object
javafx.animation.Interpolator
public abstract class Interpolator
extends Object
The abstract class defines several interpolate methods, which are used to calculate interpolated values. Various built-in implementations of this class are offered. Applications may choose to implement their own Interpolator to get custom interpolation behavior.

A custom Interpolator has to be defined in terms of a " curve()".

Since:
JavaFX 2.0

  • Field Summary

    Fields 
    Modifier and Type Field Description
    static Interpolator DISCRETE
    Built-in interpolator that provides discrete time interpolation.
    static Interpolator EASE_BOTH
    Built-in interpolator instance that provides ease in/out behavior.
    static Interpolator EASE_IN
    Built-in interpolator instance that provides ease in behavior.
    static Interpolator EASE_OUT
    Built-in interpolator instance that provides ease out behavior.
    static Interpolator LINEAR
    Built-in interpolator that provides linear time interpolation.

  • Constructor Summary

    Constructors 
    Modifier Constructor Description
    protected Interpolator()
    The constructor of Interpolator.

  • Method Summary

    Modifier and Type Method Description
    protected abstract double curve​(double t)
    Mapping from [0.0..1.0] to itself.
    boolean interpolate​(boolean startValue, boolean endValue, double fraction)
    This method takes two boolean values along with a fraction between 0.0 and 1.0 and returns the interpolated value.
    double interpolate​(double startValue, double endValue, double fraction)
    This method takes two double values along with a fraction between 0.0 and 1.0 and returns the interpolated value.
    int interpolate​(int startValue, int endValue, double fraction)
    This method takes two int values along with a fraction between 0.0 and 1.0 and returns the interpolated value.
    long interpolate​(long startValue, long endValue, double fraction)
    This method takes two int values along with a fraction between 0.0 and 1.0 and returns the interpolated value.
    Object interpolate​(Object startValue, Object endValue, double fraction)
    This method takes two Objects along with a fraction between 0.0 and 1.0 and returns the interpolated value.
    static Interpolator SPLINE​(double x1, double y1, double x2, double y2)
    Creates an Interpolator, which curve() is shaped using the spline control points defined by (x1, y1 ) and (x2, y2).
    static Interpolator TANGENT​(Duration t, double v)
    Creates a tangent interpolator, for which in-tangent and out-tangent are identical.
    static Interpolator TANGENT​(Duration t1, double v1, Duration t2, double v2)
    Create a tangent interpolator.

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Field Details

    • DISCRETE

      public static final Interpolator DISCRETE
      Built-in interpolator that provides discrete time interpolation. The return value of interpolate() is endValue only when the input fraction is 1.0, and startValue otherwise.

    • LINEAR

      public static final Interpolator LINEAR
      Built-in interpolator that provides linear time interpolation. The return value of interpolate() is startValue + (endValue - startValue) * fraction.

    • EASE_BOTH

      public static final Interpolator EASE_BOTH
      Built-in interpolator instance that provides ease in/out behavior.

      An ease-both interpolator will make an animation start slow, then accelerate and slow down again towards the end, all in a smooth manner.

      The implementation uses the algorithm for easing defined in SMIL 3.0 with an acceleration and deceleration factor of 0.2, respectively.

    • EASE_IN

      public static final Interpolator EASE_IN
      Built-in interpolator instance that provides ease in behavior.

      An ease-in interpolator will make an animation start slow and then accelerate smoothly.

      The implementation uses the algorithm for easing defined in SMIL 3.0 with an acceleration factor of 0.2.

    • EASE_OUT

      public static final Interpolator EASE_OUT
      Built-in interpolator instance that provides ease out behavior.

      An ease-out interpolator will make an animation slow down toward the end smoothly.

      The implementation uses the algorithm for easing defined in SMIL 3.0 with an deceleration factor of 0.2.

  • Constructor Details

    • Interpolator

      protected Interpolator()
      The constructor of Interpolator.

  • Method Details

    • SPLINE

      public static Interpolator SPLINE​(double x1, double y1, double x2, double y2)
      Creates an Interpolator, which curve() is shaped using the spline control points defined by (x1, y1 ) and (x2, y2). The anchor points of the spline are implicitly defined as (0.0, 0.0) and (1.0, 1.0).
      Parameters:
      x1 - x coordinate of the first control point
      y1 - y coordinate of the first control point
      x2 - x coordinate of the second control point
      y2 - y coordinate of the second control point
      Returns:
      A spline interpolator

    • TANGENT

      public static Interpolator TANGENT​(Duration t1, double v1, Duration t2, double v2)
      Create a tangent interpolator. A tangent interpolator allows to define the behavior of an animation curve very precisely by defining the tangents close to a key frame. A tangent interpolator defines the behavior to the left and to the right of a key frame, therefore it is only useful within a Timeline. If used in a KeyFrame after a KeyFrame that has different interpolator, it's treated as if the out-tangent of that KeyFrame was equal to the value in the KeyFrame.

      A tangent interpolator defines the behavior to the left and to the right of a key frame, therefore it is only useful within a Timeline

      The parameters define the tangent of the animation curve for the in tangent (before a key frame) and out tangent (after a key frame). Each tangent is specified with a pair, the distance to the key frame and the value of the tangent at this moment.

      The interpolation then follows a bezier curve, with 2 control points defined by the specified tangent and positioned at 1/3 of the duration before the second KeyFrame or after the first KeyFrame. See the picture above.

      Parameters:
      t1 - The delta time of the in-tangent, relative to the KeyFrame
      v1 - The value of the in-tangent
      t2 - The delta time of the out-tangent, relative to the KeyFrame
      v2 - The value of the out-tangent
      Returns:
      the new tangent interpolator

    • TANGENT

      public static Interpolator TANGENT​(Duration t, double v)
      Creates a tangent interpolator, for which in-tangent and out-tangent are identical. This is especially useful for the first and the last key frame of a Timeline, because for these key frames only one tangent is used.
      Parameters:
      t - The delta time of the tangent
      v - The value of the tangent
      Returns:
      the new Tangent interpolator
      See Also:
      TANGENT(Duration, double, Duration, double)

    • interpolate

      public Object interpolate​(Object startValue, Object endValue, double fraction)
      This method takes two Objects along with a fraction between 0.0 and 1.0 and returns the interpolated value.

      If both Objects implement Number, their values are interpolated. If startValue implements Interpolatable the calculation defined in interpolate() is used. If neither of these conditions are met, a discrete interpolation is used, i.e. endValue is returned if and only if fraction is 1.0, otherwise startValue is returned.

      Before calculating the interpolated value, the fraction is altered according to the function defined in curve().

      Parameters:
      startValue - start value
      endValue - end value
      fraction - a value between 0.0 and 1.0
      Returns:
      interpolated value

    • interpolate

      public boolean interpolate​(boolean startValue, boolean endValue, double fraction)
      This method takes two boolean values along with a fraction between 0.0 and 1.0 and returns the interpolated value.

      Before calculating the interpolated value, the fraction is altered according to the function defined in curve().

      Parameters:
      startValue - the first data point
      endValue - the second data point
      fraction - the fraction in [0.0...1.0]
      Returns:
      the interpolated value

    • interpolate

      public double interpolate​(double startValue, double endValue, double fraction)
      This method takes two double values along with a fraction between 0.0 and 1.0 and returns the interpolated value.

      Before calculating the interpolated value, the fraction is altered according to the function defined in curve().

      Parameters:
      startValue - the first data point
      endValue - the second data point
      fraction - the fraction in [0.0...1.0]
      Returns:
      the interpolated value

    • interpolate

      public int interpolate​(int startValue, int endValue, double fraction)
      This method takes two int values along with a fraction between 0.0 and 1.0 and returns the interpolated value.

      Before calculating the interpolated value, the fraction is altered according to the function defined in curve().

      Parameters:
      startValue - the first data point
      endValue - the second data point
      fraction - the fraction in [0.0...1.0]
      Returns:
      the interpolated value

    • interpolate

      public long interpolate​(long startValue, long endValue, double fraction)
      This method takes two int values along with a fraction between 0.0 and 1.0 and returns the interpolated value.

      Before calculating the interpolated value, the fraction is altered according to the function defined in curve().

      Parameters:
      startValue - the first data point
      endValue - the second data point
      fraction - the fraction in [0.0...1.0]
      Returns:
      the interpolated value

    • curve

      protected abstract double curve​(double t)
      Mapping from [0.0..1.0] to itself.
      Parameters:
      t - time, but normalized to the range [0.0..1.0], where 0.0 is the start of the current interval, while 1.0 is the end of the current interval. Usually a function that increases monotonically.
      Returns:
      the curved value