org.monte.media
Class SplineInterpolator

java.lang.Object
  org.monte.media.Interpolator
      org.monte.media.AbstractSplineInterpolator
          org.monte.media.SplineInterpolator

public class SplineInterpolator
extends AbstractSplineInterpolator

A spline interpolator for use in conjunction with an Animator object.

This class interpolates fractional values using Bezier splines. The anchor points for the spline are assumed to be (0, 0) and (1, 1). Control points should all be in the range [0, 1].

For more information on how splines are used to interpolate, refer to the SMIL specification at http://w3c.org.

http://www.w3.org/TR/smil/smil-animation.html#animationNS-InterpolationKeysplines

Version:

$Id: SplineInterpolator.java 156 2012-01-28 16:08:21Z werner $

Author:

Werner Randelshofer

Constructor Summary

SplineInterpolator(float x1, float y1, float x2, float y2)
Creates a new instance of SplineInterpolator with the control points defined by (x1, y1) and (x2, y2).

SplineInterpolator(float x1, float y1, float x2, float y2, boolean reverse, long timespan)
Creates a new instance of SplineInterpolator with the control points defined by (x1, y1) and (x2, y2).

SplineInterpolator(float x1, float y1, float x2, float y2, long timespan)
Creates a new instance of SplineInterpolator with the control points defined by (x1, y1) and (x2, y2).

Method Summary

java.awt.geom.Point2D.Float	getXY(float t, java.awt.geom.Point2D.Float p) Evaluates the spline function at curve parameter time t.
float	getY(float t) Evaluates the spline function at curve parameter time t.

Methods inherited from class org.monte.media.AbstractSplineInterpolator

getFraction, update, updateFractions

Methods inherited from class org.monte.media.Interpolator

finish, initialize, interpolate, isElapsed, isFinished, isSequential, replaces, setTimespan

Methods inherited from class java.lang.Object

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

Constructor Detail

SplineInterpolator

public SplineInterpolator(float x1,
                          float y1,
                          float x2,
                          float y2)

Creates a new instance of SplineInterpolator with the control points defined by (x1, y1) and (x2, y2). The anchor points are implicitly defined as (0, 0) and (1, 1).

The interpolator runs for one second.

Parameters:

x1 - The x coordinate for the first bezier control point.

y1 - The y coordinate for the first bezier control point.

x2 - The x coordinate for the second bezier control point.

y2 - The x coordinate for the second bezier control point.

Throws:

java.lang.IllegalArgumentException - This exception is thrown when values beyond the allowed [0,1] range are passed in

SplineInterpolator

public SplineInterpolator(float x1,
                          float y1,
                          float x2,
                          float y2,
                          long timespan)

Creates a new instance of SplineInterpolator with the control points defined by (x1, y1) and (x2, y2). The anchor points are implicitly defined as (0, 0) and (1, 1).

The interpolator runs for the specified time span.

Parameters:

x1 - The x coordinate for the first bezier control point.

y1 - The y coordinate for the first bezier control point.

x2 - The x coordinate for the second bezier control point.

y2 - The x coordinate for the second bezier control point.

timespan - The time span in milliseconds.

Throws:

java.lang.IllegalArgumentException - This exception is thrown when values beyond the allowed [0,1] range are passed in

SplineInterpolator

public SplineInterpolator(float x1,
                          float y1,
                          float x2,
                          float y2,
                          boolean reverse,
                          long timespan)

Creates a new instance of SplineInterpolator with the control points defined by (x1, y1) and (x2, y2). The anchor points are implicitly defined as (0, 0) and (1, 1).

The interpolator runs for the specified time span.

Parameters:

x1 - The x coordinate for the first bezier control point.

y1 - The y coordinate for the first bezier control point.

x2 - The x coordinate for the second bezier control point.

y2 - The x coordinate for the second bezier control point.

reverse - Run interpolator in the reverse direction.

timespan - The time span in milliseconds.

Throws:

java.lang.IllegalArgumentException - This exception is thrown when values beyond the allowed [0,1] range are passed in

Method Detail

getXY

public java.awt.geom.Point2D.Float getXY(float t,
                                         java.awt.geom.Point2D.Float p)

Evaluates the spline function at curve parameter time t.

Specified by:

getXY in class AbstractSplineInterpolator

getY

public float getY(float t)

Evaluates the spline function at curve parameter time t.

Specified by:

getY in class AbstractSplineInterpolator