org.jaitools.jts
Class AbstractSmoother

java.lang.Object
  org.jaitools.jts.AbstractSmoother

Direct Known Subclasses:

LineSmoother, PolygonSmoother

public abstract class AbstractSmoother
extends Object

Base class for Bezier smoothing of JTS Geometry objects.

Since:

1.1

Version:

$Id$

Author:

Michael Bedward

Nested Class Summary

protected static class

AbstractSmoother.InterpPoint Class to hold interpolation parameters for a given point.

Field Summary

protected SmootherControl	control The current SmootherControl instance.
static SmootherControl	DEFAULT_CONTROL Default smoothing control.
protected com.vividsolutions.jts.geom.GeometryFactory	geomFactory The current GeometryFactory being used.
protected Map<Integer,WeakReference<AbstractSmoother.InterpPoint[]>>	lookup Cache of previously calculated interpolation parameters

Constructor Summary

AbstractSmoother(com.vividsolutions.jts.geom.GeometryFactory geomFactory)
Creates a new smoother that will use the given GeometryFactory.

Method Summary

protected com.vividsolutions.jts.geom.Coordinate[]	cubicBezier(com.vividsolutions.jts.geom.Coordinate start, com.vividsolutions.jts.geom.Coordinate end, com.vividsolutions.jts.geom.Coordinate ctrl1, com.vividsolutions.jts.geom.Coordinate ctrl2, int nv) Calculates vertices along a cubic Bazier curve given start point, end point and two control points.
protected AbstractSmoother.InterpPoint[]	getInterpPoints(int npoints) Gets the interpolation parameters for a Bezier curve approximated by the given number of vertices.
void	setControl(SmootherControl control) Sets a new Control object to for smoothing.

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_CONTROL

public static final SmootherControl DEFAULT_CONTROL

Default smoothing control. Specifies no minimum vertex distance and a constant number of points per smoothed segment.

control

protected SmootherControl control

The current SmootherControl instance.

geomFactory

protected final com.vividsolutions.jts.geom.GeometryFactory geomFactory

The current GeometryFactory being used.

lookup

protected Map<Integer,WeakReference<AbstractSmoother.InterpPoint[]>> lookup

Cache of previously calculated interpolation parameters

Constructor Detail

AbstractSmoother

public AbstractSmoother(com.vividsolutions.jts.geom.GeometryFactory geomFactory)

Creates a new smoother that will use the given GeometryFactory.

Parameters:

geomFactory - factory to use for creating smoothed objects

Throws:

IllegalArgumentException - if geomFactory is null

Method Detail

setControl

public void setControl(SmootherControl control)

Sets a new Control object to for smoothing.

Parameters:

control - the control to use for smoothing; if null the default control will be set

cubicBezier

protected com.vividsolutions.jts.geom.Coordinate[] cubicBezier(com.vividsolutions.jts.geom.Coordinate start,
                                                               com.vividsolutions.jts.geom.Coordinate end,
                                                               com.vividsolutions.jts.geom.Coordinate ctrl1,
                                                               com.vividsolutions.jts.geom.Coordinate ctrl2,
                                                               int nv)

Calculates vertices along a cubic Bazier curve given start point, end point and two control points.

Parameters:

start - start position

end - end position

ctrl1 - first control point

ctrl2 - second control point

nv - number of vertices including the start and end points

Returns:

vertices along the Bezier curve

getInterpPoints

protected AbstractSmoother.InterpPoint[] getInterpPoints(int npoints)

Gets the interpolation parameters for a Bezier curve approximated by the given number of vertices.

Parameters:

npoints - number of vertices

Returns:

array of InterpPoint objects holding the parameter values