GeometricShapeBuilder.java

/*
* The JTS Topology Suite is a collection of Java classes that
* implement the fundamental operations required to validate a given
* geo-spatial data set to a known topological specification.
*
* Copyright (C) 2001 Vivid Solutions
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*
* For more information, contact:
*
*     Vivid Solutions
*     Suite #1A
*     2328 Government Street
*     Victoria BC  V8T 5G5
*     Canada
*
*     (250)385-6040
*     www.vividsolutions.com
*/

package com.vividsolutions.jts.shape;

import com.vividsolutions.jts.geom.*;

public abstract class GeometricShapeBuilder 
{
	protected Envelope extent = new Envelope(0, 1, 0, 1);
	protected int numPts = 0;
	protected GeometryFactory geomFactory;
	
	public GeometricShapeBuilder(GeometryFactory geomFactory)
	{
		this.geomFactory = geomFactory;
	}
	
	public void setExtent(Envelope extent)
	{
		this.extent = extent;
	}
	
	public Envelope getExtent()
	{
		return extent;
	}
	
	public Coordinate getCentre()
	{
		return extent.centre();
	}
	
	public double getDiameter()
	{
		return Math.min(extent.getHeight(), extent.getWidth());
	}
	
	public double getRadius()
	{
		return getDiameter() / 2;
	}
	
	public LineSegment getSquareBaseLine()
	{
		double radius = getRadius();
		
		Coordinate centre = getCentre();
		Coordinate p0 = new Coordinate(centre.x - radius, centre.y - radius);
		Coordinate p1 = new Coordinate(centre.x + radius, centre.y - radius);
		return new LineSegment(p0, p1);
	}
	
	public Envelope getSquareExtent()
	{
		double radius = getRadius();
		
		Coordinate centre = getCentre();
		return new Envelope(centre.x - radius, centre.x + radius,
				centre.y - radius, centre.y + radius);
	}
	

  /**
   * Sets the total number of points in the created {@link Geometry}.
   * The created geometry will have no more than this number of points,
   * unless more are needed to create a valid geometry.
   */
  public void setNumPoints(int numPts) { this.numPts = numPts; }

  public abstract Geometry getGeometry();

  protected Coordinate createCoord(double x, double y)
  {
  	Coordinate pt = new Coordinate(x, y);
  	geomFactory.getPrecisionModel().makePrecise(pt);
    return pt;
  }
  

}