/*---------------- FILE HEADER ------------------------------------------
This file is part of deegree.
Copyright (C) 2001-2006 by:
EXSE, Department of Geography, University of Bonn
http://www.giub.uni-bonn.de/deegree/
lat/lon GmbH
http://www.lat-lon.de
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
Contact:
Andreas Poth
lat/lon GmbH
Aennchenstr. 19
53177 Bonn
Germany
E-Mail: poth@lat-lon.de
Prof. Dr. Klaus Greve
Department of Geography
University of Bonn
Meckenheimer Allee 166
53115 Bonn
Germany
E-Mail: greve@giub.uni-bonn.de
---------------------------------------------------------------------------*/
package org.deegree.io.shpapi;
import java.util.ArrayList;
import org.deegree.model.crs.CoordinateSystem;
import org.deegree.model.spatialschema.Curve;
import org.deegree.model.spatialschema.CurveSegment;
import org.deegree.model.spatialschema.GeometryFactory;
import org.deegree.model.spatialschema.Point;
import org.deegree.model.spatialschema.Position;
import org.deegree.model.spatialschema.Surface;
import org.deegree.model.spatialschema.SurfaceInterpolation;
import org.deegree.model.spatialschema.SurfaceInterpolationImpl;
/**
* the class SHP2WKS transforms a polygon structure read from a shape-file<BR>
* into a WKSLinearPolygon specified by the sf-specifications<BR>
*
* @version $Revision: 1.11 $
* @author <a href="mailto:poth@lat-lon.de">Andreas Poth</a>
* @author last edited by: $Author: poth $
*
* @version 1.0. $Revision: 1.11 $, $Date: 2006/07/12 14:46:14 $
*
* @since 2.0
*/
public class SHP2WKS {
/**
* method: Point transformPoint(CS_CoordinateSystem srs,<BR>
* SHPPoint shppoint))<BR>
* transforms a SHPPoint to a WKSGeometry<BR>
* gets a point that should be transformed<BR>
*/
public Point transformPoint( CoordinateSystem crs, SHPPoint shppoint ) {
return GeometryFactory.createPoint( shppoint.x, shppoint.y, crs );
}
/**
* method: Point[] transformMultiPoint(CS_CoordinateSystem srs,<BR>
* SHPMultiPoint shpmultipoint))<BR>
* transforms a SHPMultiPoint to a WKSGeometry<BR>
* gets a multipoint that should be transformed<BR>
*/
public Point[] transformMultiPoint( CoordinateSystem srs, SHPMultiPoint shpmultipoint ) {
Point[] gm_points = new Point[shpmultipoint.numPoints];
for ( int i = 0; i < shpmultipoint.numPoints; i++ )
gm_points[i] = GeometryFactory.createPoint( shpmultipoint.points[i].x,
shpmultipoint.points[i].y, srs );
return gm_points;
}
/**
* method: Point[][] transformPolyLine(CS_CoordinateSystem srs,<BR>
* SHPPolyLine shppolyline))<BR>
* transforms a SHPPolyLine to a WKSGeometry<BR>
* gets a polyline that should be transformed<BR>
*/
public Curve[] transformPolyLine( CoordinateSystem crs, SHPPolyLine shppolyline ) {
Curve[] curve = new Curve[shppolyline.numParts];
try {
for ( int j = 0; j < shppolyline.numParts; j++ ) {
Position[] gm_points = new Position[shppolyline.points[j].length];
for ( int i = 0; i < shppolyline.points[j].length; i++ ) {
gm_points[i] = GeometryFactory.createPosition( shppolyline.points[j][i].x,
shppolyline.points[j][i].y );
}
CurveSegment cs = GeometryFactory.createCurveSegment( gm_points, crs );
curve[j] = GeometryFactory.createCurve( cs );
}
} catch ( Exception e ) {
e.printStackTrace();
}
return curve;
}
/**
* method: private boolean isInsideRing(Point[] ring, Point point)<BR>
* checks if a point is inside a polygon. the algorithm is taken from:<BR>
* http://www.ics.uci.edu/~eppstein/161/960307.html#intest<BR>
*/
private boolean isInsideRing( Position[] ring, Position point ) {
int crossings = 0;
for ( int i = 0; i < ring.length; i++ ) {
int z = i + 1;
if ( ( i + 1 ) >= ring.length ) {
z = 0;
}
//check if point.x is between x of vertex i and z of ring
if ( ( ring[i].getX() < point.getX() && point.getX() < ring[z].getX() )
|| ( ring[i].getX() > point.getX() && point.getX() > ring[z].getX() ) ) {
double t = ( point.getX() - ring[z].getX() ) / ( ring[i].getX() - ring[z].getX() );
double cy = ( t * ring[i].getY() ) + ( ( 1 - t ) * ring[z].getY() );
if ( point.getY() == cy ) { //point is on border of ring
return false;
} else if ( point.getY() > cy ) { //downwards vertical line through point crosses ring
crossings++;
}
}
//check if point.x equals x of vertex i of ring while point.y > ring[i].y
if ( ( ring[i].getX() == point.getX() ) && ( ring[i].getY() <= point.getY() ) ) {
if ( ring[i].getY() == point.getY() ) { //point is on border of ring
return false;
}
//find next point on ring with different x
// (adjacent points in shapefile can have equal x&y)
while ( ring[z].getX() == point.getX() ) {
if ( z == i ) {
return false;
}
z += 1;
if ( z == ring.length ) {
z = 0;
}
}
//find previous point on ring with different x
int zz = i - 1;
if ( zz < 0 ) {
zz = ring.length - 1;
}
while ( ring[zz].getX() == point.getX() ) {
if ( zz == i ) {
return false;
}
zz -= 1;
if ( zz < 0 ) {
zz = ring.length - 1;
}
}
//if point.x between previous and next x then crossing
if ( ring[z].getX() < point.getX() && point.getX() < ring[zz].getX()
|| ring[z].getX() > point.getX() && point.getX() > ring[zz].getX() ) {
crossings++;
}
}
}
if ( ( crossings % 2 ) != 0 ) {
return true;
}
return false;
}
/**
* transforms the SHPPolygon to a WKSGeometry<BR>
* gets the polygon that should be transformed<BR>
*/
public Surface[] transformPolygon( CoordinateSystem crs, SHPPolygon shppolygon ) {
ArrayList all_rings = new ArrayList( shppolygon.numRings );
ArrayList outer_rings = new ArrayList( shppolygon.numRings );
ArrayList inner_rings = new ArrayList( shppolygon.numRings );
for ( int i = 0; i < shppolygon.numRings; i++ ) {
Position[] ring = new Position[shppolygon.rings.points[i].length];
for ( int k = 0; k < shppolygon.rings.points[i].length; k++ ) {
ring[k] = GeometryFactory.createPosition( shppolygon.rings.points[i][k].x,
shppolygon.rings.points[i][k].y );
}
all_rings.add( ring );
}
// for every outer ring
for ( int i = 0; i < all_rings.size(); i++ ) {
Position[] out_ring = (Position[]) all_rings.get( i );
boolean inn = false;
for ( int j = 0; j < all_rings.size(); j++ ) {
if ( i == j )
continue;
Position[] inring = (Position[]) all_rings.get( j );
// check if one or more points of a inner ring are
// within the actual outer ring
try {
if ( isInsideRing( inring, out_ring[0] ) ) {
inn = true;
inner_rings.add( out_ring );
break;
}
} catch ( Exception e ) {
e.printStackTrace();
}
}
if ( !inn ) {
outer_rings.add( out_ring );
}
}
ArrayList wkslp = new ArrayList( outer_rings.size() );
SurfaceInterpolation si = new SurfaceInterpolationImpl();
for ( int i = 0; i < outer_rings.size(); i++ ) {
Position[] out_ring = (Position[]) outer_rings.get( i );
int count = inner_rings.size() - 1;
ArrayList list = new ArrayList( count + 2 );
// find inner rings of the current outter ring
for ( int k = count; k >= 0; k-- ) {
Position[] in_ring = (Position[]) inner_rings.get( k );
if ( isInsideRing( out_ring, in_ring[0] ) ) {
list.add( inner_rings.remove( k ) );
}
}
Position[][] inrings = (Position[][]) list.toArray( new Position[list.size()][] );
try {
Surface sur = GeometryFactory.createSurface( out_ring, inrings, si, crs );
wkslp.add( sur );
} catch ( Exception e ) {
e.printStackTrace();
}
}
return (Surface[]) wkslp.toArray( new Surface[wkslp.size()] );
}
}
/*
* Last changes:
* $Log: SHP2WKS.java,v $
* Revision 1.11 2006/07/12 14:46:14 poth
* comment footer added
*
* Revision 1.10 2006/06/25 08:01:03 poth
* fix for shapes having inner rings where all x-values are identical
*
* Revision 1.9 2006/06/05 15:21:53 poth
* support for polygonz type added
*
* Revision 1.8 2006/05/01 20:15:27 poth
* *** empty log message ***
*
* Revision 1.7 2006/04/06 20:25:23 poth
* *** empty log message ***
*
* Revision 1.6 2006/04/04 20:39:41 poth
* *** empty log message ***
*
* Revision 1.5 2006/03/30 21:20:24 poth
* *** empty log message ***
*
* Revision 1.4 2006/01/11 14:52:32 poth
* *** empty log message ***
*
* Revision 1.3 2005/12/06 13:45:20 poth
* System.out.println substituted by logging api
*
* Revision 1.2 2005/02/13 21:34:58 friebe
* fix javadoc errors
*
* 14.12.1999 ap: import clauses added<BR>
* 08.02.2000 ap: method transformPoint(..) declared and implemented<BR>
* 21.03.2000 ap: method: transformMultiPoint(..) declared and implemented<BR>
* 21.03.2000 ap: method: transformPolyLine(..) declared and implemented<BR>
*/
/* ********************************************************************
Changes to this class. What the people have been up to:
$Log: SHP2WKS.java,v $
Revision 1.11 2006/07/12 14:46:14 poth
comment footer added
********************************************************************** */