If there is any method or class who can do the job. So, I want to know if I don't miss something.
______________________________________________________________--------------------------------------------------------------------------------------------------------------------------------------------- -----Original Message----- From: jts-devel-boun...@lists.jump-project.org [mailto:jts-devel-boun...@lists.jump-project.org] On Behalf Of Martin Davis Sent: donderdag 5 november 2009 17:54 To: JTS Topology Suite Development Subject: Re: [jts-devel] Extend a LineString in a Polygon Minze, What do you mean by "still curious about the API support"? Tolsma, Minze wrote: > This Works fine for me. I'm still curious about the API support. :-) > > Thanks! > > Minze > > -----Original Message----- > From: jts-devel-boun...@lists.jump-project.org > [mailto:jts-devel-boun...@lists.jump-project.org] On Behalf Of Michael Bedward > Sent: donderdag 5 november 2009 1:56 > To: JTS Topology Suite Development > Subject: Re: [jts-devel] Extend a LineString in a Polygon > > Below is one way of doing it. I can almost guarantee there will be a > much better way :) > > Michael > > > import com.vividsolutions.jts.geom.Coordinate; > import com.vividsolutions.jts.geom.Geometry; > import com.vividsolutions.jts.geom.GeometryFactory; > import com.vividsolutions.jts.geom.LineString; > import com.vividsolutions.jts.geom.Point; > import com.vividsolutions.jts.io.WKTReader; > > public class Foo { > > public static void main(String[] args) throws Exception { > GeometryFactory gf = new GeometryFactory(); > > WKTReader reader = new WKTReader(gf); > > Geometry poly = reader.read("POLYGON((0 0, 0 10, 10 10, 10 0, 0 0))"); > // a line inside the square > LineString line = (LineString) reader.read("LINESTRING(4 4, 6 5)"); > > if (!line.intersects(poly)) { > System.out.println("line does not intersect polygon"); > return; > } > > Coordinate[] coords = line.getCoordinates(); > final int END = coords.length - 1; > > // extend start point beyond poly > Coordinate newStart = new Coordinate(coords[0]); > Point testP = gf.createPoint(newStart); > while (poly.contains(testP)) { > newStart.x += newStart.x - coords[1].x; > newStart.y += newStart.y - coords[1].y; > testP = gf.createPoint(newStart); > } > > // extend end point beyond poly > Coordinate newEnd = new Coordinate(coords[END]); > testP = gf.createPoint(newEnd); > while (poly.contains(testP)) { > newEnd.x += newEnd.x - coords[END-1].x; > newEnd.y += newEnd.y - coords[END-1].y; > testP = gf.createPoint(newEnd); > } > > LineString extended = gf.createLineString(new > Coordinate[]{newStart, newEnd}); > System.out.println("extended line: " + extended); > System.out.println("crosses polygon: " + extended.crosses(poly)); > } > > } > _______________________________________________ > jts-devel mailing list > jts-devel@lists.jump-project.org > http://lists.refractions.net/mailman/listinfo/jts-devel > > > > > > > This message contains information that may be privileged or confidential and > is the property of the Capgemini Group. It is > intended only for the person to whom it is addressed. If you are not the > intended recipient, you are not authorized to > read, print, retain, copy, disseminate, distribute, or use this message or > any part thereof. If you receive this message > in error, please notify the sender immediately and delete all copies of this > message. > > _______________________________________________ > jts-devel mailing list > jts-devel@lists.jump-project.org > http://lists.refractions.net/mailman/listinfo/jts-devel > > -- Martin Davis Senior Technical Architect Refractions Research, Inc. (250) 383-3022 _______________________________________________ jts-devel mailing list jts-devel@lists.jump-project.org http://lists.refractions.net/mailman/listinfo/jts-devel This message contains information that may be privileged or confidential and is the property of the Capgemini Group. It is intended only for the person to whom it is addressed. If you are not the intended recipient, you are not authorized to read, print, retain, copy, disseminate, distribute, or use this message or any part thereof. If you receive this message in error, please notify the sender immediately and delete all copies of this message. _______________________________________________ jts-devel mailing list jts-devel@lists.jump-project.org http://lists.refractions.net/mailman/listinfo/jts-devel
