/*
* GeoTools - The Open Source Java GIS Toolkit
* http://geotools.org
*
* (C) 2006-2008, Open Source Geospatial Foundation (OSGeo)
*
* 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;
* version 2.1 of the License.
*
* 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.
*/
package org.geotools.graph.util.delaunay;
import java.awt.geom.Line2D;
import java.awt.geom.Point2D;
import org.geotools.graph.structure.Edge;
import org.geotools.graph.structure.Node;
import org.geotools.graph.structure.line.XYNode;
import com.vividsolutions.jts.geom.Coordinate;
import com.vividsolutions.jts.geom.GeometryFactory;
import com.vividsolutions.jts.geom.LinearRing;
import com.vividsolutions.jts.geom.Point;
import com.vividsolutions.jts.geom.Polygon;
/**
*
* @author jfc173
*
*
* @source $URL$
*/
public class Triangle {
Edge edge1, edge2, edge3;
Node node1, node2, node3;
GeometryFactory fact = new GeometryFactory();
public final static int OUTSIDE = 0;
public final static int INSIDE = 1;
public final static int ON_EDGE = 2;
private final static double TOLERANCE = 0.0001;
/** Creates a new instance of Triangle */
public Triangle(Edge e1, Edge e2, Edge e3) {
Node n1a = e1.getNodeA();
Node n1b = e1.getNodeB();
Node n2a = e2.getNodeA();
Node n2b = e2.getNodeB();
Node n3a = e3.getNodeA();
Node n3b = e3.getNodeB();
Node temp1, temp2, temp3;
if (n1a.equals(n2a)){
temp1 = n1a; //==n2a
temp2 = n1b;
temp3 = n2b;
if (n3a.equals(temp2)){
if (n3b.equals(temp3)){
assign(e1, e2, e3, temp1, temp2, temp3);
} else {
whinge(e1, e2, e3);
}
} else if (n3a.equals(temp3)){
if (n3b.equals(temp2)){
assign(e1, e2, e3, temp1, temp2, temp3);
} else {
whinge(e1, e2, e3);
}
} else {
whinge(e1, e2, e3);
}
} else if (n1a.equals(n2b)){
temp1 = n1a; //==n2b
temp2 = n1b;
temp3 = n2a;
if (n3a.equals(temp2)){
if (n3b.equals(temp3)){
assign(e1, e2, e3, temp1, temp2, temp3);
} else {
whinge(e1, e2, e3);
}
} else if (n3a.equals(temp3)){
if (n3b.equals(temp2)){
assign(e1, e2, e3, temp1, temp2, temp3);
} else {
whinge(e1, e2, e3);
}
} else {
whinge(e1, e2, e3);
}
} else if (n1b.equals(n2a)){
temp1 = n1a;
temp2 = n1b; //==n2a
temp3 = n2b;
if (n3a.equals(temp1)){
if (n3b.equals(temp3)){
assign(e1, e2, e3, temp1, temp2, temp3);
} else {
whinge(e1, e2, e3);
}
} else if (n3a.equals(temp3)){
if (n3b.equals(temp1)){
assign(e1, e2, e3, temp1, temp2, temp3);
} else {
whinge(e1, e2, e3);
}
} else {
whinge(e1, e2, e3);
}
} else if (n1b.equals(n2b)){
temp1 = n1a;
temp2 = n1b; //==n2b
temp3 = n2a;
if (n3a.equals(temp1)){
if (n3b.equals(temp3)){
assign(e1, e2, e3, temp1, temp2, temp3);
} else {
whinge(e1, e2, e3);
}
} else if (n3a.equals(temp3)){
if (n3b.equals(temp1)){
assign(e1, e2, e3, temp1, temp2, temp3);
} else {
whinge(e1, e2, e3);
}
} else {
whinge(e1, e2, e3);
}
} else {
whinge(e1, e2, e3);
}
}
private void assign(Edge e1, Edge e2, Edge e3, Node n1, Node n2, Node n3){
edge1 = e1;
edge2 = e2;
edge3 = e3;
node1 = n1;
node2 = n2;
node3 = n3;
}
private void whinge(Edge e1, Edge e2, Edge e3){
throw new RuntimeException("You didn't give me a proper triangle. " + e1 + ", " + e2 + ", " + e3);
}
public int relate(XYNode n){
int ret;
if ((!(node1 instanceof XYNode)) ||
(!(node2 instanceof XYNode)) ||
(!(node3 instanceof XYNode))){
throw new RuntimeException("I can't perform a relate function on a non-spatial triangle");
}
LinearRing lr = fact.createLinearRing(new Coordinate[]{((XYNode)node1).getCoordinate(), ((XYNode)node2).getCoordinate(), ((XYNode)node3).getCoordinate(), ((XYNode)node1).getCoordinate()});
Polygon poly = fact.createPolygon(lr, null);
Point nPoint = fact.createPoint(n.getCoordinate());
Line2D.Double line12 = new Line2D.Double(((XYNode)node1).getCoordinate().x, ((XYNode)node1).getCoordinate().y, ((XYNode)node2).getCoordinate().x, ((XYNode)node2).getCoordinate().y);
Line2D.Double line13 = new Line2D.Double(((XYNode)node1).getCoordinate().x, ((XYNode)node1).getCoordinate().y, ((XYNode)node3).getCoordinate().x, ((XYNode)node3).getCoordinate().y);
Line2D.Double line23 = new Line2D.Double(((XYNode)node2).getCoordinate().x, ((XYNode)node2).getCoordinate().y, ((XYNode)node3).getCoordinate().x, ((XYNode)node3).getCoordinate().y);
Point2D.Double point2D = new Point2D.Double(n.getCoordinate().x, n.getCoordinate().y);
if ((line12.ptSegDist(point2D) <= TOLERANCE) ||
(line13.ptSegDist(point2D) <= TOLERANCE) ||
(line23.ptSegDist(point2D) <= TOLERANCE)){
ret = ON_EDGE;
} else if (poly.contains(nPoint)){
ret = INSIDE;
} else {
ret = OUTSIDE;
}
return ret;
}
public Edge getBoundaryEdge(XYNode n){
if (!(relate(n) == ON_EDGE)){
throw new RuntimeException("Can't get the boundary edge for a point that isn't on an edge.");
}
Point2D.Double point = new Point2D.Double(n.getCoordinate().x, n.getCoordinate().y);
Line2D.Double line1 = new Line2D.Double(((XYNode) edge1.getNodeA()).getCoordinate().x, ((XYNode) edge1.getNodeA()).getCoordinate().y,
((XYNode) edge1.getNodeB()).getCoordinate().x, ((XYNode) edge1.getNodeB()).getCoordinate().y);
Line2D.Double line2 = new Line2D.Double(((XYNode) edge2.getNodeA()).getCoordinate().x, ((XYNode) edge2.getNodeA()).getCoordinate().y,
((XYNode) edge2.getNodeB()).getCoordinate().x, ((XYNode) edge2.getNodeB()).getCoordinate().y);
Line2D.Double line3 = new Line2D.Double(((XYNode) edge3.getNodeA()).getCoordinate().x, ((XYNode) edge3.getNodeA()).getCoordinate().y,
((XYNode) edge3.getNodeB()).getCoordinate().x, ((XYNode) edge3.getNodeB()).getCoordinate().y);
Edge ret = null;
if (line1.ptSegDist(point) <= TOLERANCE){
ret = edge1;
} else if (line2.ptSegDist(point) <= TOLERANCE){
ret = edge2;
} else if (line3.ptSegDist(point) <= TOLERANCE){
ret = edge3;
} else {
throw new RuntimeException("So... node " + n + " is on an edge of " + this.toString() + " but isn't on any of its edges: " + edge1 + ", " + edge2 + ", or " + edge3);
}
return ret;
}
public Node getThirdNode(Edge e){
if (e.getNodeA().equals(node1)){
if (e.getNodeB().equals(node2)){
return node3;
} else if (e.getNodeB().equals(node3)){
return node2;
} else {
throw new RuntimeException("Edge e must be in this triangle for Triangle.getThirdNode to work!");
}
} else if (e.getNodeA().equals(node2)){
if(e.getNodeB().equals(node1)){
return node3;
} else if (e.getNodeB().equals(node3)){
return node1;
} else {
throw new RuntimeException("Edge e must be in this triangle for Triangle.getThirdNode to work!");
}
} else if (e.getNodeA().equals(node3)){
if (e.getNodeB().equals(node2)){
return node1;
} else if (e.getNodeB().equals(node1)){
return node2;
} else {
throw new RuntimeException("Edge e must be in this triangle for Triangle.getThirdNode to work!");
}
} else {
throw new RuntimeException("Edge " + e + " must be in this triangle " + this.toString() + " for Triangle.getThirdNode to work!");
}
}
public Edge getOppositeEdge(Node n){
if ((edge1.getNodeA().equals(n) || (edge1.getNodeB().equals(n)))){
if ((edge2.getNodeA().equals(n) || (edge2.getNodeB().equals(n)))){
return edge3;
} else if ((edge3.getNodeA().equals(n) || (edge3.getNodeB().equals(n)))){
return edge2;
} else {
throw new RuntimeException("Node n must be in this triangle for Triangle.getOppositeEdge to work!");
}
} else if ((edge2.getNodeA().equals(n) || (edge2.getNodeB().equals(n)))){
if ((edge3.getNodeA().equals(n) || (edge3.getNodeB().equals(n)))){
return edge1;
} else {
throw new RuntimeException("Node n must be in this triangle for Triangle.getOppositeEdge to work!");
}
} else {
throw new RuntimeException("Node n must be in this triangle for Triangle.getOppositeEdge to work!");
}
}
public Edge getSharedEdge(Triangle t){
Edge[] tEdges = t.getEdges();
Edge shared = null;
for (int i = 0; i < 3; i++){
if (tEdges[i].equals(edge1)){
shared = edge1;
} else if (tEdges[i].equals(edge2)){
shared = edge2;
} else if (tEdges[i].equals(edge3)){
shared = edge3;
}
}
return shared;
}
public Edge[] getEdges(){
return new Edge[]{edge1, edge2, edge3};
}
public Node[] getNodes(){
return new Node[]{node1, node2, node3};
}
public double getArea(){
if ((node1 instanceof XYNode) ||
(node2 instanceof XYNode) ||
(node3 instanceof XYNode)){
double x1 = ((XYNode) node1).getCoordinate().x;
double y1 = ((XYNode) node1).getCoordinate().y;
double x2 = ((XYNode) node2).getCoordinate().x;
double y2 = ((XYNode) node2).getCoordinate().y;
double x3 = ((XYNode) node3).getCoordinate().x;
double y3 = ((XYNode) node3).getCoordinate().y;
double length1_2 = Math.sqrt((x1-x2)*(x1-x2) + (y1-y2)*(y1-y2));
double length1_3 = Math.sqrt((x1-x3)*(x1-x3) + (y1-y3)*(y1-y3));
double length2_3 = Math.sqrt((x2-x3)*(x2-x3) + (y2-y3)*(y2-y3));
double s = (length1_2 + length1_3 + length2_3)/2;
return Math.sqrt((s) * (s - length1_2) * (s - length1_3) * (s - length2_3));
} else {
throw new RuntimeException("I can't calculate the area if the triangle doesn't have XY coordinates.");
}
}
public boolean containsEdge(Edge e){
return ((edge1.equals(e)) || (edge2.equals(e)) || (edge3.equals(e)));
}
public boolean equals(Object o){
boolean ret;
if (o instanceof Triangle){
ret = ((this.containsEdge(((Triangle) o).getEdges()[0])) &&
(this.containsEdge(((Triangle) o).getEdges()[1])) &&
(this.containsEdge(((Triangle) o).getEdges()[2])));
} else {
ret = false;
}
return ret;
}
public String toString(){
return ("{" + node1.toString() + ", " + node2.toString() + ", " + node3.toString() + "}");
}
}