/*
* 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.geomgraph;
import com.vividsolutions.jts.geomgraph.Position;
import com.vividsolutions.jts.geom.Location;
/**
* A TopologyLocation is the labelling of a
* GraphComponent's topological relationship to a single Geometry.
* <p>
* If the parent component is an area edge, each side and the edge itself
* have a topological location. These locations are named
* <ul>
* <li> ON: on the edge
* <li> LEFT: left-hand side of the edge
* <li> RIGHT: right-hand side
* </ul>
* If the parent component is a line edge or node, there is a single
* topological relationship attribute, ON.
* <p>
* The possible values of a topological location are
* {Location.NONE, Location.EXTERIOR, Location.BOUNDARY, Location.INTERIOR}
* <p>
* The labelling is stored in an array location[j] where
* where j has the values ON, LEFT, RIGHT
* @version 1.7
*/
public class TopologyLocation {
int location[];
public TopologyLocation(int[] location)
{
init(location.length);
}
/**
* Constructs a TopologyLocation specifying how points on, to the left of, and to the
* right of some GraphComponent relate to some Geometry. Possible values for the
* parameters are Location.NULL, Location.EXTERIOR, Location.BOUNDARY,
* and Location.INTERIOR.
* @see Location
*/
public TopologyLocation(int on, int left, int right) {
init(3);
location[Position.ON] = on;
location[Position.LEFT] = left;
location[Position.RIGHT] = right;
}
public TopologyLocation(int on) {
init(1);
location[Position.ON] = on;
}
public TopologyLocation(TopologyLocation gl) {
init(gl.location.length);
if (gl != null) {
for (int i = 0; i < location.length; i++) {
location[i] = gl.location[i];
}
}
}
private void init(int size)
{
location = new int[size];
setAllLocations(Location.NONE);
}
public int get(int posIndex)
{
if (posIndex < location.length) return location[posIndex];
return Location.NONE;
}
/**
* @return true if all locations are NULL
*/
public boolean isNull()
{
for (int i = 0; i < location.length; i++) {
if (location[i] != Location.NONE) return false;
}
return true;
}
/**
* @return true if any locations are NULL
*/
public boolean isAnyNull()
{
for (int i = 0; i < location.length; i++) {
if (location[i] == Location.NONE) return true;
}
return false;
}
public boolean isEqualOnSide(TopologyLocation le, int locIndex)
{
return location[locIndex] == le.location[locIndex];
}
public boolean isArea() { return location.length > 1; }
public boolean isLine() { return location.length == 1; }
public void flip()
{
if (location.length <= 1) return;
int temp = location[Position.LEFT];
location[Position.LEFT] = location[Position.RIGHT];
location[Position.RIGHT] = temp;
}
public void setAllLocations(int locValue)
{
for (int i = 0; i < location.length; i++) {
location[i] = locValue;
}
}
public void setAllLocationsIfNull(int locValue)
{
for (int i = 0; i < location.length; i++) {
if (location[i] == Location.NONE) location[i] = locValue;
}
}
public void setLocation(int locIndex, int locValue)
{
location[locIndex] = locValue;
}
public void setLocation(int locValue)
{
setLocation(Position.ON, locValue);
}
public int[] getLocations() { return location; }
public void setLocations(int on, int left, int right) {
location[Position.ON] = on;
location[Position.LEFT] = left;
location[Position.RIGHT] = right;
}
public boolean allPositionsEqual(int loc)
{
for (int i = 0; i < location.length; i++) {
if (location[i] != loc) return false;
}
return true;
}
/**
* merge updates only the NULL attributes of this object
* with the attributes of another.
*/
public void merge(TopologyLocation gl)
{
// if the src is an Area label & and the dest is not, increase the dest to be an Area
if (gl.location.length > location.length) {
int [] newLoc = new int[3];
newLoc[Position.ON] = location[Position.ON];
newLoc[Position.LEFT] = Location.NONE;
newLoc[Position.RIGHT] = Location.NONE;
location = newLoc;
}
for (int i = 0; i < location.length; i++) {
if (location[i] == Location.NONE && i < gl.location.length)
location[i] = gl.location[i];
}
}
public String toString()
{
StringBuffer buf = new StringBuffer();
if (location.length > 1) buf.append(Location.toLocationSymbol(location[Position.LEFT]));
buf.append(Location.toLocationSymbol(location[Position.ON]));
if (location.length > 1) buf.append(Location.toLocationSymbol(location[Position.RIGHT]));
return buf.toString();
}
}