org.jgrasstools.gears.utils.math.interpolation.splines.ControlCurve Maven / Gradle / Ivy
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/*
* JGrass - Free Open Source Java GIS http://www.jgrass.org
* (C) HydroloGIS - www.hydrologis.com
*
* This library is free software; you can redistribute it and/or modify it under
* the terms of the GNU Library General Public License as published by the Free
* Software Foundation; either version 2 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 Library General Public License for more
* details.
*
* You should have received a copy of the GNU Library General Public License
* along with this library; if not, write to the Free Foundation, Inc., 59
* Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
package org.jgrasstools.gears.utils.math.interpolation.splines;
import java.util.ArrayList;
import java.util.List;
import com.vividsolutions.jts.geom.Coordinate;
/**
* This class represents a curve defined by a sequence of control points
*
* @author Tim Lambert (http://www.cse.unsw.edu.au/~lambert/)
* @author Andrea Antonello (www.hydrologis.com)
*/
public abstract class ControlCurve {
public static final int EPSILON = 36; /* square of distance for picking */
protected List pts;
protected int selection = -1;
public ControlCurve() {
pts = new ArrayList();
}
/**
* return index of control point near to (x,y) or -1 if nothing near
*/
public int selectPoint( double x, double y ) {
double mind = Double.POSITIVE_INFINITY;
selection = -1;
for( int i = 0; i < pts.size(); i++ ) {
Coordinate coordinate = pts.get(i);
double d = sqr(coordinate.x - x) + sqr(coordinate.y - y);
if (d < mind && d < EPSILON) {
mind = d;
selection = i;
}
}
return selection;
}
static double sqr( double x ) {
return x * x;
}
/** add a control point, return index of new control point */
public double addPoint( double x, double y ) {
pts.add(new Coordinate(x, y));
return selection = pts.size() - 1;
}
/** set selected control point */
public void setPoint( double x, double y ) {
if (selection >= 0) {
Coordinate coordinate = new Coordinate(x, y);
pts.set(selection, coordinate);
}
}
/** remove selected control point */
public void removePoint() {
if (selection >= 0) {
pts.remove(selection);
// pts.npoints--;
// for( int i = selection; i < pts.npoints; i++ ) {
// pts.xpoints[i] = pts.xpoints[i + 1];
// pts.ypoints[i] = pts.ypoints[i + 1];
// }
}
}
public abstract List getInterpolated();
public String toString() {
StringBuffer result = new StringBuffer();
for( int i = 0; i < pts.size(); i++ ) {
result.append(" " + pts.get(i));
}
return result.toString();
}
}