signalprocesser.voronoi.eventqueue.VSiteEvent Maven / Gradle / Ivy
/*
* "Concave" hulls by Glenn Hudson and Matt Duckham
*
* Source code downloaded from https://archive.md/l3Un5#selection-571.0-587.218 on 3rd November 2021.
*
* - This software is Copyright (C) 2008 Glenn Hudson released under Gnu Public License (GPL). Under
* GPL you are free to use, modify, and redistribute the software. Please acknowledge Glenn Hudson
* and Matt Duckham as the source of this software if you do use or adapt the code in further research
* or other work. For full details of GPL see http://www.gnu.org/licenses/gpl-3.0.txt.
* - This software comes with no warranty of any kind, expressed or implied.
*
* A paper with full details of the characteristic hulls algorithm is published in Pattern Recognition.
* Duckham, M., Kulik, L., Worboys, M.F., Galton, A. (2008) Efficient generation of simple polygons for
* characterizing the shape of a set of points in the plane. Pattern Recognition v41, 3224-3236
*
* The software was developed by Glenn Hudson while working with me as an RA. The characteristic shapes
* algorithm is collaborative work between Matt Duckham, Lars Kulik, Antony Galton, and Mike Worboys.
*
*/
package signalprocesser.voronoi.eventqueue;
import signalprocesser.voronoi.VPoint;
public class VSiteEvent extends VEvent {
/* ***************************************************** */
// Variables
private VPoint point;
public double a;
public double b;
public double c;
/* ***************************************************** */
// Constructors
public VSiteEvent(VPoint _point) {
if ( _point==null ) {
throw new IllegalArgumentException("Point for siteevent cannot be null");
}
this.point = _point;
}
/* ***************************************************** */
// Methods
public void calcParabolaConstants(double sweepline) {
double yminussweepline = ( point.y - sweepline );
a = 0.5 / yminussweepline;
b = -1.0 * point.x / yminussweepline;
c = (point.x * point.x) / (2.0 * yminussweepline) + 0.5 * yminussweepline;
}
public int getYValueOfParabola(int x) {
return (int) (( a * (double)x + b ) * (double)x + c);
}
public int getYValueOfParabola(double x) {
return (int) (( a * x + b ) * x + c);
}
/* ***************************************************** */
// Abstract Methods
public int getX() { return point.x; }
public int getY() { return point.y; }
public VPoint getPoint() { return point; }
public boolean isSiteEvent() { return true; }
public boolean isCircleEvent() { return false; }
/* ***************************************************** */
// To String Method
public String toString() {
return "VSiteEvent (" + point.x + "," + point.y + ")";
}
/* ***************************************************** */
}