/*
* __ .__ .__ ._____.
* _/ |_ _______ __|__| ____ | | |__\_ |__ ______
* \ __\/ _ \ \/ / |/ ___\| | | || __ \ / ___/
* | | ( <_> > <| \ \___| |_| || \_\ \\___ \
* |__| \____/__/\_ \__|\___ >____/__||___ /____ >
* \/ \/ \/ \/
*
* Copyright (c) 2006-2011 Karsten Schmidt
*
* 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.
*
* http://creativecommons.org/licenses/LGPL/2.1/
*
* 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
*/
package spimedb.util.geom;
/**
* This class handles Circle-Ray2D intersections by implementing the
* {@link Intersector2D} interface.
*
*/
public class CircleIntersector implements Intersector2D {
private final IsectData2D isec = new IsectData2D();
private Circle circle;
public CircleIntersector(Circle circle) {
this.circle = circle;
}
public Circle getCircle() {
return circle;
}
public IsectData2D getIntersectionData() {
return isec;
}
public boolean intersectsRay(Ray2D ray) {
isec.clear();
Vec2D q = circle.sub(ray);
float distSquared = q.magSquared();
float v = q.dot(ray.getDirection());
float r = circle.getRadius();
float d = r * r - (distSquared - v * v);
if (d >= 0.0) {
isec.isIntersection = true;
isec.dist = v - (float) Math.sqrt(d);
isec.pos = ray.getPointAtDistance(isec.dist);
isec.normal = isec.pos.sub(circle).normalize();
}
return isec.isIntersection;
}
public void setCircle(Circle circle) {
this.circle = circle;
}
}