001/* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017package org.apache.commons.math3.geometry.spherical.twod; 018 019import org.apache.commons.math3.geometry.euclidean.threed.Vector3D; 020import org.apache.commons.math3.geometry.partitioning.AbstractSubHyperplane; 021import org.apache.commons.math3.geometry.partitioning.Hyperplane; 022import org.apache.commons.math3.geometry.partitioning.Region; 023import org.apache.commons.math3.geometry.spherical.oned.Arc; 024import org.apache.commons.math3.geometry.spherical.oned.ArcsSet; 025import org.apache.commons.math3.geometry.spherical.oned.Sphere1D; 026import org.apache.commons.math3.util.FastMath; 027 028/** This class represents a sub-hyperplane for {@link Circle}. 029 * @since 3.3 030 */ 031public class SubCircle extends AbstractSubHyperplane<Sphere2D, Sphere1D> { 032 033 /** Simple constructor. 034 * @param hyperplane underlying hyperplane 035 * @param remainingRegion remaining region of the hyperplane 036 */ 037 public SubCircle(final Hyperplane<Sphere2D> hyperplane, 038 final Region<Sphere1D> remainingRegion) { 039 super(hyperplane, remainingRegion); 040 } 041 042 /** {@inheritDoc} */ 043 @Override 044 protected AbstractSubHyperplane<Sphere2D, Sphere1D> buildNew(final Hyperplane<Sphere2D> hyperplane, 045 final Region<Sphere1D> remainingRegion) { 046 return new SubCircle(hyperplane, remainingRegion); 047 } 048 049 /** {@inheritDoc} */ 050 @Override 051 public SplitSubHyperplane<Sphere2D> split(final Hyperplane<Sphere2D> hyperplane) { 052 053 final Circle thisCircle = (Circle) getHyperplane(); 054 final Circle otherCircle = (Circle) hyperplane; 055 final double angle = Vector3D.angle(thisCircle.getPole(), otherCircle.getPole()); 056 057 if (angle < thisCircle.getTolerance() || angle > FastMath.PI - thisCircle.getTolerance()) { 058 // the two circles are aligned or opposite 059 return new SplitSubHyperplane<Sphere2D>(null, null); 060 } else { 061 // the two circles intersect each other 062 final Arc arc = thisCircle.getInsideArc(otherCircle); 063 final ArcsSet.Split split = ((ArcsSet) getRemainingRegion()).split(arc); 064 final ArcsSet plus = split.getPlus(); 065 final ArcsSet minus = split.getMinus(); 066 return new SplitSubHyperplane<Sphere2D>(plus == null ? null : new SubCircle(thisCircle.copySelf(), plus), 067 minus == null ? null : new SubCircle(thisCircle.copySelf(), minus)); 068 } 069 070 } 071 072}