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 */ 017 package org.apache.commons.math3.geometry.partitioning; 018 019 import org.apache.commons.math3.geometry.Vector; 020 import org.apache.commons.math3.geometry.Space; 021 022 /** This interface represents an hyperplane of a space. 023 024 * <p>The most prominent place where hyperplane appears in space 025 * partitioning is as cutters. Each partitioning node in a {@link 026 * BSPTree BSP tree} has a cut {@link SubHyperplane sub-hyperplane} 027 * which is either an hyperplane or a part of an hyperplane. In an 028 * n-dimensions euclidean space, an hyperplane is an (n-1)-dimensions 029 * hyperplane (for example a traditional plane in the 3D euclidean 030 * space). They can be more exotic objects in specific fields, for 031 * example a circle on the surface of the unit sphere.</p> 032 033 * @param <S> Type of the space. 034 035 * @version $Id: Hyperplane.java 1416643 2012-12-03 19:37:14Z tn $ 036 * @since 3.0 037 */ 038 public interface Hyperplane<S extends Space> { 039 040 /** Copy the instance. 041 * <p>The instance created is completely independant of the original 042 * one. A deep copy is used, none of the underlying objects are 043 * shared (except for immutable objects).</p> 044 * @return a new hyperplane, copy of the instance 045 */ 046 Hyperplane<S> copySelf(); 047 048 /** Get the offset (oriented distance) of a point. 049 * <p>The offset is 0 if the point is on the underlying hyperplane, 050 * it is positive if the point is on one particular side of the 051 * hyperplane, and it is negative if the point is on the other side, 052 * according to the hyperplane natural orientation.</p> 053 * @param point point to check 054 * @return offset of the point 055 */ 056 double getOffset(Vector<S> point); 057 058 /** Check if the instance has the same orientation as another hyperplane. 059 * <p>This method is expected to be called on parallel hyperplanes. The 060 * method should <em>not</em> re-check for parallelism, only for 061 * orientation, typically by testing something like the sign of the 062 * dot-products of normals.</p> 063 * @param other other hyperplane to check against the instance 064 * @return true if the instance and the other hyperplane have 065 * the same orientation 066 */ 067 boolean sameOrientationAs(Hyperplane<S> other); 068 069 /** Build a sub-hyperplane covering the whole hyperplane. 070 * @return a sub-hyperplane covering the whole hyperplane 071 */ 072 SubHyperplane<S> wholeHyperplane(); 073 074 /** Build a region covering the whole space. 075 * @return a region containing the instance 076 */ 077 Region<S> wholeSpace(); 078 079 }