1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one or more 3 * contributor license agreements. See the NOTICE file distributed with 4 * this work for additional information regarding copyright ownership. 5 * The ASF licenses this file to You under the Apache License, Version 2.0 6 * (the "License"); you may not use this file except in compliance with 7 * the License. You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 */ 17 package org.apache.commons.geometry.core; 18 19 /** Interface representing a point in a mathematical space. 20 * 21 * <p>Implementations of this interface are sufficient to define a 22 * space since they define both the structure of the points making up 23 * the space and the operations permitted on them. The only mathematical 24 * requirement at this level is that the represented space have a defined 25 * distance metric, meaning an operation that can compute the distance 26 * between two points (ie, the space must be a metric space). 27 * </p> 28 * 29 * <p>This interface uses self-referencing generic parameters to ensure 30 * that implementations are only used with instances of their own type. 31 * This removes the need for casting inside of methods in order to access 32 * implementation-specific data, such as coordinate values. 33 * </p> 34 * 35 * @see <a href="https://en.wikipedia.org/wiki/Metric_space">Metric space</a> 36 * 37 * @param <P> Point implementation type 38 */ 39 public interface Point<P extends Point<P>> extends Spatial { 40 41 /** Compute the distance between this point and another point. 42 * @param p second point 43 * @return the distance between this point and p 44 */ 45 double distance(P p); 46 }