Here you can find the source of nearestColinearPoint(final double x1, final double y1, final double x2, final double y2, double x, double y)
| Parameter | Description |
|---|---|
| x1 | <var>x</var> value of the first point on the line. |
| y1 | <var>y</var> value of the first point on the line. |
| x2 | <var>x</var> value of the last point on the line. |
| y2 | <var>y</var> value of the last point on the line. |
| x | <var>x</var> value of a point close to the given line. |
| y | <var>y</var> value of a point close to the given line. |
public static Point2D.Double nearestColinearPoint(final double x1, final double y1, final double x2, final double y2, double x, double y)
//package com.java2s; /*/*from w w w. j a va2 s .com*/ * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You under the Apache License, Version 2.0 * (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ import java.awt.geom.Point2D; public class Main { /** * Returns the point on the given {@code line} segment which is closest to the given {@code point}. * Let {@code result} be the returned point. This method guarantees (except for rounding errors) that: * * <ul> * <li>{@code result} is a point on the {@code line} segment. It is located between the * {@linkplain Line2D#getP1() P1} and {@linkplain Line2D#getP2() P2} ending points * of that line segment.</li> * <li>The distance between the {@code result} point and the given {@code point} is * the shortest distance among the set of points meeting the previous condition. * This distance can be obtained with {@code point.distance(result)}.</li> * </ul> * * @param x1 <var>x</var> value of the first point on the line. * @param y1 <var>y</var> value of the first point on the line. * @param x2 <var>x</var> value of the last point on the line. * @param y2 <var>y</var> value of the last point on the line. * @param x <var>x</var> value of a point close to the given line. * @param y <var>y</var> value of a point close to the given line. * @return The nearest point on the given line. * * @see #colinearPoint(double,double , double,double , double,double , double) * * @todo This method is used by Geotk (a sandbox for code that may migrate to SIS), but not yet by SIS. * We temporarily keep this code here, but may delete or move it elsewhere in a future SIS version * depending whether we port to SIS the sandbox code. */ public static Point2D.Double nearestColinearPoint(final double x1, final double y1, final double x2, final double y2, double x, double y) { final double slope = (y2 - y1) / (x2 - x1); if (!Double.isInfinite(slope)) { final double y0 = (y2 - slope * x2); x = ((y - y0) * slope + x) / (slope * slope + 1); y = x * slope + y0; } else { x = x2; } if (x1 <= x2) { if (x < x1) x = x1; if (x > x2) x = x2; } else { if (x > x1) x = x1; if (x < x2) x = x2; } if (y1 <= y2) { if (y < y1) y = y1; if (y > y2) y = y2; } else { if (y > y1) y = y1; if (y < y2) y = y2; } return new Point2D.Double(x, y); } }