Given a line formed by points Point1 and Point2, returns the point at a given distance from the Point1 along the same line. - Java 2D Graphics

Java examples for 2D Graphics:Line

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Description

Given a line formed by points Point1 and Point2, returns the point at a given distance from the Point1 along the same line.

Demo Code

/*/*from ww  w. j  av  a2  s .  co  m*/
 * Copyright (c) 2001-2002 Regents of the University of California.
 * All rights reserved.
 *
 * This software was developed at the University of California, Irvine.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by the University of California, Irvine.  The name of the
 * University may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */
//package com.java2s;

import java.awt.Point;

public class Main {
    /**
     * Given a line formed by points Point1 and Point2, returns
     * the point at a given distance from the Point1 along the
     * same line.
     */
    public static Point calcPointOnLineAtDist(Point Point1, Point Point2,
            int Dist) {
        double A = Point2.getX() - Point1.getX();
        double B = -(Point2.getY() - Point1.getY()); //negate for graphic coords
        if (A == 0) {
            return new Point(Point1.x, Point2.y + Dist);
        }
        double angle = Math.atan(B / A);
        double a = Dist * Math.cos(angle);
        double b = Dist * Math.sin(angle);
        if (A > 0) {
            return new Point((int) (Point1.x + a), (int) (Point1.y - b));
        } else {
            return new Point((int) (Point1.x - a), (int) (Point1.y + b));
        }
    }
}

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