The Chop box Anchor's location is found by calculating the intersection of a line drawn from the center point of a box to a reference point and that box. - Java 2D Graphics

Java examples for 2D Graphics:Line

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Description

The Chop box Anchor's location is found by calculating the intersection of a line drawn from the center point of a box to a reference point and that box.

Demo Code

/*-------------------------------------------------------------------------+
|                                                                          |
| Copyright 2005-2011 The ConQAT Project                                   |
|                                                                          |
| Licensed 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                                  |
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|    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.                                           |
+-------------------------------------------------------------------------*/
//package com.java2s;
import java.awt.Point;
import java.awt.Rectangle;

public class Main {
    /**//from  w w  w. j av  a2 s . c  o m
     * The ChopboxAnchor's location is found by calculating the intersection of
     * a line drawn from the center point of a box to a reference point and that
     * box. Code borrowed from org.eclipse.draw2d.ChopboxAnchor.
     */
    public static Point getChopboxAnchor(Rectangle box, Point referencePoint) {

        double baseX = box.getCenterX();
        double baseY = box.getCenterY();
        double refX = referencePoint.x;
        double refY = referencePoint.y;

        // This avoids divide-by-zero
        if (box.isEmpty() || (refX == baseX && refY == baseY)) {
            return new Point((int) refX, (int) refY);
        }

        double dx = refX - baseX;
        double dy = refY - baseY;

        // r.width, r.height, dx, and dy are guaranteed to be non-zero.
        double scale = 0.5 / Math.max(Math.abs(dx) / box.width,
                Math.abs(dy) / box.height);
        baseX += dx * scale;
        baseY += dy * scale;
        return new Point((int) Math.round(baseX), (int) Math.round(baseY));
    }
}

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