shorten CubicCurve2D - Java 2D Graphics

Java examples for 2D Graphics:Curve

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Description

shorten CubicCurve2D

Demo Code

/* ------------------------------------------------------------------------
 * PlantUML : a free UML diagram generator
 * ------------------------------------------------------------------------
 *
 * (C) Copyright 2009, Arnaud Roques//from  w  w w.ja v  a  2  s  .com
 *
 * Project Info:  http://plantuml.sourceforge.net
 * 
 * This file is part of PlantUML.
 *
 * PlantUML is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * PlantUML distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
 * License for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
 * USA.
 *
 * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
 * in the United States and other countries.]
 *
 * Original Author:  Arnaud Roques
 *
 * Revision $Revision: 4236 $
 * 
 */
//package com.java2s;

import java.awt.Shape;
import java.awt.geom.CubicCurve2D;

public class Main {
    static void shorten(CubicCurve2D.Double bez, Shape shape) {
        final boolean contains1 = shape.contains(bez.x1, bez.y1);
        final boolean contains2 = shape.contains(bez.x2, bez.y2);
        if (contains1 ^ contains2 == false) {
            throw new IllegalArgumentException();
        }
        if (contains1 == false) {
            bez.setCurve(bez.x2, bez.y2, bez.ctrlx2, bez.ctrly2,
                    bez.ctrlx1, bez.ctrly1, bez.x1, bez.y1);
        }
        assert shape.contains(bez.x1, bez.y1)
                && shape.contains(bez.x2, bez.y2) == false;
        final CubicCurve2D.Double left = new CubicCurve2D.Double();
        final CubicCurve2D.Double right = new CubicCurve2D.Double();
        subdivide(bez, left, right, 0.5);

        if (isCutting(left, shape) ^ isCutting(right, shape) == false) {
            throw new IllegalArgumentException();
        }

        if (isCutting(left, shape)) {
            bez.setCurve(left);
        } else {
            bez.setCurve(right);
        }

    }

    public static void subdivide(CubicCurve2D src, CubicCurve2D left,
            CubicCurve2D right, final double coef) {
        final double coef1 = coef;
        final double coef2 = 1 - coef;
        final double centerxA = src.getCtrlX1() * coef1 + src.getCtrlX2()
                * coef2;
        final double centeryA = src.getCtrlY1() * coef1 + src.getCtrlY2()
                * coef2;

        final double ctrlx1 = src.getX1() * coef1 + src.getCtrlX1() * coef1;
        final double ctrly1 = src.getY1() * coef1 + src.getCtrlY1() * coef1;
        final double ctrlx2 = src.getX2() * coef1 + src.getCtrlX2() * coef1;
        final double ctrly2 = src.getY2() * coef1 + src.getCtrlY2() * coef1;

        final double ctrlx12 = ctrlx1 * coef1 + centerxA * coef1;
        final double ctrly12 = ctrly1 * coef1 + centeryA * coef1;
        final double ctrlx21 = ctrlx2 * coef1 + centerxA * coef1;
        final double ctrly21 = ctrly2 * coef1 + centeryA * coef1;
        final double centerxB = ctrlx12 * coef1 + ctrlx21 * coef1;
        final double centeryB = ctrly12 * coef1 + ctrly21 * coef1;
        left.setCurve(src.getX1(), src.getY1(), ctrlx1, ctrly1, ctrlx12,
                ctrly12, centerxB, centeryB);
        right.setCurve(centerxB, centeryB, ctrlx21, ctrly21, ctrlx2,
                ctrly2, src.getX2(), src.getY2());
    }

    static boolean isCutting(CubicCurve2D.Double bez, Shape shape) {
        final boolean contains1 = shape.contains(bez.x1, bez.y1);
        final boolean contains2 = shape.contains(bez.x2, bez.y2);
        return contains1 ^ contains2;
    }
}

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