Check if a specified polyline intersects a specified rectangle. - Java 2D Graphics

Java examples for 2D Graphics:Rectangle

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Description

Check if a specified polyline intersects a specified rectangle.

Demo Code

/*******************************************************************************
 * Copyright (c) 2011 MadRobot.//from w ww  .  jav  a2 s . c o m
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the GNU Lesser Public License v2.1
 * which accompanies this distribution, and is available at
 * http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
 * 
 * Contributors:
 *  Elton Kent - initial API and implementation
 ******************************************************************************/

public class Main{

    /**
     * Check if a specified polyline intersects a specified rectangle.
     * Integer domain.
     * 
     * @param x
     *            , y Polyline to check.
     * @param x0
     *            , y0, x1, y1 Upper left and lower left corner of rectangle
     *            (inclusive).
     * @return True if the polyline intersects the rectangle,
     *         false otherwise.
     */
    public static boolean isPolylineIntersectingRectangle(float[] x,
            float[] y, float x0, float y0, float x1, float y1) {
        if (x.length == 0) {
            return false;
        }

        if (isPointInsideRectangle(x[0], y[0], x0, y0, x1, y1)) {
            return true;
        } else if (x.length == 1) {
            return false;
        }

        for (int i = 1; i < x.length; i++) {
            if ((x[i - 1] != x[i]) || (y[i - 1] != y[i])) {
                if (LineUtils.isLineIntersectingRectangle(x[i - 1],
                        y[i - 1], x[i], y[i], x0, y0, x1, y1)) {
                    return true;
                }
            }
        }

        return false;
    }
    /**
     * Check if a specified point is inside a specified rectangle.
     * 
     * @param x0
     *            , y0, x1, y1 Upper left and lower right corner of rectangle
     *            (inclusive)
     * @param x
     *            ,y Point to check.
     * @return True if the point is inside the rectangle,
     *         false otherwise.
     */
    public static boolean isPointInsideRectangle(float x0, float y0,
            float x1, float y1, float x, float y) {
        return (x >= x0) && (x < x1) && (y >= y0) && (y < y1);
    }
}

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