Draws a line with a specified thickness - Java 2D Graphics

Java examples for 2D Graphics:Line

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Description

Draws a line with a specified thickness

Demo Code

/****************************************************************************************
 * Copyright (c) 2009 Armin Widegreen <armin.widegreen@gmail.com>                       *
 *                    Dirk Reske <email@dirkreske.de>                                   *
 *                                                                                      *
 * This program 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.                                                                             *
 *                                                                                      *
 * This program is 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 General Public License for more details.             *
 *                                                                                      *
 * You should have received a copy of the GNU General Public License along with         *
 * this program.  If not, see <http://www.gnu.org/licenses/>.                           *
 ****************************************************************************************/
//package com.java2s;
import java.awt.Graphics;

public class Main {
    /**/*from   ww  w .java2s. co  m*/
     * Draws a line with a specified thickness
     * 
     * @param g
     *            Graphics context to paint on
     * @param x1
     *            x coordinates of the line start point
     * @param y1
     *            y coordinates of the line start point
     * @param x2
     *            x coordinates of the line end point
     * @param y2
     *            y coordinates of the line end point
     * @param thickness
     *            The thickness of the line
     */
    public static void drawThickLine(Graphics g, int x1, int y1, int x2,
            int y2, int thickness) {
        if (thickness == 1) {
            g.drawLine(x1, y1, x2, y2);
        } else {
            // The thick line is in fact a filled polygon
            int dX = x2 - x1;
            int dY = y2 - y1;
            // line length
            double lineLength = Math.sqrt(dX * dX + dY * dY);

            double scale = (double) (thickness) / (2 * lineLength);

            // The x,y increments from an endpoint needed to create a
            // rectangle...
            double ddx = -scale * (double) dY;
            double ddy = scale * (double) dX;
            ddx += (ddx > 0) ? 0.5 : -0.5;
            ddy += (ddy > 0) ? 0.5 : -0.5;
            int dx = (int) ddx;
            int dy = (int) ddy;

            // Now we can compute the corner points...
            int[] xPoints = new int[4];
            int[] yPoints = new int[4];

            xPoints[0] = x1 + dx;
            yPoints[0] = y1 + dy;
            xPoints[1] = x1 - dx;
            yPoints[1] = y1 - dy;
            xPoints[2] = x2 - dx;
            yPoints[2] = y2 - dy;
            xPoints[3] = x2 + dx;
            yPoints[3] = y2 + dy;

            g.fillPolygon(xPoints, yPoints, 4);
        }
    }
}

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