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graphics/arrows

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/* $Id: arrows.java,v 1.9 2013/01/15 10:11:59 stm Exp $

 * Arrows:

 * Create an arrow using different methods

 *

 * Method I: Draw a simple horizontal arrow.

 * Method II: Draw an arrow with the aid of its unit vector respresentation.

 * Method III: Draw an arrow using coordinate system translation and rotation.

 *

 * Required software: PDFlib/PDFlib+PDI/PPS 9

 * Required data: none

 */

package com.pdflib.cookbook.pdflib.graphics;


import com.pdflib.pdflib;

import com.pdflib.PDFlibException;


public class arrows

{

    public static void main (String argv[])

    {

    /* This is where the data files are. Adjust if necessary. */

    String searchpath = "../input";

    String outfile = "arrows.pdf";

    String title = "Arrows";


    int startx, starty, stopx, stopy, ahl, ahw, sw;

    double l, angle;

    double x, y, dx, dy;

    double ux, uy, pux, puy;    /* unit vector and its perpendicular */


    pdflib p = null;


    int font;


    try {

        p = new pdflib();


        p.set_option("searchpath={" + searchpath + "}");


        /* This means we must check return values of load_font() etc. */

        p.set_option("errorpolicy=return");


        if (p.begin_document(outfile, "") == -1)

            throw new Exception("Error: " + p.get_errmsg());


        p.set_info("Creator", "PDFlib Cookbook");

        p.set_info("Title", title + " $Revision: 1.9 $");

       

        /* Load the font. */

        font = p.load_font("Helvetica", "unicode", "");

        if (font == -1)

            throw new Exception("Error: " + p.get_errmsg());


        p.begin_page_ext(0, 0, "width=500 height=500");


        /* Method I:

         * Draw a horizontal green arrow from left to right. Start at the given

         * start point located in the middle of the arrow shaft.

         * The following values are given:

         */

        startx = 100;       /* x coordinate of the starting point */

        starty = 100;       /* y coordinate of the starting point */

        stopx = 400;        /* x coordinate of the end point */

        stopy = 100;        /* y coordinate of the end point */

        ahl = 40;           /* arrow head length */

        ahw = 10;           /* arrow head width */

        sw = 20;            /* shaft width */

        l = stopx - startx; /* length of the arrow */


        /* Set the drawing properties */

        p.setlinewidth(5.0);

        p.setcolor("stroke", "rgb", 0.0, 0.5, 0.5, 0.0);

        p.setcolor("fill", "rgb", 1, 1, 1, 0.0);

        p.set_graphics_option("linejoin=1 linecap=1");


        /* Start drawing the arrow */

        p.moveto(startx, starty);


        x = startx;

        y = starty + sw/2;

        p.lineto(x, y);


        x = x + (l - ahl);

        p.lineto(x, y);


        y = y + ahw;

        p.lineto(x, y);


        p.lineto(stopx, stopy);


        y = y - (2*ahw + sw);

        p.lineto(x, y);


        y = y + ahw;

        p.lineto(x, y);


        x = x - (l - ahl);

        p.lineto(x, y);


        y = starty + sw/2;

        p.lineto(x, y);

        p.fill_stroke();


        /* Method II:

         * Draw a non-horizontal pink arrow from left to right. Start at the

         * given start point located in the middle of the arrow shaft.

         * The following values are given:

         */

        startx = 100;       /* x coordinate of the starting point */

        starty = 200;       /* y coordinate of the starting point */

        stopx = 400;        /* x coodingate of the end point */

        stopy = 300;        /* y coordinate of the end point */

        ahl = 40;           /* arrow head length */

        ahw = 20;           /* arrow head width */

        sw = 20;            /* shaft width */


        /* Calculate the unit vector (ux, uy) and its perpendicular

         * (pux, puy)

         */

        dx = stopx - startx;

        dy = stopy - starty;

        l = Math.sqrt(dx*dx + dy*dy);

        ux = dx/l;

        uy = dy/l;

        pux = uy;

        puy = -ux;


        /* Set the drawing properties */

        p.setlinewidth(5.0);

        p.setcolor("stroke", "rgb", 1.0, 0.5, 1.0, 0.0);

        p.setcolor("fill", "rgb", 0.9, 0.8, 0.8, 0.0);

        p.set_graphics_option("linejoin=1 linecap=1");


        /* Start at the given start point located in the middle of the arrow

         * shaft

         */

        p.moveto(startx, starty);


        x = startx + sw/2 * pux;

        y = starty + sw/2 * puy;

        p.lineto(x, y);


        x = x + (l - ahl) * ux;

        y = y + (l - ahl) * uy;

        p.lineto(x, y);


        x = x + ahw * pux;

        y = y + ahw * puy;

        p.lineto(x, y);


        p.lineto(stopx, stopy);


        x = x - (2*ahw + sw) * pux;

        y = y - (2*ahw + sw) * puy;

        p.lineto(x, y);


        x = x + ahw * pux;

        y = y + ahw * puy;

        p.lineto(x, y);


        x = x - (l - ahl) * ux;

        y = y - (l - ahl) * uy;

        p.lineto(x, y);


        x = startx + sw/2 * pux;

        y = starty + sw/2 * puy;

        p.lineto(x, y);


        p.fill_stroke();


        /* Method III:

         * Draw a non-horizontal black arrow from left to right. Start at the

         * given start point located in the middle of the arrow shaft.

         * The following values are given:

         */

        startx = 100;       /* x coordinate of the starting point */

        starty = 300;       /* y coordinate of the starting point */

        angle = 40;         /* Rotation angle in degrees */

        l = 200;            /* length of the arrow */

        ahl = 30;           /* arrow head length */

        ahw = 10;           /* arrow head width */

        sw = 4;             /* shaft width */


        /* Set the drawing properties */

        p.setlinewidth(3.0);

        p.setcolor("stroke", "rgb", 0.0, 0.0, 0.0, 0.0);

        p.setcolor("fill", "rgb", 0.0, 0.0, 0.0, 0.0);

        p.set_graphics_option("linejoin=1 linecap=1");


        /* Rotate and translate the coordinate system */

        p.translate(startx, starty);

        p.rotate(angle);


        /* Start drawing the arrow */

        p.moveto(0, 0);


        x = 0;

        y = sw/2;

        p.lineto(x, y);


        x = x + (l - ahl);

        p.lineto(x, y);


        y = y + ahw;

        p.lineto(x, y);


        x = x + ahl;

        y = y - (ahw + sw/2);

        p.lineto(x, y);


        x = x - ahl;

        y = y - (ahw + sw/2);

        p.lineto(x, y);


        y = y + ahw;

        p.lineto(x, y);


        x = x - (l - ahl);

        p.lineto(x, y);


        y = y + sw/2;

        p.lineto(x, y);

        p.fill_stroke();


        p.end_page_ext("");


        p.end_document("");


        } catch (PDFlibException e) {

            System.err.print("PDFlib exception occurred:\n");

            System.err.print("[" + e.get_errnum() + "] " + e.get_apiname() +

                ": " + e.get_errmsg() + "\n");

        } catch (Exception e) {

            System.err.println(e.getMessage());

        } finally {

            if (p != null) {

                p.delete();

            }

        }

    }

}