graphics/arrows

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<?php

/* $Id: arrows.php,v 1.7 2013/02/22 16:02:39 rp 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

*/

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

$searchpath = dirname(dirname(dirname(__FILE__)))."/input";

$outfile = "";

$title = "Arrows";

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");

$p->set_option("stringformat=utf8");

if ($p->begin_document($outfile, "") == 0)

throw new Exception("Error: " . $p->get_errmsg());

$p->set_info("Creator", "PDFlib Cookbook");

$p->set_info("Title", $title );

$font = $p->load_font("Helvetica", "unicode", "");

if ($font == 0)

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;

$l = sqrt($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("");

$buf = $p->get_buffer();

$len = strlen($buf);

header("Content-type: application/pdf");

header("Content-Length: $len");

header("Content-Disposition: inline; filename=arrows.pdf");

print $buf;

} catch (PDFlibException $e){

die("PDFlib exception occurred:\n" .

"[" . $e->get_errnum() . "] " . $e->get_apiname() .

": " . $e->get_errmsg() . "\n");

} catch (Exception $e) {

die($e->getMessage());

}

$p = 0;

?>