graphics/transparent_graphics

<?php

/* $Id: transparent_graphics.php,v 1.2 2012/05/03 14:00:37 stm Exp $

 * Transparent graphics:

 * Create some transparent graphics objects

 *

 * Display a yellow rectangle and show some transparent graphics objects

 * overlapping with it. Create transparency by applying an extended graphics

 * state with the "opacityfill" option set to a value less than 1.

 *

 * Required software: PDFlib Lite/PDFlib/PDFlib+PDI/PPS 7

 * Required data: none

 */

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

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

$outfile = "";

$title = "Transparent Graphics";

try {

    $p = new pdflib();

    $p->set_parameter("SearchPath", $searchpath);

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

    $p->set_parameter("errorpolicy", "return");

    $p->set_parameter("textformat", "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 );

   

    /* Load the font; for PDFlib Lite: change "unicode" to "winansi" */

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

    if ($font == 0)

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

    /* Start page */

    $p->begin_page_ext(0, 0, "width=a4.width height=a4.height");

   

    /* Draw a yellow background rectangle */

    $p->setcolor("fill", "rgb", 1, 0.9, 0.58, 0);

    $p->rect(50, 50, 500, 750);

    $p->fill();

   

    /* Display some descriptive red text */

    $p->setcolor("fill", "rgb", 0.73, 0.12, 0.30, 0);

    $p->fit_textline("Transparent vector graphics", 100, 100, "font=" . $font .

        " fontsize=20");

   

    /* Save the current graphics state. The save/restore of the current

     * state is not necessarily required, but it will help you get back to

     * a graphics state without any transparency.

     */

    $p->save();

   

    /* Create an extended graphics state with transparency set to 50%, using

     * create_gstate() with the "opacityfill" option set to 0.5.

     */

    $gstate = $p->create_gstate("opacityfill=.5");

   

    /* Apply the extended graphics state */

    $p->set_gstate($gstate);

   

    /* Draw a blue rectangle which will be transparent according to the

     * graphics state set

     */

    $p->setcolor("fill", "rgb", 0, 0.52, 0.64, 0);

    $p->rect(100, 500, 200, 600);

    $p->fill();

   

    /* Draw a red circle which will be transparent according to the

     * graphics state set

     */

    $p->setcolor("fill", "rgb", 0.73, 0.12, 0.30, 0);

    $p->arc(100, 100, 200, 0, 360);

    $p->fill();

   

    /* Restore the current graphics state */

    $p->restore();

   

    $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=transparent_graphics.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;

?>