<?php
/*
 * Transparent images:
 * Create transparent images
 *
 * Display a colored background rectangle. Output two transparent background
 * images over that rectangle, then output a non-transparent image in the
 * foreground. Create transparency by applying an extended graphics
 * state with the "opacityfill" option set to a value less than 1.
 *
 * Required software: PDFlib/PDFlib+PDI/PPS 10
 * Required data: image file
 */

/* This is where the data files are. Adjust as necessary. */
$searchpath = dirname(__FILE__,3)."/input";
$outfile = "";
$title = "Transparent Images";

$imagefile = "nesrin.jpg";

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, "") == 0)
        throw new Exception("Error: " . $p->get_errmsg());

    $p->set_info("Creator", "PDFlib Cookbook");
    $p->set_info("Title", $title);
    
    /* Load image */
    $image = $p->load_image("auto", $imagefile, "");
    if ($image == 0)
        throw new Exception("Error: " . $p->get_errmsg());
    
    /* Start page 1 */
    $p->begin_page_ext(0, 0, "width=a4.height height=a4.width");
    
    /* Draw a yellow background rectangle */
    $p->setcolor("fill", "rgb", 1, 0.9, 0.58, 0);
    $p->rect(0, 0, 421, 595);
    $p->fill();
    
    /* Display some descriptive text */
    $p->setcolor("fill", "gray", 0, 0, 0, 0);
    $p->fit_textline("Two transparent background images with a " .
        "non-transparent image placed in the foreground", 50, 530, 
        "fontname=NotoSerif-Regular fontsize=16");
    
    /* 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);
    
    /* Display two images which will be transparent according to the
     * graphics state set.
     */
    $p->fit_image($image, 0, 0, "boxsize={842 595} position={center bottom}");
    $p->fit_image($image, 0, 0, "boxsize={842 595} position={center bottom} " .
        "scale=0.7");
      
    /* Restore the current graphics state */
    $p->restore();
    
    /* Display the image again. It will not be transparent since the old
     * graphics state has been restored with no transparency set.
     */ 
    $p->fit_image($image, 0, 0, "boxsize={842 595} position={center bottom} " .
        "scale=0.35");
    
    $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_images.pdf");
    print $buf;

} catch (PDFlibException $e) {
    echo("PDFlib exception occurred:\n".
        "[" . $e->get_errnum() . "] " . $e->get_apiname() .
        ": " . $e->get_errmsg() . "\n");
    exit(1);
} catch (Throwable $e) {
    echo("PHP exception occurred: " . $e->getMessage() . "\n");
    exit(1);
}

$p = 0;

?>