<?php
/*
 * Glyph replacement:
 * Show the effects of glyph substitution in case of glyphs missing in the font
 * 
 * Load the font and specify a replacement character to be used to output
 * missing glyphs.
 * Demonstrate various notations to output the Euro sign as U+20AC which is
 * available in the font.
 * Show various other combinations of available and unavailable glyphs.
 * 
 * Required software: PDFlib/PDFlib+PDI/PPS 9
 * Required data: font file
 */

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

$x=30;
$x2=180; 
$x3=360; 
$x4=520; 
$y=550; 
$yoff=30;

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 the font "NotoSerif-Regular" with "unicode" encoding.
     * "replacementchar=?" defines a question mark to be used for glyph
     * substitution in case of a missing glyph.
     */
    $font = $p->load_font("NotoSerif-Regular", "unicode", "replacementchar=?");
    if ($font == 0)
        throw new Exception("Error: " . $p->get_errmsg());
    
    /* Start page */
    $p->begin_page_ext(0, 0, "width=a4.height height=a4.width");
    
    /* Define three option lists for fit_textline().
     * The "inp" option list is just for descriptive text.
     * The "repl" option list enables the interpretation of character 
     * references using "charref" and uses glyph substitution which is 
     * enabled by default ("glyphcheck=replace").
     * The second option list enables the interpretation of character 
     * references using "charref" but explicitly disables glyph 
     * substitution. Alternatively, glyph substitution can be disabled
     * with $p->set_option("glyphcheck=none");
     */
    $inp = "font=" . $font . " fontsize=14";
    $repl = "charref font=" . $font . " fontsize=22";
    $norepl = "charref glyphcheck=none font=" . $font . " fontsize=22";
    
    /* Output some descriptive header lines for the input, output, and
     * remark column
     */

    $p->fit_textline("Glyphs in the NotoSerif-Regular font", $x, $y, 
        "font=" . $font . " fontsize=16");
    $opts = " underline underlinewidth=1";
    $p->fit_textline("Input", $x, $y-=2*$yoff, $inp . $opts);
    $p->fit_textline("Output", $x2, $y, $inp . $opts);
    $p->fit_textline("Remark", $x4, $y, $inp . $opts);
    $p->fit_textline("glyphcheck=replace", $x2, $y-=$yoff, $inp . $opts);
    $p->fit_textline("glyphcheck=none", $x3, $y, $inp . $opts);
    
    
    /* ------------------------------------------------------------------
     * Use various notations to output the Euro symbol as U+20AC which is
     * available in the font.
     * ------------------------------------------------------------------ 
     */
    
    /* PHP Unicode notation, 
     * The first string "\\u{20AC}" is a descriptive text and results 
     * in an output of "\u{20AC}" since the two slashes are resolved by 
     * the PHP interpreter to one slash. 
     */
    $p->fit_textline("U+20AC literal", $x, $y-=$yoff, $inp);  
    $p->fit_textline("\u{20AC}", $x2, $y, $repl ); 
    $p->fit_textline("\u{20AC}", $x3, $y, $norepl);
    $p->fit_textline("Euro glyph available in the font", $x4, $y, $inp);
    
    /* Character reference in HTML style with hexadecimal number */
    $p->fit_textline("&#x20AC;", $x, $y-=$yoff, $inp);
    $p->fit_textline("&#x20AC;", $x2, $y, $repl);
    $p->fit_textline("&#x20AC;", $x3, $y, $norepl);
    $p->fit_textline("Euro glyph available in the font", $x4, $y, $inp);
    
    /* Character reference in HTML style with decimal number */
    $p->fit_textline("&#8364;", $x, $y-=$yoff, $inp);
    $p->fit_textline("&#8364;", $x2, $y, $repl);
    $p->fit_textline("&#8364;", $x3, $y, $norepl);
    $p->fit_textline("Euro glyph available in the font", $x4, $y, $inp);
    
    /* Character reference in HTML style with entity name */
    $p->fit_textline("&euro;", $x, $y-=$yoff, $inp);
    $p->fit_textline("&euro;", $x2, $y, $repl);
    $p->fit_textline("&euro;", $x3, $y, $norepl);
    $p->fit_textline("Euro glyph available in the font", $x4, $y, $inp);
    
    /* Character reference using a glyph name provided by the font or the
     * Adobe Glyph List (AGL)
     */
    $p->fit_textline("&.Euro;", $x, $y-=$yoff, $inp);
    $p->fit_textline("&.Euro;", $x2, $y, $repl);
    $p->fit_textline("&.Euro;", $x3, $y, $norepl);
    $p->fit_textline("Euro glyph available in the font", $x4, $y, $inp);
    
    /* Character reference using a glyph name provided by the Adobe Glyph
     * list (AGL)
     */
    $p->fit_textline("&.uni20AC;", $x, $y-=$yoff, $inp);
    $p->fit_textline("&.uni20AC;", $x2, $y, $repl); 
    $p->fit_textline("&.uni20AC;", $x3, $y, $norepl);
    $p->fit_textline("Euro glyph available in the font", $x4, $y, $inp);
    

    /* ---------------------------------------------------------------------
     * Use various notations to output the ligature "ffi" which is available
     * in the font
     * --------------------------------------------------------------------- 
     */
    
    /* PHP Unicode notation */
    $p->fit_textline("U+FB03 literal", $x, $y-=$yoff, $inp);
    $p->fit_textline("\u{FB03}", $x2, $y, $repl );
    $p->fit_textline("\u{FB03}", $x3, $y, $norepl );
    $p->fit_textline("ffi ligature available in the font", $x4, $y, $inp);
    
    /* Character reference using a glyph name provided by the font or the
     * Adobe Glyph List (AGL)
     */
    $p->fit_textline("&.ffi;", $x, $y-=$yoff, $inp);
    $p->fit_textline("&.ffi;", $x2, $y, $repl);
    $p->fit_textline("&.ffi;", $x3, $y, $norepl);
    $p->fit_textline("ffi ligature available in the font", $x4, $y, $inp);
           
   
    /* --------------------------------------------------------------------
     * Output the glyph for a glyph which is not available in the font
     * (this problem can be addressed with fallback fonts)
     * --------------------------------------------------------------------
     */

    $p->fit_textline("U+05D0 literal", $x, $y-=$yoff, $inp);
    $p->fit_textline("\u{05D0}", $x2, $y, $repl);
    $p->fit_textline("\u{05D0}", $x3, $y, $norepl);
    $p->fit_textline("Hebrew glyph Aleph not available in the font", $x4, $y, $inp);
    
    /* Finish page */
    $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=glyph_replacement.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;

?>