<?php
/*
 * 
 * Create text on a path
 * 
 * Required software: PDFlib/PDFlib+PDI/PPS 9
 * Required data: Image file with clipping path
 */


/**
 * Interface for the different use cases.
 */
interface use_case {
    function create_page_content($p);
    function use_case_description();
}

class useCase1 implements use_case{
    function use_case_description() {
        return "Text on Explicitly Constructed Path";
    }

    function create_page_content($p){
        global $a4_width, $a4_height, $font;
        $x = $a4_width / 2; $y = $a4_height / 2;
        $radius = 150;

        /* Draw a circle in the origin; use "clockwise=false"
         * to place text in the reverse direction.
         */
        $path = 0;
        $path = $p->add_path_point($path, 0, 0, "circle",
                            "clockwise=true radius=" . $radius);

        /* Place text on the path */
        $p->setfont($font, 36);

        /* By default the circle and therefore the text starts at
         * the "western" side of the circle. We translate to the
         * origin of the circle and then rotate to start the text
         * at the top (or some other location on the circle,
         * e.g. use +90 to start the text at the bottom).
         */
        $p->save();
            $p->translate($x, $y);
            $p->rotate(-90);
            $p->fit_textline(
                "Long Distance Glider with sensational range!",
                0, 0,
                "textpath={path=" . $path . "} position={left bottom}");

            /* We also draw the path for demonstration purposes */
            $p->draw_path($path, 0, 0, "stroke");
        $p->restore();
        
        $p->delete_path($path);
    }
};

class useCase2 implements use_case{
    function use_case_description() {
        return "Text on Clipping Path of Image";
    }

    function create_page_content($p){
        global $a4_width, $a4_height, $font, $imagefile;
        /*
         * Load image and retrieve its clipping path.
         */
        $image = $p->load_image("auto", $imagefile, "");
        if ($image == 0)
            throw new Exception("Error: " . $p->get_apiname() . ": "
                    . $p->get_errmsg());

        $image_clipping_path = $p->info_image($image, "clippingpath", "");
        if ($image_clipping_path == 0)
            throw new Exception(
                "Error: Image does not contain a clipping path");
        
        /*
         * Center the image on the page, scale it to half the size
         * of the page.
         */
        $img_width = $a4_height / 2; 
        $img_height = $a4_width / 2;
        $box_llx = $a4_width / 2 - $img_width / 2; 
        $box_lly = $a4_height / 2 - $img_height / 2;
        
        $fit_options = "boxsize={" . $img_width . " "
                . $img_height . "} position=center fitmethod=meet";
        $p->fit_image($image, $box_llx, $box_lly, $fit_options);
        
        $image_llx = $box_llx + $p->info_image($image, "x1", $fit_options);
        $image_lly = $box_lly + $p->info_image($image, "y1", $fit_options);

        /*
         * Determine the scaling factors for the image.
         */
        $img_scale_factor_x = $p->info_image($image, "fitscalex", $fit_options);
        $img_scale_factor_y = $p->info_image($image, "fitscaley", $fit_options);
        $scale_option = "scale={" . $img_scale_factor_x
            . " " . $img_scale_factor_y . "}";
        
        /* Place text on the path; we start at 23% of the
         * path length for a nice effect.
         */
        $p->setfont($font, 24);
        $p->fit_textline(
            "Hi! I'm Louise!",
            $image_llx, $image_lly,
            "textpath={path=" . $image_clipping_path . " " 
            . $scale_option . "} position={23 bottom} " .
            "matchbox={boxheight={capheight descender}}");
        
        $p->delete_path($image_clipping_path);
        $p->close_image($image);
    }
};

class useCase3 implements use_case{
    function use_case_description() {
        return "Create a Gap Between Text and Path";
    }

    function create_page_content($p){
        global $a4_width, $a4_height, $font;
        /*
         * Create a path defined by Bezier curves. The path extends
         * through a box that is half the size of the page. The box
         * is centered on the page.
         */
        $box_center_x = $a4_width / 2;
        $box_center_y = $a4_height / 2;
        $box_width = $box_center_y; 
        $box_height = $box_center_x;
        $box_llx = $box_center_x - $box_width / 2; 
        $box_lly = $box_center_y - $box_height / 2;
        
        /*
         * The path is defined through the implicit point at (0, 0)
         * and six additional control points
         */
        $step = $box_width / 6;
        $path = $p->add_path_point(0, $step * 1, 
                    $box_height / 2, "control", "");
        $path = $p->add_path_point($path, $step * 2, 
                    $box_height / 2, "control", "");
        $path = $p->add_path_point($path, $step * 3, 
                    $box_height / 2, "curve", "");
        $path = $p->add_path_point($path, $step * 4, 
                    $box_height / 2, "control", "");
        $path = $p->add_path_point($path, $step * 5, 
                    $box_height / 2, "control", "");
        $path = $p->add_path_point($path, $step * 6, 
                    $box_height, "curve", "");
        
        /* Place text on the path */
        $p->setfont($font, 24);
        $p->fit_textline(
            "Long Distance Glider with sensational range!",
            $box_llx, $box_lly,
            "textpath={path=" . $path . "} position={center bottom} "
            . "matchbox={boxheight={capheight descender}}");
        
        /* We also draw the path for demonstration purposes */
        $p->draw_path($path, $box_llx, $box_lly, "stroke");
        
        $p->delete_path($path);
    }
};

class useCase4 implements use_case{
    function use_case_description() {
        return "Place Text on Right Side of Path";
    }

    function create_page_content($p){
        global $a4_width, $a4_height, $font;
        /*
         * Create a path defined by Bezier curves. The path extends
         * through a box that is half the size of the page. The box
         * is centered on the page.
         */
        $box_center_x = $a4_width / 2;
        $box_center_y = $a4_height / 2;
        $box_width = $box_center_y; 
        $box_height = $box_center_x;
        $box_llx = $box_center_x - $box_width / 2; 
        $box_lly = $box_center_y - $box_height / 2;
        
        /*
         * The path this time starts at the upper left corner of the
         * box.
         */
        $step = $box_width / 6;
        $path = $p->add_path_point(0, $step * 0, $box_height, 
                                    "move", "");
        $path = $p->add_path_point($path, $step * 1, $box_height / 2, 
                                    "control", "");
        $path = $p->add_path_point($path, $step * 2, $box_height / 2, 
                                    "control", "");
        $path = $p->add_path_point($path, $step * 3, $box_height / 2, 
                                    "curve", "");
        $path = $p->add_path_point($path, $step * 4, $box_height / 2, 
                                    "control", "");
        $path = $p->add_path_point($path, $step * 5, $box_height / 2, 
                                    "control", "");
        $path = $p->add_path_point($path, $step * 6, 0, "curve", "");
        
        /* Place text on the path */
        $p->setfont($font, 24);
        $p->fit_textline(
            "Long Distance Glider with sensational range!",
            $box_llx, $box_lly,
            "textpath={path=" . $path . "} position={center top}");
        
        /* We also draw the path for demonstration purposes */
        $p->draw_path($path, $box_llx, $box_lly, "stroke");
        
        $p->delete_path($path);
    }
};
        

/**
 * Execute the example.
 */
/* This is where the data files are. Adjust as necessary. */
$searchpath = dirname(__FILE__,3)."/input";
$outfile = "";
$imagefile = "luise.jpg";
$title = "Text on a Path";

/* The page dimensions */
$a4_width = 595; $a4_height = 842;

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_apiname() . ": "
                . $p->get_errmsg());

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

    $font = $p->load_font("NotoSerif-Regular", "unicode", "");
    if ($font == 0)
        throw new Exception("Error: " . $p->get_apiname() . ": "
                . $p->get_errmsg());

    $use_cases = array(
        new UseCase1(),
        new UseCase2(),
        new UseCase3(),
        new UseCase4());
    
    /*
     * Place the use cases.
     */
    $headline_x = $a4_width / 2; 
    $headline_y = $a4_height * 4 / 5;
    
    for ($i = 0; $i < count($use_cases); $i += 1) {
        $c = $use_cases[$i];
        
        $p->begin_page_ext(0, 0, "width=a4.width height=a4.height");

        /*
         * Options for the per-example header line
         */
        $optlist = "position=center";
        $p->setfont($font, 30);
        $p->fit_textline($c->use_case_description(), $headline_x, $headline_y,
                        $optlist);
        
        $c->create_page_content($p);

        $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=text_on_a_path.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;

?>