<?php

/**
 * CodeIgniter
 *
 * An open source application development framework for PHP
 *
 * This content is released under the MIT License (MIT)
 *
 * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 *
 * @package	CodeIgniter
 * @author	EllisLab Dev Team
 * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
 * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
 * @license	http://opensource.org/licenses/MIT	MIT License
 * @link	https://codeigniter.com
 * @since	Version 1.0.0
 * @filesource
 */
defined('BASEPATH') OR exit('No direct script access allowed');

/**
 * Image Manipulation class
 *
 * @package		CodeIgniter
 * @subpackage	Libraries
 * @category	Image_lib
 * @author		EllisLab Dev Team
 * @link		https://codeigniter.com/user_guide/libraries/image_lib.html
 */
class CI_Image_lib {

    /**
     * PHP extension/library to use for image manipulation
     * Can be: imagemagick, netpbm, gd, gd2
     *
     * @var string
     */
    public $image_library = 'gd2';

    /**
     * Path to the graphic library (if applicable)
     *
     * @var string
     */
    public $library_path = '';

    /**
     * Whether to send to browser or write to disk
     *
     * @var bool
     */
    public $dynamic_output = FALSE;

    /**
     * Path to original image
     *
     * @var string
     */
    public $source_image = '';

    /**
     * Path to the modified image
     *
     * @var string
     */
    public $new_image = '';

    /**
     * Image width
     *
     * @var int
     */
    public $width = '';

    /**
     * Image height
     *
     * @var int
     */
    public $height = '';

    /**
     * Quality percentage of new image
     *
     * @var int
     */
    public $quality = 90;

    /**
     * Whether to create a thumbnail
     *
     * @var bool
     */
    public $create_thumb = FALSE;

    /**
     * String to add to thumbnail version of image
     *
     * @var string
     */
    public $thumb_marker = '_thumb';

    /**
     * Whether to maintain aspect ratio when resizing or use hard values
     *
     * @var bool
     */
    public $maintain_ratio = TRUE;

    /**
     * auto, height, or width.  Determines what to use as the master dimension
     *
     * @var string
     */
    public $master_dim = 'auto';

    /**
     * Angle at to rotate image
     *
     * @var string
     */
    public $rotation_angle = '';

    /**
     * X Coordinate for manipulation of the current image
     *
     * @var int
     */
    public $x_axis = '';

    /**
     * Y Coordinate for manipulation of the current image
     *
     * @var int
     */
    public $y_axis = '';

    // --------------------------------------------------------------------------
    // Watermark Vars
    // --------------------------------------------------------------------------

    /**
     * Watermark text if graphic is not used
     *
     * @var string
     */
    public $wm_text = '';

    /**
     * Type of watermarking.  Options:  text/overlay
     *
     * @var string
     */
    public $wm_type = 'text';

    /**
     * Default transparency for watermark
     *
     * @var int
     */
    public $wm_x_transp = 4;

    /**
     * Default transparency for watermark
     *
     * @var int
     */
    public $wm_y_transp = 4;

    /**
     * Watermark image path
     *
     * @var string
     */
    public $wm_overlay_path = '';

    /**
     * TT font
     *
     * @var string
     */
    public $wm_font_path = '';

    /**
     * Font size (different versions of GD will either use points or pixels)
     *
     * @var int
     */
    public $wm_font_size = 17;

    /**
     * Vertical alignment:   T M B
     *
     * @var string
     */
    public $wm_vrt_alignment = 'B';

    /**
     * Horizontal alignment: L R C
     *
     * @var string
     */
    public $wm_hor_alignment = 'C';

    /**
     * Padding around text
     *
     * @var int
     */
    public $wm_padding = 0;

    /**
     * Lets you push text to the right
     *
     * @var int
     */
    public $wm_hor_offset = 0;

    /**
     * Lets you push text down
     *
     * @var int
     */
    public $wm_vrt_offset = 0;

    /**
     * Text color
     *
     * @var string
     */
    protected $wm_font_color = '#ffffff';

    /**
     * Dropshadow color
     *
     * @var string
     */
    protected $wm_shadow_color = '';

    /**
     * Dropshadow distance
     *
     * @var int
     */
    public $wm_shadow_distance = 2;

    /**
     * Image opacity: 1 - 100  Only works with image
     *
     * @var int
     */
    public $wm_opacity = 50;

    // --------------------------------------------------------------------------
    // Private Vars
    // --------------------------------------------------------------------------

    /**
     * Source image folder
     *
     * @var string
     */
    public $source_folder = '';

    /**
     * Destination image folder
     *
     * @var string
     */
    public $dest_folder = '';

    /**
     * Image mime-type
     *
     * @var string
     */
    public $mime_type = '';

    /**
     * Original image width
     *
     * @var int
     */
    public $orig_width = '';

    /**
     * Original image height
     *
     * @var int
     */
    public $orig_height = '';

    /**
     * Image format
     *
     * @var string
     */
    public $image_type = '';

    /**
     * Size of current image
     *
     * @var string
     */
    public $size_str = '';

    /**
     * Full path to source image
     *
     * @var string
     */
    public $full_src_path = '';

    /**
     * Full path to destination image
     *
     * @var string
     */
    public $full_dst_path = '';

    /**
     * File permissions
     *
     * @var	int
     */
    public $file_permissions = 0644;

    /**
     * Name of function to create image
     *
     * @var string
     */
    public $create_fnc = 'imagecreatetruecolor';

    /**
     * Name of function to copy image
     *
     * @var string
     */
    public $copy_fnc = 'imagecopyresampled';

    /**
     * Error messages
     *
     * @var array
     */
    public $error_msg = array();

    /**
     * Whether to have a drop shadow on watermark
     *
     * @var bool
     */
    protected $wm_use_drop_shadow = FALSE;

    /**
     * Whether to use truetype fonts
     *
     * @var bool
     */
    public $wm_use_truetype = FALSE;

    /**
     * Initialize Image Library
     *
     * @param	array	$props
     * @return	void
     */
    public function __construct($props = array()) {
        if (count($props) > 0) {
            $this->initialize($props);
        }

        /**
         * A work-around for some improperly formatted, but
         * usable JPEGs; known to be produced by Samsung
         * smartphones' front-facing cameras.
         *
         * @see	https://github.com/bcit-ci/CodeIgniter/issues/4967
         * @see	https://bugs.php.net/bug.php?id=72404
         */
        ini_set('gd.jpeg_ignore_warning', 1);

        log_message('info', 'Image Lib Class Initialized');
    }

    // --------------------------------------------------------------------

    /**
     * Initialize image properties
     *
     * Resets values in case this class is used in a loop
     *
     * @return	void
     */
    public function clear() {
        $props = array('thumb_marker', 'library_path', 'source_image', 'new_image', 'width', 'height', 'rotation_angle', 'x_axis', 'y_axis', 'wm_text', 'wm_overlay_path', 'wm_font_path', 'wm_shadow_color', 'source_folder', 'dest_folder', 'mime_type', 'orig_width', 'orig_height', 'image_type', 'size_str', 'full_src_path', 'full_dst_path');

        foreach ($props as $val) {
            $this->$val = '';
        }

        $this->image_library = 'gd2';
        $this->dynamic_output = FALSE;
        $this->quality = 90;
        $this->create_thumb = FALSE;
        $this->thumb_marker = '_thumb';
        $this->maintain_ratio = TRUE;
        $this->master_dim = 'auto';
        $this->wm_type = 'text';
        $this->wm_x_transp = 4;
        $this->wm_y_transp = 4;
        $this->wm_font_size = 17;
        $this->wm_vrt_alignment = 'B';
        $this->wm_hor_alignment = 'C';
        $this->wm_padding = 0;
        $this->wm_hor_offset = 0;
        $this->wm_vrt_offset = 0;
        $this->wm_font_color = '#ffffff';
        $this->wm_shadow_distance = 2;
        $this->wm_opacity = 50;
        $this->create_fnc = 'imagecreatetruecolor';
        $this->copy_fnc = 'imagecopyresampled';
        $this->error_msg = array();
        $this->wm_use_drop_shadow = FALSE;
        $this->wm_use_truetype = FALSE;
    }

    // --------------------------------------------------------------------

    /**
     * initialize image preferences
     *
     * @param	array
     * @return	bool
     */
    public function initialize($props = array()) {
        // Convert array elements into class variables
        if (count($props) > 0) {
            foreach ($props as $key => $val) {
                if (property_exists($this, $key)) {
                    if (in_array($key, array('wm_font_color', 'wm_shadow_color'), TRUE)) {
                        if (preg_match('/^#?([0-9a-f]{3}|[0-9a-f]{6})$/i', $val, $matches)) {
                            /* $matches[1] contains our hex color value, but it might be
                             * both in the full 6-length format or the shortened 3-length
                             * value.
                             * We'll later need the full version, so we keep it if it's
                             * already there and if not - we'll convert to it. We can
                             * access string characters by their index as in an array,
                             * so we'll do that and use concatenation to form the final
                             * value:
                             */
                            $val = (strlen($matches[1]) === 6) ? '#' . $matches[1] : '#' . $matches[1][0] . $matches[1][0] . $matches[1][1] . $matches[1][1] . $matches[1][2] . $matches[1][2];
                        } else {
                            continue;
                        }
                    } elseif (in_array($key, array('width', 'height'), TRUE) && !ctype_digit((string) $val)) {
                        continue;
                    }

                    $this->$key = $val;
                }
            }
        }

        // Is there a source image? If not, there's no reason to continue
        if ($this->source_image === '') {
            $this->set_error('imglib_source_image_required');
            return FALSE;
        }

        /* Is getimagesize() available?
         *
         * We use it to determine the image properties (width/height).
         * Note: We need to figure out how to determine image
         * properties using ImageMagick and NetPBM
         */
        if (!function_exists('getimagesize')) {
            $this->set_error('imglib_gd_required_for_props');
            return FALSE;
        }

        $this->image_library = strtolower($this->image_library);

        /* Set the full server path
         *
         * The source image may or may not contain a path.
         * Either way, we'll try use realpath to generate the
         * full server path in order to more reliably read it.
         */
        if (($full_source_path = realpath($this->source_image)) !== FALSE) {
            $full_source_path = str_replace('\\', '/', $full_source_path);
        } else {
            $full_source_path = $this->source_image;
        }

        $x = explode('/', $full_source_path);
        $this->source_image = end($x);
        $this->source_folder = str_replace($this->source_image, '', $full_source_path);

        // Set the Image Properties
        if (!$this->get_image_properties($this->source_folder . $this->source_image)) {
            return FALSE;
        }

        /*
         * Assign the "new" image name/path
         *
         * If the user has set a "new_image" name it means
         * we are making a copy of the source image. If not
         * it means we are altering the original. We'll
         * set the destination filename and path accordingly.
         */
        if ($this->new_image === '') {
            $this->dest_image = $this->source_image;
            $this->dest_folder = $this->source_folder;
        } elseif (strpos($this->new_image, '/') === FALSE && strpos($this->new_image, '\\') === FALSE) {
            $this->dest_image = $this->new_image;
            $this->dest_folder = $this->source_folder;
        } else {
            // Is there a file name?
            if (!preg_match('#\.(jpg|jpeg|gif|png)$#i', $this->new_image)) {
                $this->dest_image = $this->source_image;
                $this->dest_folder = $this->new_image;
            } else {
                $x = explode('/', str_replace('\\', '/', $this->new_image));
                $this->dest_image = end($x);
                $this->dest_folder = str_replace($this->dest_image, '', $this->new_image);
            }

            $this->dest_folder = realpath($this->dest_folder) . '/';
        }

        /* Compile the finalized filenames/paths
         *
         * We'll create two master strings containing the
         * full server path to the source image and the
         * full server path to the destination image.
         * We'll also split the destination image name
         * so we can insert the thumbnail marker if needed.
         */
        if ($this->create_thumb === FALSE OR $this->thumb_marker === '') {
            $this->thumb_marker = '';
        }

        $xp = $this->explode_name($this->dest_image);

        $filename = $xp['name'];
        $file_ext = $xp['ext'];

        $this->full_src_path = $this->source_folder . $this->source_image;
        $this->full_dst_path = $this->dest_folder . $filename . $this->thumb_marker . $file_ext;

        /* Should we maintain image proportions?
         *
         * When creating thumbs or copies, the target width/height
         * might not be in correct proportion with the source
         * image's width/height. We'll recalculate it here.
         */
        if ($this->maintain_ratio === TRUE && ($this->width !== 0 OR $this->height !== 0)) {
            $this->image_reproportion();
        }

        /* Was a width and height specified?
         *
         * If the destination width/height was not submitted we
         * will use the values from the actual file
         */
        if ($this->width === '') {
            $this->width = $this->orig_width;
        }

        if ($this->height === '') {
            $this->height = $this->orig_height;
        }

        // Set the quality
        $this->quality = trim(str_replace('%', '', $this->quality));

        if ($this->quality === '' OR $this->quality === 0 OR ! ctype_digit($this->quality)) {
            $this->quality = 90;
        }

        // Set the x/y coordinates
        is_numeric($this->x_axis) OR $this->x_axis = 0;
        is_numeric($this->y_axis) OR $this->y_axis = 0;

        // Watermark-related Stuff...
        if ($this->wm_overlay_path !== '') {
            $this->wm_overlay_path = str_replace('\\', '/', realpath($this->wm_overlay_path));
        }

        if ($this->wm_shadow_color !== '') {
            $this->wm_use_drop_shadow = TRUE;
        } elseif ($this->wm_use_drop_shadow === TRUE && $this->wm_shadow_color === '') {
            $this->wm_use_drop_shadow = FALSE;
        }

        if ($this->wm_font_path !== '') {
            $this->wm_use_truetype = TRUE;
        }

        return TRUE;
    }

    // --------------------------------------------------------------------

    /**
     * Image Resize
     *
     * This is a wrapper function that chooses the proper
     * resize function based on the protocol specified
     *
     * @return	bool
     */
    public function resize() {
        $protocol = ($this->image_library === 'gd2') ? 'image_process_gd' : 'image_process_' . $this->image_library;
        return $this->$protocol('resize');
    }

    // --------------------------------------------------------------------

    /**
     * Image Crop
     *
     * This is a wrapper function that chooses the proper
     * cropping function based on the protocol specified
     *
     * @return	bool
     */
    public function crop() {
        $protocol = ($this->image_library === 'gd2') ? 'image_process_gd' : 'image_process_' . $this->image_library;
        return $this->$protocol('crop');
    }

    // --------------------------------------------------------------------

    /**
     * Image Rotate
     *
     * This is a wrapper function that chooses the proper
     * rotation function based on the protocol specified
     *
     * @return	bool
     */
    public function rotate() {
        // Allowed rotation values
        $degs = array(90, 180, 270, 'vrt', 'hor');

        if ($this->rotation_angle === '' OR ! in_array($this->rotation_angle, $degs)) {
            $this->set_error('imglib_rotation_angle_required');
            return FALSE;
        }

        // Reassign the width and height
        if ($this->rotation_angle === 90 OR $this->rotation_angle === 270) {
            $this->width = $this->orig_height;
            $this->height = $this->orig_width;
        } else {
            $this->width = $this->orig_width;
            $this->height = $this->orig_height;
        }

        // Choose resizing function
        if ($this->image_library === 'imagemagick' OR $this->image_library === 'netpbm') {
            $protocol = 'image_process_' . $this->image_library;
            return $this->$protocol('rotate');
        }

        return ($this->rotation_angle === 'hor' OR $this->rotation_angle === 'vrt') ? $this->image_mirror_gd() : $this->image_rotate_gd();
    }

    // --------------------------------------------------------------------

    /**
     * Image Process Using GD/GD2
     *
     * This function will resize or crop
     *
     * @param	string
     * @return	bool
     */
    public function image_process_gd($action = 'resize') {
        $v2_override = FALSE;

        // If the target width/height match the source, AND if the new file name is not equal to the old file name
        // we'll simply make a copy of the original with the new name... assuming dynamic rendering is off.
        if ($this->dynamic_output === FALSE && $this->orig_width === $this->width && $this->orig_height === $this->height) {
            if ($this->source_image !== $this->new_image && @copy($this->full_src_path, $this->full_dst_path)) {
                chmod($this->full_dst_path, $this->file_permissions);
            }

            return TRUE;
        }

        // Let's set up our values based on the action
        if ($action === 'crop') {
            // Reassign the source width/height if cropping
            $this->orig_width = $this->width;
            $this->orig_height = $this->height;

            // GD 2.0 has a cropping bug so we'll test for it
            if ($this->gd_version() !== FALSE) {
                $gd_version = str_replace('0', '', $this->gd_version());
                $v2_override = ($gd_version == 2);
            }
        } else {
            // If resizing the x/y axis must be zero
            $this->x_axis = 0;
            $this->y_axis = 0;
        }

        // Create the image handle
        if (!($src_img = $this->image_create_gd())) {
            return FALSE;
        }

        /* Create the image
         *
         * Old conditional which users report cause problems with shared GD libs who report themselves as "2.0 or greater"
         * it appears that this is no longer the issue that it was in 2004, so we've removed it, retaining it in the comment
         * below should that ever prove inaccurate.
         *
         * if ($this->image_library === 'gd2' && function_exists('imagecreatetruecolor') && $v2_override === FALSE)
         */
        if ($this->image_library === 'gd2' && function_exists('imagecreatetruecolor')) {
            $create = 'imagecreatetruecolor';
            $copy = 'imagecopyresampled';
        } else {
            $create = 'imagecreate';
            $copy = 'imagecopyresized';
        }

        $dst_img = $create($this->width, $this->height);

        if ($this->image_type === 3) { // png we can actually preserve transparency
            imagealphablending($dst_img, FALSE);
            imagesavealpha($dst_img, TRUE);
        }

        $copy($dst_img, $src_img, 0, 0, $this->x_axis, $this->y_axis, $this->width, $this->height, $this->orig_width, $this->orig_height);

        // Show the image
        if ($this->dynamic_output === TRUE) {
            $this->image_display_gd($dst_img);
        } elseif (!$this->image_save_gd($dst_img)) { // Or save it
            return FALSE;
        }

        // Kill the file handles
        imagedestroy($dst_img);
        imagedestroy($src_img);

        chmod($this->full_dst_path, $this->file_permissions);

        return TRUE;
    }

    // --------------------------------------------------------------------

    /**
     * Image Process Using ImageMagick
     *
     * This function will resize, crop or rotate
     *
     * @param	string
     * @return	bool
     */
    public function image_process_imagemagick($action = 'resize') {
        // Do we have a vaild library path?
        if ($this->library_path === '') {
            $this->set_error('imglib_libpath_invalid');
            return FALSE;
        }

        if (!preg_match('/convert$/i', $this->library_path)) {
            $this->library_path = rtrim($this->library_path, '/') . '/convert';
        }

        // Execute the command
        $cmd = $this->library_path . ' -quality ' . $this->quality;

        if ($action === 'crop') {
            $cmd .= ' -crop ' . $this->width . 'x' . $this->height . '+' . $this->x_axis . '+' . $this->y_axis;
        } elseif ($action === 'rotate') {
            $cmd .= ($this->rotation_angle === 'hor' OR $this->rotation_angle === 'vrt') ? ' -flop' : ' -rotate ' . $this->rotation_angle;
        } else { // Resize
            if ($this->maintain_ratio === TRUE) {
                $cmd .= ' -resize ' . $this->width . 'x' . $this->height;
            } else {
                $cmd .= ' -resize ' . $this->width . 'x' . $this->height . '\!';
            }
        }

        $cmd .= ' ' . escapeshellarg($this->full_src_path) . ' ' . escapeshellarg($this->full_dst_path) . ' 2>&1';

        $retval = 1;
        // exec() might be disabled
        if (function_usable('exec')) {
            @exec($cmd, $output, $retval);
        }

        // Did it work?
        if ($retval > 0) {
            $this->set_error('imglib_image_process_failed');
            return FALSE;
        }

        chmod($this->full_dst_path, $this->file_permissions);

        return TRUE;
    }

    // --------------------------------------------------------------------

    /**
     * Image Process Using NetPBM
     *
     * This function will resize, crop or rotate
     *
     * @param	string
     * @return	bool
     */
    public function image_process_netpbm($action = 'resize') {
        if ($this->library_path === '') {
            $this->set_error('imglib_libpath_invalid');
            return FALSE;
        }

        // Build the resizing command
        switch ($this->image_type) {
            case 1 :
                $cmd_in = 'giftopnm';
                $cmd_out = 'ppmtogif';
                break;
            case 2 :
                $cmd_in = 'jpegtopnm';
                $cmd_out = 'ppmtojpeg';
                break;
            case 3 :
                $cmd_in = 'pngtopnm';
                $cmd_out = 'ppmtopng';
                break;
        }

        if ($action === 'crop') {
            $cmd_inner = 'pnmcut -left ' . $this->x_axis . ' -top ' . $this->y_axis . ' -width ' . $this->width . ' -height ' . $this->height;
        } elseif ($action === 'rotate') {
            switch ($this->rotation_angle) {
                case 90: $angle = 'r270';
                    break;
                case 180: $angle = 'r180';
                    break;
                case 270: $angle = 'r90';
                    break;
                case 'vrt': $angle = 'tb';
                    break;
                case 'hor': $angle = 'lr';
                    break;
            }

            $cmd_inner = 'pnmflip -' . $angle . ' ';
        } else { // Resize
            $cmd_inner = 'pnmscale -xysize ' . $this->width . ' ' . $this->height;
        }

        $cmd = $this->library_path . $cmd_in . ' ' . $this->full_src_path . ' | ' . $cmd_inner . ' | ' . $cmd_out . ' > ' . $this->dest_folder . 'netpbm.tmp';

        $retval = 1;
        // exec() might be disabled
        if (function_usable('exec')) {
            @exec($cmd, $output, $retval);
        }

        // Did it work?
        if ($retval > 0) {
            $this->set_error('imglib_image_process_failed');
            return FALSE;
        }

        // With NetPBM we have to create a temporary image.
        // If you try manipulating the original it fails so
        // we have to rename the temp file.
        copy($this->dest_folder . 'netpbm.tmp', $this->full_dst_path);
        unlink($this->dest_folder . 'netpbm.tmp');
        chmod($this->full_dst_path, $this->file_permissions);

        return TRUE;
    }

    // --------------------------------------------------------------------

    /**
     * Image Rotate Using GD
     *
     * @return	bool
     */
    public function image_rotate_gd() {
        // Create the image handle
        if (!($src_img = $this->image_create_gd())) {
            return FALSE;
        }

        // Set the background color
        // This won't work with transparent PNG files so we are
        // going to have to figure out how to determine the color
        // of the alpha channel in a future release.

        $white = imagecolorallocate($src_img, 255, 255, 255);

        // Rotate it!
        $dst_img = imagerotate($src_img, $this->rotation_angle, $white);

        // Show the image
        if ($this->dynamic_output === TRUE) {
            $this->image_display_gd($dst_img);
        } elseif (!$this->image_save_gd($dst_img)) { // ... or save it
            return FALSE;
        }

        // Kill the file handles
        imagedestroy($dst_img);
        imagedestroy($src_img);

        chmod($this->full_dst_path, $this->file_permissions);

        return TRUE;
    }

    // --------------------------------------------------------------------

    /**
     * Create Mirror Image using GD
     *
     * This function will flip horizontal or vertical
     *
     * @return	bool
     */
    public function image_mirror_gd() {
        if (!$src_img = $this->image_create_gd()) {
            return FALSE;
        }

        $width = $this->orig_width;
        $height = $this->orig_height;

        if ($this->rotation_angle === 'hor') {
            for ($i = 0; $i < $height; $i++) {
                $left = 0;
                $right = $width - 1;

                while ($left < $right) {
                    $cl = imagecolorat($src_img, $left, $i);
                    $cr = imagecolorat($src_img, $right, $i);

                    imagesetpixel($src_img, $left, $i, $cr);
                    imagesetpixel($src_img, $right, $i, $cl);

                    $left++;
                    $right--;
                }
            }
        } else {
            for ($i = 0; $i < $width; $i++) {
                $top = 0;
                $bottom = $height - 1;

                while ($top < $bottom) {
                    $ct = imagecolorat($src_img, $i, $top);
                    $cb = imagecolorat($src_img, $i, $bottom);

                    imagesetpixel($src_img, $i, $top, $cb);
                    imagesetpixel($src_img, $i, $bottom, $ct);

                    $top++;
                    $bottom--;
                }
            }
        }

        // Show the image
        if ($this->dynamic_output === TRUE) {
            $this->image_display_gd($src_img);
        } elseif (!$this->image_save_gd($src_img)) { // ... or save it
            return FALSE;
        }

        // Kill the file handles
        imagedestroy($src_img);

        chmod($this->full_dst_path, $this->file_permissions);

        return TRUE;
    }

    // --------------------------------------------------------------------

    /**
     * Image Watermark
     *
     * This is a wrapper function that chooses the type
     * of watermarking based on the specified preference.
     *
     * @return	bool
     */
    public function watermark() {
        return ($this->wm_type === 'overlay') ? $this->overlay_watermark() : $this->text_watermark();
    }

    // --------------------------------------------------------------------

    /**
     * Watermark - Graphic Version
     *
     * @return	bool
     */
    public function overlay_watermark() {
        if (!function_exists('imagecolortransparent')) {
            $this->set_error('imglib_gd_required');
            return FALSE;
        }

        // Fetch source image properties
        $this->get_image_properties();

        // Fetch watermark image properties
        $props = $this->get_image_properties($this->wm_overlay_path, TRUE);
        $wm_img_type = $props['image_type'];
        $wm_width = $props['width'];
        $wm_height = $props['height'];

        // Create two image resources
        $wm_img = $this->image_create_gd($this->wm_overlay_path, $wm_img_type);
        $src_img = $this->image_create_gd($this->full_src_path);

        // Reverse the offset if necessary
        // When the image is positioned at the bottom
        // we don't want the vertical offset to push it
        // further down. We want the reverse, so we'll
        // invert the offset. Same with the horizontal
        // offset when the image is at the right

        $this->wm_vrt_alignment = strtoupper($this->wm_vrt_alignment[0]);
        $this->wm_hor_alignment = strtoupper($this->wm_hor_alignment[0]);

        if ($this->wm_vrt_alignment === 'B')
            $this->wm_vrt_offset = $this->wm_vrt_offset * -1;

        if ($this->wm_hor_alignment === 'R')
            $this->wm_hor_offset = $this->wm_hor_offset * -1;

        // Set the base x and y axis values
        $x_axis = $this->wm_hor_offset + $this->wm_padding;
        $y_axis = $this->wm_vrt_offset + $this->wm_padding;

        // Set the vertical position
        if ($this->wm_vrt_alignment === 'M') {
            $y_axis += ($this->orig_height / 2) - ($wm_height / 2);
        } elseif ($this->wm_vrt_alignment === 'B') {
            $y_axis += $this->orig_height - $wm_height;
        }

        // Set the horizontal position
        if ($this->wm_hor_alignment === 'C') {
            $x_axis += ($this->orig_width / 2) - ($wm_width / 2);
        } elseif ($this->wm_hor_alignment === 'R') {
            $x_axis += $this->orig_width - $wm_width;
        }

        // Build the finalized image
        if ($wm_img_type === 3 && function_exists('imagealphablending')) {
            @imagealphablending($src_img, TRUE);
        }

        // Set RGB values for text and shadow
        $rgba = imagecolorat($wm_img, $this->wm_x_transp, $this->wm_y_transp);
        $alpha = ($rgba & 0x7F000000) >> 24;

        // make a best guess as to whether we're dealing with an image with alpha transparency or no/binary transparency
        if ($alpha > 0) {
            // copy the image directly, the image's alpha transparency being the sole determinant of blending
            imagecopy($src_img, $wm_img, $x_axis, $y_axis, 0, 0, $wm_width, $wm_height);
        } else {
            // set our RGB value from above to be transparent and merge the images with the specified opacity
            imagecolortransparent($wm_img, imagecolorat($wm_img, $this->wm_x_transp, $this->wm_y_transp));
            imagecopymerge($src_img, $wm_img, $x_axis, $y_axis, 0, 0, $wm_width, $wm_height, $this->wm_opacity);
        }

        // We can preserve transparency for PNG images
        if ($this->image_type === 3) {
            imagealphablending($src_img, FALSE);
            imagesavealpha($src_img, TRUE);
        }

        // Output the image
        if ($this->dynamic_output === TRUE) {
            $this->image_display_gd($src_img);
        } elseif (!$this->image_save_gd($src_img)) { // ... or save it
            return FALSE;
        }

        imagedestroy($src_img);
        imagedestroy($wm_img);

        return TRUE;
    }

    // --------------------------------------------------------------------

    /**
     * Watermark - Text Version
     *
     * @return	bool
     */
    public function text_watermark() {
        if (!($src_img = $this->image_create_gd())) {
            return FALSE;
        }

        if ($this->wm_use_truetype === TRUE && !file_exists($this->wm_font_path)) {
            $this->set_error('imglib_missing_font');
            return FALSE;
        }

        // Fetch source image properties
        $this->get_image_properties();

        // Reverse the vertical offset
        // When the image is positioned at the bottom
        // we don't want the vertical offset to push it
        // further down. We want the reverse, so we'll
        // invert the offset. Note: The horizontal
        // offset flips itself automatically

        if ($this->wm_vrt_alignment === 'B') {
            $this->wm_vrt_offset = $this->wm_vrt_offset * -1;
        }

        if ($this->wm_hor_alignment === 'R') {
            $this->wm_hor_offset = $this->wm_hor_offset * -1;
        }

        // Set font width and height
        // These are calculated differently depending on
        // whether we are using the true type font or not
        if ($this->wm_use_truetype === TRUE) {
            if (empty($this->wm_font_size)) {
                $this->wm_font_size = 17;
            }

            if (function_exists('imagettfbbox')) {
                $temp = imagettfbbox($this->wm_font_size, 0, $this->wm_font_path, $this->wm_text);
                $temp = $temp[2] - $temp[0];

                $fontwidth = $temp / strlen($this->wm_text);
            } else {
                $fontwidth = $this->wm_font_size - ($this->wm_font_size / 4);
            }

            $fontheight = $this->wm_font_size;
            $this->wm_vrt_offset += $this->wm_font_size;
        } else {
            $fontwidth = imagefontwidth($this->wm_font_size);
            $fontheight = imagefontheight($this->wm_font_size);
        }

        // Set base X and Y axis values
        $x_axis = $this->wm_hor_offset + $this->wm_padding;
        $y_axis = $this->wm_vrt_offset + $this->wm_padding;

        if ($this->wm_use_drop_shadow === FALSE) {
            $this->wm_shadow_distance = 0;
        }

        $this->wm_vrt_alignment = strtoupper($this->wm_vrt_alignment[0]);
        $this->wm_hor_alignment = strtoupper($this->wm_hor_alignment[0]);

        // Set vertical alignment
        if ($this->wm_vrt_alignment === 'M') {
            $y_axis += ($this->orig_height / 2) + ($fontheight / 2);
        } elseif ($this->wm_vrt_alignment === 'B') {
            $y_axis += $this->orig_height - $fontheight - $this->wm_shadow_distance - ($fontheight / 2);
        }

        // Set horizontal alignment
        if ($this->wm_hor_alignment === 'R') {
            $x_axis += $this->orig_width - ($fontwidth * strlen($this->wm_text)) - $this->wm_shadow_distance;
        } elseif ($this->wm_hor_alignment === 'C') {
            $x_axis += floor(($this->orig_width - ($fontwidth * strlen($this->wm_text))) / 2);
        }

        if ($this->wm_use_drop_shadow) {
            // Offset from text
            $x_shad = $x_axis + $this->wm_shadow_distance;
            $y_shad = $y_axis + $this->wm_shadow_distance;

            /* Set RGB values for shadow
             *
             * First character is #, so we don't really need it.
             * Get the rest of the string and split it into 2-length
             * hex values:
             */
            $drp_color = str_split(substr($this->wm_shadow_color, 1, 6), 2);
            $drp_color = imagecolorclosest($src_img, hexdec($drp_color[0]), hexdec($drp_color[1]), hexdec($drp_color[2]));

            // Add the shadow to the source image
            if ($this->wm_use_truetype) {
                imagettftext($src_img, $this->wm_font_size, 0, $x_shad, $y_shad, $drp_color, $this->wm_font_path, $this->wm_text);
            } else {
                imagestring($src_img, $this->wm_font_size, $x_shad, $y_shad, $this->wm_text, $drp_color);
            }
        }

        /* Set RGB values for text
         *
         * First character is #, so we don't really need it.
         * Get the rest of the string and split it into 2-length
         * hex values:
         */
        $txt_color = str_split(substr($this->wm_font_color, 1, 6), 2);
        $txt_color = imagecolorclosest($src_img, hexdec($txt_color[0]), hexdec($txt_color[1]), hexdec($txt_color[2]));

        // Add the text to the source image
        if ($this->wm_use_truetype) {
            imagettftext($src_img, $this->wm_font_size, 0, $x_axis, $y_axis, $txt_color, $this->wm_font_path, $this->wm_text);
        } else {
            imagestring($src_img, $this->wm_font_size, $x_axis, $y_axis, $this->wm_text, $txt_color);
        }

        // We can preserve transparency for PNG images
        if ($this->image_type === 3) {
            imagealphablending($src_img, FALSE);
            imagesavealpha($src_img, TRUE);
        }

        // Output the final image
        if ($this->dynamic_output === TRUE) {
            $this->image_display_gd($src_img);
        } else {
            $this->image_save_gd($src_img);
        }

        imagedestroy($src_img);

        return TRUE;
    }

    // --------------------------------------------------------------------

    /**
     * Create Image - GD
     *
     * This simply creates an image resource handle
     * based on the type of image being processed
     *
     * @param	string
     * @param	string
     * @return	resource
     */
    public function image_create_gd($path = '', $image_type = '') {
        if ($path === '') {
            $path = $this->full_src_path;
        }

        if ($image_type === '') {
            $image_type = $this->image_type;
        }

        switch ($image_type) {
            case 1:
                if (!function_exists('imagecreatefromgif')) {
                    $this->set_error(array('imglib_unsupported_imagecreate', 'imglib_gif_not_supported'));
                    return FALSE;
                }

                return imagecreatefromgif($path);
            case 2:
                if (!function_exists('imagecreatefromjpeg')) {
                    $this->set_error(array('imglib_unsupported_imagecreate', 'imglib_jpg_not_supported'));
                    return FALSE;
                }

                return imagecreatefromjpeg($path);
            case 3:
                if (!function_exists('imagecreatefrompng')) {
                    $this->set_error(array('imglib_unsupported_imagecreate', 'imglib_png_not_supported'));
                    return FALSE;
                }

                return imagecreatefrompng($path);
            default:
                $this->set_error(array('imglib_unsupported_imagecreate'));
                return FALSE;
        }
    }

    // --------------------------------------------------------------------

    /**
     * Write image file to disk - GD
     *
     * Takes an image resource as input and writes the file
     * to the specified destination
     *
     * @param	resource
     * @return	bool
     */
    public function image_save_gd($resource) {
        switch ($this->image_type) {
            case 1:
                if (!function_exists('imagegif')) {
                    $this->set_error(array('imglib_unsupported_imagecreate', 'imglib_gif_not_supported'));
                    return FALSE;
                }

                if (!@imagegif($resource, $this->full_dst_path)) {
                    $this->set_error('imglib_save_failed');
                    return FALSE;
                }
                break;
            case 2:
                if (!function_exists('imagejpeg')) {
                    $this->set_error(array('imglib_unsupported_imagecreate', 'imglib_jpg_not_supported'));
                    return FALSE;
                }

                if (!@imagejpeg($resource, $this->full_dst_path, $this->quality)) {
                    $this->set_error('imglib_save_failed');
                    return FALSE;
                }
                break;
            case 3:
                if (!function_exists('imagepng')) {
                    $this->set_error(array('imglib_unsupported_imagecreate', 'imglib_png_not_supported'));
                    return FALSE;
                }

                if (!@imagepng($resource, $this->full_dst_path)) {
                    $this->set_error('imglib_save_failed');
                    return FALSE;
                }
                break;
            default:
                $this->set_error(array('imglib_unsupported_imagecreate'));
                return FALSE;
                break;
        }

        return TRUE;
    }

    // --------------------------------------------------------------------

    /**
     * Dynamically outputs an image
     *
     * @param	resource
     * @return	void
     */
    public function image_display_gd($resource) {
        header('Content-Disposition: filename=' . $this->source_image . ';');
        header('Content-Type: ' . $this->mime_type);
        header('Content-Transfer-Encoding: binary');
        header('Last-Modified: ' . gmdate('D, d M Y H:i:s', time()) . ' GMT');

        switch ($this->image_type) {
            case 1 : imagegif($resource);
                break;
            case 2 : imagejpeg($resource, NULL, $this->quality);
                break;
            case 3 : imagepng($resource);
                break;
            default: echo 'Unable to display the image';
                break;
        }
    }

    // --------------------------------------------------------------------

    /**
     * Re-proportion Image Width/Height
     *
     * When creating thumbs, the desired width/height
     * can end up warping the image due to an incorrect
     * ratio between the full-sized image and the thumb.
     *
     * This function lets us re-proportion the width/height
     * if users choose to maintain the aspect ratio when resizing.
     *
     * @return	void
     */
    public function image_reproportion() {
        if (($this->width === 0 && $this->height === 0) OR $this->orig_width === 0 OR $this->orig_height === 0
                OR ( !ctype_digit((string) $this->width) && !ctype_digit((string) $this->height))
                OR ! ctype_digit((string) $this->orig_width) OR ! ctype_digit((string) $this->orig_height)) {
            return;
        }

        // Sanitize
        $this->width = (int) $this->width;
        $this->height = (int) $this->height;

        if ($this->master_dim !== 'width' && $this->master_dim !== 'height') {
            if ($this->width > 0 && $this->height > 0) {
                $this->master_dim = ((($this->orig_height / $this->orig_width) - ($this->height / $this->width)) < 0) ? 'width' : 'height';
            } else {
                $this->master_dim = ($this->height === 0) ? 'width' : 'height';
            }
        } elseif (($this->master_dim === 'width' && $this->width === 0)
                OR ( $this->master_dim === 'height' && $this->height === 0)) {
            return;
        }

        if ($this->master_dim === 'width') {
            $this->height = (int) ceil($this->width * $this->orig_height / $this->orig_width);
        } else {
            $this->width = (int) ceil($this->orig_width * $this->height / $this->orig_height);
        }
    }

    // --------------------------------------------------------------------

    /**
     * Get image properties
     *
     * A helper function that gets info about the file
     *
     * @param	string
     * @param	bool
     * @return	mixed
     */
    public function get_image_properties($path = '', $return = FALSE) {
        // For now we require GD but we should
        // find a way to determine this using IM or NetPBM

        if ($path === '') {
            $path = $this->full_src_path;
        }

        if (!file_exists($path)) {
            $this->set_error('imglib_invalid_path');
            return FALSE;
        }

        $vals = getimagesize($path);
        if ($vals === FALSE) {
            $this->set_error('imglib_invalid_image');
            return FALSE;
        }

        $types = array(1 => 'gif', 2 => 'jpeg', 3 => 'png');
        $mime = isset($types[$vals[2]]) ? 'image/' . $types[$vals[2]] : 'image/jpg';

        if ($return === TRUE) {
            return array(
                'width' => $vals[0],
                'height' => $vals[1],
                'image_type' => $vals[2],
                'size_str' => $vals[3],
                'mime_type' => $mime
            );
        }

        $this->orig_width = $vals[0];
        $this->orig_height = $vals[1];
        $this->image_type = $vals[2];
        $this->size_str = $vals[3];
        $this->mime_type = $mime;

        return TRUE;
    }

    // --------------------------------------------------------------------

    /**
     * Size calculator
     *
     * This function takes a known width x height and
     * recalculates it to a new size. Only one
     * new variable needs to be known
     *
     * 	$props = array(
     * 			'width'		=> $width,
     * 			'height'	=> $height,
     * 			'new_width'	=> 40,
     * 			'new_height'	=> ''
     * 		);
     *
     * @param	array
     * @return	array
     */
    public function size_calculator($vals) {
        if (!is_array($vals)) {
            return;
        }

        $allowed = array('new_width', 'new_height', 'width', 'height');

        foreach ($allowed as $item) {
            if (empty($vals[$item])) {
                $vals[$item] = 0;
            }
        }

        if ($vals['width'] === 0 OR $vals['height'] === 0) {
            return $vals;
        }

        if ($vals['new_width'] === 0) {
            $vals['new_width'] = ceil($vals['width'] * $vals['new_height'] / $vals['height']);
        } elseif ($vals['new_height'] === 0) {
            $vals['new_height'] = ceil($vals['new_width'] * $vals['height'] / $vals['width']);
        }

        return $vals;
    }

    // --------------------------------------------------------------------

    /**
     * Explode source_image
     *
     * This is a helper function that extracts the extension
     * from the source_image.  This function lets us deal with
     * source_images with multiple periods, like: my.cool.jpg
     * It returns an associative array with two elements:
     * $array['ext']  = '.jpg';
     * $array['name'] = 'my.cool';
     *
     * @param	array
     * @return	array
     */
    public function explode_name($source_image) {
        $ext = strrchr($source_image, '.');
        $name = ($ext === FALSE) ? $source_image : substr($source_image, 0, -strlen($ext));

        return array('ext' => $ext, 'name' => $name);
    }

    // --------------------------------------------------------------------

    /**
     * Is GD Installed?
     *
     * @return	bool
     */
    public function gd_loaded() {
        if (!extension_loaded('gd')) {
            /* As it is stated in the PHP manual, dl() is not always available
             * and even if so - it could generate an E_WARNING message on failure
             */
            return (function_exists('dl') && @dl('gd.so'));
        }

        return TRUE;
    }

    // --------------------------------------------------------------------

    /**
     * Get GD version
     *
     * @return	mixed
     */
    public function gd_version() {
        if (function_exists('gd_info')) {
            $gd_version = @gd_info();
            return preg_replace('/\D/', '', $gd_version['GD Version']);
        }

        return FALSE;
    }

    // --------------------------------------------------------------------

    /**
     * Set error message
     *
     * @param	string
     * @return	void
     */
    public function set_error($msg) {
        $CI = & get_instance();
        $CI->lang->load('imglib');

        if (is_array($msg)) {
            foreach ($msg as $val) {
                $msg = ($CI->lang->line($val) === FALSE) ? $val : $CI->lang->line($val);
                $this->error_msg[] = $msg;
                log_message('error', $msg);
            }
        } else {
            $msg = ($CI->lang->line($msg) === FALSE) ? $msg : $CI->lang->line($msg);
            $this->error_msg[] = $msg;
            log_message('error', $msg);
        }
    }

    // --------------------------------------------------------------------

    /**
     * Show error messages
     *
     * @param	string
     * @param	string
     * @return	string
     */
    public function display_errors($open = '<p>', $close = '</p>') {
        return (count($this->error_msg) > 0) ? $open . implode($close . $open, $this->error_msg) . $close : '';
    }

}
