File Source for lib

<?php
/*
 * Lokorin.com
 * Copyright 2004-2006
 * Licensed under the GNU LGPL. See COPYING for full terms.
 */
/**
 * A library that contains everything that has to do with images and loading
 * graphical elements.
 * @author Andreas Launila
 * @version $Revision: 1.11 $
 * @package com.lokorin.lokorin.lib
 * @license http://www.gnu.org/copyleft/lesser.html GNU Lesser General Public License
 */
 
/**
 * For access to common constants and functions.
 */
require_once('common.php');
 
/**
 * The default maximum width to allow image to have.
 * @var integer 
 * @access private
 */
define('MAX_WIDTH', 500);
/**
 * The default maximum file size in kB to allow image to have.
 * @var integer 
 * @access private
 */
define('MAX_FILE_SIZE', 40);
/**
 * The default width a produced thumbnail image should have.
 * @var integer 
 * @access private
 */
define('THUMB_WIDTH', 450);
/**
 * The default file size in kB that a produced thumbnail image should aim at.
 * @var integer 
 * @access private
 */
define('THUMB_SIZE', 25);
 
/**
 * Gets the XHTML code for an image within the defined paramaters. If the
 * default source of the specified image does not meet the define parameters
 * then the function created an resized version of the image so that does.
 * @param string $imageName The name of the image i.e. 'foo.jpg' that should
 *          be retrived.
 * @param string $alt An optional alternative text to be used with the image.
 *          The text will be displayed if the image can not, for some reason, be
 *          displayed.
 * @param integer $maxWidth The maximum width in pixels that the image is
 *          allowed to have.
 * @param integer $maxSize The maximum size in kilobytes that the image is
 *          allowed to have.
 * @param integer $thumbWidth The width in pixels that a resized image should
 *          have.
 * @param integer $thumbSize The size in kilobytes that a resized image should
 *          aim for.
 * @return string XHTML compliant code representing the specified image within
 *          the specified parameters.
 * @access public
 */
function getImage($imageName, $alt = '', $maxWidth = MAX_WIDTH, 
        $maxSize = MAX_FILE_SIZE, $thumbWidth = THUMB_WIDTH, $thumbSize = THUMB_SIZE) {
    $img = array();
    $img['path'] = ROOT.FOLDER_IMAGES.$imageName;
    if(!file_exists($img['path'])) {
        logException(new FileNotFoundException('The image does not exist: ('.
                $img['path'].')'));
    }
    list($img['width'], $img['height']) = getimagesize($img['path']);
    $img['size'] = filesize($img['path']);
    
    if($img['width'] > $maxWidth || $img['size'] > $maxSize*1024) {
        //We replace it with a thumbnail.
        $thumb = array();
        $thumb['path'] = FOLDER_THUMBNAILS.preg_replace("/(.*)\..*$/",
            "$1_".$maxWidth."_".$thumbWidth."_".$thumbSize.".jpg",basename($img['path']));
        if(!file_exists($thumb['path'])) {
            //We have to create the thumbnail.
            /*
             * Check if a resized version of the image exists, if so then 
             * use the resized version. This is used if the original image
             * is too large to be resized (because of memory limits).
             */
            $imgToResize = preg_replace('/(.*?)(\.[^.]*)$/', '$1.resized$2', $img['path']);
            if(!file_exists($imgToResize)) {
                //There is no resized version, use the real image instead.
                $imgToResize = $img['path'];
            }
            list($img['width'], $img['height']) = getimagesize($imgToResize);
            $thumb['src'] = getImageResource($imgToResize);
            if($thumb['src'] === false) {
                logException(new IOException('Failed to create a thumbnail for: ('.
                    $imgToResize.')'));
            }
            if($img['width'] > $maxWidth) {
                //Resize it but keep the proportions
                $thumb['height'] = $thumbWidth*($img['height']/$img['width']);
                $thumb['width'] = $thumbWidth;
            } else {
                //No resize needed
                $thumb['height'] = $img['height'];
                $thumb['width'] = $img['width'];
            }
            //Resample it
            $thumb['dest'] = imagecreatetruecolor($thumb['width'], $thumb['height']);
            imagecopyresampled($thumb['dest'], $thumb['src'], 0, 0, 0, 0, $thumb['width'], $thumb['height'], $img['width'], $img['height']);
            imageinterlace($thumb['dest'], 1);
            touch($thumb['path']);
            imagejpeg($thumb['dest'], $thumb['path']);
            //Make sure that the thumbnail is below the thumb file size limit
            $thumb['size'] = filesize($thumb['path']);
            if($thumb['size'] > $thumbSize*1024) {
                //It's not small enough, reduce the thumb's quality
                //The file size and the quality might not be linearly connected but it should work
                //as a decent approximation.
                $quality = (int)(75*$thumbSize*1024/$thumb['size']);
                imagejpeg($thumb['dest'], $thumb['path'], $quality);
            }
        }
        //The file is now in the cache, use it.
        $imageCode = getImageCode($thumb['path'], $alt, 'Click for a larger image');
        return '<a href="'.ROOT_PATH.FOLDER_IMAGES.$imageName.'">'.$imageCode.'</a>';
    }
    return getImageCode($img['path'], $alt);
}
 
/**
 * Gets the XHTML code for a specified image.
 * @param string $imagePath The path to the image relative to the page root.
 * @param string $alt An optional alternative text to be used with the image.
 *          The text will be displayed if the image can not, for some reason, be
 *          displayed.
 * @param string $title An optional title for the image. The title will show up
 *          if the user holds the cursor over the image.
 * @param string $class An optional css class to use for the image element.
 * @return string XHTML compliant code representing the image.
 * @access public
 */
function getImageCode($imagePath, $alt = '', $title = '', $cssClass = '') {
    list($width, $height) = getimagesize(ROOT.$imagePath);
    if($title != '') {
        $title = ' title="'.htmlspecialchars($title).'"';
    }
    if($cssClass != '') {
        $class = ' class="'.$cssClass.'"';
    } else {
        $class = '';    
    }
    //<div class="alpha_shadow"><div>...</div></div><br style="clear: both" />
    return '<img src="'.ROOT_PATH.$imagePath.'" width="'.$width.
            '" height="'.$height.'" '.'alt="'.htmlspecialchars($alt).'"'.
            $title.$class.' />';
}
 
/**
 * Gets the image resource of the specified image file.
 * @param string $path The path to the image file.
 * @return imageResource An image resource or a boolean false if something went
 *          wrong.
 * @access private
 */
function getImageResource($path) {
    if(!file_exists($path)) {
        return false;
    }
    
    $match = array();
    preg_match("/.*\.(.*)$/", $path, $match);
    $format = $match[1];
    $format = strtolower($format);
    if($format == "jpg" || $format == "jpeg") {
        return imagecreatefromjpeg($path);
    } else if($format == "png") {
        return imagecreatefrompng($path);
    } else if($format == "gif") {
        return imagecreatefromgif($path);
    } else if($format == "wbmp") {
        return imagecreatefromwbmp($path);
    } else {
        return false;
    }
}
?>
Source for file lib_images.php
