freaCMS/app/modules/cachedimage.php

<?php

namespace Modules;

class CachedImage {

    public $original;
    public $cache_dir = "tmp/";
    public $default_width = 500;
    public $format;
    public $quality;
    private $usecache = true;

    function __construct($path,$format=false) {
        $f3 = \Base::instance();
        $this->original = $path;
        $this->format = $f3->get('cachedImageFormat') ? : 'jpeg';
        $this->quality = $f3->get('cachedImageQuality') ? : false;

        if (is_string($format)) {
            $format = strtolower($format);
            if (in_array($format, ['png','jpg','jpeg'])) {
                $this->format = $format;
            } elseif ($format == "nocache") {
                $this->usecache = false;
            }
        }
        
        if ($this->quality === false) {
            switch($this->format) {
            case 'png':
                $this->quality = 6;
                break;
            case 'jpg':
            case 'jpeg':
                $this->quality = 75;
                break;
            }
        }
    }
    
    function get_src($inwidth = false) {
        $f3 = \Base::instance();
        if($this->is_image($this->original) && $this->usecache) {
            $info = pathinfo($this->original);
            $fn = basename($this->original,'.'.$info['extension']);
            $width = $inwidth ? $inwidth : $this->default_width;
            $name = md5($this->original.$width);
        
            $name =  sprintf("%s_%s.%s",$fn,$name,$this->format);
        
            $out = $this->cache_dir.$name;
    
            //if(!file_exists($this->original)) { $this->original='rsc/img/default.png'; }
    
            if(!file_exists($out)) {
                $img1 = new \Image($this->original);
                $img1->resize($width);
                $f3->write($out,$img1->dump($this->format,$this->quality));
                unset($img1);
            }
        } else {
            $out = $this->original;
        }
        return "/".$out;
    }

    function is_image($path) {
        // this protects from accidently calling this class on a wrong file
        // it doesn't ensure that the file actually contains valid image data
        $ex = explode('.',$path);
        $ext = array_pop($ex);
        return in_array(strtolower($ext),array( 'jpg', 'jpeg', 'png' ));
    }
}