image resize

CzImage.php

<?php
class CzImage{
    protected $resource;
    protected $newResource;
    protected $name;
    protected $path;
    protected $width;
    protected $height;
    protected $ext;
    protected $mime;
    private $_saveFunctionName;

    /**
     * @param $path
     * @throws CzImageArgumentException
     * @throws CzImageTypeException
     */
    public function __construct($path)
    {
        $this->path = $path;
        $imageInfo = getimagesize($this->path);
        if($imageInfo===false) throw new CzImageArgumentException('load image failure,path: '.$this->path);
        switch($imageInfo[2]){
            case IMAGETYPE_GIF:
                $this->resource = @imagecreatefromgif($this->path);
                $this->ext = '.gif';
                $this->_saveFunctionName = 'imagegif';
                break;
            case IMAGETYPE_JPEG:
                $this->resource = @imagecreatefromjpeg($this->path);
                $this->ext = '.jpg';
                $this->_saveFunctionName = 'imagejpeg';
                break;
            case IMAGETYPE_PNG:
                $this->resource = @imagecreatefrompng($this->path);
                $this->ext = '.png';
                $this->_saveFunctionName = 'imagepng';
                break;
            default:
                throw new CzImageTypeException('Not support this image type:'.$this->path);
                break;
        }
        if($this->resource===false) throw new CzImageArgumentException('create image failure,path: '.$this->path);
        $this->width = $imageInfo[0];
        $this->height = $imageInfo[1];
        $this->mime = $imageInfo['mime'];
        $this->name = substr($this->path,strrpos($this->path,'/')+1);
    }

    /**
     * @param int|null $newWidth
     * @param int|null $newHeight
     */
    public function resize($newWidth=null,$newHeight=null)
    {
        $newWidth = intval($newWidth);
        $newWidth = intval($newWidth);
        if($newWidth<=0&&$newHeight>0){
            $newWidth = intval($newHeight*$this->width/$this->height);
        }elseif($newWidth>0&&$newHeight<=0){
            $newHeight = intval($newWidth*$this->height/$this->width);
        }else{
            $newWidth = $this->width;
            $newHeight = $this->height;
        }
        $this->newResource = imagecreatetruecolor($newWidth, $newHeight);
        imagecopyresampled($this->newResource,$this->resource,0,0,0,0,$newWidth,$newHeight,$this->width,$this->height);
        $this->width = $newWidth;
        $this->height = $newHeight;
    }

    /**
     * @param $path
     * @param int $jpgQuality
     * @return bool
     */
    public function save($path,$jpgQuality=75)
    {
        if(isset($this->newResource)){
            $resource = $this->newResource;
        }else{
            $resource = $this->resource;
        }
        $dir = substr($path,0,strrpos($path,'/')+1);
        $params = array($resource,$path);
        if($this->_saveFunctionName == 'imagejpeg')$params[2] = intval($jpgQuality);
        if(!file_exists($dir)){
            if(mkdir($dir)){
                return call_user_func_array($this->_saveFunctionName,$params) !== false;
            }
        }else{
            return call_user_func_array($this->_saveFunctionName,$params) !== false;
        }
        return false;
    }

    /**
     * @param int $jpgQuality
     * @return bool
     */
    public function output($jpgQuality=75){
        if(isset($this->newResource)){
            $resource = $this->newResource;
        }else{
            $resource = $this->resource;
        }
        $params = array($resource,null);
        if($this->_saveFunctionName == 'imagejpeg')$params[2] = $jpgQuality;
        return call_user_func_array($this->_saveFunctionName,$params) !== false;
    }

    public function __destruct()
    {
        imagedestroy($this->resource);
        imagedestroy($this->newResource);
    }

    /**
     * @return string
     */
    public function getName()
    {
        return $this->name;
    }

    /**
     * @return int
     */
    public function getWidth()
    {
        return $this->width;
    }

    /**
     * @return int
     */
    public function getHeight()
    {
        return $this->height;
    }

    /**
     * @return string
     */
    public function getMime()
    {
        return $this->mime;
    }

}
class CzImageTypeException extends Exception{}
class CzImageArgumentException extends Exception{}