php旋转图片角度

    public function test()
    {
        $this->flip($filename, $src, 90); 
    }

    /**
     * @param $filename // 图片原始地址
     * @param $src // 旋转后图片保存地址
     * @param int $degrees // 旋转角度
     * @return bool
     */
    public function flip($filename,$src,$degrees = 90)
    {
        //读取图片
        $data = @getimagesize($filename);

        if($data==false)return false;
        //读取旧图片
        switch ($data[2]) {
            case 1:
                $src_f = imagecreatefromgif($filename);break;
            case 2:
                $src_f = imagecreatefromjpeg($filename);break;
            case 3:
                $src_f = imagecreatefrompng($filename);break;
        }
        if($src_f=="")return false;
        $rotate = @imagerotate($src_f, $degrees,0);
        if(!imagejpeg($rotate,$src,100))return false;
        @imagedestroy($rotate);
        return true;
    }