PHP 图片水印类

<?php
/**
 * 加水印类，支持文字图片水印的透明度设置、水印图片背景透明。
 *      $obj = new WaterMask($imgFileName);          //实例化对象
 *      $obj->$waterType = 1;                        //类型：0为文字水印、1为图片水印
 *      $obj->$transparent = 45;                     //水印透明度
 *      $obj->$waterStr = 'www.itwhy.org';           //水印文字
 *      $obj->$fontSize = 16;                        //文字字体大小
 *      $obj->$fontColor = array(255,0255);          //水印文字颜色（RGB）
 *      $obj->$fontFile = = 'AHGBold.ttf';           //字体文件
 *      $obj->output();                              //输出水印图片文件覆盖到输入的图片文件
 */
class WaterMask{
    public  $waterType          = ;                //水印类型：0为文字水印、1为图片水印
    public  $pos                = ;                //水印位置
    public  $transparent        = ;               //水印透明度
 
    public  $waterStr           = 'www.itwhy.org';  //水印文字
    public  $fontSize           = ;               //文字字体大小
    public  $fontColor          = array(,,); //水印文字颜色（RGB）
    public  $fontFile           = 'AHGBold.ttf';    //字体文件
 
    public  $waterImg           = 'logo.png';       //水印图片
 
    private $srcImg             = '';               //需要添加水印的图片
    private $im                 = '';               //图片句柄
    private $water_im           = '';               //水印图片句柄
    private $srcImg_info        = '';               //图片信息
    private $waterImg_info      = '';               //水印图片信息
    private $str_w              = '';               //水印文字宽度
    private $str_h              = '';               //水印文字高度
    private $x                  = '';               //水印X坐标
    private $y                  = '';               //水印y坐标
 
    function __construct($img) {        //析构函数
        $this->srcImg = file_exists($img) ? $img : die('"'.$img.'" 源文件不存在！');
    }
    private function imginfo() {                //获取需要添加水印的图片的信息，并载入图片。
        $this->srcImg_info = getimagesize($this->srcImg);
        switch ($this->srcImg_info[]) {
            case :
                $this->im = imagecreatefrompng($this->srcImg);
                break ;
            case :
                $this->im = imagecreatefromjpeg($this->srcImg);
                break ;
            case :
                $this->im = imagecreatefromgif($this->srcImg);
                break ;
            default:
                die('原图片（'.$this->srcImg.'）格式不对，只支持PNG、JPEG、GIF。');
        }
    }
    private function waterimginfo() {           //获取水印图片的信息，并载入图片。
        $this->waterImg_info = getimagesize($this->waterImg);
        switch ($this->waterImg_info[]) {
            case :
                $this->water_im = imagecreatefrompng($this->waterImg);
                break ;
            case :
                $this->water_im = imagecreatefromjpeg($this->waterImg);
                break ;
            case :
                $this->water_im = imagecreatefromgif($this->waterImg);
                break ;
            default:
                die('水印图片（'.$this->srcImg.'）格式不对，只支持PNG、JPEG、GIF。');
        }
    }
    private function waterpos() {               //水印位置算法
        switch ($this->pos) {
            case :     //随机位置
                $this->x = rand(,$this->srcImg_info[]-$this->waterImg_info[]);
                $this->y = rand(,$this->srcImg_info[]-$this->waterImg_info[]);
                break ;
            case :     //上左
                $this->x = ;
                $this->y = ;
                break ;
            case :     //上中
                $this->x = ($this->srcImg_info[]-$this->waterImg_info[])/;
                $this->y = ;
                break ;
            case :     //上右
                $this->x = $this->srcImg_info[]-$this->waterImg_info[];
                $this->y = ;
                break ;
            case :     //中左
                $this->x = ;
                $this->y = ($this->srcImg_info[]-$this->waterImg_info[])/;
                break ;
            case :     //中中
                $this->x = ($this->srcImg_info[]-$this->waterImg_info[])/;
                $this->y = ($this->srcImg_info[]-$this->waterImg_info[])/;
                break ;
            case :     //中右
                $this->x = $this->srcImg_info[]-$this->waterImg_info[];
                $this->y = ($this->srcImg_info[]-$this->waterImg_info[])/;
                break ;
            case :     //下左
                $this->x = ;
                $this->y = $this->srcImg_info[]-$this->waterImg_info[];
                break ;
            case :     //下中
                $this->x = ($this->srcImg_info[]-$this->waterImg_info[])/;
                $this->y = $this->srcImg_info[]-$this->waterImg_info[];
                break ;
            default:    //下右
                $this->x = $this->srcImg_info[]-$this->waterImg_info[];
                $this->y = $this->srcImg_info[]-$this->waterImg_info[];
                break ;
        }
    }
    private function waterimg() {
        if ($this->srcImg_info[] <= $this->waterImg_info[] || $this->srcImg_info[] <= $this->waterImg_info[]){
            die('水印比原图大！');
        }
        $this->waterpos();
        $cut = imagecreatetruecolor($this->waterImg_info[],$this->waterImg_info[]);
        imagecopy($cut,$this->im,,,$this->x,$this->y,$this->waterImg_info[],$this->waterImg_info[]);
        $pct = $this->transparent;
        imagecopy($cut,$this->water_im,,,,,$this->waterImg_info[],$this->waterImg_info[]);
        imagecopymerge($this->im,$cut,$this->x,$this->y,,,$this->waterImg_info[],$this->waterImg_info[],$pct);
    }
    private function waterstr() {
        $rect = imagettfbbox($this->fontSize,,$this->fontFile,$this->waterStr);
        $w = abs($rect[]-$rect[]);
        $h = abs($rect[]-$rect[]);
        $fontHeight = $this->fontSize;
        $this->water_im = imagecreatetruecolor($w, $h);
        imagealphablending($this->water_im,false);
        imagesavealpha($this->water_im,true);
        $white_alpha = imagecolorallocatealpha($this->water_im,,,,);
        imagefill($this->water_im,,,$white_alpha);
        $color = imagecolorallocate($this->water_im,$this->fontColor[],$this->fontColor[],$this->fontColor[]);
        imagettftext($this->water_im,$this->fontSize,,,$this->fontSize,$color,$this->fontFile,$this->waterStr);
        $this->waterImg_info = array(=>$w,=>$h);
        $this->waterimg();
    }
    function output() {
        $this->imginfo();
        if ($this->waterType == ) {
            $this->waterstr();
        }else {
            $this->waterimginfo();
            $this->waterimg();
        }
        switch ($this->srcImg_info[]) {
            case :
                imagepng($this->im,$this->srcImg);
                break ;
            case :
                imagejpeg($this->im,$this->srcImg);
                break ;
            case :
                imagegif($this->im,$this->srcImg);
                break ;
            default:
                die('添加水印失败！');
                break;
        }
        imagedestroy($this->im);
        imagedestroy($this->water_im);
    }
}
?>