php图片加水印类，支持文字水印、透明度设置、自定义水印类

$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.codetc.com';              //水印文字
 
 *      $obj->$fontSize = 18;                        //文字字体大小
 
 *      $obj->$fontColor = array(255,255,255);               //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          = 0;                    //水印类型：0为文字水印、1为图片水印
 
    public  $pos                = 0;                 //水印位置
 
    public  $transparent        = 45;                    //水印透明度
 
  
 
    public  $waterStr           = 'www.codetc.com';         //水印文字
 
    public  $fontSize           = 18;                   //文字字体大小
 
    public  $fontColor          = array(255,255,255);           //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[2]) {
 
            case 3:
 
                $this->im = imagecreatefrompng($this->srcImg);
 
                break 1;
 
            case 2:
 
                $this->im = imagecreatefromjpeg($this->srcImg);
 
                break 1;
 
            case 1:
 
                $this->im = imagecreatefromgif($this->srcImg);
 
                break 1;
 
            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[2]) {
 
            case 3:
 
                $this->water_im = imagecreatefrompng($this->waterImg);
 
                break 1;
 
            case 2:
 
                $this->water_im = imagecreatefromjpeg($this->waterImg);
 
                break 1;
 
            case 1:
 
                $this->water_im = imagecreatefromgif($this->waterImg);
 
                break 1;
 
            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 0:     //随机位置
 
                $this->x = rand(0,$this->srcImg_info[0]-$this->waterImg_info[0]);
 
                $this->y = rand(0,$this->srcImg_info[1]-$this->waterImg_info[1]);
 
                break 1;
 
            case 1:     //上左
 
                $this->x = 0;
 
                $this->y = 0;
 
                break 1;
 
            case 2:     //上中
 
                $this->x = ($this->srcImg_info[0]-$this->waterImg_info[0])/2;
 
                $this->y = 0;
 
                break 1;
 
            case 3:     //上右
 
                $this->x = $this->srcImg_info[0]-$this->waterImg_info[0];
 
                $this->y = 0;
 
                break 1;
 
            case 4:     //中左
 
                $this->x = 0;
 
                $this->y = ($this->srcImg_info[1]-$this->waterImg_info[1])/2;
 
                break 1;
 
            case 5:     //中中
 
                $this->x = ($this->srcImg_info[0]-$this->waterImg_info[0])/2;
 
                $this->y = ($this->srcImg_info[1]-$this->waterImg_info[1])/2;
 
                break 1;
 
            case 6:     //中右
 
                $this->x = $this->srcImg_info[0]-$this->waterImg_info[0];
 
                $this->y = ($this->srcImg_info[1]-$this->waterImg_info[1])/2;
 
                break 1;
 
            case 7:     //下左
 
                $this->x = 0;
 
                $this->y = $this->srcImg_info[1]-$this->waterImg_info[1];
 
                break 1;
 
            case 8:     //下中
 
                $this->x = ($this->srcImg_info[0]-$this->waterImg_info[0])/2;
 
                $this->y = $this->srcImg_info[1]-$this->waterImg_info[1];
 
                break 1;
 
            default:    //下右
 
                $this->x = $this->srcImg_info[0]-$this->waterImg_info[0];
 
                $this->y = $this->srcImg_info[1]-$this->waterImg_info[1];
 
                break 1;
 
        }
 
    }
 
 
 
    private function waterimg() {
 
        if ($this->srcImg_info[0] <= $this->waterImg_info[0] || $this->srcImg_info[1] <= $this->waterImg_info[1]){
 
            die('注意:水印比原图大！');
 
        }
 
        $this->waterpos();
 
        $cut = imagecreatetruecolor($this->waterImg_info[0],$this->waterImg_info[1]);
 
        imagecopy($cut,$this->im,0,0,$this->x,$this->y,$this->waterImg_info[0],$this->waterImg_info[1]);
 
        $pct = $this->transparent;
 
        imagecopy($cut,$this->water_im,0,0,0,0,$this->waterImg_info[0],$this->waterImg_info[1]);
 
        imagecopymerge($this->im,$cut,$this->x,$this->y,0,0,$this->waterImg_info[0],$this->waterImg_info[1],$pct);
 
    }
 
 
 
    private function waterstr() {
 
        $rect = imagettfbbox($this->fontSize,0,$this->fontFile,$this->waterStr);
 
        $w = abs($rect[2]-$rect[6]);
 
        $h = abs($rect[3]-$rect[7]);
 
        $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,255,255,255,127);
 
        imagefill($this->water_im,0,0,$white_alpha);
 
        $color = imagecolorallocate($this->water_im,$this->fontColor[0],$this->fontColor[1],$this->fontColor[2]);
 
        imagettftext($this->water_im,$this->fontSize,0,0,$this->fontSize,$color,$this->fontFile,$this->waterStr);
 
        $this->waterImg_info = array(0=>$w,1=>$h);
 
        $this->waterimg();
 
    }
 
 
 
    function output() {
 
        $this->imginfo();
 
        if ($this->waterType == 0) {
 
            $this->waterstr();
 
        }else {
 
            $this->waterimginfo();
 
            $this->waterimg();
 
        }
 
        switch ($this->srcImg_info[2]) {
 
            case 3:
 
                imagepng($this->im,$this->srcImg);
 
                break 1;
 
            case 2:
 
                imagejpeg($this->im,$this->srcImg);
 
                break 1;
 
            case 1:
 
                imagegif($this->im,$this->srcImg);
 
                break 1;
 
            default:
 
                die('添加水印失败哦！');
 
                break;
 
        }
 
        imagedestroy($this->im);
 
        imagedestroy($this->water_im);
 
    }
 
}
 
?>