php 文字水印功能

<?php
header("Content-Type:text/html;   charset=UTF-8");
class WaterMask{
    public  $waterType          = 0;  //水印类型：0为文字水印、1为图片水印
    public  $pos                = 5;  //水印位置
    public  $transparent        = 45; //水印透明度
    public  $waterStr           = ‘www.codefans.net‘;  //水印文字
    public  $fontSize           = 16; //文字字体大小
    public  $fontColor          = array(255,255,255); //水印文字颜色（RGB）
    public  $fontFile           = ‘arial.ttf‘;//字体文件
    public  $waterImg           = ‘logo.png‘;//水印图片
    public $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) {
        $this->srcImg = file_exists($img)?  $img : die(‘"‘.$img.‘" 对不起，水印文件不存在！‘);
    }
    private function imginfo() {//获取水印图片信息，并加载。
        $this->srcImg_info = getimagesize($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(‘水印图片（‘.$this->srcImg.‘）水印图片格式不对，请选择PNG、JPEG、GIF格式的图片。‘);
        }
    }
    private function waterimginfo() {//获取水印图片并载入。
        $this->waterImg_info = getimagesize($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(‘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() {
        $this->waterStr = $this->autowrap($this->fontSize, 0, $this->fontFile, $this->waterStr, 250); // 自动换行处理
        echo $this->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 autowrap($fontsize, $angle, $fontface, $string, $width) {
// 这几个变量分别是 字体大小, 角度, 字体名称, 字符串, 预设宽度
        $content = "";
        // 将字符串拆分成一个个单字 保存到数组 letter 中
        for ($i=0;$i<mb_strlen($string);$i++) {
            $letter[] = mb_substr($string, $i, 1);
        }
        foreach ($letter as $l) {
            $teststr = $content." ".$l;
            $testbox = imagettfbbox($fontsize, $angle, $fontface, $teststr);
            // 判断拼接后的字符串是否超过预设的宽度
            if (($testbox[2] > $width) && ($content !== "")) {
                $content .= "\n";
            }
            $content .= $l;
        }
        return $content;
    }
    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(‘原因未知：水印添加失败！‘);
                break;
        }
        imagedestroy($this->im);
        imagedestroy($this->water_im);
    }
}
?>

 include("WaterMask.php");
            $imgFileName="$loadpath";
            $obj = new WaterMask($imgFileName);
            $obj->waterType = 0;//水印类型：0为文字水印、1为图片水印
            $obj->transparent = 100;//水印透明度
            $obj->waterStr = $_POST["Content"];//水印文字
            $obj->fontSize = 20;//字体大小
            $obj->fontColor = array(0,0,0);//水印文字颜色（RGB值）
            $obj->fontFile = ‘D:/WWW/wenzi1.ttf‘; //字体名称
            $obj->output(); //输出水印图片