/**
 * 图片加文字水印类库
 *
 * @param 
 * @author 编程之家 jb51.cc jb51.cc
 * 该类库暂时只支持文字水印，位置为右下角，颜色随机
  
 * 调用方法：
 * 1、在需要加水印的文件顶部引入类库：
      include_once 'imageClass.PHP';
 * 2、声明新类：
 * $tpl=new image_fu;
 * 3、给图片水印提供参数：
      $tpl->img(图片路径,水印文字,字体路径,字体大小,字体角度);
 * 比如：$tpl->img('abc.jpg','这是水印文字','ziti.ttf',30,0)
 **/
 class image_fu{
  
  private $image;
  private $img_info;
  private $img_width;
  private $img_height;
  private $img_im;
  private $img_text;
  private $img_ttf='';
  private $img_new;
  private $img_text_size;
  private $img_jd;
  
  
  function img($img='',$txt='',$ttf='',$size=12,$jiaodu=0){
  if(isset($img)&&file_exists($img)){//检测图片是否存在
     $this->image   =$img; 
     $this->img_text=$txt;
     $this->img_text_size=$size;
     $this->img_jd=$jiaodu;
    if(file_exists($ttf)){
     $this->img_ttf=$ttf;
    }else{
     exit('字体文件：'.$ttf.'不存在！'); 
    }
     $this->imgyesno();
  }else{
       exit('图片文件:'.$img.'不存在');
    } 
  }
 
  private function imgyesno(){
  
  $this->img_info  =getimagesize($this->image);
  $this->img_width =$this->img_info[0];//图片宽
  $this->img_height=$this->img_info[1];//图片高
  
  //检测图片类型
  switch($this->img_info[2]){
             case 1:$this->img_im = imagecreatefromgif($this->image);break; 
             case 2:$this->img_im = imagecreatefromjpeg($this->image);break; 
             case 3:$this->img_im = imagecreatefrompng($this->image);break; 
             default:exit('图片格式不支持水印'); 
  }
  
     $this->img_text();
  }
  
  
  private function img_text(){
   
   imagealphablending($this->img_im,true);
   
   //设定颜色
    $color=imagecolorallocate($this->img_im,rand(0,255),255));
    $txt_height=$this->img_text_size;
    $txt_jiaodu=$this->img_jd;
    $ttf_im=imagettfbBox($txt_height,$txt_jiaodu,$this->img_ttf,$this->img_text);
    $w = $ttf_im[2] - $ttf_im[6]; 
          $h = $ttf_im[3] - $ttf_im[7]; 
    //$w = $ttf_im[7]; 
          //$h = $ttf_im[8];
          unset($ttf_im);
    
    $txt_y     =$this->img_height-$h;
    $txt_x     =$this->img_width-$w;
    //$txt_y     =0;
    //$txt_x     =0;
    
    
    $this->img_new=@imagettftext($this->img_im,$txt_height,$txt_x,$txt_y,$color,$this->img_text);

   @unlink($this->image);//删除图片
  switch($this->img_info[2]) {//取得背景图片的格式 
          case 1:imagegif($this->img_im,$this->image);break; 
          case 2:imagejpeg($this->img_im,$this->image);break; 
          case 3:imagepng($this->img_im,$this->image);break; 
          default: exit('水印图片失败'); 
        }
  }
  
  
  //显示图片
  function img_show(){echo '<img src="'.$this->image.'" border="0" alt="'.$this->img_text."" />';
  //释放内存
  private function img_nothing(){
   unset($this->img_info); 
         imagedestroy($this->img_im); 
  }
 }
/***   代码来自编程之家 jb51.cc（jb51.cc）   ***/