智能的PHP缩图类

*作者：落梦天蝎（beluckly）
*完成时间：2006-12-18
*类名：CreatMiniature
*功能：生成多种类型的缩略图
*基本参数：$srcFile,$echoType
*方法用到的参数：
$toFile,生成的文件
$toW,生成的宽
$toH,生成的高
$bk1,背景颜色参数 以255为最高
$bk2,背景颜色参数
$bk3,背景颜色参数

*例子：

 < ?php

 /***************************************
 *作者：落梦天蝎（beluckly）
 *完成时间：2006-12-18
 *类名：CreatMiniature
 *功能：生成多种类型的缩略图
 *基本参数：$srcFile,$echoType
 *方法用到的参数：
                 $toFile,生成的文件
                 $toW,生成的宽
                 $toH,生成的高
                 $bk1,背景颜色参数 以255为最高
                 $bk2,背景颜色参数
                 $bk3,背景颜色参数

 *例子：

     include("thumb.php");
     $cm=new CreatMiniature();
     $cm->SetVar("1.jpg","file");
     $cm->Distortion("dis_bei.jpg",150,200);
     $cm->Prorate("pro_bei.jpg",150,200);
     $cm->Cut("cut_bei.jpg",150,200);
     $cm->BackFill("fill_bei.jpg",150,200);

 ***************************************/

 class CreatMiniature
 {
     //公共变量
     var $srcFile="";        //原图
     var $echoType;            //输出图片类型，link--不保存为文件；file--保存为文件
     var $im="";                //临时变量
     var $srcW="";            //原图宽
     var $srcH="";            //原图高

     //设置变量及初始化
     function SetVar($srcFile,$echoType)
     {
         $this->srcFile=$srcFile;
         $this->echoType=$echoType;

         $info = "";
         $data = GetImageSize($this->srcFile,$info);
         switch ($data[2])
         {
          case 1:
            if(!function_exists("imagecreatefromgif")){
             echo "你的GD库不能使用GIF格式的图片，请使用Jpeg或PNG格式！<a href='javascript:go(-1);'>返回</a>";
             exit();
            }
            $this->im = ImageCreateFromGIF($this->srcFile);
            break;
         case 2:
           if(!function_exists("imagecreatefromjpeg")){
            echo "你的GD库不能使用jpeg格式的图片，请使用其它格式的图片！<a href='javascript:go(-1);'>返回</a>";
            exit();
           }
           $this->im = ImageCreateFromJpeg($this->srcFile);
           break;
         case 3:
           $this->im = ImageCreateFromPNG($this->srcFile);
           break;
       }
       $this->srcW=ImageSX($this->im);
       $this->srcH=ImageSY($this->im);
     }

     //生成扭曲型缩图
     function Distortion($toFile,$toW,$toH)
     {
         $cImg=$this->CreatImage($this->im,$toW,$toH,0,0,0,0,$this->srcW,$this->srcH);
         return $this->EchoImage($cImg,$toFile);
         ImageDestroy($cImg);
     }

     //生成按比例缩放的缩图
     function Prorate($toFile,$toW,$toH)
     {
         $toWH=$toW/$toH;
         $srcWH=$this->srcW/$this->srcH;
         if($toWH< =$srcWH)
         {
             $ftoW=$toW;
             $ftoH=$ftoW*($this->srcH/$this->srcW);
         }
         else
         {
               $ftoH=$toH;
               $ftoW=$ftoH*($this->srcW/$this->srcH);
         }
         if($this->srcW>$toW||$this->srcH>$toH)
         {
             $cImg=$this->CreatImage($this->im,$ftoW,$ftoH,0,0,0,0,$this->srcW,$this->srcH);
             return $this->EchoImage($cImg,$toFile);
             ImageDestroy($cImg);
         }
         else
         {
             $cImg=$this->CreatImage($this->im,$this->srcW,$this->srcH,0,0,0,0,$this->srcW,$this->srcH);
             return $this->EchoImage($cImg,$toFile);
             ImageDestroy($cImg);
         }
     }

     //生成最小裁剪后的缩图
     function Cut($toFile,$toW,$toH)
     {
           $toWH=$toW/$toH;
           $srcWH=$this->srcW/$this->srcH;
           if($toWH< =$srcWH)
           {
                $ctoH=$toH;
                $ctoW=$ctoH*($this->srcW/$this->srcH);
           }
           else
           {
               $ctoW=$toW;
               $ctoH=$ctoW*($this->srcH/$this->srcW);
           }
         $allImg=$this->CreatImage($this->im,$ctoW,$ctoH,0,0,0,0,$this->srcW,$this->srcH);
         $cImg=$this->CreatImage($allImg,$toW,$toH,0,0,($ctoW-$toW)/2,($ctoH-$toH)/2,$toW,$toH);
         return $this->EchoImage($cImg,$toFile);
         ImageDestroy($cImg);
         ImageDestroy($allImg);
     }

     //生成背景填充的缩图
     function BackFill($toFile,$toW,$toH,$bk1=255,$bk2=255,$bk3=255)
     {
         $toWH=$toW/$toH;
         $srcWH=$this->srcW/$this->srcH;
         if($toWH< =$srcWH)
         {
             $ftoW=$toW;
             $ftoH=$ftoW*($this->srcH/$this->srcW);
         }
         else
         {
               $ftoH=$toH;
               $ftoW=$ftoH*($this->srcW/$this->srcH);
         }
         if(function_exists("imagecreatetruecolor"))
         {
             @$cImg=ImageCreateTrueColor($toW,$toH);
             if(!$cImg)
             {
                 $cImg=ImageCreate($toW,$toH);
             }
         }
         else
         {
             $cImg=ImageCreate($toW,$toH);
         }
         $backcolor = imagecolorallocate($cImg, $bk1, $bk2, $bk3);        //填充的背景颜色
         ImageFilledRectangle($cImg,0,0,$toW,$toH,$backcolor);
         if($this->srcW>$toW||$this->srcH>$toH)
         {
             $proImg=$this->CreatImage($this->im,$ftoW,$ftoH,0,0,0,0,$this->srcW,$this->srcH);
             /*
              if($ftoW< $toW)
              {
                  ImageCopyMerge($cImg,$proImg,($toW-$ftoW)/2,0,0,0,$ftoW,$ftoH,100);
              }
              else if($ftoH<$toH)
              {
                  ImageCopyMerge($cImg,$proImg,0,($toH-$ftoH)/2,0,0,$ftoW,$ftoH,100);
              }
              */
             if($ftoW<$toW)
             {
                  ImageCopy($cImg,$proImg,($toW-$ftoW)/2,0,0,0,$ftoW,$ftoH);
             }
             else if($ftoH<$toH)
             {
                  ImageCopy($cImg,$proImg,0,($toH-$ftoH)/2,0,0,$ftoW,$ftoH);
             }
             else
             {
                  ImageCopy($cImg,$proImg,0,0,0,0,$ftoW,$ftoH);
             }
         }
         else
         {
              ImageCopyMerge($cImg,$this->im,($toW-$ftoW)/2,($toH-$ftoH)/2,0,0,$ftoW,$ftoH,100);
         }
         return $this->EchoImage($cImg,$toFile);
         ImageDestroy($cImg);
     }

     function CreatImage($img,$creatW,$creatH,$dstX,$dstY,$srcX,$srcY,$srcImgW,$srcImgH)
     {
         if(function_exists("imagecreatetruecolor"))
         {
             @$creatImg = ImageCreateTrueColor($creatW,$creatH);
             if($creatImg)
                 ImageCopyResampled($creatImg,$img,$dstX,$dstY,$srcX,$srcY,$creatW,$creatH,$srcImgW,$srcImgH);
             else
             {
                 $creatImg=ImageCreate($creatW,$creatH);
                 ImageCopyResized($creatImg,$img,$dstX,$dstY,$srcX,$srcY,$creatW,$creatH,$srcImgW,$srcImgH);
             }
          }
          else
          {
             $creatImg=ImageCreate($creatW,$creatH);
             ImageCopyResized($creatImg,$img,$dstX,$dstY,$srcX,$srcY,$creatW,$creatH,$srcImgW,$srcImgH);
          }
          return $creatImg;
     }

     //输出图片，link---只输出，不保存文件。file--保存为文件
     function EchoImage($img,$to_File)
     {
         switch($this->echoType)
         {
             case "link":
                 if(function_exists('imagejpeg')) return ImageJpeg($img);
                 else return ImagePNG($img);
                 break;
             case "file":
                 if(function_exists('imagejpeg')) return ImageJpeg($img,$to_File);
                 else return ImagePNG($img,$to_File);
                 break;
         }
     }

 }
 ?>