PHP图片等比例缩放生成缩略图函数分享

               }
               if($dstimgH&&$$dstimgH<$pic_H){
                   $dsimgHratio=$dstimgH/$pic_H;
                   $resizerreagH=true;
               }
               //缩略图宽高和原图宽高比，取最小的那个
               if($resizereagW&&$resizerreagH){
                   if($dsimgWratio<$dsimgHratio)
                       $radio=$dsimgWratio;
                   else
                       $radio=$dsimgHratio;     
               }
               if($resizereagW&&!$resizerreagH){
                       $radio=$dsimgWratio;
               }
               if(!$resizereagW&&$resizerreagH){
                      $radio=$dsimgHratio;
               }
               $imgnewW=$pic_W*$radio;
               $imgnewH=$pic_H*$radio;
               if(function_exists("imgcopyresampled")){
                     //创建目标资源画布
                   $dst=imagecreatetruecolor($imgnewW,$imgnewH);
                   imagecopyresampled($dst,$im,0,0,0,0,$imgnewW,$imgnewH,$pic_W,$pic_H);
               }else{
            $dst=imagecreate($imgnewW,$imgnewH);
            imagecopyresized($dst,$im,0,0,0,0,$imgnewW,$imgnewH,$imgnewH,$pic_W,$pic_H);
               }

       $arr[$filetype]($dst,$thumbname.".$filetype");
       imagedestroy($dst);
   }else{//缩略图自身的宽和高已经大于了原图的宽和高
          //则缩略图的宽和缩略的高就是原图的宽和原图的高
        $arr[$filetype]($im,$thumbname.".$filetype");
        imagedestroy();
   }
}
?>