<?php
//影象處理類
class Image {
 private $file;    //圖片地址
 private $width;   //圖片長度
 private $height;   //圖片長度
 private $type;    //圖片型別
 private $img;    //原圖的資源控制代碼
 private $new;    //新圖的資源控制代碼
 
 //構造方法，初始化
 public function __construct($_file) {
  $this->file = $_SERVER["DOCUMENT_ROOT"].$_file;
  list($this->width, $this->height, $this->type) = getimagesize($this->file);
  $this->img = $this->getFromImg($this->file, $this->type);
 }
 //縮圖(固定長高容器，影象等比例，擴容填充，裁剪)[固定了大小，不失真，不變形]
 public function thumb($new_width = 0,$new_height = 0) {
  
  if (empty($new_width) && empty($new_height)) {
   $new_width = $this->width;
   $new_height = $this->height;
  }
  
  if (!is_numeric($new_width) || !is_numeric($new_height)) {
   $new_width = $this->width;
   $new_height = $this->height;
  }
  
  //建立一個容器
  $_n_w = $new_width;
  $_n_h = $new_height;
  
  //建立裁剪點
  $_cut_width = 0;
  $_cut_height = 0;
  
  if ($this->width < $this->height) {
   $new_width = ($new_height / $this->height) * $this->width;
  } else {
   $new_height = ($new_width / $this->width) * $this->height;
  }
 
  
  
  
  if ($new_width < $_n_w) { //如果新高度小於新容器高度
   $r = $_n_w / $new_width; //按長度求出等比例因子
   $new_width *= $r; //擴充套件填充後的長度
   $new_height *= $r; //擴充套件填充後的高度
   $_cut_height = ($new_height - $_n_h) / 2; //求出裁剪點的高度
  }
  
  if ($new_height < $_n_h) { //如果新高度小於容器高度
   $r = $_n_h / $new_height; //按高度求出等比例因子
   $new_width *= $r; //擴充套件填充後的長度
   $new_height *= $r; //擴充套件填充後的高度
   $_cut_width = ($new_width - $_n_w) / 2; //求出裁剪點的長度
  }
   
  
  $this->new = imagecreatetruecolor($_n_w,$_n_h);
  imagecopyresampled($this->new,$this->img,0,0,$_cut_width,$_cut_height,$new_width,$new_height,$this->width,$this->height);
 }
 
 //載入圖片，各種型別，返回圖片的資源控制代碼
 private function getFromImg($_file, $_type) {
  switch ($_type) {
   case 1 :
    $img = imagecreatefromgif($_file);
    break;
   case 2 :
    $img = imagecreatefromjpeg($_file);
    break;
   case 3 : 
    $img = imagecreatefrompng($_file);
    break;
   default:
    Tool::alertBack('警告：此圖片型別本系統不支援！');
  }
  return $img;
 }
 
 //影象輸出
 public function out() {
  imagepng($this->new,$this->file);
  imagedestroy($this->img);
  imagedestroy($this->new);
 }
}


 


?>




 //使用方法：
$_path = 'd:/1.jpg';
$_img = new Image($_path);//$_path為圖片檔案的路徑
 $_img->thumb(150, 100);
 $_img->out();