学习笔记-php图像等比例剪裁-2016.4.7

因为小区附近宽带升级，所以笔记暂时没有更新，但是学习一直继续！今天继续，

<?php
/**
 * Created by PhpStorm.
 * User: 兰小宇
 * Date: 2016/3/30
 * Time: 23:08
 */
//图像处理类
class Image{
    private $file;          //图像地址
    private $width;         //获取图像的宽度
    private $height;        //获取图像的高度
    private $type;          //获取图像的类型
    private $img;           //原来图像的资源句柄
    private $new;           //新的资源句柄
    //构造方法
    public function __construct($file){
        $this->file = $_SERVER['DOCUMENT_ROOT'].$file;
        list($this->width,$this->height,$this->type) = getimagesize($this->file);
        $this->img = $this->getType($this->file,$this->type);
    }


   public function thumb($new_height,$new_width){
      if ($this->width < $this->height) {
           //让长度和新高度等比例
           $new_width = ($new_height / $this->height) * $this->width;
       }else{
           //让新高度和新长度等比例
           $new_height = ($new_width / $this->width) * $this->height;
       }
       $this->new = imagecreatetruecolor($new_width,$new_height);
      //创建剪裁后的图像
       imagecopyresampled($this->new,$this->img,0,0,0,0,$new_width,$new_height,$this->width,$this->height);
  }

  

    //判断图像类型，然后加载图像资源
    private function getType($file,$type){
        $img = '';
        switch($type){
            case 1:
                $img = imagecreatefromgif($file);
                break;
            case 2:
                $img = imagecreatefromjpeg($file);
                break;
            case 3:
                $img = imagecreatefrompng($file);
                break;
            default:
                Tool::alertBack('请上传图片类型为gif,jpg,png的文件！');
        }
        return $img;
    }
    //图像输出
    public function out(){
        imagepng($this->new,$this->file);//输出
        imagedestroy($this->img);//销毁资源
        imagedestroy($this->new);//销毁
    }
}