?php
 
namespace App\Tool\Validate;
 
//驗證碼類
class ValidateCode {
  private $charset = 'abcdefghkmnprstuvwxyzABCDEFGHKMNPRSTUVWXYZ23456789';//隨機因子
  private $code;//驗證碼
  private $codelen = 4;//驗證碼長度
  private $width = 130;//寬度
  private $height = 50;//高度
  private $img;//圖形資源句柄
  private $font;//指定的字體
  private $fontsize = 20;//指定字體大小
  private $fontcolor;//指定字體顏色
 
  //構造方法初始化
  public function __construct()
  {
    $this->font = public_path() . '/fonts/Elephant.ttf';//注意字體路徑要寫對，否則顯示不了圖片
    $this->createCode();
  }
  //生成隨機碼
  private function createCode()
  {
    $_len = strlen($this->charset) - 1;
    for ($i = 0;$i  $this->codelen;++$i) {
      $this->code .= $this->charset[mt_rand(0, $_len)];
    }
  }
  //生成背景
  private function createBg()
  {
    $this->img = imagecreatetruecolor($this->width, $this->height);
    $color = imagecolorallocate($this->img, mt_rand(157, 255), mt_rand(157, 255), mt_rand(157, 255));
    imagefilledrectangle($this->img, 0, $this->height, $this->width, 0, $color);
  }
  //生成文字
  private function createFont()
  {
    $_x = $this->width / $this->codelen;
    for ($i = 0;$i  $this->codelen;++$i) {
      $this->fontcolor = imagecolorallocate($this->img, mt_rand(0, 156), mt_rand(0, 156), mt_rand(0, 156));
      imagettftext($this->img, $this->fontsize, mt_rand(-30, 30), $_x * $i + mt_rand(1, 5), $this->height / 1.4, $this->fontcolor, $this->font, $this->code[$i]);
    }
  }
  //生成線條、雪花
  private function createLine()
  {
    //線條
    for ($i = 0;$i  6;++$i) {
      $color = imagecolorallocate($this->img, mt_rand(0, 156), mt_rand(0, 156), mt_rand(0, 156));
      imageline($this->img, mt_rand(0, $this->width), mt_rand(0, $this->height), mt_rand(0, $this->width), mt_rand(0, $this->height), $color);
    }
    //雪花
    for ($i = 0;$i  100;++$i) {
      $color = imagecolorallocate($this->img, mt_rand(200, 255), mt_rand(200, 255), mt_rand(200, 255));
      imagestring($this->img, mt_rand(1, 5), mt_rand(0, $this->width), mt_rand(0, $this->height), '*', $color);
    }
  }
  //輸出
  private function outPut()
  {
    header('Content-type:image/png');
    imagepng($this->img);
    imagedestroy($this->img);
  }
  //對外生成
  public function doimg()
  {
    $this->createBg();
    $this->createLine();
    $this->createFont();
    $this->outPut();
  }
  //獲取驗證碼
  public function getCode()
  {
    return strtolower($this->code);
  }
}