<?php
namespace captcha;
/*
*驗證碼類
*verify方法生成驗證碼字符串
*entry方法生成驗證碼
*特別提醒：這里要先用entry生成驗證碼，再用verify生成驗證碼的字符串，也就是必須先調(diào)用entry，然后才能夠調(diào)用verify生成驗證碼的字符串，原因代碼已經(jīng)說明問題了，因為驗證碼的字符串是在entry方法調(diào)用captchaImage生成的，所以必須先調(diào)用它才行
*有的地方對中文的字體要求比較高，所以，有的地方不支持中文驗證碼
*/
class Captcha{
  //配置參數(shù)
  private $config = array();
  //驗證碼
  private $verifyCode = '';
  //獲取配置文件的配置信息，給類傳參數(shù)就行，例如new Captcha($config);$config是你的配置文件信息
  public function __construct($config=array('width'=>100,'height'=>40,'length'=>4,'size'=>7,'lines'=>0,'dots'=>0,'font'=>'simfang.ttf','rectangle'=>array(255,55,122),'charset'=>true,'chinese'=>'來到新機場主航站樓建設(shè)在婚姻關(guān)系存續(xù)期間所負債務(wù)她在收到要求她償還前夫在婚姻關(guān)系存續(xù)期間所欠債務(wù)的法院傳票后要精益求精善始善終')){
    $this->config = $config;
  }
  //創(chuàng)建驗證碼
  private function captchaImage(){
    //畫布
    $img = imagecreatetruecolor($this->config['width'],$this->config['height']);
    //填充畫布顏色
    imagefill($img,0,0,imagecolorallocate($img,mt_rand(200,255),mt_rand(200,255),mt_rand(200,255)));
    //需要邊框則畫邊框
    if($this->config['rectangle'] && is_array($this->config['rectangle']) && count($this->config['rectangle']) == 3){
      $this->tangle($img);
    }
    $this->verifyCode = $this->code($img,$this->config['charset'],$this->config['chinese']);
    //存在則添加干擾線
    if($this->config['lines']){
      $this->codeLines($img);
    }
    //存在則添加干擾點
    if($this->config['dots']){
      $this->codeDots($img);
    }
    return $img;
  }
  private function codeLines($img){
    //繪制干擾線
    for($i=0;$i<$this->config['lines'];$i++){
      imageline($img,mt_rand(0,$this->config['width'] / 10),mt_rand(0,$this->config['height']),mt_rand($this->config['width'] * 7/ 10,$this->config['width'] * 9/ 10),mt_rand(0,$this->config['height']),imagecolorallocate($img,mt_rand(0,255),mt_rand(0,255),mt_rand(0,255)));
    }
  }
  private function codeDots($img){
    //添加噪點
    for($i=0;$i<$this->config['dots'];$i++){
      //噪點顏色
      $color = imagecolorallocate($img,mt_rand(0,180),mt_rand(0,180),mt_rand(0,180));
      imagestring($img,mt_rand(1,3),mt_rand(0,170),mt_rand(0,30),'*',$color);
    
    }
  }
  /*畫布邊框*/
  private function tangle($img){
    imagerectangle($img,0,0,$this->config['width']-1,$this->config['height']-1,imagecolorallocate($img,$this->config['rectangle'][0],$this->config['rectangle'][1],$this->config['rectangle'][2]));
  }
  /*生成驗證碼,默認英文，$ch為true則為中文*/
  private function code($img,$ch=false,$set=''){
    $str = "";
    //計算間隔
    $span = ceil($this->config['width']/($this->config['length']+1));
    if($ch && !empty($set)){
      //隨機產(chǎn)生字符
      $set = $this->config['chinese'];
      for($i=0;$i<$this->config['length'];$i++){
        $end = strlen($set)/3;
        $pos = mt_rand(0,$end-1);
        $str .= substr($set,$pos*3,3);
      }
      //每次繪制一個字符
      for($i=1;$i<=$this->config['length'];$i++){
        imagettftext($img,16,mt_rand(-30,60),$i*$span,$this->config['height']*3/5,imagecolorallocate($img,mt_rand(0,180),mt_rand(0,180),mt_rand(0,180)),$this->config['font'],substr($str,($i-1)*3,3));
      }
    }else{
      //隨機生成字母或者數(shù)字
      for($i=0;$i<$this->config['length'];$i++){
        switch(mt_rand(0,2)){
          case 0:
          $str .= chr(mt_rand(65,90));
          break;
        case 1:
          $str .= chr(mt_rand(97,122));
          break;
        case 2:
          $str .= chr(mt_rand(48,57));
        }
      }
      //每次繪制一個字符
      for($i=1;$i<=$this->config['length'];$i++){
        imagestring($img,$this->config['size'],$i*$span,0,$str[$i-1],imagecolorallocate($img,mt_rand(0,180),mt_rand(0,180),mt_rand(0,180)));
      }
    }
    return $str;
  }
  //獲取驗證碼
  public function verify(){
    return $this->verifyCode;
  }
  //生成驗證碼
  public function entry(){
    header("content-type:image/png");
    imagepng($this->captchaImage());
  }
}
$ob = new Captcha;
$ob->entry();