<?php
/**
 * @name   Captcha Class
 * @file   captcha_image.cls.php
 * @date   2016-08-11 17:40
 * @author sancia@foxmail.com
**/
class Captcha_image {
	public  $image_width  = 0;
	public  $image_height = 0;
	public  $code_length  = 0;
	private $im           = null;
	private $code         = '';
	private $ttf_file     = '';
	private $multi_color  = array();
	private $cur_gmt_time = '';
	/**
	* @param $image_width  integer 图片宽度
	* @param $image_height integer 图片高度
	* @param $code_length  integer 验证码长度
	**/
	public function __construct( $image_width=120, $image_height=30, $ttf='scood.ttf'){
		$base_dir = str_replace('\\','/', dirname(__FILE__));
		$this->cur_gmt_time = gmdate('D, d M Y H:i:s'). ' GMT' ;
		$this->image_width  = $image_width;
		$this->image_height = $image_height;
		if($ttf ){
			$this->ttf_file = $base_dir . '/'. $ttf;
		}else{
			$this->ttf_file = $base_dir . '/scood.ttf'.;
		}
		$this->multi_color  = array(
			array( 102 , 102 ,255 ),
			array( 102 , 0   ,0   ),
			array( 55  , 187 ,99  ),
			array( 51  , 51  ,204 ),
			array( 153 , 51  ,0   ),
			array( 0   , 96  ,204 ),
			array( 220 , 50  ,200 ),
			array( 102 , 51  ,204 ),
			array( 210 , 20  ,100 ),
			array( 0   , 102 ,102 ),
			array( 204 , 51  ,102 ),
			array( 96  , 146 ,220 ),
			array( 255 , 167 ,0   )
		);

		$this->im  = imagecreatetruecolor($this->image_width, $this->image_height);
		$fillcolor = imagecolorAllocate($this->im, 255 , 255, 255);
		imagefill($this->im, 0, 0, $fillcolor);
	}
	/**
	* 创建 - 验证码
	* @access private
	**/
    private function create_code(){
        global $captcha_dict;
        $_dict_len         = mt_rand( 0 , count( $captcha_dict ) -1 ) ;
        $this->code        = $captcha_dict[ $_dict_len ] ;
        $this->code_length = strlen($this->code ) ;
        $_SESSION['securcode'] = strtolower($code);
		unset( $captcha_dict ) ;
	}
	/**
	* 绘制 - 线条
	* @access private
	**/
	private function draw_line() {
        $color      = null;
        $line_num   = intval( $this->image_height / 4.3 ) ;
        $arc_width  = intval( $this->image_width  / 2.2 ) ;
        $arc_height = intval( $this->image_height / 1.8 ) ;
        for ($i= 0; $i < $line_num ; $i++) {
            $color = imageColorAllocate(
                $this->im,
                mt_rand( 160, 200 ),
                mt_rand( 160, 200 ),
                mt_rand( 160, 200 )
            );
            imagefilledarc( 
                $this->im, 
                mt_rand( 5 ,$this->image_width ) ,
                mt_rand( 5 ,$this->image_height) , 
                $arc_width ,
                $arc_height,
                0 ,
                360 ,
                $color,
                IMG_ARC_NOFILL 
            );
        }
	}
	/**
	* 绘制 - 图形验证码
	* @access
	**/
    public function draw_word(){
        $color_num = 0 ;
        $font_size = $this->image_height * 0.66;
        $_x        = floor($this->image_width / $this->code_length);
        $code_rand = count($this->multi_color) - 1;
        $rand_color= array() ;
        $base_h_zb = $this->image_height / 1.26 ;
        for ( $i = 0; $i< $this->code_length; $i++ ) {
			$im_roll_jd = mt_rand( -10, 10) ;
            $color_num  = mt_rand(0, $code_rand);
            $rand_color = $this->multi_color[$color_num] ;
            $this->fontcolor = imagecolorallocate(
                $this->im, 
                $rand_color[0] ,    
                $rand_color[1] ,    
                $rand_color[2] 
            );
            imagettftext( 
                $this->im,
                $font_size ,
				$im_roll_jd, 
                $_x * $i + 5, 
                $base_h_zb,
                $this->fontcolor,
                $this->ttf_file,
                $this->code[$i]
            );
        }
    }
	/**
	* 输出图片到浏览器
	* @access private
	**/
	private function browser(){
		header('Date: '. $this->cur_gmt_time );
		header('Expires: Mon, 1 May 2016 01:01:01 GMT');
		header('Last-Modified: '.  $this->cur_gmt_time );
		header('Cache-Control: no-store, no-cache, must-revalidate, post-check=0, pre-check=0', false);
		header('Pragma: no-cache');
		header('Content-Type: image/gif');
		ob_clean();
		imagegif($this->im);
	}
	/**
	* 返回验证码
	* @access private
	**/
	public function get_code(){
		return $this->code;
	}
	/**
	* 创建验证码图片 & 输出到浏览器
	* @access public
	**/
	public function show(){
		$this->create_code();
		$this->draw_line();
		$this->draw_word();
		$this->browser();
		imagedestroy($this->im);
	}
}