<?php
/** Click Captcha 验证码类
* Date: 2013-05-04
* Author: fdipzone
* Ver: 1.0
*/
class ClickCaptcha { // class start
public $sess_name = 'm_captcha';
public $width = 500;
public $height = 200;
public $icon = 5;
public $iconColor = array(255, 255, 0);
public $backgroundColor = array(0, 0, 0);
public $iconSize = 56;
private $_img_res = null;
public function __construct(){
if(session_id() == ''){
session_start();
}
}
/** 创建验证码 */
public function create(){
// 创建图象
$this->_img_res = imagecreate($this->width, $this->height);
// 填充背景
ImageColorAllocate($this->_img_res, $this->backgroundColor[0], $this->backgroundColor[1], $this->backgroundColor[2]);
// 分配颜色
$col_ellipse = imagecolorallocate($this->_img_res, $this->iconColor[0], $this->iconColor[1], $this->iconColor[2]);
$minArea = $this->iconSize/2+3;
// 混淆用图象,不完整的圆
for($i=0; $i<$this->icon; $i++){
$x = mt_rand($minArea, $this->width-$minArea);
$y = mt_rand($minArea, $this->height-$minArea);
$s = mt_rand(0, 360);
$e = $s + 330;
imagearc($this->_img_res, $x, $y, $this->iconSize, $this->iconSize, $s, $e, $col_ellipse);
}
// 验证用图象,完整的圆
$x = mt_rand($minArea, $this->width-$minArea);
$y = mt_rand($minArea, $this->height-$minArea);
$r = $this->iconSize/2;
imagearc($this->_img_res, $x, $y, $this->iconSize, $this->iconSize, 0, 360, $col_ellipse);
// 记录圆心坐标及半径
$this->captcha_session($this->sess_name, array($x, $y, $r));
// 生成图象
Header("Content-type: image/PNG");
ImagePNG($this->_img_res);
ImageDestroy($this->_img_res);
exit();
}
/** 检查验证码
* @param String $captcha 验证码
* @param int $flag 验证成功后 0:不清除session 1:清除session
* @return boolean
*/
public function check($captcha, $flag=1){
if(trim($captcha)==''){
return false;
}
if(!is_array($this->captcha_session($this->sess_name))){
return false;
}
list($px, $py) = explode(',', $captcha);
list($cx, $cy, $cr) = $this->captcha_session($this->sess_name);
if(isset($px) && is_numeric($px) && isset($py) && is_numeric($py) &&
isset($cx) && is_numeric($cx) && isset($cy) && is_numeric($cy) && isset($cr) && is_numeric($cr)){
if($this->pointInArea($px,$py,$cx,$cy,$cr)){
if($flag==1){
$this->captcha_session($this->sess_name,'');
}
return true;
}
}
return false;
}
/** 判断点是否在圆中
* @param int $px 点x
* @param int $py 点y
* @param int $cx 圆心x
* @param int $cy 圆心y
* @param int $cr 圆半径
* sqrt(x^2+y^2)<r
*/
private function pointInArea($px, $py, $cx, $cy, $cr){
$x = $cx-$px;
$y = $cy-$py;
return round(sqrt($x*$x + $y*$y))<$cr;
}
/** 验证码session处理方法
* @param String $name captcha session name
* @param String $value
* @return String
*/
private function captcha_session($name,$value=null){
if(isset($value)){
if($value!==''){
$_SESSION[$name] = $value;
}else{
unset($_SESSION[$name]);
}
}else{
return isset($_SESSION[$name])? $_SESSION[$name] : '';
}
}
} // class end
?>
