1 <?php
2 //header("Content-type: image/GIF");
3 class Captcha{
4 private $width;
5 private $height;
6 private $counts;//要生成的验证码个数
7 private $distrubCode;//用于生成验证码的字符串
8 private $fontUrl;//字体
9
10 public function __construct($arr = array()){
11 $this->width = isset($arr['width']) ? $arr['width'] : 120;
12 $this->height = isset($arr['height']) ? $arr['height'] : 30;
13 $this->counts = isset($arr['counts']) ? $arr['counts'] : 5;
14 $this->distrubCode = isset($arr['distrubCode']) ? $arr['distrubCode'] : '1235467890qwertyuipkjhgfdaszxcvbnm';
15 $this->fontUrl = isset($arr['fontUrl']) ? $arr['fontUrl'] : 'ITCBLKAD.TTF';
16 //session_start();
17 $this->getCaptchar();
18 }
19 //输出验证码
20 public function getCaptchar(){
21 //创建图片在内存
22 $image = $this->createImageSource();
23 //设置图片背景色
24 $this->setImageBGColor($image);
25 //设置验证码
26 $this->setCode($image);
27 //字符干扰码
28 $this->setDistrubCode($image);
29 //黑点干扰码
30 //$this->setDistrubPixel($image);
31 //干扰线
32 //$this->setDistrubLine($image);
33 //雪花干扰
34 //$this->setDistrubString($image);
35 //生成圆孤干扰
36 //$this->setDistrubArc($image);
37 //生成虚线干扰
38 //$this->setDistrubImaginary($image);
39 //输出图片
40 imagegif($image);
41 //从内存中销毁
42 imagedestroy($image);
43 }
44 //创建画布
45 private function createImageSource(){
46 return imagecreatetruecolor($this->width,$this->height);
47 }
48 //设置画布的背景色
49 private function setImageBGColor($image){
50 //创建画布的背景色
51 $bgcolor = imagecolorallocate($image,mt_rand(200,255),mt_rand(200,255),mt_rand(200,255));
52 //为画布填充背景色
53 imagefill($image,0,0,$bgcolor);
54 }
55 //设置验证码中的干扰码
56 private function setDistrubCode($image){
57 $count_h = $this->height;
58 //设置干扰码的数量
59 $cou = floor($count_h/2);
60 for($i = 0;$i<$cou;$i++){
61 //随机生成X,Y
62 $x = mt_rand(0,$this->width);
63 $y = mt_rand(0,$this->height);
64 //生成倾斜的角度
65 $angle = mt_rand(0,360);
66 //生成字体的大小
67 $fontSize = mt_rand(8,15);
68 //字体的样式
69 $fontUrl = $this->fontUrl;
70 //用于生成验证码的字符串
71 $distrubCode = $this->distrubCode;
72 //取得字符串的长度
73 $codeLenth = strlen($distrubCode);
74 //随机取出一个字符
75 $dscode = $distrubCode[mt_rand(0,$codeLenth-1)];
76 //创建的一个字体颜色
77 $fontColor = imagecolorallocate($image,mt_rand(40,140),mt_rand(40,140),mt_rand(40,140));
78 //把字体添加到画布上
79 imagettftext($image,$fontSize,$angle,$x,$y,$fontColor,$fontUrl,$dscode);
80 }
81 }
82 //生成验证码
83 private function setCode($image){
84 $width = $this->width;
85 $height = $this->height;
86 $counts = $this->counts;
87 $code = $this->sessionCode();
88 //生成Y坐标
89 $y = floor($height/2)+floor($height/4)+8;
90 $fontSize = mt_rand(30,35);
91 //$fontUrl = 'C:\Windows\Fonts\ALGER.TTF';
92 $fontUrl = 'ALGER.TTF';
93 //$fontUrl = $this->fontUrl;
94 //添加验证码
95 $counts=$this->counts;
96 for($i=0;$i<$counts;$i++){
97 //取得字符
98 $char = $code[$i];
99 //生成X的坐标
100 $x = floor($width/$counts-1)*$i+3;
101 //倾斜角度
102 $angle = mt_rand(-20,30);
103 $fontColor = imagecolorallocate($image,mt_rand(0,50),mt_rand(50,100),mt_rand(50,140));
104 //把字体添加到画布上
105 imagettftext($image,$fontSize,$angle,$x,$y,$fontColor,$fontUrl,$char);
106 }
107 }
108 //生成要进行验证的字符串
109 public function sessionCode(){
110 $code = $this->distrubCode;
111 $len = strlen($code);
112 $_dscode = '';
113 $counts = $this->counts;
114 //取得要验证的字符串
115 for($i = 0;$i<$counts;$i++){
116 $dscode = $code[mt_rand(0,$len-1)];
117 $_dscode .= $dscode;
118 }
119 $_SESSION['captcha'] = $_dscode;
120 return $_dscode;
121 }
122 //生成黑点干扰码
123 private function setDistrubPixel($image){
124 $width = $this->width;
125 $height = $this->height;
126 //生成黑点
127 for($i=0;$i<$width*5;$i++){
128 $pixelColor = imagecolorallocate($image,mt_rand(100,200),mt_rand(100,200),mt_rand(100,200));
129 imagesetpixel($image,mt_rand(0,$width),mt_rand(0,$height),$pixelColor);
130 }
131 }
132 //生成干扰线
133 private function setDistrubLine($image){
134 $width = $this->width;
135 $height = $this->height;
136 //生成干扰线
137 for($i=0;$i<30;$i++){
138 $lineColor = imagecolorallocate($image,mt_rand(100,200),mt_rand(100,200),mt_rand(100,200));
139 imageline($image,mt_rand(0,$width),mt_rand(0,$height),mt_rand(0,$width),mt_rand(0,$height),$lineColor);
140 }
141 }
142 //生成雪花干扰
143 private function setDistrubString($image){
144 $width = $this->width;
145 $height = $this->height;
146 //生成随机雪花
147 for($i=0;$i<50;$i++){
148 $stringColor = imagecolorallocate($image,mt_rand(100,200),mt_rand(100,200),mt_rand(100,200));
149 imagestring($image,mt_rand(1,5),mt_rand(0,$width),mt_rand(0,$height),'*',$stringColor);
150 }
151 }
152 //生成圆弧干扰
153 private function setDistrubArc($image){
154 $width = $this->width;
155 $height = $this->height;
156 //生成随机圆弧
157 for($i=0;$i<30;$i++){
158 $arcColor = imagecolorallocate($image,mt_rand(100,200),mt_rand(100,200),mt_rand(100,200));
159 imagearc($image,mt_rand(0,$width),mt_rand(0,$height),mt_rand(0,$width/2),mt_rand(0,$height/2),mt_rand(0,360),mt_rand(100,360),$arcColor);
160 }
161 }
162 //生成虚线干扰
163 private function setDistrubImaginary($image){
164 $width = $this->width;
165 $height = $this->height;
166 //生成虚线干扰线
167 for($i=0;$i<20;$i++){
168 $black = imagecolorallocate($image,mt_rand(0,255),mt_rand(0,255),mt_rand(0,255));
169 $gray = imagecolorallocate($image,mt_rand(0,255),mt_rand(0,255),mt_rand(0,255));
170 $style = array ($black,$black,$black,$black,$black,$gray,$gray,$gray,$gray,$gray);
171 imagesetstyle($image,$style);
172 imageline($image,mt_rand(0,$width),mt_rand(0,$height),mt_rand(0,$width),mt_rand(0,$height),IMG_COLOR_STYLED);
173 }
174 }
175 public static function checkCaptcha($char){
176 return (strtolower($char) === strtolower($_SESSION['captcha']));
177 }
178 }
