PHP验证框

hao1nan

　　接触PHP一个星期了，boss要写一个图片验证框。在网上查了很多的资料，总结后得到如下最终的代码。以下代码生成的验证码有干扰条，干扰像素，字体旋转等。如果有不足的地方请回帖。

<?php
header("Pragma: no-cache");
header("Cache-Control: max-age=1, s-maxage=1, no-cache, must-revalidate");
session_start();
unset ($_SESSION['validate']);
$strnum = 8; //产生密码的位数
$str = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'; //显示的字符范围
$font_file = 'Fregne Myriad v2.ttf';//指定字体文件
$disturbpiont = true; //是否显示干扰素
$disturbpiontnum = 600; //干扰素的点的数目
$disturbline = true; //是否有干扰条
$disturblinenum = 8; //干扰条的数目
$l = strlen($str);
$randStr = array ();
$validate;
for ($i = 0; $i < $strnum; ++ $i) {
$randStr[$i] = $str[rand(0, $l)];
}
for ($i = 0; $i < $strnum; ++ $i) {
if ($randStr[$i] == '')
$randStr[$i] = '*';
$validate = $validate . $randStr[$i];
}

function RgbToHsv($R, $G, $B) {
$tmp = min($R, $G);
$min = min($tmp, $B);
$tmp = max($R, $G);
$max = max($tmp, $B);
$V = $max;
$delta = $max - $min;
if ($max != 0)
$S = $delta / $max; // s
else {
$S = 0;
return;
}
if ($R == $max)
$H = ($G - $B) / $delta; // between yellow & magenta
else
if ($G == $max)
$H = 2 + ($B - $R) / $delta; // between cyan & yellow
else
$H = 4 + ($R - $G) / $delta; // between magenta & cyan
$H *= 60; // degrees
if ($H < 0)
$H += 360;
return array (
$H,
$S,
$V
);
}
function HsvToRgb($H, $S, $V) {
if ($S == 0) {
// achromatic (grey)
$R = $G = $B = $V;
return;
}
$H /= 60; // sector 0 to 5
$i = floor($H);
$f = $H - $i; // factorial part of h
$p = $V * (1 - $S);
$q = $V * (1 - $S * $f);
$t = $V * (1 - $S * (1 - $f));
switch ($i) {
case 0 :
$R = $V;
$G = $t;
$B = $p;
break;
case 1 :
$R = $q;
$G = $V;
$B = $p;
break;
case 2 :
$R = $p;
$G = $V;
$B = $t;
break;
case 3 :
$R = $p;
$G = $q;
$B = $V;
break;
case 4 :
$R = $t;
$G = $p;
$B = $V;
break;
default : // case 5:
$R = $V;
$G = $p;
$B = $q;
break;
}
return array (
$R,
$G,
$B
);
}
$size = 30;
$width = $size * $strnum +10;
$height = $size +10;
$degrees = array ();
for ($i = 0; $i < $strnum; ++ $i) {
$degrees[$i] = rand(0, 35);
} // 生成数字旋转角度
for ($i = 0; $i < $strnum; ++ $i) {
if (rand() % 2);
else
$degrees[$i] = - $degrees[$i];
}
$image = imagecreatetruecolor($size, $size); // 数字图片画布
$validatepic = imagecreatetruecolor($width, $height); // 最终验证码画布
$back = imagecolorallocate($image, 255, 255, 255); // 背景色
$border = imagecolorallocate($image, 0, 0, 0); // 边框
imagefilledrectangle($validatepic, 0, 0, $width, $height, $back); // 画出背景色
// 数字颜色
for ($i = 0; $i < $strnum; ++ $i) {
// 考虑为使字符容易看清使用颜色较暗的颜色
$temp = RgbToHsv(rand(0, 255), rand(0, 255), rand(0, 255));
if ($temp[2] > 60)
$temp[2] = 60;
$temp = HsvToRgb($temp[0], $temp[1], $temp[2]);
$textcolor[$i] = imagecolorallocate($image, $temp[0], $temp[1], $temp[2]);
}
for ($i = 0; $i < $disturbpiontnum && $disturbpiont; ++ $i) //加入干扰象素
{
$randpixelcolor = ImageColorallocate($validatepic, rand(0, 255), rand(0, 255), rand(0, 255));
imagesetpixel($validatepic, rand(1, $width -1), rand(1, $height -1), $randpixelcolor);
}
// 干扰线使用颜色较明亮的颜色
$temp = RgbToHsv(rand(0, 255), rand(0, 255), rand(0, 255));
if ($temp[2] < 200)
$temp[2] = 255;
$temp = HsvToRgb($temp[0], $temp[1], $temp[2]);
$randlinecolor = imagecolorallocate($image, $temp[0], $temp[1], $temp[2]);
// 画干扰线
for ($i = 0; $i < $disturblinenum && $disturbline; $i++)
imageline($validatepic, rand(1, 239), rand(1, 39), rand(1, 239), rand(1, 39), $randpixelcolor);
for ($i = 0; $i < $strnum; ++ $i) {
$image = imagecreatetruecolor($size, $size); // 刷新画板
imagefilledrectangle($image, 0, 0, $size, $size, $back); // 画出背景色
imagefttext($image, 13, 0, 5, 20, $textcolor[$i], $font_file, $randStr[$i]);
$image = imagerotate($image, $degrees[$i], $back);
imagecolortransparent($image, $back);
imagecopymerge($validatepic, $image, 5 + 30 * $i, 5, 0, 0, imagesx($image), imagesy($image), 100);
}
imagerectangle($validatepic, 0, 0, $width -1, $height -1, $border); // 画出边框
header('Content-type: image/png');
imagepng($validatepic);
imagedestroy($validatepic);
imagedestroy($image);
$_SESSION['code'] = $validate;//将验证码存入session，如果实际应用，请md5.
?>
　　字体文件和该文件放在同一目录下即可，如果不是请设置

$font_file
　　需要设置背景颜色请修改

$back = imagecolorallocate($image, 255, 255, 255); // 背景色
　　显示图框的大小会随着设置显示的字符数变化。使用起来还是比较方便的。