www.gusucode.com > php框架系统：MDPHP麦迪源码 v1.xPHP源码程序 > php框架系统：MDPHP麦迪源码 v1.x/mdphp_v1.0.beta/mdphp_v1.0.beta/Library/Captcha/public.php

    <?php

	/**
	 * 麦迪验证码类(泡PHP)
	 * @author: 麦迪科技 <i@md8.cc>
	 * @link: http://soft.md8.cc
	 * @version: 1.0
	 */

	namespace MDPHP;

	C('SESSION.START', true) || session_start();
	final class Captcha{

		public $id, $image=null, $fonts, $width=90, $height=28, $length=4, $phrase=null, $string=array('A','B','C','D','E','F','H','J','K','L','M','N','P','R','S','T','U','V','W','X','Y','Z');

		public function __construct($id=0){
			if (!extension_loaded('gd')) error('Captcha Unable Load GD Library.', '无法加载GD库');
			$this->id = $id;
			$this->fonts = dirname(__FILE__) . '/Fonts/';
		}

		public function Phrase(){
			if(strlen($this->phrase) != $this->length){
				$phrase = null;
				$rand = array_rand($this->string, $this->length);
				foreach ($rand as $index)
					$phrase .= $this->string[$index];
				$this->phrase = $phrase;
			}
			return $this->phrase;
		}

		/**
		 * 生成并显示验证码
		 */
		public function Generate(){
			$image = is_resource($this->image) ? $this->image : $this->GenerateImage();
			header('Content-type: image/png');
			imagepng($image);
			imagedestroy($image);
		}

		private function CreateImage(){
			if (!is_resource($this->image)){

				$this->image = imagecreatetruecolor($this->width, $this->height);
				$color1 = imagecolorallocate($this->image, mt_rand(200, 255),mt_rand(200, 255), mt_rand(150, 255));
				$color2 = imagecolorallocate($this->image, mt_rand(200, 255),mt_rand(200, 255), mt_rand(150, 255));
				$color1 = imagecolorsforindex($this->image, $color1);
				$color2 = imagecolorsforindex($this->image, $color2);
				$steps = $this->width;

				$r1 = ($color1['red'] - $color2['red']) / $steps;
				$g1 = ($color1['green'] - $color2['green']) / $steps;
				$b1 = ($color1['blue'] - $color2['blue']) / $steps;

				$x1 = 0; $y1 =& $i; $x2 = $this->width; $y2 =& $i;

				for($i=0; $i<=$steps; $i++){
					$r2 = $color1['red'] - floor($i * $r1);
					$g2 = $color1['green'] - floor($i * $g1);
					$b2 = $color1['blue'] - floor($i * $b1);
					$color = imagecolorallocate($this->image, $r2, $g2, $b2);
					imageline($this->image, $x1, $y1, $x2, $y2, $color);
				}

				for($i=0, $count=mt_rand(10, 20); $i<$count; $i++){
					$color = imagecolorallocatealpha($this->image, mt_rand(20, 255), mt_rand(20, 255),
					mt_rand(100, 255), mt_rand(80, 120));
					imageline($this->image, mt_rand(0, $this->width), 0,
					mt_rand(0, $this->width), $this->height, $color);
				}
			}
			return $this->image;
		}

		public function GenerateImage($phrase=null){
			$image = $this->CreateImage();
			$phrase == null && $phrase = $this->Phrase();
			$fontsize = min($this->width, $this->height * 2) / (strlen($phrase));
			$spacing = (integer) ($this->width * 0.9 / strlen($phrase));
			is_dir($this->fonts) && $this->fonts = glob($this->fonts.'*.{ttf,otf}', GLOB_BRACE);
			for($i=0, $strlen=strlen($phrase); $i<$strlen; $i++){
				$font = $this->fonts[array_rand($this->fonts)];
				$color = imagecolorallocate($image, mt_rand(0, 160), mt_rand(0, 160), mt_rand(0, 160));
				$angle = mt_rand(-30, 30);
				$size = $fontsize / 12 * mt_rand(12, 14);
				$box = imageftbbox($size, $angle, $font, $phrase[$i]);
				$x = $spacing / 4 + $i * $spacing + 2;
				$y = $this->height / 2 + ($box[2] - $box[5]) / 4;
				imagefttext($image, $size, $angle, $x, $y, $color, $font, $phrase[$i]);
			}
			$this->image = $image;
			$_SESSION['MAIDI_CAPTCHA_'.$this->id.'_KEY'] = $phrase;
			return $this->image;
		}

		/**
		 * 检测输入是否正确
		 * @param	string	$str	用户所输入验证码
		 * @return	boolean/string	成功返回验证码, 失败返回false
		 */
		public static function Verify($str=null, $id=0){
			$key = $_SESSION['MAIDI_CAPTCHA_'.$id.'_KEY'];
			if(!empty($_SESSION['MAIDI_CAPTCHA_'.$id.'_KEY']) && !empty($str) && strtolower($str) === strtolower($key)){
				$_SESSION['MAIDI_CAPTCHA_'.$id.'_KEY'] = null;
				unset($_SESSION['MAIDI_CAPTCHA_'.$id.'_KEY']);
				return strtolower($str);
			}else{
				return false;
			}
		}

	}