<?php

/**

 * 验证码类

 */

class Code{

    //资源

    private $img;

    //画布宽度

    public $width = 150;

    //画布高度

    public $height = 45;

    //背景颜色

    public $bgColor = "#ffffff";

    //验证码

    public $code;

    //验证码的随机种子

    public $codeStr = "123456789abcdefghijklmnpqrstuvwsyz";

    //验证码长度

    public $codeLen = 4;

    //验证码字体

    public $font = "";//具体环境具体需要更改路径

    //验证码字体大小

    public $fontSize = 22;

    //验证码字体颜色

    public $fontColor = "";

    /**

     * 构造函数

     */

    public function __construct($arr = array()) {

        $width = '';

        $height = '';

        $codeLen = '';

        $fontSize = '';

        $bgColor = '';

        $fontColor = '';

        if(!empty($arr)){

           extract($arr);

        }

        $this->font = BASEPATH . "fonts/font.ttf";

        if (!is_file($this->font)) {

            error("验证码字体文件不存在");

        }

        $this->width = empty($width) ? $this->width : $width;

        $this->height = empty($height) ? $this->height : $height;

        $this->bgColor = empty($bgColor) ? $this->bgColor : $bgColor;

        $this->codeLen = empty($codeLen) ? $this->codeLen : $codeLen;

        $this->fontSize = empty($fontSize) ? $this->fontSize : $fontSize;

        $this->fontColor = empty($fontColor) ? $this->fontColor : $fontColor;

        $this->create();//生成验证码

    }

    /**

     * 生成验证码

     */

    private function createCode() {

        $code = '';

        for ($i = 0; $i < $this->codeLen; $i++) {

            $code .= $this->codeStr [mt_rand(0, strlen($this->codeStr) - 1)];

        }

        $this->code = strtoupper($code);

        if(!isset($_SESSION)){

            session_start();

        }

        $_SESSION ['code'] = $this->code;

    }

    /**

     * 返回验证码

     */

    public function getCode() {

        return $this->code;

    }

    /**

     * 建画布

     */

    public function create() {

        if (!$this->checkGD())

            return false;

        $w = $this->width;

        $h = $this->height;

        $bgColor = $this->bgColor;

        $img = imagecreatetruecolor($w, $h);

        $bgColor = imagecolorallocate($img, hexdec(substr($bgColor, 1, 2)), hexdec(substr($bgColor, 3, 2)), hexdec(substr($bgColor, 5, 2)));

        imagefill($img, 0, 0, $bgColor);

        $this->img = $img;

        $this->createLine();

        $this->createFont();

        $this->createPix();

        $this->createRec();

    }

    /**

    *  画线

    */

    private function createLine(){

        $w = $this->width;

        $h = $this->height;

        $line_height = $h/10;

        $line_color = "#D0D0D0";

        $color = imagecolorallocate($this->img, hexdec(substr($line_color, 1, 2)), hexdec(substr($line_color, 3, 2)), hexdec(substr($line_color, 5, 2)));

        for($i=0;$i<10;$i++){

            $step =$line_height*$i+2;

            imageline($this->img, 0, $step, $w,$step, $color);

        }

        $line_width = $w/10;

        for($i=0;$i<10;$i++){

            $step =$line_width*$i+2;

            imageline($this->img, $step-2, 0, $step+2,$h, $color);

        }

    }

    /**

     * 画矩形边框

     */

    private function createRec() {

        imagerectangle($this->img, 0, 0, $this->width - 1, $this->height - 1, $this->fontColor);

    }

    /**

     * 写入验证码文字

     */

    private function createFont() {

        $this->createCode();

        $color = $this->fontColor;

        if (!empty($color)) {

            $fontColor = imagecolorallocate($this->img, hexdec(substr($color, 1, 2)), hexdec(substr($color, 3, 2)), hexdec(substr($color, 5, 2)));

        }

        $x = ($this->width - 10) / $this->codeLen;

        for ($i = 0; $i < $this->codeLen; $i++) {

            if (empty($color)) {

                $fontColor = imagecolorallocate($this->img, mt_rand(50, 155), mt_rand(50, 155), mt_rand(50, 155));

            }

            imagettftext($this->img, $this->fontSize, mt_rand(- 30, 30), $x * $i + mt_rand(6, 10), mt_rand($this->height / 1.3, $this->height - 5), $fontColor, $this->font, $this->code [$i]);

        }

        $this->fontColor = $fontColor;

    }

    /**

     * 画线

     */

    private function createPix() {

        $pix_color = $this->fontColor;

        for ($i = 0; $i < 50; $i++) {

            imagesetpixel($this->img, mt_rand(0, $this->width), mt_rand(0, $this->height), $pix_color);

        }

        for ($i = 0; $i < 2; $i++) {

            imageline($this->img, mt_rand(0, $this->width), mt_rand(0, $this->height), mt_rand(0, $this->width), mt_rand(0, $this->height), $pix_color);

        }

        //画圆弧

        for ($i = 0; $i < 1; $i++) {

            // 设置画线宽度

           // imagesetthickness($this->img, mt_rand(1, 3));

            imagearc($this->img, mt_rand(0, $this->width), mt_rand(0, $this->height), mt_rand(0, $this->width), mt_rand(0, $this->height)

                    , mt_rand(0, 160), mt_rand(0, 200), $pix_color);

        }

        imagesetthickness($this->img, 1);

    }

    /**

     * 显示验证码

     */

    public function show() {

        header("Content-type:image/png");

        imagepng($this->img);

        imagedestroy($this->img);

        exit;

    }

    /**

     * 验证GD库是不否打开imagepng函数是否可用

     */

    private function checkGD() {

        return extension_loaded('gd') && function_exists("imagepng");

    }

}