captcha.ttf文件在本站的根目录可以直接下载

<?php

/**
 * 生成验证码类
 * ============================================================================

 */

if (!defined('IN_T'))
{
	//die('hacking attempt');
}

class Captcha{
 var $Width      = 60;           //图片宽
 var $Height     = 30;           //图片高
 var $Length     = 4;            //验证码位数
 var $BgColor    = "#ffffff";    //背景色
 var $TFonts = array("captcha.ttf");
 var $TFontSize = array(15,20); //字体大小范围
 var $TFontAngle = array(-20,20); //旋转角度
 var $Chars   = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";         //验证码范围（字母数字）
 var $Code    = array();              //验证码
 var $Image   = "";              //图形对象
 var $FontColors = array('#f36161','#6bc146','#5368bd');  //字体颜色,红绿蓝
 var $TPadden = 0.75;///字符间距,多少个字符
 var $Txbase = 5;///x轴两边距离
 var $Tybase =5 ;///y轴两边距离
 var $TLine =true; ///画干扰线
 
 public function RandRSI() ///生成验证码
 {
  $this->TFontAngle=range($this->TFontAngle[0],$this->TFontAngle[1]);
  $this->TFontSize=range($this->TFontSize[0],$this->TFontSize[1]);
  $arr=array();
  $Chars=$this->Chars;
  $TFontAngle=$this->TFontAngle;
  $TFontSize=$this->TFontSize;
  $FontColors=$this->FontColors;
  $code = "";
  $font = ROOT_PATH."static/fonts/".$this->TFonts[0];
  $charlen=strlen($Chars)-1;
  $anglelen=count($TFontAngle)-1; // 角度范围
  $fontsizelen=count($TFontSize)-1; // 角度范围
  $fontcolorlen=count($FontColors)-1; // 角度范围
  for($i=0;$i<$this->Length;$i++) ///得到字符与颜色
  {
   $char=$Chars[rand(0,$charlen)]; ///得到字符
   $angle=$TFontAngle[rand(0,$anglelen)]; ///旋转角度
   $fontsize=$TFontSize[rand(0,$fontsizelen)]; ///字体大小
   $fontcolor=$FontColors[rand(0,$fontcolorlen)]; ///字体大小
   $bound=$this->_calculateTextBox($fontsize,$angle,$font,$char); ///得到范围
   $arr[]=array($fontsize,$angle,$fontcolor,$char,$font,$bound);  ///得到矩形框
   $code.=$char;
  }
  $this->Code=$arr; //验证码
  return $code;
 }
 
 public function Draw() ///画图
 {
  if(empty($this->Code)) $this->RandRSI();
  $codes=$this->Code; ///用户验证码
  $wh=$this->_getImageWH($codes);
  $width=$wh[0];
  $height=$wh[1]; ///高度
  $this->Width=$width;
  $this->Height=$height;
 
  /* 绘制基本框架  */
  $this->Image = imagecreatetruecolor($this->Width, $this->Height);

  $image=$this->Image;
  $bg_color = imagecolorallocate($image, 235, 236, 237);
  imagefilledrectangle($image, 0, 0, $this->Width, $this->Height, $bg_color);
  $border_color = imagecolorallocate($image, 118, 151, 199);
  imagerectangle($image, 0, 0, $this->Width -1, $this->Height -1, $border_color);
  
  //$back = $this->_getColor2($this->_getColor( $this->BgColor)); ///背景颜色
  //imagefilledrectangle($image, 0, 0, $width, $height, $back); ///填充背景
  $TPadden=$this->TPadden;
  $basex=$this->Txbase;
  $color=null;
  foreach ($codes as $v) ///逐个画字符
  {
   $bound=$v[5];
   $color=$this->_getColor2($this->_getColor($v[2]));
   imagettftext($image, $v[0], $v[1], $basex, $bound['height'],$color , $v[4], $v[3]);
   $basex=$basex+$bound['width']*$TPadden-$bound['left'];///计算下一个左边距
  }
  $this->TLine?$this->_wirteSinLine($color,$basex):null; ///画干扰线
  //清除之前出现的多余输入
  @ob_end_clean();
  header("Content-type: image/png");
  imagepng( $image);
  imagedestroy($image);
 }
 /**
  *通过字体角度得到字体矩形宽度*
  *
  * @param int $font_size 字体尺寸
  * @param float $font_angle 旋转角度
  * @param string $font_file 字体文件路径
  * @param string $text 写入字符
  * @return array 返回长宽高
  */
 private function _calculateTextBox($font_size, $font_angle, $font_file, $text) {
  $box = imagettfbbox($font_size, $font_angle, $font_file, $text);
  $min_x = min(array($box[0], $box[2], $box[4], $box[6]));
  $max_x = max(array($box[0], $box[2], $box[4], $box[6]));
  $min_y = min(array($box[1], $box[3], $box[5], $box[7]));
  $max_y = max(array($box[1], $box[3], $box[5], $box[7]));
  return array(
  'left' => ($min_x >= -1) ? -abs($min_x + 1) : abs($min_x + 2),
  'top' => abs($min_y),
  'width' => $max_x - $min_x,
  'height' => $max_y - $min_y,
  'box' => $box
  );
 }
 private function  _getColor( $color ) //#ffffff
 {
  return array(hexdec($color[1].$color[2]),hexdec($color[3].$color[4]),hexdec($color[5].$color[6]));
 }
 private function  _getColor2( $color ) //#ffffff
 {
  return imagecolorallocate ($this->Image, $color[0], $color[1], $color[2]);
 }
 private function _getImageWH($data)
 {
  $TPadden=$this->TPadden;
  $w=$this->Txbase;
  $h=0;
  foreach ($data as $v)
  {
   $w=$w+$v[5]['width']*$TPadden-$v[5]['left'];
   $h=$h>$v[5]['height']?$h:$v[5]['height'];
  }
  return array(max($w,$this->Width),max($h,$this->Height));
 }
 //画正弦干扰线
 private function _wirteSinLine($color,$w)
 {
  $img=$this->Image;
  $h=$this->Height;
  $h1=rand(-5,5);
  $h2=rand(-1,1);
  $w2=rand(10,15);
  $h3=rand(4,6);
  for($i=-$w/2;$i<$w/2;$i=$i+0.1)
  {
   $y=$h/$h3*sin($i/$w2)+$h/2+$h1;
   imagesetpixel($img,$i+$w/2,$y,$color);
   $h2!=0?imagesetpixel($img,$i+$w/2,$y+$h2,$color):null;
  }
 }
}
?>