<?php# KCAPTCHA PROJECT VERSION 1.2.6# Automatic test to tell computers and humans apart# Copyright by Kruglov Sergei, 2006, 2007, 2008# www.captcha.ru, www.kruglov.ru# System requirements: PHP 4.0.6+ w/ GD# KCAPTCHA is a free software. You can freely use it for building own site or software.# If you use this software as a part of own sofware, you must leave copyright notices intact or add KCAPTCHA copyright notices to own.# As a default configuration, KCAPTCHA has a small credits text at bottom of CAPTCHA image.# You can remove it, but I would be pleased if you left it. ;)# See kcaptcha_config.php for customizationclass KCAPTCHA{	// generates keystring and image	function KCAPTCHA(){		require(dirname(__FILE__).'/kcaptcha_config.php');		$fonts=array();		$fontsdir_absolute=dirname(__FILE__).'/'.$fontsdir;		if ($handle = opendir($fontsdir_absolute)) {			while (false !== ($file = readdir($handle))) {				if (preg_match('/\.png$/i', $file)) {					$fonts[]=$fontsdir_absolute.'/'.$file;				}			}		    closedir($handle);		}				$alphabet_length=strlen($alphabet);				do{			// generating random keystring			while(true){				$this->keystring='';				for($i=0;$i<$length;$i++){					$this->keystring.=$allowed_symbols{mt_rand(0,strlen($allowed_symbols)-1)};				}				if(!preg_match('/cp|cb|ck|c6|c9|rn|rm|mm|co|do|cl|db|qp|qb|dp|ww/', $this->keystring)) break;			}					$font_file=$fonts[mt_rand(0, count($fonts)-1)];			$font=imagecreatefrompng($font_file);			imagealphablending($font, true);			$fontfile_width=imagesx($font);			$fontfile_height=imagesy($font)-1;			$font_metrics=array();			$symbol=0;			$reading_symbol=false;			// loading font			for($i=0;$i<$fontfile_width && $symbol<$alphabet_length;$i++){				$transparent = (imagecolorat($font, $i, 0) >> 24) == 127;				if(!$reading_symbol && !$transparent){					$font_metrics[$alphabet{$symbol}]=array('start'=>$i);					$reading_symbol=true;					continue;				}				if($reading_symbol && $transparent){					$font_metrics[$alphabet{$symbol}]['end']=$i;					$reading_symbol=false;					$symbol++;					continue;				}			}			$img=imagecreatetruecolor($width, $height);			imagealphablending($img, true);			$white=imagecolorallocate($img, 255, 255, 255);			$black=imagecolorallocate($img, 0, 0, 0);			imagefilledrectangle($img, 0, 0, $width-1, $height-1, $white);			// draw text			$x=1;			for($i=0;$i<$length;$i++){				$m=$font_metrics[$this->keystring{$i}];				$y=mt_rand(-$fluctuation_amplitude, $fluctuation_amplitude)+($height-$fontfile_height)/2+2;				if($no_spaces){					$shift=0;					if($i>0){						$shift=10000;						for($sy=7;$sy<$fontfile_height-20;$sy+=1){							for($sx=$m['start']-1;$sx<$m['end'];$sx+=1){				        		$rgb=imagecolorat($font, $sx, $sy);				        		$opacity=$rgb>>24;								if($opacity<127){									$left=$sx-$m['start']+$x;									$py=$sy+$y;									if($py>$height) break;									for($px=min($left,$width-1);$px>$left-12 && $px>=0;$px-=1){						        		$color=imagecolorat($img, $px, $py) & 0xff;										if($color+$opacity<190){											if($shift>$left-$px){												$shift=$left-$px;											}											break;										}									}									break;								}							}						}						if($shift==10000){							$shift=mt_rand(4,6);						}					}				}else{					$shift=1;				}				imagecopy($img, $font, $x-$shift, $y, $m['start'], 1, $m['end']-$m['start'], $fontfile_height);				$x+=$m['end']-$m['start']-$shift;			}		}while($x>=$width-10); // while not fit in canvas		$center=$x/2;		// credits. To remove, see configuration file		$img2=imagecreatetruecolor($width, $height+($show_credits?12:0));		$foreground=imagecolorallocate($img2, $foreground_color[0], $foreground_color[1], $foreground_color[2]);		$background=imagecolorallocate($img2, $background_color[0], $background_color[1], $background_color[2]);		imagefilledrectangle($img2, 0, 0, $width-1, $height-1, $background);				imagefilledrectangle($img2, 0, $height, $width-1, $height+12, $foreground);		$credits=empty($credits)?$_SERVER['HTTP_HOST']:$credits;		imagestring($img2, 2, $width/2-imagefontwidth(2)*strlen($credits)/2, $height-2, $credits, $background);		// periods		$rand1=mt_rand(750000,1200000)/10000000;		$rand2=mt_rand(750000,1200000)/10000000;		$rand3=mt_rand(750000,1200000)/10000000;		$rand4=mt_rand(750000,1200000)/10000000;		// phases		$rand5=mt_rand(0,31415926)/10000000;		$rand6=mt_rand(0,31415926)/10000000;		$rand7=mt_rand(0,31415926)/10000000;		$rand8=mt_rand(0,31415926)/10000000;		// amplitudes		$rand9=mt_rand(330,420)/110;		$rand10=mt_rand(330,450)/110;		//wave distortion		for($x=0;$x<$width;$x++){			for($y=0;$y<$height;$y++){				$sx=$x+(sin($x*$rand1+$rand5)+sin($y*$rand3+$rand6))*$rand9-$width/2+$center+1;				$sy=$y+(sin($x*$rand2+$rand7)+sin($y*$rand4+$rand8))*$rand10;				if($sx<0 || $sy<0 || $sx>=$width-1 || $sy>=$height-1){					continue;				}else{					$color=imagecolorat($img, $sx, $sy) & 0xFF;					$color_x=imagecolorat($img, $sx+1, $sy) & 0xFF;					$color_y=imagecolorat($img, $sx, $sy+1) & 0xFF;					$color_xy=imagecolorat($img, $sx+1, $sy+1) & 0xFF;				}				if($color==255 && $color_x==255 && $color_y==255 && $color_xy==255){					continue;				}else if($color==0 && $color_x==0 && $color_y==0 && $color_xy==0){					$newred=$foreground_color[0];					$newgreen=$foreground_color[1];					$newblue=$foreground_color[2];				}else{					$frsx=$sx-floor($sx);					$frsy=$sy-floor($sy);					$frsx1=1-$frsx;					$frsy1=1-$frsy;					$newcolor=(						$color*$frsx1*$frsy1+						$color_x*$frsx*$frsy1+						$color_y*$frsx1*$frsy+						$color_xy*$frsx*$frsy);					if($newcolor>255) $newcolor=255;					$newcolor=$newcolor/255;					$newcolor0=1-$newcolor;					$newred=$newcolor0*$foreground_color[0]+$newcolor*$background_color[0];					$newgreen=$newcolor0*$foreground_color[1]+$newcolor*$background_color[1];					$newblue=$newcolor0*$foreground_color[2]+$newcolor*$background_color[2];				}				imagesetpixel($img2, $x, $y, imagecolorallocate($img2, $newred, $newgreen, $newblue));			}		}				header('Expires: Mon, 26 Jul 1997 05:00:00 GMT'); 		header('Cache-Control: no-store, no-cache, must-revalidate'); 		header('Cache-Control: post-check=0, pre-check=0', FALSE); 		header('Pragma: no-cache');				if(function_exists("imagejpeg")){			header("Content-Type: image/jpeg");			imagejpeg($img2, null, $jpeg_quality);		}else if(function_exists("imagegif")){			header("Content-Type: image/gif");			imagegif($img2);		}else if(function_exists("imagepng")){			header("Content-Type: image/x-png");			imagepng($img2);		}	}	// returns keystring	function getKeyString(){		return $this->keystring;	}}?>