Файл: core/classes/class.kcaptcha.php
Строк: 226
<?php
# KCAPTCHA PROJECT VERSION 1.2.4
# Automatic test to tell computers and humans apart
# Copyright by Kruglov Sergei, 2006
# 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 customizing
class KCAPTCHA{
// generates keystring and image
function KCAPTCHA(){
require('core/classes/kcaptcha_config.php');
$fonts=array();
$fontsdir_absolute= $fontsdir;
if ($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);
while(true){
// 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/', $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){
$shift=1000;
for($sy=7;$sy<$fontfile_height-20;$sy+=1){
//for($sx=$m['start']-1;$sx<$m['end'];$sx+=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==1000){
$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;
}
if($x<$width-10) break; // 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, $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(0,3141592)/500000;
$rand6=mt_rand(0,3141592)/500000;
$rand7=mt_rand(0,3141592)/500000;
$rand8=mt_rand(0,3141592)/500000;
// 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){
$color=255;
$color_x=255;
$color_y=255;
$color_xy=255;
}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==0 && $color_x==0 && $color_y==0 && $color_xy==0){
$newred=$foreground_color[0];
$newgreen=$foreground_color[1];
$newblue=$foreground_color[2];
}else if($color==255 && $color_x==255 && $color_y==255 && $color_xy==255){
$newred=$background_color[0];
$newgreen=$background_color[1];
$newblue=$background_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, $newblue));
}
}
if(function_exists("imagejpeg")){
header("Content-Type: image/jpeg");
imagejpeg($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;
}
}
?>