Просмотр файла img.php

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<?php
session_start();
if(!isset($_SESSION['sgb_code'])) exit;
$keystring=$_SESSION['sgb_code'];
$length=strlen($keystring);

// --- CAPTCHA ---

$alphabet = "0123456789abcdefghijklmnopqrstuvwxyz"; # do not change without changing font files!

# folder with fonts
$fontsdir = 'captcha';

# CAPTCHA image size (you do not need to change it, whis parameters is optimal)
$width = 94;
$height = 50;

# symbol's vertical fluctuation amplitude divided by 2
$fluctuation_amplitude = 5;

# increase safety by prevention of spaces between symbols
$no_spaces = true;

# show credits
$show_credits = false; # set to false to remove credits line. Credits adds 12 pixels to image height
$credits = ''; # if empty, HTTP_HOST will be shown

# CAPTCHA image colors (RGB, 0-255)
//$foreground_color = array(0, 0, 0);
//$background_color = array(220, 230, 255);
$foreground_color = array(mt_rand(0,100), mt_rand(0,100), mt_rand(0,100));
$background_color = array(mt_rand(200,255), mt_rand(200,255), mt_rand(200,255));

# JPEG quality of CAPTCHA image (bigger is better quality, but larger file size)
$jpeg_quality = 90;


$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);

   while(true){

		$font_file=$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[$keystring{$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, 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));
			}
		}

		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);
		}
        header('Cache-Control: no-cache, must-revalidate');

?>