<?php
/**
 * Creates square thumbnail images; the thumbnails retain their aspect ratio and
 * their background color can be set (''=transparent).
 * Default is 128x128 transparent.
 * 
 * @author Zarel <aesoft.org>
 */

/**
 * Directory thumnail maker
 *
 * Makes thumbnails of all images in directory. Saves thumbnails in
 * format _thumb_[size]_[bgcolor]_filename.gif
 * Thumbnails will be square.
 *
 * Usage:
 *   mkthumbdir(string $dir, int $size, sting $color);
 * 
 * Example:
 *   mkthumbdir();
 * Makes thumbnails of everything in the current directory.
 * A thumbnail of myself.jpg will be named _thumb_128_myself.gif
 *
 * Example:
 *   mkthumbdir('/home/example/',32,'ffffff');
 * Makes a 32x32 thumbnail with a white background of everything
 * in /home/example/
 * A thumbnail of myself.jpg will be named _thumb_32_ffffff_myself.gif
 * 
 * @param Directory (defaults to current directory)
 * @param Width and height (same number; defaults to 128 -> 128x128)
 * @param Color in hex form (defaults to '' -> transparent)
 * @return TRUE = success
 */
function mkthumbdir($dir='.',$size=128,$color='')
{
	if ($color!=='' && (strlen($color)!=6 || !ctype_xdigit($color)) ||
		intval($size)<=0) /* $size or $color is not valid */
		return FALSE;
	$size=intval($size);$color=hexlower($color); /*sanitize $size and $color */
	
	$files = @opendir($dir) or die('Cannot open specified directory.');
	while (false !== ($file = @readdir($files)))
	{
		if (substr($file,0,1)!=='.') /* skip '.', '..', and any hidden file */
			mkthumb($dir.'/'.$file,$size,$color);
	}
	@closedir($files);
	return TRUE;
}

/**
 * Thumnail maker
 *
 * Makes thumbnails of an image. Saves thumbnails in
 * format _thumb_[size]_[bgcolor]_filename.gif
 * Thumbnails will be square.
 *
 * Usage:
 *   mkthumb(string $image, int $size, sting $color);
 *
 * Example:
 *   mkthumb('myself.jpg');
 * Creates a 128x128 thumbnail of myself.jpg named
 * _thumb_128_myself.gif
 * 
 * Example: 
 *   mkthumb('dragon.png',64,'00ffff');
 * Creates a 64x64 thumbnail with cyan background of dragon.png named
 * _thumb_64_00ffff_dragon.gif
 *
 * @param Directory (defaults to current directory)
 * @param Width and height (same number; defaults to 128 -> 128x128)
 * @param Color in hex form (defaults to '' -> transparent)
 * @return TRUE = success
 */
function mkthumb($file,$size=128,$color='')
{
	/** sanity checks **/
	if ($color!=='' && (strlen($color)!=6 || !ctype_xdigit($color))
	|| intval($size)<=0) /* $size or $color is not valid */
		return FALSE;
	$size=intval($size); $color=hexlower($color); $ic=hexdec($color);
	if (is_dir($file) || preg_match('/^_thumb_[0-9]+(_[0-9a-f]{6})?_/',
	basename($file)) || (substr($file,-4)!='.gif' &&substr($file,-4)!='.png'
	&& substr($file,-5)!='.jpeg' && substr($file,-4)!='.jpg'))
		return FALSE; /* skip non-images and thumbs */
	$thumbn = dirname($file).'/_thumb_'.$size.($color?'_'.hexlower($color):
	'').'_'.substr(basename($file),0,strrpos(basename($file),'.')).'.gif';
	if (file_exists($thumbn)) return FALSE;
	
	/** import to GD **/
	if (substr($file,-4)=='.gif')
	{	if (!$srci = @imagecreatefromgif($file)) return FALSE;}
	else if (substr($file,-4)=='.png')
	{	if (!$srci = @imagecreatefrompng($file)) return FALSE;}
	else
	{	if (!$srci = @imagecreatefromjpeg($file)) return FALSE;}
	
	/** make thumbnail **/
	$srcw = imagesx($srci); $srch = imagesy($srci); /* get img dimensions */
	$desti = imagecreatetruecolor($size,$size);
	if ($color)
		imagefilledrectangle($desti, 0,0, $size,$size,
		imagecolorallocate($desti, 0xFF&($ic>>0x10),0xFF&($ic>>0x8), 0xFF&$ic));
	else /* transparent */
	{
		imagefilledrectangle($desti, 0,0, $size,$size,
		imagecolorallocate($desti, 253,13,248));
		imagecolortransparent($desti, imagecolorallocate($desti,253,13,248));
	}
	if ($srcw >$srch) /* landscape */
		imagecopyresampled($desti,$srci,0, round(($srcw-$srch)*$size/$srcw/2),
		0,0,$size,round($srch*$size/$srcw), $srcw,$srch);
	else /* portrait */
		imagecopyresampled($desti,$srci, round(($srch-$srcw)*$size/$srch/2),0,
		0,0,round($srcw*$size/$srch),$size,$srcw,$srch);
	imagedestroy($srci); imagegif($desti,$thumbn); imagedestroy($desti);
	return TRUE;
}

/**
 * Turns hex lowercase
 * 
 * Faster than strtolower
 */
function hexlower($str)
{
	return strtr($str, 'ABCDEF', 'abcdef');
}

/*
 * The following code makes a thumbnail of everything in the current
 * directory. Get rid of it if you don't want that to happen.
 */

mkthumbdir() or die('Error.');

echo 'Done.';

?>