egroupware/calendar/inc/gradient.php

73 lines
1.9 KiB
PHP

<?php
/**
* eGroupWare Calendar: rounded corners
*
* @link http://www.egroupware.org
* @author Ralf Becker <RalfBecker-AT-outdoor-training.de>
* @package calendar
* @copyright (c) 2004-9 by Ralf Becker <RalfBecker-AT-outdoor-training.de>
* @license http://opensource.org/licenses/gpl-license.php GPL - GNU General Public License
* @version $Id$
*/
include_once('../../phpgwapi/inc/common_functions.inc.php');
check_load_extension('gd',true); // true = throw exception if not loadable
foreach(array('width'=>1,'height'=>1,'color1'=>'000080','color2'=>'ffffff') as $name => $default)
{
$$name = isset($_GET[$name]) ? $_GET[$name] : $default;
}
foreach(array('color1','color2') as $name)
{
preg_match('/^#?([0-9A-Fa-f]{2})([0-9A-Fa-f]{2})([0-9A-Fa-f]{2})$/',$$name,$rgb) or
die("Wrong value '".htmlspecialchars($$name)."' for $name, should be something like #80FFFF' !!!");
$$name = array('r'=>hexdec($rgb[1]),'g'=>hexdec($rgb[2]),'b'=>hexdec($rgb[3]));
}
$image = @imagecreate(abs($width),abs($height))
or die("Cannot Initialize new GD image stream");
$length = max($width,$height);
$dist = $length / 256;
if ($dist < 1) $dist = 1;
$anz = round($length / $dist);
foreach ($color1 as $c => $val)
{
$c_step[$c] = ($color2[$c] - $val) / $anz;
}
$rgb = $color1;
for ($l = 0; $l < $length; $l += $dist)
{
$color = imagecolorallocate($image,(int)$rgb['r'],(int)$rgb['g'],(int)$rgb['b']);
foreach($rgb as $c => $val)
{
$rgb[$c] += $c_step[$c];
}
if ($width > $height)
{
imagefilledrectangle($image,(int)$l,0,(int) ($l+$dist),$height-1,$color);
}
else
{
imagefilledrectangle($image,0,(int)$l,$width-1,(int) ($l+$dist),$color);
}
}
// allow caching for 7 days
header('Cache-Control: public');
header('Expires: ' . gmdate('D, d M Y H:i:s', time()+7*24*60*60) . ' GMT');
if (function_exists('imagegif'))
{
header("Content-type: image/gif");
imagegif($image);
}
else
{
header("Content-type: image/png");
imagepng($image);
}
imagedestroy($image);