From 45b3e55e660aac661f98fbb3a58b41ab3736851c Mon Sep 17 00:00:00 2001
From: Uwe Steinmann <steinm@debian.org>
Date: Wed, 14 Jul 2021 20:24:37 +0200
Subject: [PATCH] add method getColorBrightness()

---
 inc/inc.Utils.php | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/inc/inc.Utils.php b/inc/inc.Utils.php
index 2cf0b1708..8f7488723 100644
--- a/inc/inc.Utils.php
+++ b/inc/inc.Utils.php
@@ -922,6 +922,14 @@ function getMandatoryApprovers($folder, $user) { /* {{{ */
 	return $approvers;
 } /* }}} */
 
+function getColorBrightness($color) { /* {{{ */
+	$red = hexdec(substr($color, 1, 2))/255.0;
+	$green = hexdec(substr($color, 3, 2))/255.0;
+	$blue = hexdec(substr($color, 5, 2))/255.0;
+	$brightness = sqrt(0.299*pow($red, 2) + 0.587*pow($green, 2) + 0.114*pow($blue, 2));
+	return $brightness;
+} /* }}} */
+
 /**
  * Class for creating encrypted api keys
  *