Mercurial > libervia-backend

comparison sat/tools/common/utils.py @ 3045:6af44ca3beac

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
tools (common): helping method to calculate luminance: - a new `utils` module has been added for backend and frontends generic utilities - per_luminance method calculate the perceived luminance of a colour (is it dark or light?). This is useful to automatically select the suitable colour in a theme.
author Goffi <goffi@goffi.org>
date Tue, 01 Oct 2019 22:49:10 +0200
parents
children 9d0df638c8b4
comparison
equal deleted inserted replaced
3044:691283719bb2 3045:6af44ca3beac
1 #!/usr/bin/env python3
2
3 # SàT: a XMPP client
4 # Copyright (C) 2009-2019 Jérôme Poisson (goffi@goffi.org)
5
6 # This program is free software: you can redistribute it and/or modify
7 # it under the terms of the GNU Affero General Public License as published by
8 # the Free Software Foundation, either version 3 of the License, or
9 # (at your option) any later version.
10
11 # This program is distributed in the hope that it will be useful,
12 # but WITHOUT ANY WARRANTY; without even the implied warranty of
13 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 # GNU Affero General Public License for more details.
15
16 # You should have received a copy of the GNU Affero General Public License
17 # along with this program. If not, see <http://www.gnu.org/licenses/>.
18
19 """Misc utils for both backend and frontends"""
20
21
22 def per_luminance(red, green, blue):
23 """Caculate the perceived luminance of a RGB color
24
25 @param red(int): 0-1 normalized value of red
26 @param green(int): 0-1 normalized value of green
27 @param blue(int): 0-1 normalized value of blue
28 @return (float): 0-1 value of luminance (<0.5 is dark, else it's light)
29 """
30 # cf. https://stackoverflow.com/a/1855903, thanks Gacek
31
32 return 0.299 * red + 0.587 * green + 0.114 * blue