2 Copyright (C) 2012-2021 Carl Hetherington <cth@carlh.net>
4 This file is part of DCP-o-matic.
6 DCP-o-matic is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2 of the License, or
9 (at your option) any later version.
11 DCP-o-matic 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 General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with DCP-o-matic. If not, see <http://www.gnu.org/licenses/>.
22 #include "maths_util.h"
27 db_to_linear (double db)
29 return pow(10, db / 20);
34 linear_to_db (double linear)
36 return 20 * log10(linear);
41 logarithmic_fade_in_curve (float t)
43 auto const c = clamp(t, 0.0f, 1.0f);
44 return std::exp(2 * (c - 1)) * c;
49 logarithmic_fade_out_curve (float t)
51 auto const c = clamp(t, 0.0f, 1.0f);
52 return std::exp(-2 * c) * (1 - c);