2 * Copyright (C) 2006 Paul Davis
3 * Copyright (C) 2007 Michael Taht
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
21 #ifndef ardour_slider_gain
22 #define ardour_slider_gain
25 gain_to_slider_position (ARDOUR::gain_t g)
28 return pow((6.0*log(g)/log(2.0)+192.0)/198.0, 8.0);
32 static inline ARDOUR::gain_t
33 slider_position_to_gain (double pos)
35 /* XXX Marcus writes: this doesn't seem right to me. but i don't have a better answer ... */
36 if (pos == 0.0) return 0;
37 return pow (2.0,(sqrt(sqrt(sqrt(pos)))*198.0-192.0)/6.0);