Mercurial > hg > svcore
annotate base/LogRange.h @ 471:0dc158c1a6c9
* tidy up uses of CachedFile
author | Chris Cannam |
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date | Tue, 28 Oct 2008 11:38:43 +0000 |
parents | 2268963dabd1 |
children | 1405f4a2caf3 |
rev | line source |
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Chris@224 | 1 /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*- vi:set ts=8 sts=4 sw=4: */ |
Chris@224 | 2 |
Chris@224 | 3 /* |
Chris@224 | 4 Sonic Visualiser |
Chris@224 | 5 An audio file viewer and annotation editor. |
Chris@224 | 6 Centre for Digital Music, Queen Mary, University of London. |
Chris@224 | 7 This file copyright 2006 Chris Cannam. |
Chris@224 | 8 |
Chris@224 | 9 This program is free software; you can redistribute it and/or |
Chris@224 | 10 modify it under the terms of the GNU General Public License as |
Chris@224 | 11 published by the Free Software Foundation; either version 2 of the |
Chris@224 | 12 License, or (at your option) any later version. See the file |
Chris@224 | 13 COPYING included with this distribution for more information. |
Chris@224 | 14 */ |
Chris@224 | 15 |
Chris@224 | 16 #ifndef _LOG_RANGE_H_ |
Chris@224 | 17 #define _LOG_RANGE_H_ |
Chris@224 | 18 |
Chris@224 | 19 class LogRange |
Chris@224 | 20 { |
Chris@224 | 21 public: |
Chris@224 | 22 /** |
Chris@224 | 23 * Map a linear range onto a logarithmic range. min and max are |
Chris@224 | 24 * passed as the extents of the linear range and returned as the |
Chris@224 | 25 * extents of the logarithmic range. thresh is the minimum value |
Chris@224 | 26 * for the log range, to be used if the linear range spans zero. |
Chris@224 | 27 */ |
Chris@224 | 28 static void mapRange(float &min, float &max, float thresh = -10); |
Chris@224 | 29 |
Chris@224 | 30 /** |
Chris@224 | 31 * Map a value onto a logarithmic range. This just means taking |
Chris@224 | 32 * the base-10 log of the absolute value, or using the threshold |
Chris@224 | 33 * value if the absolute value is zero. |
Chris@224 | 34 */ |
Chris@224 | 35 static float map(float value, float thresh = -10); |
Chris@266 | 36 |
Chris@266 | 37 /** |
Chris@266 | 38 * Map a value from the logarithmic range back again. This just |
Chris@266 | 39 * means taking the value'th power of ten. |
Chris@266 | 40 */ |
Chris@266 | 41 static float unmap(float value); |
Chris@224 | 42 }; |
Chris@224 | 43 |
Chris@224 | 44 #endif |