Mercurial > hg > svcore
annotate data/model/PowerOfTwoZoomConstraint.cpp @ 766:2444ef08b7eb
Merge
author | Chris Cannam |
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date | Mon, 25 Mar 2013 12:15:36 +0000 |
parents | 3a13b0d4934e |
children | 59e7fe1b1003 |
rev | line source |
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Chris@147 | 1 /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*- vi:set ts=8 sts=4 sw=4: */ |
Chris@147 | 2 |
Chris@147 | 3 /* |
Chris@147 | 4 Sonic Visualiser |
Chris@147 | 5 An audio file viewer and annotation editor. |
Chris@147 | 6 Centre for Digital Music, Queen Mary, University of London. |
Chris@147 | 7 This file copyright 2006 Chris Cannam. |
Chris@147 | 8 |
Chris@147 | 9 This program is free software; you can redistribute it and/or |
Chris@147 | 10 modify it under the terms of the GNU General Public License as |
Chris@147 | 11 published by the Free Software Foundation; either version 2 of the |
Chris@147 | 12 License, or (at your option) any later version. See the file |
Chris@147 | 13 COPYING included with this distribution for more information. |
Chris@147 | 14 */ |
Chris@147 | 15 |
Chris@147 | 16 #include "PowerOfTwoZoomConstraint.h" |
Chris@147 | 17 |
Chris@147 | 18 size_t |
Chris@147 | 19 PowerOfTwoZoomConstraint::getNearestBlockSize(size_t req, |
Chris@147 | 20 RoundingDirection dir) const |
Chris@147 | 21 { |
Chris@147 | 22 size_t result = 0; |
Chris@147 | 23 |
Chris@147 | 24 for (size_t bs = 1; ; bs *= 2) { |
Chris@147 | 25 if (bs >= req) { |
Chris@147 | 26 if (dir == RoundNearest) { |
Chris@147 | 27 if (bs - req < req - bs/2) { |
Chris@147 | 28 result = bs; |
Chris@147 | 29 break; |
Chris@147 | 30 } else { |
Chris@147 | 31 result = bs/2; |
Chris@147 | 32 break; |
Chris@147 | 33 } |
Chris@147 | 34 } else if (dir == RoundDown) { |
Chris@147 | 35 result = bs/2; |
Chris@147 | 36 break; |
Chris@147 | 37 } else { |
Chris@147 | 38 result = bs; |
Chris@147 | 39 break; |
Chris@147 | 40 } |
Chris@147 | 41 } |
Chris@147 | 42 } |
Chris@147 | 43 |
Chris@147 | 44 if (result > getMaxZoomLevel()) result = getMaxZoomLevel(); |
Chris@147 | 45 return result; |
Chris@147 | 46 } |
Chris@147 | 47 |