svcore
1.9
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00001 /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*- vi:set ts=8 sts=4 sw=4: */ 00002 00003 /* 00004 Sonic Visualiser 00005 An audio file viewer and annotation editor. 00006 Centre for Digital Music, Queen Mary, University of London. 00007 This file copyright 2006 Chris Cannam. 00008 00009 This program is free software; you can redistribute it and/or 00010 modify it under the terms of the GNU General Public License as 00011 published by the Free Software Foundation; either version 2 of the 00012 License, or (at your option) any later version. See the file 00013 COPYING included with this distribution for more information. 00014 */ 00015 00016 #include "PowerOfTwoZoomConstraint.h" 00017 00018 int 00019 PowerOfTwoZoomConstraint::getNearestBlockSize(int req, 00020 RoundingDirection dir) const 00021 { 00022 int result = 0; 00023 00024 for (int bs = 1; ; bs *= 2) { 00025 if (bs >= req) { 00026 if (dir == RoundNearest) { 00027 if (bs - req < req - bs/2) { 00028 result = bs; 00029 break; 00030 } else { 00031 result = bs/2; 00032 break; 00033 } 00034 } else if (dir == RoundDown) { 00035 result = bs/2; 00036 break; 00037 } else { 00038 result = bs; 00039 break; 00040 } 00041 } 00042 } 00043 00044 if (result > getMaxZoomLevel()) result = getMaxZoomLevel(); 00045 return result; 00046 } 00047