annotate data/model/PowerOfTwoZoomConstraint.cpp @ 817:9089d0546efa tonioni

some visualisation changes
author matthiasm
date Thu, 20 Jun 2013 11:07:57 +0100
parents 3a13b0d4934e
children 59e7fe1b1003
rev   line source
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