view data/model/PowerOfTwoZoomConstraint.cpp @ 249:d3ac9f953ebf

* Fix #1672407 confused by plugin-named files in cwd (or home?)
* Fix #1491848 crash when loading new file while transform plugin runs
* Fix #1502287 Background remains black after spectrogram layer deleted
* Fix #1604477 Replacing the main audio file silences secondary audio file
* Fix failure to initialise property box layout to last preference on startup
* Fix resample/wrong-rate display in Pane, ensure that right rate is chosen
  if all current models have an acceptable rate even if previous main model
  had a different one
* Fix "global zoom" broken in previous commit
* Some fixes to spectrogram cache area updating (makes spectrogram appear
  more quickly, previously it had a tendency to refresh with empty space)
* Fixes to colour 3d plot normalization

/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */

/*
    Sonic Visualiser
    An audio file viewer and annotation editor.
    Centre for Digital Music, Queen Mary, University of London.
    This file copyright 2006 Chris Cannam.
    
    This program is free software; you can redistribute it and/or
    modify it under the terms of the GNU General Public License as
    published by the Free Software Foundation; either version 2 of the
    License, or (at your option) any later version.  See the file
    COPYING included with this distribution for more information.
*/

#include "PowerOfTwoZoomConstraint.h"

size_t
PowerOfTwoZoomConstraint::getNearestBlockSize(size_t req,
					      RoundingDirection dir) const
{
    size_t result = 0;

    for (size_t bs = 1; ; bs *= 2) {
	if (bs >= req) {
	    if (dir == RoundNearest) {
		if (bs - req < req - bs/2) {
		    result = bs;
		    break;
		} else {
		    result = bs/2;
		    break;
		}
	    } else if (dir == RoundDown) {
		result = bs/2;
		break;
	    } else {
		result = bs;
		break;
	    }
	}
    }

    if (result > getMaxZoomLevel()) result = getMaxZoomLevel();
    return result;
}