view data/model/PowerOfTwoZoomConstraint.cpp @ 297:c022976d18e8

* Merge from sv-match-alignment branch (excluding alignment-specific document).
  - add aggregate wave model (not yet complete enough to be added as a true
    model in a layer, but there's potential)
  - add play solo mode
  - add alignment model -- unused in plain SV
  - fix two plugin leaks
  - add m3u playlist support (opens all files at once, potentially hazardous)
  - fix retrieval of pre-encoded URLs
  - add ability to resample audio files on import, so as to match rates with
    other files previously loaded; add preference for same
  - add preliminary support in transform code for range and rate of transform
    input
  - reorganise preferences dialog, move dark-background option to preferences,
    add option for temporary directory location

/* -*- 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;
}