view data/model/PowerOfTwoZoomConstraint.cpp @ 985:f073d924a7c3

Fix #1058 clicking row in Layer Edit dialog when colour 3d plot layer active jumps to wrong frame (was using sample rate where resolution intended)
author Chris Cannam
date Tue, 16 Sep 2014 10:29:19 +0100
parents 59e7fe1b1003
children d4a28d1479a8 48e9f538e6e9
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/* -*- 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"

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

    for (int 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;
}