lbajardsilogic@0: /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
lbajardsilogic@0: 
lbajardsilogic@0: /*
lbajardsilogic@0:     Sonic Visualiser
lbajardsilogic@0:     An audio file viewer and annotation editor.
lbajardsilogic@0:     Centre for Digital Music, Queen Mary, University of London.
lbajardsilogic@0:     This file copyright 2006 Chris Cannam.
lbajardsilogic@0:     
lbajardsilogic@0:     This program is free software; you can redistribute it and/or
lbajardsilogic@0:     modify it under the terms of the GNU General Public License as
lbajardsilogic@0:     published by the Free Software Foundation; either version 2 of the
lbajardsilogic@0:     License, or (at your option) any later version.  See the file
lbajardsilogic@0:     COPYING included with this distribution for more information.
lbajardsilogic@0: */
lbajardsilogic@0: 
lbajardsilogic@0: #include "PowerOfTwoZoomConstraint.h"
lbajardsilogic@0: 
lbajardsilogic@0: size_t
lbajardsilogic@0: PowerOfTwoZoomConstraint::getNearestBlockSize(size_t req,
lbajardsilogic@0: 					      RoundingDirection dir) const
lbajardsilogic@0: {
lbajardsilogic@0:     size_t result = 0;
lbajardsilogic@0: 
lbajardsilogic@0:     for (size_t bs = 1; ; bs *= 2) {
lbajardsilogic@0: 	if (bs >= req) {
lbajardsilogic@0: 	    if (dir == RoundNearest) {
lbajardsilogic@0: 		if (bs - req < req - bs/2) {
lbajardsilogic@0: 		    result = bs;
lbajardsilogic@0: 		    break;
lbajardsilogic@0: 		} else {
lbajardsilogic@0: 		    result = bs/2;
lbajardsilogic@0: 		    break;
lbajardsilogic@0: 		}
lbajardsilogic@0: 	    } else if (dir == RoundDown) {
lbajardsilogic@0: 		result = bs/2;
lbajardsilogic@0: 		break;
lbajardsilogic@0: 	    } else {
lbajardsilogic@0: 		result = bs;
lbajardsilogic@0: 		break;
lbajardsilogic@0: 	    }
lbajardsilogic@0: 	}
lbajardsilogic@0:     }
lbajardsilogic@0: 
lbajardsilogic@0:     if (result > getMaxZoomLevel()) result = getMaxZoomLevel();
lbajardsilogic@0:     return result;
lbajardsilogic@0: }
lbajardsilogic@0: