diff data/model/PowerOfTwoZoomConstraint.cpp @ 147:3a13b0d4934e

* Reorganising code base.  This revision will not compile.

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/data/model/PowerOfTwoZoomConstraint.cpp	Mon Jul 31 11:44:37 2006 +0000
@@ -0,0 +1,47 @@
+/* -*- 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;
+}
+