vidalia-roundbandwidth.patch

diff -urN vidalia-0.3.0-alpha/src//vidalia/bwgraph/GraphFrame.cpp vidalia-0.3.0-alpha-roundbandwidth/src//vidalia/bwgraph/GraphFrame.cpp
--- vidalia-0.3.0-alpha/src//vidalia/bwgraph/GraphFrame.cpp     2011-05-08 19:54:48.000000000 -0300
+++ vidalia-0.3.0-alpha-roundbandwidth/src//vidalia/bwgraph/GraphFrame.cpp      2012-02-16 15:57:43.565950942 -0300
@@ -15,6 +15,8 @@
 
 #include "GraphFrame.h"
 
+#include <cmath>
+
 #include <QtGlobal>
 
 
@@ -56,6 +58,19 @@
   return width;
 }
 
+/** Return the smallest “round number” greater than or equal to value. 
+ * A number is “round” if it is either a power of ten, two times a
+ * power of ten (equivalently one fifth of a power of ten), or five
+ * times a power of ten (equivalently half of a power of ten).
+ */
+static inline qreal roundUp(qreal value)
+{
+  qreal powerOfTen = exp(ceil(log(value)/log(10)) * log(10));
+  if (value < powerOfTen / 5) return powerOfTen / 5;
+  if (value < powerOfTen / 2) return powerOfTen / 2;
+  return powerOfTen;
+}
+
 /** Adds new data points to the graph. */
 void
 GraphFrame::addPoints(qreal recv, qreal send)
@@ -75,8 +90,8 @@
   _totalRecv += recv;
   
   /* Check for a new maximum value */
-  if (send > _maxValue) _maxValue = send;
-  if (recv > _maxValue) _maxValue = recv;
+  if (send > _maxValue) _maxValue = roundUp(send);
+  if (recv > _maxValue) _maxValue = roundUp(recv);
 
   this->update();
 }