[Kst] branches/work/kst/portto4/kst/src/libkstapp

[Adam Treat]

SVN commit 724215 by treat:

* Properly initialize the Auto zoom mode.


 M  +16 -8     plotrenderitem.cpp  


--- branches/work/kst/portto4/kst/src/libkstapp/plotrenderitem.cpp #724214:724215
@@ -796,13 +796,14 @@
 
 
 void PlotRenderItem::computeAuto(Qt::Orientation orientation, qreal *min, qreal *max) const {
+  //The previous values are of no consequence as this algorithm does not depend
+  //on the previous values.  So start over so that first active relation initializes.
+  qreal minimum;
+  qreal maximum;
+  bool unInitialized = true;
+
   bool axisLog = orientation == Qt::Horizontal ? isXAxisLog() : isYAxisLog();
 
-  //The previous values are of no consequence as this algorithm does not depend
-  //on the previous values.  So start over...
-  qreal minimum = axisLog ? 0.0 : -0.1;
-  qreal maximum = 0.1;
-
   foreach (RelationPtr relation, relationList()) {
       if (relation->ignoreAutoScale())
         continue;
@@ -814,13 +815,20 @@
       //If the axis is in log mode, the lower extent will be the
       //minimum value larger than zero.
       if (axisLog)
-        minimum = minimum <= 0.0 ? minPos_ : qMin(minPos_, minimum);
+        minimum = unInitialized ? minPos_ : qMin(minPos_, minimum);
       else
-        minimum = qMin(min_, minimum);
+        minimum = unInitialized ? min_ : qMin(min_, minimum);
 
-      maximum = qMax(max_, maximum);
+      maximum = unInitialized ? max_ : qMax(max_, maximum);
+
+      unInitialized = false;
   }
 
+  if (unInitialized || maximum <= minimum) {
+    minimum = axisLog ? 0.0 : -0.1;
+    minimum = 0.1;
+  }
+
   *min = minimum;
   *max = maximum;
 }