Added constructor for ObserverFrame that takes a generic ReferenceFrame.

src/celengine/observer.cpp

@@ -1416,6 +1416,10 @@ ObserverFrame::ObserverFrame() :
 }
 
 
+/*! Create a new frame with the specified coordinate system and
+ *  reference object. The targetObject is only needed for phase
+ *  lock frames; the argument is ignored for other frames.
+ */
 ObserverFrame::ObserverFrame(CoordinateSystem _coordSys,
                              const Selection& _refObject,
                              const Selection& _targetObject) :
@@ -1428,6 +1432,18 @@ ObserverFrame::ObserverFrame(CoordinateSystem _coordSys,
 }
 
 
+/*! Create a new ObserverFrame with the specified reference frame.
+ *  The coordinate system of this frame will be marked as unknown.
+ */
+ObserverFrame::ObserverFrame(const ReferenceFrame &f) :
+    coordSys(Unknown),
+    frame(&f)
+{
+    frame->addRef();
+}
+
+
+/*! Copy constructor. */
 ObserverFrame::ObserverFrame(const ObserverFrame& f) :
     coordSys(f.coordSys),
     frame(f.frame),
@@ -1603,3 +1619,4 @@ ObserverFrame::createFrame(CoordinateSystem _coordSys,
     }
 }
 
+

src/celengine/observer.h

@@ -52,6 +52,7 @@ public:
                   const Selection& _refObject,
                   const Selection& _targetObj = Selection());
     ObserverFrame(const ObserverFrame&);
+    ObserverFrame(const ReferenceFrame& f);
     
     ~ObserverFrame();
     
@@ -84,7 +85,7 @@ private:
     
 private:
     CoordinateSystem coordSys;
-    ReferenceFrame* frame;
+    const ReferenceFrame* frame;
     Selection targetObject;
 };