[DataEngine] FIX: SimpleDataEngine can use datatracker in doUpdate()

SofaKernel/framework/framework_test/core/DataEngine_test.cpp

@@ -114,12 +114,12 @@ class SimpleTestEngine : public core::SimpleDataEngine
 private:
     void doUpdate() override
     {
-        // SimpleDataEngines cannot check whether a datafield is dirty or not:
-        // all input fields must be considered dirty in update.
-        if (output.getValue() != NO_CHANGED)
-            output.setValue(NO_CHANGED);
-        else
+        // true only iff the DataTracker associated to the Data 'input' is Dirty
+        // that could only happen if 'input' was dirtied since last update
+        if( m_dataTracker.isDirty( input ) )
             output.setValue(CHANGED);
+        else
+            output.setValue(NO_CHANGED);
     }
 };
 

SofaKernel/framework/sofa/core/DataEngine.h

@@ -218,17 +218,23 @@ class SOFA_CORE_API SimpleDataEngine : public sofa::core::DataEngine
     SimpleDataEngine() : Inherit1() {}
     virtual ~SimpleDataEngine() {}
 
-    /// Updates your inputs and calls cleanDirty() for you.
-    /// User implementation moved to doUpdate()
-    virtual void update() final
+
+    virtual void updateAllInputs()
     {
         for(auto& input : getInputs())
         {
             static_cast<sofa::core::objectmodel::BaseData*>(input)
                     ->updateIfDirty();
         }
-        cleanDirty();
+    }
+    /// Updates your inputs and calls cleanDirty() for you.
+    /// User implementation moved to doUpdate()
+    virtual void update() final
+    {
+        updateAllInputs();
+        DDGNode::cleanDirty();
         doUpdate();
+        m_dataTracker.clean();
     }
 
     /// Automatically adds the input fields to the datatracker