Fix bug when no run-time visualization is enabled (neither Irrlicht nor VSG)

Author: rserban

CMakeLists.txt

@@ -416,10 +416,20 @@ set(HCGUI_HEADERS
 
 set(HCGUI_SOURCES
     src/gui/guihelper.cpp
-    src/gui/guihelperIRR.cpp
-    src/gui/guihelperVSG.cpp
 )
 
+if(HYDROCHRONO_ENABLE_IRRLICHT)
+  set(HCGUI_SOURCES ${HCGUI_SOURCES}
+      src/gui/guihelperIRR.cpp
+  )
+endif()
+
+if(HYDROCHRONO_ENABLE_VSG)
+  set(HCGUI_SOURCES ${HCGUI_SOURCES}
+      src/gui/guihelperVSG.cpp
+  )
+endif()
+
 add_library(HydroChronoGUI ${HCGUI_SOURCES} ${HCGUI_HEADERS})
 
 target_compile_features(HydroChronoGUI PUBLIC ${HC_CXX_STANDARD})

src/gui/guihelperIRR.cpp

@@ -1,10 +1,8 @@
 #include "guihelper_impl.h"
 using namespace hydroc::gui;
 
-#ifdef HYDROCHRONO_HAVE_IRRLICHT
-
-    #include <IEventReceiver.h>  // irrlicht
-    #include <chrono_irrlicht/ChIrrMeshTools.h>
+#include <IEventReceiver.h>  // irrlicht
+#include <chrono_irrlicht/ChIrrMeshTools.h>
 
 using namespace chrono::irrlicht;
 
@@ -291,5 +289,3 @@ bool GUIImplIRR::IsRunning(double timestep) {
     return true;
     // ========== END TEMPORARY DIAGNOSTIC CODE ==========
 }
-
-#endif  // HYDROCHRONO_HAVE_IRRLICHT

src/gui/guihelperVSG.cpp

@@ -1,8 +1,6 @@
 #include "guihelper_impl.h"
 using namespace hydroc::gui;
 
-#ifdef HYDROCHRONO_HAVE_VSG
-
 using namespace chrono::vsg3d;
 
 // -----------------------------------------------------------------------------
@@ -83,5 +81,3 @@ bool GUIImplVSG::IsRunning(double timestep) {
 
     return true;
 }
-
-#endif  // HYDROCHRONO_HAVE_VSG

src/gui/guihelper_impl.h

@@ -30,6 +30,7 @@ namespace gui {
 // Base class for private GUI implementation.
 class GUIImpl {
   public:
+    GUIImpl() {}
     virtual ~GUIImpl() {}
     GUIImpl(const GUIImpl&)            = delete;
     GUIImpl& operator=(const GUIImpl&) = delete;
@@ -40,9 +41,6 @@ class GUIImpl {
     }
     virtual void SetCamera(double x, double y, double z, double dirx, double diry, double dirz) {}
     virtual bool IsRunning(double timestep) { return true; }
-
-  protected:
-    GUIImpl() {}
 };
 
 #ifdef HYDROCHRONO_HAVE_IRRLICHT