geant events for multiple scattering

src/HEP/Geant/SteppingAction.hh

@@ -0,0 +1,30 @@
+#ifndef U_GEANT_STEPPINGACTION_HH
+#define U_GEANT_STEPPINGACTION_HH
+
+#include "G4UserSteppingAction.hh"
+#include "Core/Vector.h"
+#include "GeantEvent.h"
+
+namespace uLib {
+namespace Geant {
+
+/// SteppingAction collects scattering data at each Geant4 step and
+/// builds GeantEvent objects in the output buffer.
+class SteppingAction : public G4UserSteppingAction {
+public:
+  /// @param output  pointer to the results vector owned by the Scene
+  SteppingAction(Vector<GeantEvent> *output);
+  virtual ~SteppingAction();
+
+  virtual void UserSteppingAction(const G4Step *step) override;
+
+private:
+  Vector<GeantEvent> *m_Output;   ///< destination for finished events
+  GeantEvent          m_Current;  ///< event being built
+  int                 m_LastEventID; ///< track event transitions
+};
+
+} // namespace Geant
+} // namespace uLib
+
+#endif