Move chrono_state_utils into chrono coupling layer

Author: dav-og

CMakeLists.txt

@@ -356,8 +356,9 @@ set(HYDROCHRONO_SOURCES
     src/hydro/waves/irregular_wave.cpp
     src/hydro/radiation/radiation_rirf_processing.cpp
     src/hydro/radiation/radiation_rirf_convolution.cpp
-    src/hydro/core/chrono_state_utils.cpp
     src/hydro/core/hydro_system.cpp
+    # Chrono coupling layer (bridges Chrono physics with Chrono-free core)
+    src/hydro/chrono/chrono_state_utils.cpp
     src/hydro/chrono/chrono_hydro_coupler.cpp
     src/hydro/force_components/hydrostatics_component.cpp
     src/hydro/force_components/radiation_component.cpp

src/hydro/chrono/chrono_hydro_coupler.cpp

@@ -4,7 +4,7 @@
  *********************************************************************/
 
 #include <hydroc/coupling/chrono_coupler.h>
-#include "../core/chrono_state_utils.h"
+#include "chrono_state_utils.h"
 
 #include <cassert>
 
@@ -22,7 +22,7 @@ ChronoHydroCoupler::ChronoHydroCoupler(
 BodyForces ChronoHydroCoupler::Evaluate(double time) {
     // Build SystemState from Chrono bodies
     SystemState system_state;
-    BuildSystemStateFromChronoBodies(bodies_, system_state);
+    chrono_coupling::BuildSystemStateFromChronoBodies(bodies_, system_state);
 
     // Evaluate forces via HydroSystem
     return hydro_system_->Evaluate(system_state, time);

src/hydro/core/chrono_state_utils.cpp src/hydro/chrono/chrono_state_utils.cppsrc/hydro/core/chrono_state_utils.cpp renamed to src/hydro/chrono/chrono_state_utils.cpp

@@ -1,11 +1,13 @@
 /*********************************************************************
  * @file  chrono_state_utils.cpp
  * @brief Implementation of Chrono-SystemState conversion utilities.
+ *
+ * Part of the Chrono coupling layer (src/hydro/chrono/).
  *********************************************************************/
 
 #include "chrono_state_utils.h"
 
-namespace hydrochrono::hydro {
+namespace hydrochrono::hydro::chrono_coupling {
 
 void BuildSystemStateFromChronoBodies(
     const std::vector<std::shared_ptr<chrono::ChBody>>& bodies,
@@ -44,5 +46,5 @@ void BuildSystemStateFromChronoBodies(
     }
 }
 
-}  // namespace hydrochrono::hydro
+}  // namespace hydrochrono::hydro::chrono_coupling
 

src/hydro/core/chrono_state_utils.h src/hydro/chrono/chrono_state_utils.hsrc/hydro/core/chrono_state_utils.h renamed to src/hydro/chrono/chrono_state_utils.h

@@ -1,22 +1,32 @@
 /*********************************************************************
  * @file  chrono_state_utils.h
  * @brief Utilities for converting between Chrono and SystemState representations.
+ *
+ * This file is part of the Chrono coupling layer (src/hydro/chrono/).
+ * It provides the bridge between Chrono physics types (ChBody) and the
+ * Chrono-free core hydrodynamics types (SystemState).
+ *
+ * ARCHITECTURE NOTE:
+ * - Core hydrodynamics (src/hydro/core/) remains Chrono-free.
+ * - This utility lives in the coupling layer because it depends on Chrono types.
+ * - The core SystemState types are defined in include/hydroc/core/system_state.h.
  *********************************************************************/
 
-#ifndef HYDRO_CORE_CHRONO_STATE_UTILS_H
-#define HYDRO_CORE_CHRONO_STATE_UTILS_H
+#ifndef HYDRO_CHRONO_CHRONO_STATE_UTILS_H
+#define HYDRO_CHRONO_CHRONO_STATE_UTILS_H
 
 #include <hydroc/core/system_state.h>
 #include <chrono/physics/ChBody.h>
 #include <memory>
 #include <vector>
 
-namespace hydrochrono::hydro {
+namespace hydrochrono::hydro::chrono_coupling {
 
 /**
  * @brief Build SystemState from Chrono bodies.
  * 
  * Extracts pose and velocity data from Chrono bodies into the SystemState structure.
+ * This function bridges the Chrono physics layer with the Chrono-free core.
  * 
  * @param bodies Vector of Chrono body pointers
  * @param out_state Output SystemState (will be populated)
@@ -25,7 +35,7 @@ void BuildSystemStateFromChronoBodies(
     const std::vector<std::shared_ptr<chrono::ChBody>>& bodies,
     SystemState& out_state);
 
-}  // namespace hydrochrono::hydro
+}  // namespace hydrochrono::hydro::chrono_coupling
 
-#endif  // HYDRO_CORE_CHRONO_STATE_UTILS_H
+#endif  // HYDRO_CHRONO_CHRONO_STATE_UTILS_H
 

src/hydro/hydro_forces.cpp

@@ -59,7 +59,7 @@
 #include <hydroc/waves/irregular_wave.h>
 #include <hydroc/logging.h>
 #include <hydroc/core/system_state.h>
-#include "core/chrono_state_utils.h"
+#include "chrono/chrono_state_utils.h"
 #include "force_components/hydrostatics_component.h"
 #include "force_components/radiation_component.h"
 #include "force_components/excitation_component.h"
@@ -349,7 +349,7 @@ const hydrochrono::hydro::SystemState& TestHydro::GetCachedSystemState(double ti
     }
 
     // Fallback: build state now (should not happen in normal flow)
-    hydrochrono::hydro::BuildSystemStateFromChronoBodies(bodies_, cached_state_);
+    hydrochrono::hydro::chrono_coupling::BuildSystemStateFromChronoBodies(bodies_, cached_state_);
     cached_state_time_ = time;
     return cached_state_;
 }
@@ -714,7 +714,7 @@ double TestHydro::CoordinateFuncForBody(int b, int dof_index) {
     prev_time = bodies_[0]->GetChTime();
 
     // Build SystemState once for this timestep
-    hydrochrono::hydro::BuildSystemStateFromChronoBodies(bodies_, cached_state_);
+    hydrochrono::hydro::chrono_coupling::BuildSystemStateFromChronoBodies(bodies_, cached_state_);
     cached_state_time_ = prev_time;
 
     // Ensure HydroSystem + ChronoHydroCoupler are initialized