Add MoorDyn submodule and improve build robustness

Author: dav-og

.gitignore

@@ -42,6 +42,10 @@ doc/user/_verification/demos/sphere_decay/*.png
 doc/user/_verification/demos/sphere_decay/*.hires.png
 _build/
 
+# MoorDyn workaround (copied at configure time, see CMakeLists.txt)
+/cmake/MoorDynConfig.cmake
+/LICENSE.txt
+
 # General
 build/
 demos/F3OF/f3of/

CMakeLists.txt

@@ -220,6 +220,20 @@ else()
   message(STATUS "Set C++ standard to: ${HC_CXX_STANDARD}")
 endif()
 
+# Detect whether Chrono has the newer ChLoadHydrodynamics API.
+# If not, fall back to HydroChrono's legacy added-mass implementation.
+set(CHRONO_HAS_LOAD_HYDRODYNAMICS FALSE)
+get_target_property(_chrono_inc_dirs Chrono::Chrono_core INTERFACE_INCLUDE_DIRECTORIES)
+foreach(_dir ${_chrono_inc_dirs})
+    if(EXISTS "${_dir}/chrono/physics/ChLoadHydrodynamics.h")
+        set(CHRONO_HAS_LOAD_HYDRODYNAMICS TRUE)
+        break()
+    endif()
+endforeach()
+if(NOT CHRONO_HAS_LOAD_HYDRODYNAMICS)
+    message(STATUS "ChLoadHydrodynamics not found in Chrono -- using legacy added-mass implementation")
+endif()
+
 # Enable Irrlicht support if requested and available
 if(HYDROCHRONO_ENABLE_IRRLICHT AND NOT TARGET Chrono::Chrono_irrlicht)
   message(FATAL_ERROR "HYDROCHRONO_ENABLE_IRRLICHT is ON but Chrono::Chrono_irrlicht target not found. Ensure Chrono was built with Irrlicht support.")
@@ -265,6 +279,23 @@ endif()
 # -- MoorDyn mooring library (optional) --
 if(HYDROCHRONO_ENABLE_MOORDYN)
     message(STATUS "\n---- MoorDyn mooring library")
+    if(NOT EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/extern/MoorDyn/CMakeLists.txt")
+        message(FATAL_ERROR
+            "MoorDyn submodule not found at extern/MoorDyn.\n"
+            "Run:  git submodule update --init extern/MoorDyn")
+    endif()
+    # MoorDyn's CMakeLists.txt uses CMAKE_SOURCE_DIR (which resolves to
+    # HydroChrono's root) for its config template and CPack license.
+    # Copy the files it expects so the configure step succeeds.
+    if(NOT EXISTS "${CMAKE_SOURCE_DIR}/cmake/MoorDynConfig.cmake")
+        file(COPY "${CMAKE_CURRENT_SOURCE_DIR}/extern/MoorDyn/cmake/MoorDynConfig.cmake"
+             DESTINATION "${CMAKE_SOURCE_DIR}/cmake/")
+    endif()
+    if(NOT EXISTS "${CMAKE_SOURCE_DIR}/LICENSE.txt")
+        file(COPY "${CMAKE_CURRENT_SOURCE_DIR}/extern/MoorDyn/LICENSE.txt"
+             DESTINATION "${CMAKE_SOURCE_DIR}/")
+    endif()
+
     set(EXTERNAL_EIGEN OFF CACHE BOOL "Use MoorDyn bundled Eigen" FORCE)
     set(PYTHON_WRAPPER OFF CACHE BOOL "Disable MoorDyn Python wrapper" FORCE)
     set(FORTRAN_WRAPPER OFF CACHE BOOL "Disable MoorDyn Fortran wrapper" FORCE)
@@ -485,6 +516,7 @@ target_compile_definitions(HydroChrono
     PUBLIC
         "HYDROCHRONO_VERSION=\"${PROJECT_VERSION}\""
         "HYDROCHRONO_BUILD_TYPE=\"$<IF:$<CONFIG:Debug>,Debug,$<IF:$<CONFIG:Release>,Release,$<IF:$<CONFIG:RelWithDebInfo>,RelWithDebInfo,$<IF:$<CONFIG:MinSizeRel>,MinSizeRel,Unknown>>>>\""
+        $<$<NOT:$<BOOL:${CHRONO_HAS_LOAD_HYDRODYNAMICS}>>:HYDROCHRONO_USE_LEGACY_ADDED_MASS>
     PRIVATE 
         $<$<BOOL:${HYDROCHRONO_ENABLE_LOGGING}>:HYDROCHRONO_ENABLE_LOGGING="1">
 )

build.ps1

@@ -63,7 +63,8 @@ if ($Help) {
     Write-Host "  -Package           Create distributable ZIP after building"
     Write-Host "  -NoIrrlicht        Disable Irrlicht (enabled by default if Chrono has it)"
     Write-Host "  -NoVSG             Disable VSG (enabled by default if Chrono has it)"
-    Write-Host "  -MoorDyn           Enable MoorDyn mooring coupling (requires extern/MoorDyn)"
+    Write-Host "  -MoorDyn           Enable MoorDyn mooring coupling"
+    Write-Host "                     Requires: git submodule update --init extern/MoorDyn"
     Write-Host "  -NoDemos           Skip demo executables"
     Write-Host "  -NoTests           Skip test targets"
     Write-Host "  -ConfigPath <path> Custom config file (default: build-config.json)`n"
@@ -80,6 +81,8 @@ if ($Help) {
     Write-Host "CONFIG FILE:" -ForegroundColor Yellow
     Write-Host '  { "ChronoDir": "C:/path/to/chrono/build/cmake" }' -ForegroundColor Gray
     Write-Host ""
+    Write-Host "DOCS:" -ForegroundColor Yellow
+    Write-Host "  Full setup guide: docs/_main_pages/developer_docs/build_instructions.md`n"
     exit 0
 }
 
@@ -188,6 +191,13 @@ try {
     exit 1
 }
 
+# MoorDyn submodule check
+if ($MoorDyn -and -not (Test-Path ".\extern\MoorDyn\CMakeLists.txt")) {
+    Write-Fail "MoorDyn submodule not found at extern/MoorDyn"
+    Write-Host "   Run: git submodule update --init extern/MoorDyn" -ForegroundColor Yellow
+    exit 1
+}
+
 # =============================================================================
 # Clean
 # =============================================================================

docs/_main_pages/developer_docs/build_instructions.md

@@ -8,29 +8,37 @@ parent_section: Developer Documentation
 
 A PowerShell script (`build.ps1`) is provided to build HydroChrono from the command line. The steps to configure, build, and test with this script are outlined below. Alternatively, you can use the CMake GUI with Visual Studio; those instructions appear later on this page.
 
-## Prerequisites (download/install these)
+## Prerequisites
+
+**Required:**
 
 - Visual Studio 2022 (Desktop development with C++)
 - CMake ≥ 3.18
-- Project Chrono (built from source; enable Parsers and Irrlicht modules)
-- HDF5 1.10.8 (CMake package)
-- Eigen 3.4 (headers)
-- Irrlicht 1.8.4 (if GUI)
-- Python 3.12 (only for tests/docs)
+- Project Chrono (built from source; enable the Parsers module at minimum)
+- HDF5 (C++ libraries, any recent version with CMake config support)
+
+**Auto-detected from Chrono** (you do not need to install these separately):
+
+- Eigen (header-only linear algebra library, bundled or referenced by Chrono)
+- Irrlicht / VSG (visualization backends, detected if Chrono was built with them)
+
+**Optional:**
+
+- Python 3.x (only needed for regression tests and building documentation)
+- MoorDyn (mooring dynamics library, included as a git submodule -- see [MoorDyn setup](#moordyn-mooring-library) below)
 
 ## Quick build with build.ps1 (recommended)
 
 1) Copy `build-config-example.json` to `build-config.json` and set paths:
 ```json
 {
   "ChronoDir": "C:/path/to/chrono/build/cmake",
-  "Hdf5Dir": "C:/path/to/hdf5/share/cmake",
-  "EigenDir": "C:/path/to/eigen-3.4.0",
-  "IrrlichtDir": "C:/path/to/irrlicht-1.8.4",
   "PythonRoot": "C:/path/to/python/env"
 }
 ```
 
+`ChronoDir` is the only required key. Eigen, HDF5, and visualization library paths are auto-detected from Chrono's build configuration. `PythonRoot` is optional and only needed if Python isn't on your PATH.
+
 2) From the repo root, run (first build) - use `-Verbose` for a more detailed output:
 ```powershell
 ./build.ps1 -Verbose
@@ -41,18 +49,22 @@ A PowerShell script (`build.ps1`) is provided to build HydroChrono from the comm
 ./build.ps1 -Verbose -Package
 ```
 
-### Useful switches
+### Switches
 
-- `-BuildType Release|Debug|RelWithDebInfo|MinSizeRel` (default: Release)
-- `-YamlRunner ON|OFF` to include/exclude the YAML runner target (default: ON)
-- `-Clean` remove existing `build/` before configuring
-- `-Package` run `cmake --install` and `cpack` (ZIP)
-- `-ConfigPath <file>` use a different JSON config
+| Switch | Description |
+|---|---|
+| `-BuildType <type>` | `Release` (default), `Debug`, `RelWithDebInfo`, or `MinSizeRel` |
+| `-Clean` | Remove existing `build/` before configuring |
+| `-Verbose` | Show full CMake and MSBuild output |
+| `-Package` | Run `cmake --install` and `cpack` to create a ZIP |
+| `-NoIrrlicht` | Disable Irrlicht visualization (auto-enabled if Chrono has it) |
+| `-NoVSG` | Disable VSG visualization (auto-enabled if Chrono has it) |
+| `-MoorDyn` | Enable MoorDyn mooring coupling (requires submodule, see [below](#moordyn-mooring-library)) |
+| `-NoDemos` | Skip building demo executables |
+| `-NoTests` | Skip building test targets |
+| `-ConfigPath <file>` | Use a different JSON config (default: `build-config.json`) |
 
-What it does:
-- Passes your dependency paths to CMake
-- Builds with VS/MSBuild
-- For `-Package`: stages a flat install tree and creates a ZIP
+Run `.\build.ps1 -Help` for the full reference.
 
 Install tree layout:
 ```
@@ -62,16 +74,34 @@ install/
   tests/  # public regression suite (run_hydrochrono)
 ```
 
+## MoorDyn mooring library
+
+[MoorDyn](https://github.com/FloatingArrayDesign/MoorDyn) is an optional mooring dynamics library included as a git submodule. To enable it:
+
+1) Initialize the submodule (one-time setup, clones MoorDyn into `extern/MoorDyn`):
+```powershell
+git submodule update --init extern/MoorDyn
+```
+
+2) Build with the `-MoorDyn` flag:
+```powershell
+./build.ps1 -MoorDyn -Verbose
+```
+
+The submodule pins a specific MoorDyn version tested with HydroChrono. Running `git submodule update` after pulling new commits will keep it in sync.
+
 ## Alternative: CMake GUI + Visual Studio
 
 1. Open CMake (GUI)
     - Source: HydroChrono repo root
     - Build: `<repo>/build`
 
 2. Configure:
-    - Set `Chrono_DIR` to `<chrono>/build/cmake`
-    - Set `HDF5_DIR`, `Irrlicht_ROOT`, `Python3_ROOT_DIR`, `EIGEN3_INCLUDE_DIR`
-    - Ensure your HydroChrono `CMAKE_MSVC_RUNTIME_LIBRARY` matches Chrono
+    - Set `Chrono_DIR` to `<chrono>/build/cmake` (required)
+    - Eigen, Irrlicht, and VSG paths are auto-detected from Chrono's build
+    - `HDF5_DIR` may need to be set if CMake doesn't find it automatically
+    - Set `HYDROCHRONO_ENABLE_MOORDYN` to `ON` if using MoorDyn (requires submodule, see [above](#moordyn-mooring-library))
+    - Ensure your `CMAKE_MSVC_RUNTIME_LIBRARY` matches the one used to build Chrono
 
 3. Generate → Open in Visual Studio → Build `run_hydrochrono` (choose the matching config, e.g., Release)
 
@@ -85,24 +115,24 @@ After a local build, you have two regression test suites - **Option A** uses CTe
 
 **Option A** - CTest:
 ```powershell
-ctest -C Release -L regression
+ctest -C Release -L regression --test-dir build
 ```
 
   - Common CTest options/examples:
 
 ```powershell
 # Show failing test output
-ctest -C Release -L regression --output-on-failure
+ctest -C Release -L regression --test-dir build --output-on-failure
 
 # Extra verbose output
-ctest -C Release -L regression -VV
+ctest -C Release -L regression --test-dir build -VV
 
 # Only run specific tests
-ctest -C Release -R f3of -L regression
-ctest -C Release -R rm3  -L regression
+ctest -C Release -R f3of -L regression --test-dir build
+ctest -C Release -R rm3  -L regression --test-dir build
 
 # Run in parallel
-ctest -C Release -j 6 -L regression
+ctest -C Release -j 6 -L regression --test-dir build
 ```
 
 **Option B** — Python-based YAML tests for the main executable:

docs/_main_pages/developer_docs/cmake_build_structure.md

@@ -41,7 +41,7 @@ Banner comments separate sections so it’s easy to navigate and reason about ch
 - Project `HydroChrono` (C++)
 - Default build type: Release (Debug/MinSizeRel/RelWithDebInfo supported)
 - `cmake/` added to `CMAKE_MODULE_PATH` (local modules)
-- Generates `version.h` under `build/generated/`
+- Generates `version.h` under `build/hydroc/`
 
 ---
 
@@ -52,6 +52,7 @@ Banner comments separate sections so it’s easy to navigate and reason about ch
 - `HYDROCHRONO_ENABLE_VSG` - Enable VSG visualization
 - `HYDROCHRONO_ENABLE_DEMOS` - Enable demo executables
 - `HYDROCHRONO_ENABLE_YAML_RUNNER` - Enable YAML-based CLI runner
+- `HYDROCHRONO_ENABLE_MOORDYN` - Enable MoorDyn mooring coupling (requires `extern/MoorDyn` submodule)
 
 Enable lean builds (e.g., CI) or developer variants.
 
@@ -61,14 +62,14 @@ Enable lean builds (e.g., CI) or developer variants.
 
 ### Chrono
 
-- `find_package(Chrono CONFIG REQUIRED)`
-- If Irrlicht is enabled, find `Irrlicht` first so `Chrono::Chrono_irrlicht` exists
-- Extend `CMAKE_MODULE_PATH` with `Chrono_DIR` when needed
+- `find_package(Chrono CONFIG REQUIRED COMPONENTS Parsers)`
+- Irrlicht and VSG targets are checked if the corresponding `HYDROCHRONO_ENABLE_*` option is ON
+- HDF5 targets are pre-loaded before Chrono to avoid conflicts with `hdf5_tools` shim targets
 
 ### HDF5 & Eigen
 
-- HDF5 required: `find_package(HDF5 REQUIRED COMPONENTS CXX)`; link static to avoid DLL issues
-- Eigen via config or module mode
+- HDF5: first tries config mode (`find_package(HDF5 CONFIG QUIET)`), falls back to module mode (`find_package(HDF5 REQUIRED COMPONENTS CXX)`). Prefers static libraries when available.
+- Eigen: auto-detected from Chrono's build configuration
 
 ### Platform notes
 
@@ -80,15 +81,15 @@ Enable lean builds (e.g., CI) or developer variants.
 
 Libraries:
 
-- `HydroChrono` — core hydrodynamics (HDF5 I/O, YAML, utilities)
-- `HydroChronoGUI` — GUI helpers when Irrlicht is enabled
+- `HydroChrono` — core hydrodynamics (HDF5 I/O, YAML, radiation, waves, utilities)
+- `HydroChronoGUI` — GUI helpers for Irrlicht and/or VSG visualization
 
-`configure_hydro_target(<tgt>)` centralizes: C++ standard, PIC, include dirs, Chrono links.
+Each target is configured directly with C++ standard, PIC, include dirs, and Chrono links.
 
 Key links:
 
-- `HydroChrono` → `Chrono::Chrono_core` (+ HDF5)
-- `HydroChronoGUI` → Chrono (+ `Chrono::Chrono_irrlicht` when enabled)
+- `HydroChrono` → `Chrono::Chrono_core`, OpenMP, HDF5 (+ MoorDyn when enabled)
+- `HydroChronoGUI` → `Chrono::Chrono_core` (+ `Chrono::Chrono_irrlicht` and/or `Chrono::Chrono_vsg` when enabled)
 
 
 ---
@@ -109,8 +110,8 @@ Key links:
 
 ### Tests & Demos
 
-- If enabled, tests are added via `add_subdirectory(tests)` and `add_subdirectory(tests/regression)`
-- A helper `configure_test_environment()` assembles PATH on Windows so Chrono/Irrlicht DLLs are found when tests run from the build tree
+- If enabled, tests are added via `add_subdirectory(tests/regression)` and `add_subdirectory(tests/unit)`
+- A helper `configure_test_environment()` assembles PATH on Windows so Chrono, HDF5, Irrlicht, VSG, and MoorDyn DLLs are found when tests run from the build tree
 - Demos can be included behind `HYDROCHRONO_ENABLE_DEMOS`
 
 Runtime concerns that affect tests:

extern/MoorDyn

@@ -20,12 +20,10 @@
 // ─────────────────────────────────────────────────────────────────────────────
 // Added Mass Implementation Toggle
 // ─────────────────────────────────────────────────────────────────────────────
-// By default, HydroChrono uses Chrono's built-in ChLoadHydrodynamics for
-// infinite-frequency added mass. To switch to HydroChrono's legacy
-// ChLoadAddedMass (ChLoadCustomMultiple-based) implementation, uncomment:
-//
-// #define HYDROCHRONO_USE_LEGACY_ADDED_MASS
-//
+// HYDROCHRONO_USE_LEGACY_ADDED_MASS is auto-detected at configure time based
+// on whether Chrono provides ChLoadHydrodynamics. When defined (legacy mode),
+// HydroChrono uses its own ChLoadAddedMass (ChLoadCustomMultiple-based)
+// implementation instead of Chrono's built-in ChLoadHydrodynamics.
 
 // Include hydro_types.h FIRST to ensure BodyForces and GeneralizedForce are available
 // before any other includes that might conflict (e.g., config/hydro_config.h)

include/hydroc/hydro_system.h

@@ -31,6 +31,10 @@ endfunction()
 
 # --- Register unit tests ---
 message(STATUS "Add HydroChrono unit tests")
-build_unit_test(test_added_mass_determinism)
+if(CHRONO_HAS_LOAD_HYDRODYNAMICS)
+    build_unit_test(test_added_mass_determinism)
+else()
+    message(STATUS "  Skipping test_added_mass_determinism (requires ChLoadHydrodynamics)")
+endif()
 build_unit_test(test_radiation_ss_model)
 build_unit_test(test_radiation_ss_fitter)