Add RoughnessModel enumerate

Core/Multilayer/RoughnessModels.cpp

+// ************************************************************************** //
+//
+//  BornAgain: simulate and fit scattering at grazing incidence
+//
+//! @file      Core/Multilayer/SpecularMatrix.cpp
+//! @brief     Implements class SpecularMatrix.
+//!
+//! @homepage  http://www.bornagainproject.org
+//! @license   GNU General Public License v3 or higher (see COPYING)
+//! @copyright Forschungszentrum Jülich GmbH 2018
+//! @authors   Scientific Computing Group at MLZ (see CITATION, AUTHORS)
+//
+// ************************************************************************** //
+
+#include "RoughnessModels.h"
+
+#include <map>
+
+namespace {
+const std::map<RoughnessModel, std::string> roughnessModelNames = {
+    {RoughnessModel::DEFAULT, "RoughnessModel::DEFAULT"},
+    {RoughnessModel::TANH, "RoughnessModel::TANH"},
+    {RoughnessModel::NEVOT_CROCE, "RoughnessModel::NEVOT_CROCE"} };
+}
+
+std::string RoughnessModelWrap::roughnessModelName(RoughnessModel model)
+{
+    auto iter = roughnessModelNames.find(model);
+    if (iter != roughnessModelNames.end())
+        return iter->second;
+    return "Invalid roughness model";
+}
+
+

Core/Multilayer/RoughnessModels.h

+// ************************************************************************** //
+//
+//  BornAgain: simulate and fit scattering at grazing incidence
+//
+//! @file      Core/Computation/ProcessedSample.cpp
+//! @brief     Implements class ProcessedSample.
+//!
+//! @homepage  http://www.bornagainproject.org
+//! @license   GNU General Public License v3 or higher (see COPYING)
+//! @copyright Forschungszentrum Jülich GmbH 2018
+//! @authors   Scientific Computing Group at MLZ (see CITATION, AUTHORS)
+//
+// ************************************************************************** //
+
+
+#ifndef ROUGHNESSMODELS_H
+#define ROUGHNESSMODELS_H
+
+#include <string>
+
+#include "WinDllMacros.h"
+
+// workaround for SWIG (instead of just writing enum class RoughnessModel ...)
+struct BA_CORE_API_ RoughnessModelWrap {
+    enum RoughnessModel { DEFAULT, TANH, NEVOT_CROCE };
+#ifndef SWIG
+    // TODO: to automatize enum to string convertion, one can possibly use this solution
+    // https://stackoverflow.com/questions/147267/easy-way-to-use-variables-of-enum-types-as-string-in-c#202511
+    static std::string roughnessModelName(RoughnessModel model);
+#endif
+};
+typedef RoughnessModelWrap::RoughnessModel RoughnessModel;
+
+
+
+#endif // ROUGHNESSMODELS_H