Refactoring: MaterialUtils namespace introduced + slight changes in documentation

Core/Material/BaseMaterialImpl.cpp

@@ -43,7 +43,7 @@ Eigen::Matrix2cd BaseMaterialImpl::polarizedSubtrSLD(const WavevectorInfo& wavev
 {
     cvector_t mag_ortho = OrthogonalToBaseVector(wavevectors.getQ(), m_magnetization);
     complex_t unit_factor = scalarSubtrSLD(wavevectors);
-    return MagnetizationCorrection(unit_factor, magnetization_prefactor, mag_ortho);
+    return MaterialUtils::MagnetizationCorrection(unit_factor, magnetization_prefactor, mag_ortho);
 }
 
 BaseMaterialImpl* BaseMaterialImpl::transformedMaterial(const Transform3D& transform) const

Core/Material/MaterialUtils.cpp

@@ -27,8 +27,10 @@ const Eigen::Matrix2cd Pauli_Z((Eigen::Matrix2cd() << 1,  0,
 }
 
 template <typename T>
-Eigen::Matrix2cd MagnetizationCorrection(complex_t unit_factor, double magnetic_factor,
-                                                      BasicVector3D<T> polarization){
+Eigen::Matrix2cd MaterialUtils::MagnetizationCorrection(complex_t unit_factor,
+                                                        double magnetic_factor,
+                                                        BasicVector3D<T> polarization)
+{
     Eigen::Matrix2cd result = unit_factor * Unit_Matrix +
         magnetic_factor * (
             Pauli_X * polarization[0] +
@@ -37,17 +39,19 @@ Eigen::Matrix2cd MagnetizationCorrection(complex_t unit_factor, double magnetic_
         );
     return result;
 }
-template Eigen::Matrix2cd MagnetizationCorrection(complex_t unit_factor, double magnetic_factor,
-                                                  kvector_t polarization);
-template Eigen::Matrix2cd MagnetizationCorrection(complex_t unit_factor, double magnetic_factor,
-                                                  cvector_t polarization);
+template Eigen::Matrix2cd MaterialUtils::MagnetizationCorrection(complex_t unit_factor,
+                                                                 double magnetic_factor,
+                                                                 kvector_t polarization);
+template Eigen::Matrix2cd MaterialUtils::MagnetizationCorrection(complex_t unit_factor,
+                                                                 double magnetic_factor,
+                                                                 cvector_t polarization);
 
-complex_t ScalarReducedPotential(complex_t n, kvector_t k, double n_ref)
+complex_t MaterialUtils::ScalarReducedPotential(complex_t n, kvector_t k, double n_ref)
 {
     return n*n - n_ref*n_ref*k.sin2Theta();
 }
 
-Eigen::Matrix2cd PolarizedReducedPotential(complex_t n, kvector_t b_field,
+Eigen::Matrix2cd MaterialUtils::PolarizedReducedPotential(complex_t n, kvector_t b_field,
                                            kvector_t k, double n_ref)
 {
     Eigen::Matrix2cd result;

Core/Material/MaterialUtils.h

@@ -2,7 +2,7 @@
 //
 //  BornAgain: simulate and fit scattering at grazing incidence
 //
-//! @file      Core/Material/Material.h
+//! @file      Core/Material/MaterialUtils.h
 //! @brief     materials-related global functions and utilities
 //!
 //! @homepage  http://www.bornagainproject.org
@@ -20,15 +20,19 @@
 #include "Vectors3D.h"
 #include "EigenCore.h"
 
+//! A number of helper functions for internal use
+//! @ingroup materials
+
+namespace MaterialUtils {
 //! Function for calculating the reduced potential, used for obtaining the Fresnel coefficients
 //! (non-polarized material case)
-complex_t ScalarReducedPotential(complex_t n, kvector_t k, double n_ref);
+BA_CORE_API_ complex_t ScalarReducedPotential(complex_t n, kvector_t k, double n_ref);
 
 #ifndef SWIG
 //! Function for calculating the reduced potential, used for obtaining the Fresnel coefficients
 //! (polarized material case)
-Eigen::Matrix2cd PolarizedReducedPotential(complex_t n, kvector_t b_field,
-                                           kvector_t k, double n_ref);
+BA_CORE_API_ Eigen::Matrix2cd PolarizedReducedPotential(complex_t n, kvector_t b_field, kvector_t k,
+                                                        double n_ref);
 
 //! Utility to compute magnetization correction for reduced potential and scattering length density
 template <typename T>
@@ -36,5 +40,6 @@ BA_CORE_API_ Eigen::Matrix2cd MagnetizationCorrection(complex_t unit_factor, dou
                                                       BasicVector3D<T> polarization);
 
 #endif /* SWIG */
+}
 
 #endif /* MATERIALUTILS_H_ */

Core/Multilayer/Layer.cpp

@@ -145,14 +145,14 @@ SafePointerVector<Layer> Layer::slice(ZLimits limits, Layer::ELayerType layer_ty
 complex_t Layer::scalarReducedPotential(kvector_t k, double n_ref) const
 {
     complex_t n = m_material.refractiveIndex(2.0 * M_PI / k.mag());
-    return ScalarReducedPotential(n, k, n_ref);
+    return MaterialUtils::ScalarReducedPotential(n, k, n_ref);
 }
 
 Eigen::Matrix2cd Layer::polarizedReducedPotential(kvector_t k, double n_ref) const
 {
     complex_t n = m_material.refractiveIndex(2.0 * M_PI / k.mag());
     kvector_t b_field = bField();
-    return PolarizedReducedPotential(n, b_field, k, n_ref);
+    return MaterialUtils::PolarizedReducedPotential(n, b_field, k, n_ref);
 }
 
 void Layer::initBField(kvector_t h_field, double b_z)