Implementation of the material embracing refractive coefficients

Redmine: #1858

Core/Material/RefractiveCoefMaterial.cpp

+#include "RefractiveCoefMaterial.h"
+#include "WavevectorInfo.h"
+
+RefractiveCoefMaterial::RefractiveCoefMaterial(const std::string& name, double delta, double beta,
+                                                 kvector_t magnetization)
+    : BaseMaterialImpl(name, magnetization)
+    , m_delta(delta)
+    , m_beta(beta)
+{}
+
+RefractiveCoefMaterial::~RefractiveCoefMaterial()
+{}
+
+RefractiveCoefMaterial* RefractiveCoefMaterial::clone() const
+{
+    return new RefractiveCoefMaterial(*this);
+}
+
+complex_t RefractiveCoefMaterial::refractiveIndex(double) const
+{
+    return complex_t(1.0 - m_delta, m_beta);
+}
+
+complex_t RefractiveCoefMaterial::refractiveIndex2(double) const
+{
+    complex_t result(1.0 - m_delta, m_beta);
+    return result * result;
+}
+
+complex_t RefractiveCoefMaterial::materialData() const
+{
+    return complex_t(m_delta, m_beta);
+}
+
+complex_t RefractiveCoefMaterial::scalarSubtrSLD(const WavevectorInfo& wavevectors) const
+{
+    double wavelength = wavevectors.getWavelength();
+    double prefactor = M_PI/wavelength/wavelength;
+    return prefactor * refractiveIndex2(wavelength);
+}
+
+void RefractiveCoefMaterial::print(std::ostream& ostr) const
+{
+    ostr << "RefractiveCoefMaterial:" << getName() << "<" << this << ">{ "
+         << "delta=" << m_delta << ", beta=" << m_beta
+         << ", B=" << magnetization() << "}";
+}
+

Core/Material/RefractiveCoefMaterial.h

+// ************************************************************************** //
+//
+//  BornAgain: simulate and fit scattering at grazing incidence
+//
+//! @file      Core/Material/RefractiveIndexMaterial.h
+//! @brief     Defines class RefractiveIndexMaterial.
+//!
+//! @homepage  http://www.bornagainproject.org
+//! @license   GNU General Public License v3 or higher (see COPYING)
+//! @copyright Forschungszentrum Jülich GmbH 2015
+//! @authors   Scientific Computing Group at MLZ Garching
+//! @authors   C. Durniak, M. Ganeva, G. Pospelov, W. Van Herck, J. Wuttke
+//
+// ************************************************************************** //
+
+#ifndef REFRACTIVECOEFMATERIAL_H_
+#define REFRACTIVECOEFMATERIAL_H_
+
+#include "BaseMaterialImpl.h"
+#include "Material.h"
+
+class BA_CORE_API_ RefractiveCoefMaterial : public BaseMaterialImpl
+{
+public:
+    //! Constructs a material with _name_ and _refractive_index_.
+    friend BA_CORE_API_ Material RefractiveIndexMaterial(const std::string&, complex_t, kvector_t);
+
+    //! Constructs a material with _name_ and refractive_index parameters
+    //! \f$\delta\f$ and \f$\beta\f$ for refractive index \f$n = 1 - \delta + i \beta\f$.
+    friend BA_CORE_API_ Material RefractiveIndexMaterial(const std::string&, double, double,
+                                                         kvector_t);
+
+    virtual ~RefractiveCoefMaterial();
+
+    //! Returns pointer to a copy of material
+    virtual RefractiveCoefMaterial* clone() const override;
+
+    virtual complex_t refractiveIndex(double wavelength) const override;
+    virtual complex_t refractiveIndex2(double wavelength) const override;
+
+    //! Returns underlying material data
+    virtual complex_t materialData() const override;
+
+    //! Returns \pi/(wl*wl) - sld, with wl being the wavelength
+    virtual complex_t scalarSubtrSLD(const WavevectorInfo& wavevectors) const override;
+
+    //! Prints object data
+    virtual void print(std::ostream &ostr) const override;
+
+private:
+    RefractiveCoefMaterial(const std::string& name, double delta, double beta,
+                           kvector_t magnetization);
+
+    double m_delta; //!< \f$\delta\f$ coefficient for refractive index \f$n = 1 - \delta + i \beta\f$
+    double m_beta; //!< \f$\beta\f$ coefficient for refractive index \f$n = 1 - \delta + i \beta\f$
+};
+
+#endif /* REFRACTIVECOEFMATERIAL_H_ */