// ============================================================================
// ==                                                                        ==
// == AMDiS - Adaptive multidimensional simulations                          ==
// ==                                                                        ==
// ============================================================================
// ==                                                                        ==
// ==  crystal growth group                                                  ==
// ==                                                                        ==
// ==  Stiftung caesar                                                       ==
// ==  Ludwig-Erhard-Allee 2                                                 ==
// ==  53175 Bonn                                                            ==
// ==  germany                                                               ==
// ==                                                                        ==
// ============================================================================
// ==                                                                        ==
// ==  http://www.caesar.de/cg/AMDiS                                         ==
// ==                                                                        ==
// ============================================================================

/** \file ElementFunction.h */

#ifndef AMDIS_ELEMENTFUNCTION_H
#define AMDIS_ELEMENTFUNCTION_H

#include "AbstractFunction.h"
#include "DOFVector.h"
#include "BasisFunction.h"

namespace AMDiS {

  // ============================================================================
  // ===== class ElementFunction ================================================
  // ============================================================================

  /** \brief
   * Abstract access to functions living on elements.
   */
  template<typename T>
  class ElementFunction : public AbstractFunction<T, DimVec<double> >
  {
  public:
    /** \brief
     * constructor.
     */
    ElementFunction() : elInfo_(NULL) {};

    /** \brief
     * destructor.
     */
    virtual ~ElementFunction() {};

    /** \brief
     * sets \ref elInfo_;
     */
    inline void setElInfo(const ElInfo *elInfo) { elInfo_ = elInfo; };

  protected:
    /** \brief
     * ElInfo the function currently lives on.
     */
    const ElInfo *elInfo_;
  };

  // ============================================================================
  // ===== class ElementFunctionAnalytic ========================================
  // ============================================================================

  /** \brief
   * ElementFunction wich encapsulates the evaluation of an analytical function.
   */
  template<typename T>
  class ElementFunctionAnalytic : public ElementFunction<T>
  {
  public:
    /** \brief
     * constructor
     */
    ElementFunctionAnalytic(const AbstractFunction<T, WorldVector<double> > *fct)
      : ElementFunction<T>(),
	fct_(fct)
    {};

    /** \brief
     * evaluation at given coordinates.
     */
    const T& operator()(const DimVec<double>& bary) const {
      const WorldVector<double> *worldCoords = this->elInfo_->coordToWorld(bary, NULL);
      return (*fct_)(*worldCoords);
    };

  protected:
    /** \brief
     * function to be avaluated at world coordinates.
     */
    const AbstractFunction<T, WorldVector<double> > *fct_;
  };


  // ============================================================================
  // ===== class ElementFunctionDOFVec ==========================================
  // ============================================================================

  /** \brief
   * ElementFunction wich encapsulates the interpolation of an DOFVector.
   */
  template<typename T>
  class ElementFunctionDOFVec : public ElementFunction<T>
  {
  public:
    /** \brief
     * constructor.
     */
    ElementFunctionDOFVec(const DOFVector<T> *dofVector) 
      : ElementFunction<T>(),
	dofVector_(dofVector)
    {};

    /** \brief
     * evaluation at given coordinates.
     */
    const T& operator()(const DimVec<double>& bary) const {
      static T t;
      const T* localVec = 
	dofVector_->getLocalVector(this->elInfo_->getElement(), NULL);
      t = dofVector_->getFESpace()->getBasisFcts()->evalUh(bary, localVec);
      return t;
    };  

  protected:
    /** \brief
     * DOFVector to be interpolated.
     */
    const DOFVector<T> *dofVector_;
  };

}

#endif