/*=========================================================================

  Program:   Visualization Toolkit
  Module:    vtkQuadratureSchemeDefinition.h

  Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
  All rights reserved.
  See Copyright.txt or http://www.kitware.com/Copyright.htm for details.

     This software is distributed WITHOUT ANY WARRANTY; without even
     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
     PURPOSE.  See the above copyright notice for more information.

=========================================================================*/
// .NAME vtkQuadratureSchemeDefinition
// .SECTION Description
// An Elemental data type that holds a definition of a
// numerical quadrature scheme. The definition contains
// the requisite information to interpolate to the so called
// quadrature points of the specific scheme. namely:
//
// <pre>
// 1)
// A matrix of shape function weights(shape functions evaluated
// at parametric coordinates of the quadrature points).
//
// 2)
// The number of quadrature points and cell nodes. These parameters
// size the matrix, and allow for convinent evaluation by users
// of the definition.
// </pre>

#ifndef vtkQuadratureSchemeDefinition_h
#define vtkQuadratureSchemeDefinition_h

#include "vtkObject.h"

class vtkInformationQuadratureSchemeDefinitionVectorKey;
class vtkInformationStringKey;
class vtkXMLDataElement;

class VTK_COMMON_EXPORT vtkQuadratureSchemeDefinition : public vtkObject
{
public:
  // vtk stuff
  vtkTypeMacro(vtkQuadratureSchemeDefinition,vtkObject);
  void PrintSelf(ostream& os, vtkIndent indent);
  static vtkInformationQuadratureSchemeDefinitionVectorKey* DICTIONARY();
  static vtkInformationStringKey* QUADRATURE_OFFSET_ARRAY_NAME();

  // Description:
  // New object in an unsuable state. You'll have to call
  // "Initilaize" to get the definition in to a usable state.
  static vtkQuadratureSchemeDefinition *New();

  // Description:
  // Deep copy.
  int DeepCopy(const vtkQuadratureSchemeDefinition *other);

  // Description:
  // Put the object into an XML representation. The element
  // passed in is assumed to be empty.
  int SaveState(vtkXMLDataElement *e);
  // Description:
  // Restore the object from an XML representation.
  int RestoreState(vtkXMLDataElement *e);

  // Description:
  // Release all allocated resources and set the 
  // object to an unitialized state.
  void Clear();

  // Description:
  // Initialize the object allocating resources as needed.
  void Initialize(int cellType,
                  int numberOfNodes,
                  int numberOfQuadraturePoints,
                  double *shapeFunctionWeights);
  // Description:
  // Initialize the object allocating resources as needed.
  void Initialize(int cellType,
                  int numberOfNodes,
                  int numberOfQuadraturePoints,
                  double *shapeFunctionWeights,
                  double *quadratureWeights);

  // Description:
  // Access the VTK cell type id.
  int GetCellType() const { return this->CellType; }
  // Description:
  // Access to an alternative key.
  int GetQuadratureKey() const { return this->QuadratureKey; }
  // Description:
  // Get the number of nodes associated with the interpolation.
  int GetNumberOfNodes() const { return this->NumberOfNodes; }
  // Description:
  // Get the number of quadrature points associated with the scheme.
  int GetNumberOfQuadraturePoints() const { return this->NumberOfQuadraturePoints; }
  // Description:
  // Get the array of shape function weights. Shape function weights are
  // the shape functions evaluated at the quadrature points. There are 
  // "NumberOfNodes" weights for each quadrature point.
  const double *GetShapeFunctionWeights() const  { return this->ShapeFunctionWeights; }
  // Description:
  // Get the array of shape function weights associated with a
  // single quadrature point.
  const double *GetShapeFunctionWeights(int quadraturePointId) const
  {
    int idx=quadraturePointId*this->NumberOfNodes;
    return this->ShapeFunctionWeights+idx;
  }
  // Description:
  // Access to the quadrature weights.
  const double *GetQuadratureWeights() const { return this->QuadratureWeights; }

protected:
  vtkQuadratureSchemeDefinition();
  ~vtkQuadratureSchemeDefinition();
private:
  // Description:
  // Allocate/De-allocate resources that will be used by the definition.
  // This must be called after Set*. Caller's responsibility.
  void ReleaseResources();
  // Description:
  // Allocate resources according to the objects
  // current internal state.
  int SecureResources();
  // Description:
  // Initialize the shape function weights definition.
  // Must call SecureResources prior.
  void SetShapeFunctionWeights(const double *W);
  // Description:
  // Initialize the shape function weights definition.
  // Must call SecureResources prior.
  void SetQuadratureWeights(const double *W);

  //
  vtkQuadratureSchemeDefinition(const vtkQuadratureSchemeDefinition &); // Not implemented.
  void operator=(const vtkQuadratureSchemeDefinition &); // Not implemented.
  friend ostream &operator<<(ostream &s, const vtkQuadratureSchemeDefinition &d);
  friend istream &operator>>(istream &s, const vtkQuadratureSchemeDefinition &d);
  //
  int CellType;
  int QuadratureKey;
  int NumberOfNodes;
  int NumberOfQuadraturePoints;
  double *ShapeFunctionWeights;
  double *QuadratureWeights;
};

#endif