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

/** \file Triangle.h */

#ifndef AMDIS_TRIANGLE_H
#define AMDIS_TRIANGLE_H

#include "Element.h"

namespace AMDiS {

  /** \ingroup Triangulation 
   * \brief
   * A Triangle is a 2-dimensional Element.
   *
   * A Triangle and its refinements:
   *
   * <img src = "triangle.png">
   */
  class Triangle : public Element
  {
  public:
    /** \brief
     * calls base class contructor.
     */
    Triangle(Mesh* aMesh) 
      : Element(aMesh) 
    {}

    ~Triangle() {}

    /** \brief
     * implements Element::clone
     */
    inline Element *clone() { 
      return new Triangle(mesh); 
    }


    /** \brief
     * implements Element::getVertexOfEdge
     */
    inline int getVertexOfEdge(int i, int j) const {
      return vertexOfEdge[i][j];
    }

    /** \brief
     * implements Element::getVertexOfPosition
     */
    int getVertexOfPosition(GeoIndex position,
			    int positionIndex,
			    int vertexIndex) const;

    /** \brief
     * implements Element::getGeo
     */
    inline int getGeo(GeoIndex i) const {
      switch(i) {
      case VERTEX: case PARTS: case NEIGH:
	return 3;
	break;
      case EDGE:
	return 3;
      case FACE:
	return 0;
      case CENTER:
	return 1;
	break;
      case DIMEN:
	return 2;
	break;
      case BOUNDARY:
	return 6;
	break;
      case PROJECTION:
	return 3;
	break;
      default:
	ERROR_EXIT("invalid geo-index\n");
	return 0;
      }
    }

    /** \brief
     * implements Element::hasSide
     */
    bool hasSide(Element* sideElem) const;

    /** \brief
     * implements Element::sortFaceIndices
     */
    const FixVec<int,WORLD>& sortFaceIndices(int face, 
					     FixVec<int,WORLD> *vec) const;

    /** \brief
     * implements Element::isLine. Returns false because this element is a 
     * Triangle
     */
    inline bool isLine() const { 
      return false; 
    }
 
    /** \brief
     * implements Element::isTriangle. Returns true because this element is a 
     * Triangle
     */
    inline bool isTriangle() const { 
      return true; 
    }

    /** \brief
     * implements Element::isTetrahedron. Returns false because this element is a 
     * Triangle
     */
    inline bool isTetrahedron() const { 
      return false; 
    }

    /** \brief
     * implements Element::getSideOfChild()
     */
    virtual int getSideOfChild(int child, int side, int) const {
      FUNCNAME("Triangle::getSideOfChild()");
      TEST_EXIT_DBG(child==0 || child==1)("child must be in (0,1)\n");
      TEST_EXIT_DBG(side >= 0 && side <= 2)("side must be between 0 and 2\n");
      return sideOfChild[child][side];
    }

    /** \brief
     * implements Element::getVertexOfParent()
     */
    virtual int getVertexOfParent(int child, int side, int=0) const {
      FUNCNAME("Triangle::getVertexOfParent()");
      TEST_EXIT_DBG(child==0 || child==1)("child must be in (0,1)\n");
      TEST_EXIT_DBG(side >= 0 && side <= 2)("side must be between 0 and 2\n");
      return vertexOfParent[child][side];
    }

    virtual int getPositionOfVertex(int side, int vertex) const {
      static int positionOfVertex[3][3] = {{-1,0,1},{1,-1,0},{0,1,-1}};
      return positionOfVertex[side][vertex];
    };

    inline int getEdgeOfFace(int face, int edge) const {
      TEST_EXIT_DBG(face == 0)("face must be zero at triangle\n");
      TEST_EXIT_DBG(edge >= 0 && edge < 3)("invalid edge\n");
      return edge;
    }

    // ===== Serializable implementation =====
  
    std::string getTypeName() const { 
      return "Triangle"; 
    }

  protected:
    /** \brief
     * vertexOfEdge[i][j] is the local number of the j-th vertex of the i-th 
     * edge of this element.
     */
    static const int vertexOfEdge[3][2];

    static const int sideOfChild[2][3];

    static const int vertexOfParent[2][3];
  };

}

#endif // AMDIS_TRIANGLE_H