ToroidalHoneycombVertexMeshGenerator.cpp

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*/

#include "ToroidalHoneycombVertexMeshGenerator.hpp"

ToroidalHoneycombVertexMeshGenerator::ToroidalHoneycombVertexMeshGenerator(unsigned numElementsAcross,
   unsigned numElementsUp,
   double cellRearrangementThreshold,
   double t2Threshold)
{
    // numElementsAcross and numElementsUp must be even for toroidal meshes
    assert(numElementsAcross > 1);
    assert(numElementsUp > 1);
    assert(numElementsAcross%2 == 0);
    assert(numElementsUp%2 == 0);

    assert(cellRearrangementThreshold > 0.0);
    assert(t2Threshold > 0.0);

    std::vector<Node<2>*> nodes;
    std::vector<VertexElement<2,2>*>  elements;

    unsigned node_index = 0;
    unsigned node_indices[6];
    unsigned element_index;

    // Create the nodes
    for (unsigned j=0; j<2*numElementsUp; j++)
    {
        for (unsigned i=0; i<numElementsAcross; i++)
        {
            double x_coord = ((j%4 == 0)||(j%4 == 3)) ? i+0.5 : i;
            double y_coord = (1.5*j - 0.5*(j%2))*0.5/sqrt(3.0);

            Node<2>* p_node = new Node<2>(node_index, false , x_coord, y_coord);
            nodes.push_back(p_node);
            node_index++;
        }
    }

    /*
     * Create the elements. The array node_indices contains the
     * global node indices from bottom, going anticlockwise.
     */
    for (unsigned j=0; j<numElementsUp; j++)
    {
        for (unsigned i=0; i<numElementsAcross; i++)
        {
            element_index = j*numElementsAcross + i;

            node_indices[0] = 2*j*numElementsAcross + i + 1*(j%2==1);
            node_indices[1] = node_indices[0] + numElementsAcross + 1*(j%2==0);
            node_indices[2] = node_indices[0] + 2*numElementsAcross + 1*(j%2==0);
            node_indices[3] = node_indices[0] + 3*numElementsAcross;
            node_indices[4] = node_indices[0] + 2*numElementsAcross - 1*(j%2==1);
            node_indices[5] = node_indices[0] + numElementsAcross - 1*(j%2==1);

            if (i == numElementsAcross-1) // on far right
            {
                node_indices[0] -= numElementsAcross*(j%2==1);
                node_indices[1] -= numElementsAcross;
                node_indices[2] -= numElementsAcross;
                node_indices[3] -= numElementsAcross*(j%2==1);
            }
            if (j == numElementsUp-1) // on far top
            {
                node_indices[2] -= 2*numElementsAcross*numElementsUp;
                node_indices[3] -= 2*numElementsAcross*numElementsUp;
                node_indices[4] -= 2*numElementsAcross*numElementsUp;
            }

            std::vector<Node<2>*> element_nodes;
            for (unsigned k=0; k<6; k++)
            {
               element_nodes.push_back(nodes[node_indices[k]]);
            }
            VertexElement<2,2>* p_element = new VertexElement<2,2>(element_index, element_nodes);
            elements.push_back(p_element);
        }
    }

    double mesh_width = numElementsAcross;
    double mesh_height = 1.5*numElementsUp/sqrt(3.0);

    mpMesh = new Toroidal2dVertexMesh(mesh_width, mesh_height, nodes, elements, cellRearrangementThreshold, t2Threshold);
}

MutableVertexMesh<2,2>* ToroidalHoneycombVertexMeshGenerator::GetMesh()
{
    EXCEPTION("A toroidal mesh was created but a normal mesh is being requested.");
    return mpMesh; // Not really
}

Toroidal2dVertexMesh* ToroidalHoneycombVertexMeshGenerator::GetToroidalMesh()
{
    return (Toroidal2dVertexMesh*) mpMesh;
}