CylindricalHoneycombVertexMeshGenerator.cpp

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#include "CylindricalHoneycombVertexMeshGenerator.hpp"
#include <boost/make_shared.hpp>
#include <boost/shared_ptr.hpp>
 
CylindricalHoneycombVertexMeshGenerator::CylindricalHoneycombVertexMeshGenerator(unsigned numElementsAcross,
                                                           unsigned numElementsUp,
                                                           bool isFlatBottom,
                                                           double cellRearrangementThreshold,
                                                           double t2Threshold)
{
    // numElementsAcross must be even for cylindrical meshes
    assert(numElementsAcross > 1);
    assert(numElementsAcross%2 == 0);
 
    assert(numElementsUp > 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+1; j++)
    {
        if (isFlatBottom && (j==1))
        {
            // Flat bottom to cylindrical mesh
            for (unsigned i=0; i<=numElementsAcross-1; i++)
            {
                Node<2>* p_node = new Node<2>(node_index, true, i, 0.0);
                nodes.push_back(p_node);
                node_index++;
            }
        }
        /*
         * On each interior row we have numElementsAcross+1 nodes. All nodes on the first, second,
         * penultimate and last rows are boundary nodes. On other rows no nodes are boundary nodes.
         */
        else
        {
            for (unsigned i=0; i<=numElementsAcross-1; 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);
                bool is_boundary_node = (j==0 || j==1 || j==2*numElementsUp || j==2*numElementsUp+1) ? true : false;
 
                Node<2>* p_node = new Node<2>(node_index, is_boundary_node , 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);
            }
 
            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);
        }
    }
 
    // If imposing a flat bottom, delete unnecessary nodes from the mesh
    if (isFlatBottom)
    {
        for (unsigned i=0; i<numElementsAcross; i++)
        {
            nodes[i]->SetPoint(nodes[i+numElementsAcross]->GetPoint());
        }
    }
    mpMesh = boost::make_shared<Cylindrical2dVertexMesh>(numElementsAcross, nodes, elements, cellRearrangementThreshold, t2Threshold);
}
 
boost::shared_ptr<MutableVertexMesh<2,2> > CylindricalHoneycombVertexMeshGenerator::GetMesh()
{
    EXCEPTION("A cylindrical mesh was created but a normal mesh is being requested.");
    return mpMesh; // Not really
}
 
boost::shared_ptr<Cylindrical2dVertexMesh> CylindricalHoneycombVertexMeshGenerator::GetCylindricalMesh()
{
    return boost::static_pointer_cast<Cylindrical2dVertexMesh>(mpMesh);
}