Пример #1
0
void RefMap::calc_inv_ref_map(int order)
{
  assert(quad_2d != NULL);
  int i, j, np = quad_2d->get_num_points(order);

  // construct jacobi matrices of the direct reference map for all integration points

  AUTOLA_OR(double2x2, m, np);
  memset(m, 0, m.size);
  ref_map_pss.force_transform(sub_idx, ctm);
  for (i = 0; i < nc; i++)
  {
    double *dx, *dy;
    ref_map_pss.set_active_shape(indices[i]);
    ref_map_pss.set_quad_order(order);
    ref_map_pss.get_dx_dy_values(dx, dy);
    for (j = 0; j < np; j++)
    {
      m[j][0][0] += coeffs[i][0] * dx[j];
      m[j][0][1] += coeffs[i][0] * dy[j];
      m[j][1][0] += coeffs[i][1] * dx[j];
      m[j][1][1] += coeffs[i][1] * dy[j];
    }
  }

  // calculate the jacobian and inverted matrix
  double trj = get_transform_jacobian();
  double2x2* irm = cur_node->inv_ref_map[order] = new double2x2[np];
  double* jac = cur_node->jacobian[order] = new double[np];
  for (i = 0; i < np; i++)
  {
    jac[i] = (m[i][0][0] * m[i][1][1] - m[i][0][1] * m[i][1][0]);
    double ij = 1.0 / jac[i];
    error_if(!finite(ij), "1/jac[%d] is infinity when calculating inv. ref. map for order %d (jac=%g)", i, order);
    assert_msg(ij == ij, "1/jac[%d] is NaN when calculating inv. ref. map for order %d (jac=%g)", i, order);

    // invert and transpose the matrix
    irm[i][0][0] =  m[i][1][1] * ij;
    irm[i][0][1] = -m[i][1][0] * ij;
    irm[i][1][0] = -m[i][0][1] * ij;
    irm[i][1][1] =  m[i][0][0] * ij;

    jac[i] *= trj;
  }
}
Пример #2
0
void RefMap::calc_tangent(int edge, int eo)
{
  int i, j;
  int np = quad_2d->get_num_points(eo);
  double3* tan = cur_node->tan[edge] = new double3[np];
  int a = edge, b = element->next_vert(edge);

  if (!element->is_curved())
  {
    // straight edges: the tangent at each point is just the edge length
    tan[0][0] = element->vn[b]->x - element->vn[a]->x;
    tan[0][1] = element->vn[b]->y - element->vn[a]->y;
    tan[0][2] = sqrt(sqr(tan[0][0]) + sqr(tan[0][1]));
    double inorm = 1.0 / tan[0][2];
    tan[0][0] *= inorm;
    tan[0][1] *= inorm;
    tan[0][2] *= (edge == 0 || edge == 2) ? ctm->m[0] : ctm->m[1];

    for (i = 1; i < np; i++)
      memcpy(tan+i, tan, sizeof(double3));
  }
  else
  {
    // construct jacobi matrices of the direct reference map at integration points along the edge
    static double2x2 m[15];
    assert(np <= 15);
    memset(m, 0, np*sizeof(double2x2));
    ref_map_pss.force_transform(sub_idx, ctm);
    for (i = 0; i < nc; i++)
    {
      double *dx, *dy;
      ref_map_pss.set_active_shape(indices[i]);
      ref_map_pss.set_quad_order(eo);
      ref_map_pss.get_dx_dy_values(dx, dy);
      for (j = 0; j < np; j++)
      {
        m[j][0][0] += coeffs[i][0] * dx[j];
        m[j][0][1] += coeffs[i][0] * dy[j];
        m[j][1][0] += coeffs[i][1] * dx[j];
        m[j][1][1] += coeffs[i][1] * dy[j];
      }
    }

    // multiply them by the vector of the reference edge
    double2* v1 = ref_map_shapeset.get_ref_vertex(a);
    double2* v2 = ref_map_shapeset.get_ref_vertex(b);
    double ex = (*v2)[0] - (*v1)[0];
    double ey = (*v2)[1] - (*v1)[1];
    for (i = 0; i < np; i++)
    {
      double3& t = tan[i];
      t[0] = m[i][0][0]*ex + m[i][0][1]*ey;
      t[1] = m[i][1][0]*ex + m[i][1][1]*ey;
      t[2] = sqrt(sqr(t[0]) + sqr(t[1]));
      double inorm = 1.0 / t[2];
      t[0] *= inorm;
      t[1] *= inorm;
      t[2] *= (edge == 0 || edge == 2) ? ctm->m[0] : ctm->m[1];
    }
  }
}