opm-core/opm/core/grid/ColumnExtract.hpp
2013-07-28 08:34:13 -03:00

123 lines
4.5 KiB
C++

#include <opm/core/grid.h>
#include <vector>
#include <map>
#include <algorithm>
namespace Opm {
namespace {
/// Helper struct for extractColumn
/// Compares the underlying k-index
struct ExtractColumnCompare
{
ExtractColumnCompare(const UnstructuredGrid& g)
: grid(g)
{
// empty
}
bool operator()(const int i, const int j)
{
// Extract k-index
int index_i = grid.global_cell ? grid.global_cell[i] : i;
int k_i = index_i / grid.cartdims[0] / grid.cartdims[1];
int index_j = grid.global_cell ? grid.global_cell[j] : j;
int k_j = index_j / grid.cartdims[0] / grid.cartdims[1];
return k_i < k_j;
}
const UnstructuredGrid& grid;
};
/// Neighbourhood query.
/// \return true if two cells are neighbours.
bool neighbours(const UnstructuredGrid& grid, const int c0, const int c1)
{
for (int hf = grid.cell_facepos[c0]; hf < grid.cell_facepos[c0 + 1]; ++hf) {
const int f = grid.cell_faces[hf];
if (grid.face_cells[2*f] == c1 || grid.face_cells[2*f+1] == c1) {
return true;
}
}
return false;
}
} // anonymous namespace
/// Extract each column of the grid.
/// \note Assumes the pillars of the grid are all vertically aligned.
/// \param grid The grid from which to extract the columns.
/// \param columns will for each (i, j) where (i, j) represents a non-empty column,
//// contain the cell indices contained in the column
/// centered at (i, j) in the second variable, and i+jN in the first variable.
inline void extractColumn( const UnstructuredGrid& grid, std::vector<std::vector<int> >& columns )
{
const int* dims = grid.cartdims;
// Keeps track of column_index ---> index of vector
std::map<int, int> global_to_local;
for (int cell = 0; cell < grid.number_of_cells; ++cell) {
// Extract Cartesian coordinates
int index = grid.global_cell ? grid.global_cell[cell] : cell; // If null, assume mapping is identity.
int i_cart = index % dims[0];
int k_cart = index / dims[0] / dims[1];
int j_cart = (index - k_cart*dims[0]*dims[1])/ dims[0];
int local_index;
std::map<int, int>::iterator local_index_iterator = global_to_local.find(i_cart+j_cart*dims[0]);
if (local_index_iterator != global_to_local.end()) {
local_index = local_index_iterator->second;
} else {
local_index = columns.size();
global_to_local[i_cart+j_cart*dims[0]] = local_index;
columns.push_back(std::vector<int>());
}
columns[local_index].push_back(cell);
}
int num_cols = columns.size();
for (int col = 0; col < num_cols; ++col) {
std::sort(columns[col].begin(), columns[col].end(), ExtractColumnCompare(grid));
}
// At this point, a column may contain multiple disjoint sets of cells.
// We must split these columns into connected parts.
std::vector< std::vector<int> > new_columns;
for (int col = 0; col < num_cols; ++col) {
const int colsz = columns[col].size();
int first_of_col = 0;
for (int k = 1; k < colsz; ++k) {
const int c0 = columns[col][k-1];
const int c1 = columns[col][k];
if (!neighbours(grid, c0, c1)) {
// Must split. Move the cells [first_of_col, ... , k-1] to
// a new column, known to be connected.
new_columns.push_back(std::vector<int>());
new_columns.back().assign(columns[col].begin() + first_of_col, columns[col].begin() + k);
// The working column now starts with index k.
first_of_col = k;
}
}
if (first_of_col != 0) {
// The column was split, the working part should be
// the entire column. We erase the cells before first_of_col.
// (Could be more efficient if we instead chop off end.)
columns[col].erase(columns[col].begin(), columns[col].begin() + first_of_col);
}
}
// Must tack on the new columns to complete the set.
const int num_cols_all = num_cols + new_columns.size();
columns.resize(num_cols_all);
for (int col = num_cols; col < num_cols_all; ++col) {
columns[col].swap(new_columns[col - num_cols]);
}
}
} // namespace Opm