/* Copyright 2013 IST Austria
Contributed by: Ulrich Bauer, Michael Kerber, Jan Reininghaus
This file is part of PHAT.
PHAT is free software: you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
PHAT is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with PHAT. If not, see . */
#pragma once
#include
#include
namespace phat {
class twist_reduction {
public:
template< typename Representation >
void operator () ( boundary_matrix< Representation >& boundary_matrix ) {
const index nr_columns = boundary_matrix.get_num_cols();
std::vector< index > lowest_one_lookup( nr_columns, -1 );
for( index cur_dim = boundary_matrix.get_max_dim(); cur_dim >= 1 ; cur_dim-- ) {
for( index cur_col = 0; cur_col < nr_columns; cur_col++ ) {
if( boundary_matrix.get_dim( cur_col ) == cur_dim ) {
index lowest_one = boundary_matrix.get_max_index( cur_col );
while( lowest_one != -1 && lowest_one_lookup[ lowest_one ] != -1 ) {
boundary_matrix.add_to( lowest_one_lookup[ lowest_one ], cur_col );
lowest_one = boundary_matrix.get_max_index( cur_col );
}
if( lowest_one != -1 ) {
lowest_one_lookup[ lowest_one ] = cur_col;
boundary_matrix.clear( lowest_one );
}
boundary_matrix.finalize( cur_col );
}
}
}
}
};
}