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    1. #include <CGAL/Linear_cell_complex_for_combinatorial_map.h>
    2. #include <CGAL/Linear_cell_complex_constructors.h>
    3. #include <CGAL/Timer.h>
    4. #include <iostream>
    5. #include <fstream>
    7. #ifdef _DEBUG
    8. #include <CGAL/draw_linear_cell_complex.h>
    9. #endif // _DEBUG
    11. typedef CGAL::Linear_cell_complex_for_combinatorial_map<2, 3> LCC_3;
    12. typedef LCC_3::Dart_handle             Dart_handle;
    13. typedef LCC_3::Point                   Point;
    14. typedef LCC_3::FT                      FT;
    16. //加载并简化OFF
    17. void load_and_simplify_off(LCC_3& lcc, const std::string& filename,
    18.     bool updateattribs, int percent)
    19. {
    20.     std::ifstream ifile(filename.c_str());
    21.     if (ifile)
    22.     {
    23.         //加载OFF文件
    24.         CGAL::load_off(lcc, ifile);
    26.         CGAL::Timer timer;
    27.         Dart_handle dh;
    29.         std::size_t nb = (lcc.number_of_darts()*percent) / 200;
    31.         timer.start();
    33.         //updateattribs为false => 不更新属性 => 自动属性管理关闭
    34.         if (!updateattribs) lcc.set_automatic_attributes_management(false);
    36.         //?
    37.         for (LCC_3::Dart_range::iterator it = lcc.darts().begin(),
    38.             itend = lcc.darts().end(); it != itend && nb > 0; )
    39.         {
    40.             dh = it++;
    41.             if (it != itend && it == lcc.beta<2>(dh)) ++it;
    42.             lcc.remove_cell<1>(dh);
    43.             --nb;
    44.         }
    46.         //updateattribs为false => 不更新属性 => 自动属性管理开启
    47.         if (!updateattribs) lcc.set_automatic_attributes_management(true);
    49.         timer.stop();
    51.         //输出线性单元复合体的特征
    52.         lcc.display_characteristics(std::cout);
    53.         std::cout << ", valid=" << lcc.is_valid()
    54.             << " time: " << timer.time() << " seconds." << std::endl;
    55.     }
    56. }
    58. int main(int narg, char** argv)
    59. {
    60.     if (narg > 1 && (!strcmp(argv[1], "-h") || !strcmp(argv[1], "-?")))
    61.     {
    62.         std::cout << "Usage: a.out file.off [percentage]" << std::endl;
    63.         return EXIT_FAILURE;
    64.     }
    66.     std::string filename;
    67.     if (narg == 1)
    68.     {
    69.         filename = std::string("data/armadillo.off");
    70.         std::cout << "No filename given: use data/armadillo.off by default." << std::endl;
    71.     }
    72.     else filename = std::string(argv[1]);
    74.     int percent = 30; // remove 30 percent of edges
    75.     if (narg > 2) { percent = atoi(argv[2]); }
    76.     std::cout << percent << "% edges to remove." << std::endl;
    78.     LCC_3 lcc;
    79.     std::cout << "Update attribute DURING operations: ";
    80.     load_and_simplify_off(lcc, filename, true, percent);
    82.     LCC_3 lcc2;
    83.     std::cout << "Update attribute AFTER operations: ";
    84.     load_and_simplify_off(lcc2, filename, false, percent);
    86. #ifdef _DEBUG
    87.     CGAL::draw(lcc);
    88. #endif // _DEBUG
    90.     return EXIT_SUCCESS;
    91. }