mapnik::geometry::geometry<double> shape_io::read_polyline_parts(shape_file::record_type & record, std::vector<std::pair<int, int>> const& parts) { mapnik::geometry::geometry<double> geom; // default empty int total_num_parts = record.read_ndr_integer(); int num_parts = parts.size(); mapnik::geometry::multi_line_string<double> multi_line; multi_line.reserve(num_parts); for (int k = 0; k < num_parts; ++k) { int start = parts[k].first; int end = parts[k].second; unsigned pos = 4 + 32 + 8 + 4 * total_num_parts + start * 16; record.set_pos(pos); mapnik::geometry::line_string<double> line; line.reserve(end - start); for (int j = start; j < end; ++j) { double x = record.read_double(); double y = record.read_double(); line.emplace_back(x, y); } multi_line.push_back(std::move(line)); } geom = std::move(multi_line); return geom; }
mapnik::geometry::geometry<double> shape_io::read_polygon_parts(shape_file::record_type & record, std::vector<std::pair<int,int>> const& parts) { mapnik::geometry::geometry<double> geom; // default empty int total_num_parts = record.read_ndr_integer(); mapnik::geometry::polygon<double> poly; mapnik::geometry::multi_polygon<double> multi_poly; int num_parts = parts.size(); for (int k = 0; k < num_parts; ++k) { int start = parts[k].first; int end = parts[k].second; unsigned pos = 4 + 32 + 8 + 4 * total_num_parts + start * 16; record.set_pos(pos); mapnik::geometry::linear_ring<double> ring; ring.reserve(end - start); for (int j = start; j < end; ++j) { double x = record.read_double(); double y = record.read_double(); ring.emplace_back(x, y); } if (k == 0) { poly.set_exterior_ring(std::move(ring)); } else if (mapnik::util::is_clockwise(ring)) { multi_poly.emplace_back(std::move(poly)); poly.interior_rings.clear(); poly.set_exterior_ring(std::move(ring)); } else { poly.add_hole(std::move(ring)); } } if (multi_poly.size() > 0) // multi { multi_poly.emplace_back(std::move(poly)); geom = std::move(multi_poly); } else { geom = std::move(poly); } mapnik::geometry::correct(geom); return geom; }