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;
}
