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I don't see enough performance gain to justify this - reverting for now

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Revert "shape.input - sqeeze a bit more performance by reinterpret casting bytes array to point {double,double}"

This reverts commit 2f8426a019.
This commit is contained in:
artemp 2014-12-18 18:44:04 +01:00
parent 2f8426a019
commit ce291a553b
2 changed files with 19 additions and 21 deletions
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35
plugins/input/shape/shape_io.cpp
View file

@ -146,14 +146,6 @@ void shape_io::read_polyline( shape_file::record_type & record, mapnik::geometry
}
}
namespace detail {
struct point
{
double x;
double y;
};
template <typename T>
bool is_clockwise(T const& points, int start, int end)
{
@ -163,26 +155,33 @@ bool is_clockwise(T const& points, int start, int end)
{
auto const& p0 = points[start + i];
auto const& p1 = points[start + (i + 1) % num_points];
area += p0.x * p1.y - p0.y * p1.x;
area += std::get<0>(p0) * std::get<1>(p1) - std::get<1>(p0) * std::get<0>(p1);
}
return ( area < 0.0) ? true : false;
}
} // ns detail
void shape_io::read_polygon(shape_file::record_type & record, mapnik::geometry_container & geom)
{
int num_parts = record.read_ndr_integer();
int num_points = record.read_ndr_integer();
std::vector<int> parts(num_parts);
using points_cont = std::vector<std::tuple<double,double> >;
points_cont points;
points.reserve(num_points);
for (int i = 0; i < num_parts; ++i)
{
parts[i] = record.read_ndr_integer();
}
detail::point const* points = reinterpret_cast<detail::point const*>(record.get_data() + record.position());
record.skip(2 * sizeof(double) * num_points);
for (int k = 0; k < num_points; ++k)
{
double x = record.read_double();
double y = record.read_double();
points.emplace_back(x,y);
}
std::unique_ptr<geometry_type> poly(new geometry_type(mapnik::geometry_type::types::Polygon));
for (int k = 0; k < num_parts; ++k)
{
@ -191,16 +190,20 @@ void shape_io::read_polygon(shape_file::record_type & record, mapnik::geometry_c
if (k == num_parts - 1) end = num_points;
else end = parts[k + 1];
auto const& pt = points[start];
if ( k > 0 && detail::is_clockwise(points, start, end))
double x = std::get<0>(pt);
double y = std::get<1>(pt);
if ( k > 0 && is_clockwise(points, start, end))
{
geom.push_back(poly.release());
poly.reset(new geometry_type(mapnik::geometry_type::types::Polygon));
}
poly->move_to(pt.x, pt.y);
poly->move_to(x, y);
for (int j = start + 1; j < end; ++j)
{
auto const& pt = points[j];
poly->line_to(pt.x, pt.y);
x = std::get<0>(pt);
y = std::get<1>(pt);
poly->line_to(x, y);
}
poly->close_path();
}

5
plugins/input/shape/shapefile.hpp
View file

@ -96,11 +96,6 @@ struct shape_record
return data;
}
size_t position() const
{
return pos;
}
void skip(unsigned n)
{
pos += n;