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#pragma once
#include <algorithm>
#include <cmath>
#include <mapbox/geojsonvt/types.hpp>
namespace mapbox {
namespace geojsonvt {
struct Tile {
mapbox::geometry::feature_collection<int16_t> features;
uint32_t num_points = 0;
uint32_t num_simplified = 0;
};
namespace detail {
class InternalTile {
public:
const uint8_t z;
const uint32_t x;
const uint32_t y;
vt_features source_features;
bool is_solid = false;
mapbox::geometry::box<double> bbox = { { 2, 1 }, { -1, 0 } };
Tile tile;
InternalTile(const vt_features& source,
const uint8_t z_,
const uint32_t x_,
const uint32_t y_,
const uint16_t extent_,
const uint16_t buffer,
const double tolerance_)
: z(z_),
x(x_),
y(y_),
z2(std::pow(2, z)),
extent(extent_),
tolerance(tolerance_),
sq_tolerance(tolerance_ * tolerance_) {
for (const auto& feature : source) {
const auto& geom = feature.geometry;
const auto& props = feature.properties;
const auto& id = feature.id;
tile.num_points += feature.num_points;
vt_geometry::visit(geom, [&](const auto& g) {
// `this->` is a workaround for https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61636
this->addFeature(g, props, id);
});
bbox.min.x = std::min(feature.bbox.min.x, bbox.min.x);
bbox.min.y = std::min(feature.bbox.min.y, bbox.min.y);
bbox.max.x = std::max(feature.bbox.max.x, bbox.max.x);
bbox.max.y = std::max(feature.bbox.max.y, bbox.max.y);
}
is_solid = isSolid(buffer);
}
private:
const double z2;
const uint16_t extent;
const double tolerance;
const double sq_tolerance;
bool isSolid(const uint16_t buffer) {
if (tile.features.size() != 1)
return false;
const auto& geom = tile.features.front().geometry;
if (!geom.is<mapbox::geometry::polygon<int16_t>>())
return false;
const auto& rings = geom.get<mapbox::geometry::polygon<int16_t>>();
if (rings.size() > 1)
return false;
const auto& ring = rings.front();
if (ring.size() != 5)
return false;
const int16_t min = -static_cast<int16_t>(buffer);
const int16_t max = static_cast<int16_t>(extent + buffer);
for (const auto& p : ring) {
if ((p.x != min && p.x != max) || (p.y != min && p.y != max))
return false;
}
return true;
}
void addFeature(const vt_point& point, const property_map& props, const optional<identifier>& id) {
tile.features.push_back({ transform(point), props, id });
}
void addFeature(const vt_line_string& line, const property_map& props, const optional<identifier>& id) {
const auto new_line = transform(line);
if (!new_line.empty())
tile.features.push_back({ std::move(new_line), props, id });
}
void addFeature(const vt_polygon& polygon, const property_map& props, const optional<identifier>& id) {
const auto new_polygon = transform(polygon);
if (!new_polygon.empty())
tile.features.push_back({ std::move(new_polygon), props, id });
}
void addFeature(const vt_geometry_collection& collection, const property_map& props, const optional<identifier>& id) {
for (const auto& geom : collection) {
vt_geometry::visit(geom, [&](const auto& g) {
// `this->` is a workaround for https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61636
this->addFeature(g, props, id);
});
}
}
template <class T>
void addFeature(const T& multi, const property_map& props, const optional<identifier>& id) {
const auto new_multi = transform(multi);
switch (new_multi.size()) {
case 0:
break;
case 1:
tile.features.push_back({ std::move(new_multi[0]), props, id });
break;
default:
tile.features.push_back({ std::move(new_multi), props, id });
break;
}
}
mapbox::geometry::point<int16_t> transform(const vt_point& p) {
++tile.num_simplified;
return { static_cast<int16_t>(::round((p.x * z2 - x) * extent)),
static_cast<int16_t>(::round((p.y * z2 - y) * extent)) };
}
mapbox::geometry::multi_point<int16_t> transform(const vt_multi_point& points) {
mapbox::geometry::multi_point<int16_t> result;
result.reserve(points.size());
for (const auto& p : points) {
result.push_back(transform(p));
}
return result;
}
mapbox::geometry::line_string<int16_t> transform(const vt_line_string& line) {
mapbox::geometry::line_string<int16_t> result;
if (line.dist > tolerance) {
for (const auto& p : line) {
if (p.z > sq_tolerance)
result.push_back(transform(p));
}
}
return result;
}
mapbox::geometry::linear_ring<int16_t> transform(const vt_linear_ring& ring) {
mapbox::geometry::linear_ring<int16_t> result;
if (ring.area > sq_tolerance) {
for (const auto& p : ring) {
if (p.z > sq_tolerance)
result.push_back(transform(p));
}
}
return result;
}
mapbox::geometry::multi_line_string<int16_t> transform(const vt_multi_line_string& lines) {
mapbox::geometry::multi_line_string<int16_t> result;
for (const auto& line : lines) {
if (line.dist > tolerance)
result.push_back(transform(line));
}
return result;
}
mapbox::geometry::polygon<int16_t> transform(const vt_polygon& rings) {
mapbox::geometry::polygon<int16_t> result;
for (const auto& ring : rings) {
if (ring.area > sq_tolerance)
result.push_back(transform(ring));
}
return result;
}
mapbox::geometry::multi_polygon<int16_t> transform(const vt_multi_polygon& polygons) {
mapbox::geometry::multi_polygon<int16_t> result;
for (const auto& polygon : polygons) {
const auto p = transform(polygon);
if (!p.empty())
result.push_back(std::move(p));
}
return result;
}
};
} // namespace detail
} // namespace geojsonvt
} // namespace mapbox
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