OrcaSlicer/src/libslic3r/Fill/Lightning/DistanceField.cpp
2021-12-02 09:30:03 +01:00

99 lines
4.4 KiB
C++

//Copyright (c) 2021 Ultimaker B.V.
//CuraEngine is released under the terms of the AGPLv3 or higher.
#include "DistanceField.hpp" //Class we're implementing.
#include "../FillRectilinear.hpp"
#include "../../ClipperUtils.hpp"
namespace Slic3r::FillLightning
{
constexpr coord_t radius_per_cell_size = 6; // The cell-size should be small compared to the radius, but not so small as to be inefficient.
DistanceField::DistanceField(const coord_t& radius, const Polygons& current_outline, const Polygons& current_overhang) :
m_cell_size(radius / radius_per_cell_size),
m_supporting_radius(radius)
{
m_supporting_radius2 = double(radius) * double(radius);
// Sample source polygons with a regular grid sampling pattern.
for (const ExPolygon &expoly : union_ex(current_outline)) {
for (const Point &p : sample_grid_pattern(expoly, m_cell_size)) {
// Find a squared distance to the source expolygon boundary.
double d2 = std::numeric_limits<double>::max();
for (size_t icontour = 0; icontour <= expoly.holes.size(); ++ icontour) {
const Polygon &contour = icontour == 0 ? expoly.contour : expoly.holes[icontour - 1];
if (contour.size() > 2) {
Point prev = contour.points.back();
for (const Point &p2 : contour.points) {
d2 = std::min(d2, Line::distance_to_squared(p, prev, p2));
prev = p2;
}
}
}
m_unsupported_points.emplace_back(p, sqrt(d2));
}
}
m_unsupported_points.sort([&radius](const UnsupportedCell &a, const UnsupportedCell &b) {
constexpr coord_t prime_for_hash = 191;
return std::abs(b.dist_to_boundary - a.dist_to_boundary) > radius ?
a.dist_to_boundary < b.dist_to_boundary :
(PointHash{}(a.loc) % prime_for_hash) < (PointHash{}(b.loc) % prime_for_hash);
});
for (auto it = m_unsupported_points.begin(); it != m_unsupported_points.end(); ++it) {
UnsupportedCell& cell = *it;
m_unsupported_points_grid.emplace(Point{ cell.loc.x() / m_cell_size, cell.loc.y() / m_cell_size }, it);
}
}
void DistanceField::update(const Point& to_node, const Point& added_leaf)
{
Vec2d v = (added_leaf - to_node).cast<double>();
auto l2 = v.squaredNorm();
Vec2d extent = Vec2d(-v.y(), v.x()) * m_supporting_radius / sqrt(l2);
BoundingBox grid;
{
Point diagonal(m_supporting_radius, m_supporting_radius);
Point iextent(extent.cast<coord_t>());
grid = BoundingBox(added_leaf - diagonal, added_leaf + diagonal);
grid.merge(to_node - iextent);
grid.merge(to_node + iextent);
grid.merge(added_leaf - iextent);
grid.merge(added_leaf + iextent);
grid.min /= m_cell_size;
grid.max /= m_cell_size;
}
Point grid_loc;
for (coord_t row = grid.min.y(); row <= grid.max.y(); ++ row) {
grid_loc.y() = row * m_cell_size;
for (coord_t col = grid.min.x(); col <= grid.max.y(); ++ col) {
grid_loc.x() = col * m_cell_size;
// Test inside a circle at the new leaf.
if ((grid_loc - added_leaf).cast<double>().squaredNorm() > m_supporting_radius2) {
// Not inside a circle at the end of the new leaf.
// Test inside a rotated rectangle.
Vec2d vx = (grid_loc - to_node).cast<double>();
double d = v.dot(vx);
if (d >= 0 && d <= l2) {
d = extent.dot(vx);
if (d < -1. || d > 1.)
// Not inside a rotated rectangle.
continue;
}
}
// Inside a circle at the end of the new leaf, or inside a rotated rectangle.
// Remove unsupported leafs at this grid location.
if (auto it = m_unsupported_points_grid.find(grid_loc); it != m_unsupported_points_grid.end()) {
std::list<UnsupportedCell>::iterator& list_it = it->second;
UnsupportedCell& cell = *list_it;
if ((cell.loc - added_leaf).cast<double>().squaredNorm() <= m_supporting_radius2) {
m_unsupported_points.erase(list_it);
m_unsupported_points_grid.erase(it);
}
}
}
}
}
} // namespace Slic3r::FillLightning