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#include "PolygonTrimmer.hpp"
#include "EdgeGrid.hpp"
#include "Geometry.hpp"
namespace Slic3r {
TrimmedLoop trim_loop(const Polygon &loop, const EdgeGrid::Grid &grid)
{
assert(! loop.empty());
assert(loop.size() >= 2);
TrimmedLoop out;
if (loop.size() >= 2) {
struct Visitor {
Visitor(const EdgeGrid::Grid &grid, const Slic3r::Point *pt_prev, const Slic3r::Point *pt_this) : grid(grid), pt_prev(pt_prev), pt_this(pt_this) {}
bool operator()(coord_t iy, coord_t ix) {
// Called with a row and colum of the grid cell, which is intersected by a line.
auto cell_data_range = grid.cell_data_range(iy, ix);
for (auto it_contour_and_segment = cell_data_range.first; it_contour_and_segment != cell_data_range.second; ++ it_contour_and_segment) {
// End points of the line segment and their vector.
auto segment = grid.segment(*it_contour_and_segment);
if (Geometry::segments_intersect(segment.first, segment.second, *pt_prev, *pt_this)) {
// The two segments intersect. Add them to the output.
}
}
// Continue traversing the grid along the edge.
return true;
}
const EdgeGrid::Grid &grid;
const Slic3r::Point *pt_this;
const Slic3r::Point *pt_prev;
} visitor(grid, &loop.points.back(), nullptr);
for (const Point &pt_this : loop.points) {
visitor.pt_this = &pt_this;
grid.visit_cells_intersecting_line(*visitor.pt_prev, pt_this, visitor);
visitor.pt_prev = &pt_this;
}
}
return out;
}
std::vector<TrimmedLoop> trim_loops(const Polygons &loops, const EdgeGrid::Grid &grid)
{
std::vector<TrimmedLoop> out;
out.reserve(loops.size());
for (const Polygon &loop : loops)
out.emplace_back(trim_loop(loop, grid));
return out;
}
}
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