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