Port automatic hole to polyhole conversion from SuperSlicer

Co-authored-by: supermerill <merill@free.fr>

src/libslic3r/PrintObject.cpp

@@ -152,6 +152,145 @@ std::vector<std::reference_wrapper<const PrintRegion>> PrintObject::all_regions(
     return out;
 }
 
+Polygons create_polyholes(const Point center, const coord_t radius, const coord_t nozzle_diameter, bool multiple)
+{
+    // n = max(round(2 * d), 3); // for 0.4mm nozzle
+    size_t nb_edges = (int)std::max(3, (int)std::round(4.0 * unscaled(radius) * 0.4 / unscaled(nozzle_diameter)));
+    // cylinder(h = h, r = d / cos (180 / n), $fn = n);
+    //create x polyholes by rotation if multiple
+    int nb_polyhole = 1;
+    float rotation = 0;
+    if (multiple) {
+        nb_polyhole = 5;
+        rotation = 2 * float(PI) / (nb_edges * nb_polyhole);
+    }
+    Polygons list;
+    for (int i_poly = 0; i_poly < nb_polyhole; i_poly++)
+        list.emplace_back();
+    for (int i_poly = 0; i_poly < nb_polyhole; i_poly++) {
+        Polygon& pts = (((i_poly % 2) == 0) ? list[i_poly / 2] : list[(nb_polyhole + 1) / 2 + i_poly / 2]);
+        const float new_radius = radius / float(std::cos(PI / nb_edges));
+        for (size_t i_edge = 0; i_edge < nb_edges; ++i_edge) {
+            float angle = rotation * i_poly + (float(PI) * 2 * (float)i_edge) / nb_edges;
+            pts.points.emplace_back(center.x() + new_radius * cos(angle), center.y() + new_radius * sin(angle));
+        }
+        pts.make_clockwise();
+    }
+    //alternate
+    return list;
+}
+
+// Detect and convert holes to polyholes, implementation is ported from SuperSlicer
+void PrintObject::_transform_hole_to_polyholes()
+{
+    // get all circular holes for each layer
+    // the id is center-diameter-extruderid
+    //the tuple is Point center; float diameter_max; int extruder_id; coord_t max_variation; bool twist;
+    std::vector<std::vector<std::pair<std::tuple<Point, float, int, coord_t, bool>, Polygon*>>> layerid2center;
+    for (size_t i = 0; i < this->m_layers.size(); i++) layerid2center.emplace_back();
+    tbb::parallel_for(
+        tbb::blocked_range<size_t>(0, m_layers.size()),
+        [this, &layerid2center](const tbb::blocked_range<size_t>& range) {
+        for (size_t layer_idx = range.begin(); layer_idx < range.end(); ++layer_idx) {
+            m_print->throw_if_canceled();
+            Layer* layer = m_layers[layer_idx];
+            for (size_t region_idx = 0; region_idx < layer->m_regions.size(); ++region_idx)
+            {
+                if (layer->m_regions[region_idx]->region().config().hole_to_polyhole) {
+                    for (Surface& surf : layer->m_regions[region_idx]->slices.surfaces) {
+                        for (Polygon& hole : surf.expolygon.holes) {
+                            //test if convex (as it's clockwise bc it's a hole, we have to do the opposite)
+                            if (hole.convex_points(PI).empty() && hole.points.size() > 8) {
+                                // Computing circle center
+                                Point center = hole.centroid();
+                                double diameter_min = std::numeric_limits<float>::max(), diameter_max = 0;
+                                double diameter_sum = 0;
+                                for (int i = 0; i < hole.points.size(); ++i) {
+                                    double dist = hole.points[i].distance_to(center);
+                                    diameter_min = std::min(diameter_min, dist);
+                                    diameter_max = std::max(diameter_max, dist);
+                                    diameter_sum += dist;
+                                }
+                                //also use center of lines to check it's not a rectangle
+                                double diameter_line_min = std::numeric_limits<float>::max(), diameter_line_max = 0;
+                                Lines hole_lines = hole.lines();
+                                for (Line l : hole_lines) {
+                                    Point midline = (l.a + l.b) / 2;
+                                    double dist = center.distance_to(midline);
+                                    diameter_line_min = std::min(diameter_line_min, dist);
+                                    diameter_line_max = std::max(diameter_line_max, dist);
+                                }
+
+
+                                // SCALED_EPSILON was a bit too harsh. Now using a config, as some may want some harsh setting and some don't.
+                                coord_t max_variation = std::max(SCALED_EPSILON, scale_(this->m_layers[layer_idx]->m_regions[region_idx]->region().config().hole_to_polyhole_threshold.get_abs_value(unscaled(diameter_sum / hole.points.size()))));
+                                bool twist = this->m_layers[layer_idx]->m_regions[region_idx]->region().config().hole_to_polyhole_twisted.value;
+                                if (diameter_max - diameter_min < max_variation * 2 && diameter_line_max - diameter_line_min < max_variation * 2) {
+                                    layerid2center[layer_idx].emplace_back(
+                                        std::tuple<Point, float, int, coord_t, bool>{center, diameter_max, layer->m_regions[region_idx]->region().config().wall_filament.value, max_variation, twist}, & hole);
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+            // for layer->slices, it will be also replaced later.
+        }
+    });
+    //sort holes per center-diameter
+    std::map<std::tuple<Point, float, int, coord_t, bool>, std::vector<std::pair<Polygon*, int>>> id2layerz2hole;
+
+    //search & find hole that span at least X layers
+    const size_t min_nb_layers = 2;
+    for (size_t layer_idx = 0; layer_idx < this->m_layers.size(); ++layer_idx) {
+        for (size_t hole_idx = 0; hole_idx < layerid2center[layer_idx].size(); ++hole_idx) {
+            //get all other same polygons
+            std::tuple<Point, float, int, coord_t, bool>& id = layerid2center[layer_idx][hole_idx].first;
+            float max_z = layers()[layer_idx]->print_z;
+            std::vector<std::pair<Polygon*, int>> holes;
+            holes.emplace_back(layerid2center[layer_idx][hole_idx].second, layer_idx);
+            for (size_t search_layer_idx = layer_idx + 1; search_layer_idx < this->m_layers.size(); ++search_layer_idx) {
+                if (layers()[search_layer_idx]->print_z - layers()[search_layer_idx]->height - max_z > EPSILON) break;
+                //search an other polygon with same id
+                for (size_t search_hole_idx = 0; search_hole_idx < layerid2center[search_layer_idx].size(); ++search_hole_idx) {
+                    std::tuple<Point, float, int, coord_t, bool>& search_id = layerid2center[search_layer_idx][search_hole_idx].first;
+                    if (std::get<2>(id) == std::get<2>(search_id)
+                        && std::get<0>(id).distance_to(std::get<0>(search_id)) < std::get<3>(id)
+                        && std::abs(std::get<1>(id) - std::get<1>(search_id)) < std::get<3>(id)
+                        ) {
+                        max_z = layers()[search_layer_idx]->print_z;
+                        holes.emplace_back(layerid2center[search_layer_idx][search_hole_idx].second, search_layer_idx);
+                        layerid2center[search_layer_idx].erase(layerid2center[search_layer_idx].begin() + search_hole_idx);
+                        search_hole_idx--;
+                        break;
+                    }
+                }
+            }
+            //check if strait hole or first layer hole (cause of first layer compensation)
+            if (holes.size() >= min_nb_layers || (holes.size() == 1 && holes[0].second == 0)) {
+                id2layerz2hole.emplace(std::move(id), std::move(holes));
+            }
+        }
+    }
+    //create a polyhole per id and replace holes points by it.
+    for (auto entry : id2layerz2hole) {
+        Polygons polyholes = create_polyholes(std::get<0>(entry.first), std::get<1>(entry.first), scale_(print()->config().nozzle_diameter.get_at(std::get<2>(entry.first) - 1)), std::get<4>(entry.first));
+        for (auto& poly_to_replace : entry.second) {
+            Polygon polyhole = polyholes[poly_to_replace.second % polyholes.size()];
+            //search the clone in layers->slices
+            for (ExPolygon& explo_slice : m_layers[poly_to_replace.second]->lslices) {
+                for (Polygon& poly_slice : explo_slice.holes) {
+                    if (poly_slice.points == poly_to_replace.first->points) {
+                        poly_slice.points = polyhole.points;
+                    }
+                }
+            }
+            // copy
+            poly_to_replace.first->points = polyhole.points;
+        }
+    }
+}
+
 // 1) Merges typed region slices into stInternal type.
 // 2) Increases an "extra perimeters" counter at region slices where needed.
 // 3) Generates perimeters, gap fills and fill regions (fill regions of type stInternal).
@@ -816,6 +955,9 @@ bool PrintObject::invalidate_state_by_config_options(
             || opt_key == "max_bridge_length"
             || opt_key == "support_interface_top_layers"
             || opt_key == "support_critical_regions_only"
+            || opt_key == "hole_to_polyhole"
+            || opt_key == "hole_to_polyhole_threshold"
+            || opt_key == "hole_to_polyhole_twisted"
             ) {
             steps.emplace_back(posSlice);
         } else if (opt_key == "enable_support") {