Added concentric infill generated using Arachne.

src/libslic3r/Fill/Fill.cpp

@@ -8,10 +8,12 @@
 #include "../Print.hpp"
 #include "../PrintConfig.hpp"
 #include "../Surface.hpp"
+#include "../PerimeterGenerator.hpp"
 
 #include "FillBase.hpp"
 #include "FillRectilinear.hpp"
 #include "FillLightning.hpp"
+#include "FillConcentric.hpp"
 
 namespace Slic3r {
 
@@ -332,6 +334,7 @@ void Layer::make_fills(FillAdaptive::Octree* adaptive_fill_octree, FillAdaptive:
     std::vector<SurfaceFill>  surface_fills  = group_fills(*this);
     const Slic3r::BoundingBox bbox           = this->object()->bounding_box();
     const auto                resolution     = this->object()->print()->config().gcode_resolution.value;
+    const auto                slicing_engine = this->object()->config().slicing_engine;
 
 #ifdef SLIC3R_DEBUG_SLICE_PROCESSING
 	{
@@ -352,6 +355,13 @@ void Layer::make_fills(FillAdaptive::Octree* adaptive_fill_octree, FillAdaptive:
         if (surface_fill.params.pattern == ipLightning)
             dynamic_cast<FillLightning::Filler*>(f.get())->generator = lightning_generator;
 
+        if (object()->config().slicing_engine.value == SlicingEngine::Arachne && surface_fill.params.pattern == ipConcentric) {
+            FillConcentric *fill_concentric = dynamic_cast<FillConcentric *>(f.get());
+            assert(fill_concentric != nullptr);
+            fill_concentric->print_config        = &this->object()->print()->config();
+            fill_concentric->print_object_config = &this->object()->config();
+        }
+
         // calculate flow spacing for infill pattern generation
         bool using_internal_flow = ! surface_fill.surface.is_solid() && ! surface_fill.params.bridge;
         double link_max_length = 0.;
@@ -377,17 +387,22 @@ void Layer::make_fills(FillAdaptive::Octree* adaptive_fill_octree, FillAdaptive:
         params.anchor_length     = surface_fill.params.anchor_length;
         params.anchor_length_max = surface_fill.params.anchor_length_max;
         params.resolution        = resolution;
+        params.use_arachne       = slicing_engine == SlicingEngine::Arachne && surface_fill.params.pattern == ipConcentric;
 
         for (ExPolygon &expoly : surface_fill.expolygons) {
 			// Spacing is modified by the filler to indicate adjustments. Reset it for each expolygon.
 			f->spacing = surface_fill.params.spacing;
 			surface_fill.surface.expolygon = std::move(expoly);
             Polylines      polylines;
+            ThickPolylines thick_polylines;
 			try {
+                if (params.use_arachne)
+                    thick_polylines = f->fill_surface_arachne(&surface_fill.surface, params);
+                else
 				    polylines = f->fill_surface(&surface_fill.surface, params);
 			} catch (InfillFailedException &) {
 			}
-	        if (! polylines.empty()) {
+            if (!polylines.empty() || !thick_polylines.empty()) {
                 // calculate actual flow from spacing (which might have been adjusted by the infill
 		        // pattern generator)
 		        double flow_mm3_per_mm = surface_fill.params.flow.mm3_per_mm();
@@ -406,6 +421,23 @@ void Layer::make_fills(FillAdaptive::Octree* adaptive_fill_octree, FillAdaptive:
 		        m_regions[surface_fill.region_id]->fills.entities.push_back(eec = new ExtrusionEntityCollection());
 		        // Only concentric fills are not sorted.
 		        eec->no_sort = f->no_sort();
+                if (params.use_arachne) {
+                    for (const ThickPolyline &thick_polyline : thick_polylines) {
+                        Flow new_flow = surface_fill.params.flow.with_spacing(float(f->spacing));
+
+                        ExtrusionPaths paths = thick_polyline_to_extrusion_paths(thick_polyline, surface_fill.params.extrusion_role, new_flow, scaled<float>(0.05), 0);
+                        // Append paths to collection.
+                        if (!paths.empty()) {
+                            if (paths.front().first_point() == paths.back().last_point())
+                                eec->entities.emplace_back(new ExtrusionLoop(std::move(paths)));
+                            else
+                                for (ExtrusionPath &path : paths)
+                                    eec->entities.emplace_back(new ExtrusionPath(std::move(path)));
+                        }
+                    }
+
+                    thick_polylines.clear();
+                } else {
                     extrusion_entities_append_paths(
                         eec->entities, std::move(polylines),
                         surface_fill.params.extrusion_role,
@@ -413,6 +445,7 @@ void Layer::make_fills(FillAdaptive::Octree* adaptive_fill_octree, FillAdaptive:
                 }
 		    }
 		}
+    }
 
     // add thin fill regions
     // Unpacks the collection, creates multiple collections per path.
@@ -618,6 +651,7 @@ void Layer::make_ironing()
 			surface_fill.expolygon = std::move(expoly);
 			Polylines polylines;
 			try {
+                assert(!fill_params.use_arachne);
 				polylines = fill.fill_surface(&surface_fill, fill_params);
 			} catch (InfillFailedException &) {
 			}

src/libslic3r/Fill/FillBase.cpp

@@ -82,16 +82,22 @@ Polylines Fill::fill_surface(const Surface *surface, const FillParams &params)
     Slic3r::ExPolygons expp = offset_ex(surface->expolygon, float(scale_(this->overlap - 0.5 * this->spacing)));
     // Create the infills for each of the regions.
     Polylines polylines_out;
-    for (size_t i = 0; i < expp.size(); ++ i)
+    for (ExPolygon &expoly : expp)
-        _fill_surface_single(
+        _fill_surface_single(params, surface->thickness_layers, _infill_direction(surface), std::move(expoly), polylines_out);
-            params,
-            surface->thickness_layers,
-            _infill_direction(surface),
-            std::move(expp[i]),
-            polylines_out);
     return polylines_out;
 }
 
+ThickPolylines Fill::fill_surface_arachne(const Surface *surface, const FillParams &params)
+{
+    // Perform offset.
+    Slic3r::ExPolygons expp = offset_ex(surface->expolygon, float(scale_(this->overlap - 0.5 * this->spacing)));
+    // Create the infills for each of the regions.
+    ThickPolylines thick_polylines_out;
+    for (ExPolygon &expoly : expp)
+        _fill_surface_single(params, surface->thickness_layers, _infill_direction(surface), std::move(expoly), thick_polylines_out);
+    return thick_polylines_out;
+}
+
 // Calculate a new spacing to fill width with possibly integer number of lines,
 // the first and last line being centered at the interval ends.
 // This function possibly increases the spacing, never decreases, 

src/libslic3r/Fill/FillBase.hpp

@@ -14,6 +14,7 @@
 #include "../Exception.hpp"
 #include "../Utils.hpp"
 #include "../ExPolygon.hpp"
+#include "../PrintConfig.hpp"
 
 namespace Slic3r {
 
@@ -57,6 +58,9 @@ struct FillParams
     // we were requested to complete each loop;
     // in this case we don't try to make more continuous paths
     bool        complete 		{ false };
+
+    // For Concentric infill, to switch between Classic and Arachne.
+    bool        use_arachne     { false };
 };
 static_assert(IsTriviallyCopyable<FillParams>::value, "FillParams class is not POD (and it should be - see constructor).");
 
@@ -103,6 +107,7 @@ public:
 
     // Perform the fill.
     virtual Polylines fill_surface(const Surface *surface, const FillParams &params);
+    virtual ThickPolylines fill_surface_arachne(const Surface *surface, const FillParams &params);
 
 protected:
     Fill() :
@@ -127,6 +132,13 @@ protected:
         ExPolygon                         /* expolygon */,
         Polylines                       & /* polylines_out */) {};
 
+    // Used for concentric infill to generate ThickPolylines using Arachne.
+    virtual void _fill_surface_single(const FillParams              &params,
+                                      unsigned int                   thickness_layers,
+                                      const std::pair<float, Point> &direction,
+                                      ExPolygon                      expolygon,
+                                      ThickPolylines                &thick_polylines_out) {}
+
     virtual float _layer_angle(size_t idx) const { return (idx & 1) ? float(M_PI/2.) : 0; }
 
     virtual std::pair<float, Point> _infill_direction(const Surface *surface) const;

src/libslic3r/Fill/FillConcentric.cpp

@@ -1,6 +1,7 @@
 #include "../ClipperUtils.hpp"
 #include "../ExPolygon.hpp"
 #include "../Surface.hpp"
+#include "Arachne/WallToolPaths.hpp"
 
 #include "FillConcentric.hpp"
 
@@ -16,11 +17,11 @@ void FillConcentric::_fill_surface_single(
     // no rotation is supported for this infill pattern
     BoundingBox bounding_box = expolygon.contour.bounding_box();
 
-    coord_t min_spacing = scale_(this->spacing);
+    coord_t min_spacing = scaled<coord_t>(this->spacing);
     coord_t distance    = coord_t(min_spacing / params.density);
 
     if (params.density > 0.9999f && !params.dont_adjust) {
-        distance = this->_adjust_solid_spacing(bounding_box.size()(0), distance);
+        distance      = Slic3r::FillConcentric::_adjust_solid_spacing(bounding_box.size()(0), distance);
         this->spacing = unscale<double>(distance);
     }
 
@@ -55,10 +56,76 @@ void FillConcentric::_fill_surface_single(
         }
     }
     if (j < polylines_out.size())
-        polylines_out.erase(polylines_out.begin() + j, polylines_out.end());
+        polylines_out.erase(polylines_out.begin() + int(j), polylines_out.end());
     //TODO: return ExtrusionLoop objects to get better chained paths,
     // otherwise the outermost loop starts at the closest point to (0, 0).
     // We want the loops to be split inside the G-code generator to get optimum path planning.
 }
 
+void FillConcentric::_fill_surface_single(const FillParams              &params,
+                                          unsigned int                   thickness_layers,
+                                          const std::pair<float, Point> &direction,
+                                          ExPolygon                      expolygon,
+                                          ThickPolylines                &thick_polylines_out)
+{
+    assert(params.use_arachne);
+    assert(this->print_config != nullptr && this->print_object_config != nullptr);
+
+    // no rotation is supported for this infill pattern
+    Point   bbox_size   = expolygon.contour.bounding_box().size();
+    coord_t min_spacing = scaled<coord_t>(this->spacing);
+
+    if (params.density > 0.9999f && !params.dont_adjust) {
+        coord_t                loops_count = std::max(bbox_size.x(), bbox_size.y()) / min_spacing + 1;
+        Polygons               polygons    = offset(expolygon, min_spacing / 2);
+        Arachne::WallToolPaths wallToolPaths(polygons, min_spacing, min_spacing, loops_count, 0, *this->print_object_config, *this->print_config);
+
+        std::vector<Arachne::VariableWidthLines>    loops = wallToolPaths.getToolPaths();
+        std::vector<const Arachne::ExtrusionLine *> all_extrusions;
+        for (Arachne::VariableWidthLines &loop : loops) {
+            if (loop.empty())
+                continue;
+            for (const Arachne::ExtrusionLine &wall : loop)
+                all_extrusions.emplace_back(&wall);
+        }
+
+        // Split paths using a nearest neighbor search.
+        size_t firts_poly_idx = thick_polylines_out.size();
+        Point  last_pos(0, 0);
+        for (const Arachne::ExtrusionLine *extrusion : all_extrusions) {
+            if (extrusion->empty())
+                continue;
+
+            ThickPolyline thick_polyline = Arachne::to_thick_polyline(*extrusion);
+            if (extrusion->is_closed && thick_polyline.points.front() == thick_polyline.points.back() && thick_polyline.width.front() == thick_polyline.width.back()) {
+                thick_polyline.points.pop_back();
+                assert(thick_polyline.points.size() * 2 == thick_polyline.width.size());
+                int nearest_idx = last_pos.nearest_point_index(thick_polyline.points);
+                std::rotate(thick_polyline.points.begin(), thick_polyline.points.begin() + nearest_idx, thick_polyline.points.end());
+                std::rotate(thick_polyline.width.begin(), thick_polyline.width.begin() + 2 * nearest_idx, thick_polyline.width.end());
+                thick_polyline.points.emplace_back(thick_polyline.points.front());
+            }
+            thick_polylines_out.emplace_back(std::move(thick_polyline));
+        }
+
+        // clip the paths to prevent the extruder from getting exactly on the first point of the loop
+        // Keep valid paths only.
+        size_t j = firts_poly_idx;
+        for (size_t i = firts_poly_idx; i < thick_polylines_out.size(); ++i) {
+            thick_polylines_out[i].clip_end(this->loop_clipping);
+            if (thick_polylines_out[i].is_valid()) {
+                if (j < i)
+                    thick_polylines_out[j] = std::move(thick_polylines_out[i]);
+                ++j;
+            }
+        }
+        if (j < thick_polylines_out.size())
+            thick_polylines_out.erase(thick_polylines_out.begin() + int(j), thick_polylines_out.end());
+    } else {
+        Polylines polylines;
+        this->_fill_surface_single(params, thickness_layers, direction, expolygon, polylines);
+        append(thick_polylines_out, to_thick_polylines(std::move(polylines), min_spacing));
+    }
+}
+
 } // namespace Slic3r

src/libslic3r/Fill/FillConcentric.hpp

@@ -19,7 +19,18 @@ protected:
 	    ExPolygon     		             expolygon,
 	    Polylines                       &polylines_out) override;
 
+    void _fill_surface_single(const FillParams              &params,
+                              unsigned int                   thickness_layers,
+                              const std::pair<float, Point> &direction,
+                              ExPolygon                      expolygon,
+                              ThickPolylines                &thick_polylines_out) override;
+
     bool no_sort() const override { return true; }
+
+    const PrintConfig       *print_config        = nullptr;
+    const PrintObjectConfig *print_object_config = nullptr;
+
+    friend class Layer;
 };
 
 } // namespace Slic3r

src/libslic3r/PerimeterGenerator.cpp

@@ -10,7 +10,7 @@
 
 namespace Slic3r {
 
-static ExtrusionPaths thick_polyline_to_extrusion_paths(const ThickPolyline &thick_polyline, ExtrusionRole role, const Flow &flow, const float tolerance, const float merge_tolerance)
+ExtrusionPaths thick_polyline_to_extrusion_paths(const ThickPolyline &thick_polyline, ExtrusionRole role, const Flow &flow, const float tolerance, const float merge_tolerance)
 {
     ExtrusionPaths paths;
     ExtrusionPath path(role);
@@ -24,7 +24,7 @@ static ExtrusionPaths thick_polyline_to_extrusion_paths(const ThickPolyline &thi
         
         double thickness_delta = fabs(line.a_width - line.b_width);
         if (thickness_delta > tolerance) {
-            const unsigned int segments = (unsigned int)ceil(thickness_delta / tolerance);
+            const auto segments = (unsigned int)ceil(thickness_delta / tolerance);
             const coordf_t seg_len = line_len / segments;
             Points pp;
             std::vector<coordf_t> width;

src/libslic3r/PerimeterGenerator.hpp

@@ -72,6 +72,8 @@ private:
     Polygons    m_lower_slices_polygons;
 };
 
+ExtrusionPaths thick_polyline_to_extrusion_paths(const ThickPolyline &thick_polyline, ExtrusionRole role, const Flow &flow, const float tolerance, const float merge_tolerance);
+
 }
 
 #endif

src/libslic3r/Polyline.cpp

@@ -235,6 +235,34 @@ ThickLines ThickPolyline::thicklines() const
     return lines;
 }
 
+// Removes the given distance from the end of the ThickPolyline
+void ThickPolyline::clip_end(double distance)
+{
+    while (distance > 0) {
+        Vec2d    last_point = this->last_point().cast<double>();
+        coordf_t last_width = this->width.back();
+        this->points.pop_back();
+        this->width.pop_back();
+        if (this->points.empty())
+            break;
+
+        Vec2d    vec            = this->last_point().cast<double>() - last_point;
+        coordf_t width_diff     = this->width.back() - last_width;
+        double   vec_length_sqr = vec.squaredNorm();
+        if (vec_length_sqr > distance * distance) {
+            double t = (distance / std::sqrt(vec_length_sqr));
+            this->points.emplace_back((last_point + vec * t).cast<coord_t>());
+            this->width.emplace_back(last_width + width_diff * t);
+            assert(this->width.size() == (this->points.size() - 1) * 2);
+            return;
+        } else
+            this->width.pop_back();
+
+        distance -= std::sqrt(vec_length_sqr);
+    }
+    assert(this->width.size() == (this->points.size() - 1) * 2);
+}
+
 Lines3 Polyline3::lines() const
 {
     Lines3 lines;

src/libslic3r/Polyline.hpp

@@ -64,7 +64,7 @@ public:
     const Point& leftmost_point() const;
     Lines lines() const override;
 
-    void clip_end(double distance);
+    virtual void clip_end(double distance);
     void clip_start(double distance);
     void extend_end(double distance);
     void extend_start(double distance);
@@ -172,10 +172,24 @@ public:
         std::swap(this->endpoints.first, this->endpoints.second);
     }
 
+    void clip_end(double distance) override;
+
     std::vector<coordf_t> width;
     std::pair<bool,bool>  endpoints;
 };
 
+inline ThickPolylines to_thick_polylines(Polylines &&polylines, const coordf_t width)
+{
+    ThickPolylines out;
+    out.reserve(polylines.size());
+    for (Polyline &polyline : polylines) {
+        out.emplace_back();
+        out.back().width.assign((polyline.points.size() - 1) * 2, width);
+        out.back().points = std::move(polyline.points);
+    }
+    return out;
+}
+
 class Polyline3 : public MultiPoint3
 {
 public:

src/libslic3r/SupportMaterial.cpp

@@ -3243,6 +3243,7 @@ static inline void fill_expolygon_generate_paths(
     Surface surface(stInternal, std::move(expolygon));
     Polylines polylines;
     try {
+        assert(!fill_params.use_arachne);
         polylines = filler->fill_surface(&surface, fill_params);
     } catch (InfillFailedException &) {
     }

tests/fff_print/test_fill.cpp

@@ -131,7 +131,7 @@ TEST_CASE("Fill: Pattern Path Length", "[Fill]") {
 		FillParams fill_params;
 		fill_params.density = 1.0;
 		filler->spacing = flow.spacing();
-
+        REQUIRE(!fill_params.use_arachne); // Make this test fail when Arachne is used because this test is not ready for it.
         for (auto angle : { 0.0, 45.0}) {
             surface.expolygon.rotate(angle, Point(0,0));
             Polylines paths = filler->fill_surface(&surface, fill_params);
@@ -443,6 +443,8 @@ bool test_if_solid_surface_filled(const ExPolygon& expolygon, double flow_spacin
 	fill_params.dont_adjust = false;
 
     Surface surface(stBottom, expolygon);
+    if (fill_params.use_arachne) // Make this test fail when Arachne is used because this test is not ready for it.
+        return false;
     Slic3r::Polylines paths = filler->fill_surface(&surface, fill_params);
 
     // check whether any part was left uncovered