Fix infill anchor missing (#9407)

* Fix infill anchor missing

* Correctly process cases without fill lines in FillRectilinear::fill_surface_with_multilines()

* Fix infill anchor missing for several other infill patterns

* Fix infill anchor missing for rectilinear and aligned rectilinear infill pattern

---------

Co-authored-by: Noisyfox <timemanager.rick@gmail.com>

src/libslic3r/Fill/Fill3DHoneycomb.cpp

@@ -273,10 +273,7 @@ void Fill3DHoneycomb::_fill_surface_single(
     if (!polylines.empty()) {
         int infill_start_idx = polylines_out.size(); // only rotate what belongs to us.
         // connect lines
-        if (params.dont_connect() || polylines.size() <= 1)
+        chain_or_connect_infill(std::move(polylines), expolygon, polylines_out, this->spacing, params);
-        append(polylines_out, chain_polylines(std::move(polylines)));
-        else
-        this->connect_infill(std::move(polylines), expolygon, polylines_out, this->spacing, params);
 
         // rotate back
         if (std::abs(infill_angle) >= EPSILON) {

src/libslic3r/Fill/FillAdaptive.cpp

@@ -1401,10 +1401,7 @@ void Filler::_fill_surface_single(
     }
 #endif /* ADAPTIVE_CUBIC_INFILL_DEBUG_OUTPUT */
 
-    if (params.dont_connect() || all_polylines_with_hooks.size() <= 1)
+    chain_or_connect_infill(std::move(all_polylines_with_hooks), expolygon, polylines_out, this->spacing, params);
-        append(polylines_out, chain_polylines(std::move(all_polylines_with_hooks)));
-    else
-        connect_infill(std::move(all_polylines_with_hooks), expolygon, polylines_out, this->spacing, params);
 
 #ifdef ADAPTIVE_CUBIC_INFILL_DEBUG_OUTPUT
     {

src/libslic3r/Fill/FillBase.cpp

@@ -1787,6 +1787,18 @@ void Fill::connect_infill(Polylines &&infill_ordered, const std::vector<const Po
 			polylines_out.emplace_back(std::move(pl));
 }
 
+void Fill::chain_or_connect_infill(Polylines &&infill_ordered, const ExPolygon &boundary, Polylines &polylines_out, const double spacing, const FillParams &params)
+{
+    if (!infill_ordered.empty()) {
+        if (params.dont_connect()) {
+            if (infill_ordered.size() > 1)
+                infill_ordered = chain_polylines(std::move(infill_ordered));
+            append(polylines_out, std::move(infill_ordered));
+        } else
+            connect_infill(std::move(infill_ordered), boundary, polylines_out, spacing, params);
+    }
+}
+
 // Extend the infill lines along the perimeters, this is mainly useful for grid aligned support, where a perimeter line may be nearly
 // aligned with the infill lines.
 static inline void base_support_extend_infill_lines(Polylines &infill, BoundaryInfillGraph &graph, const double spacing, const FillParams &params)

src/libslic3r/Fill/FillBase.hpp

@@ -191,6 +191,8 @@ public:
     static void connect_infill(Polylines &&infill_ordered, const Polygons &boundary, const BoundingBox& bbox, Polylines &polylines_out, const double spacing, const FillParams &params);
     static void connect_infill(Polylines &&infill_ordered, const std::vector<const Polygon*> &boundary, const BoundingBox &bbox, Polylines &polylines_out, double spacing, const FillParams &params);
 
+    static void chain_or_connect_infill(Polylines &&infill_ordered, const ExPolygon &boundary, Polylines &polylines_out, const double spacing, const FillParams &params);
+
     static void connect_base_support(Polylines &&infill_ordered, const std::vector<const Polygon*> &boundary_src, const BoundingBox &bbox, Polylines &polylines_out, const double spacing, const FillParams &params);
     static void connect_base_support(Polylines &&infill_ordered, const Polygons &boundary_src, const BoundingBox &bbox, Polylines &polylines_out, const double spacing, const FillParams &params);
 

src/libslic3r/Fill/FillCrossHatch.cpp

@@ -218,10 +218,7 @@ void FillCrossHatch ::_fill_surface_single(
     if (!polylines.empty()) {
         int infill_start_idx = polylines_out.size(); // only rotate what belongs to us.
         // connect lines
-        if (params.dont_connect() || polylines.size() <= 1)
+        chain_or_connect_infill(std::move(polylines), expolygon, polylines_out, this->spacing, params);
-            append(polylines_out, chain_polylines(std::move(polylines)));
-        else
-            this->connect_infill(std::move(polylines), expolygon, polylines_out, this->spacing, params);
 
         // rotate back
         if (std::abs(infill_angle) >= EPSILON) {

src/libslic3r/Fill/FillGyroid.cpp

@@ -194,10 +194,7 @@ void FillGyroid::_fill_surface_single(
 	if (! polylines.empty()) {
 		// connect lines
 		size_t polylines_out_first_idx = polylines_out.size();
-		if (params.dont_connect())
+        chain_or_connect_infill(std::move(polylines), expolygon, polylines_out, this->spacing, params);
-        	append(polylines_out, chain_polylines(polylines));
-        else
-            this->connect_infill(std::move(polylines), expolygon, polylines_out, this->spacing, params);
 
 	    // new paths must be rotated back
         if (std::abs(infill_angle) >= EPSILON) {

src/libslic3r/Fill/FillHoneycomb.cpp

@@ -74,10 +74,7 @@ void FillHoneycomb::_fill_surface_single(
     }
     
     all_polylines = intersection_pl(std::move(all_polylines), expolygon);
-    if (params.dont_connect() || all_polylines.size() <= 1)
+    chain_or_connect_infill(std::move(all_polylines), expolygon, polylines_out, this->spacing, params);
-        append(polylines_out, chain_polylines(std::move(all_polylines)));
-    else
-        connect_infill(std::move(all_polylines), expolygon, polylines_out, this->spacing, params);
 }
 
 } // namespace Slic3r

src/libslic3r/Fill/FillLightning.cpp

@@ -16,10 +16,7 @@ void Filler::_fill_surface_single(
     const Layer &layer      = generator->getTreesForLayer(this->layer_id);
     Polylines    fill_lines = layer.convertToLines(to_polygons(expolygon), scaled<coord_t>(0.5 * this->spacing - this->overlap));
 
-    if (params.dont_connect() || fill_lines.size() <= 1) {
+    chain_or_connect_infill(std::move(fill_lines), expolygon, polylines_out, this->spacing, params);
-        append(polylines_out, chain_polylines(std::move(fill_lines)));
-    } else
-        connect_infill(std::move(fill_lines), expolygon, polylines_out, this->spacing, params);
 }
 
 void GeneratorDeleter::operator()(Generator *p) {

src/libslic3r/Fill/FillRectilinear.cpp

@@ -2928,7 +2928,7 @@ void make_fill_lines(const ExPolygonWithOffset &poly_with_offset, Point refpt, d
 
 bool FillRectilinear::fill_surface_by_multilines(const Surface *surface, FillParams params, const std::initializer_list<SweepParams> &sweep_params, Polylines &polylines_out)
 {
-    assert(sweep_params.size() > 1);
+    assert(sweep_params.size() >= 1);
     assert(! params.full_infill());
     params.density /= double(sweep_params.size());
     assert(params.density > 0.0001f && params.density <= 1.f);
@@ -2948,12 +2948,14 @@ bool FillRectilinear::fill_surface_by_multilines(const Surface *surface, FillPar
         make_fill_lines(ExPolygonWithOffset(poly_with_offset_base, - angle), rotate_vector.second.rotated(-angle), angle, line_width + coord_t(SCALED_EPSILON), line_spacing, coord_t(scale_(sweep.pattern_shift)), fill_lines);
     }
 
-    if (params.dont_connect() || fill_lines.size() <= 1) {
+    if (!fill_lines.empty()) {
-        if (fill_lines.size() > 1)
+        if (params.dont_connect()) {
-            fill_lines = chain_polylines(std::move(fill_lines));
+            if (fill_lines.size() > 1)
-        append(polylines_out, std::move(fill_lines));
+                fill_lines = chain_polylines(std::move(fill_lines));
-    } else
+            append(polylines_out, std::move(fill_lines));
-        connect_infill(std::move(fill_lines), poly_with_offset_base.polygons_outer, get_extents(surface->expolygon.contour), polylines_out, this->spacing, params);
+        } else
+            connect_infill(std::move(fill_lines), poly_with_offset_base.polygons_outer, get_extents(surface->expolygon.contour), polylines_out, this->spacing, params);
+    }
 
     return true;
 }
@@ -2961,8 +2963,13 @@ bool FillRectilinear::fill_surface_by_multilines(const Surface *surface, FillPar
 Polylines FillRectilinear::fill_surface(const Surface *surface, const FillParams &params)
 {
     Polylines polylines_out;
-    if (! fill_surface_by_lines(surface, params, 0.f, 0.f, polylines_out))
+    if (params.full_infill()) {
-        BOOST_LOG_TRIVIAL(error) << "FillRectilinear::fill_surface() failed to fill a region.";
+        if (!fill_surface_by_lines(surface, params, 0.f, 0.f, polylines_out))
+            BOOST_LOG_TRIVIAL(error) << "FillRectilinear::fill_surface() fill_surface_by_lines() failed to fill a region.";
+    } else {
+        if (!fill_surface_by_multilines(surface, params, {{0.f, 0.f}}, polylines_out))
+            BOOST_LOG_TRIVIAL(error) << "FillRectilinear::fill_surface() fill_surface_by_multilines() failed to fill a region.";
+    }
     return polylines_out;
 }