Ported PrintObject::slice() to C++

lib/Slic3r/Print/Object.pm

@@ -34,95 +34,6 @@ sub support_layers {
     return [ map $self->get_support_layer($_), 0..($self->support_layer_count - 1) ];
 }
 
-# 1) Decides Z positions of the layers,
-# 2) Initializes layers and their regions
-# 3) Slices the object meshes
-# 4) Slices the modifier meshes and reclassifies the slices of the object meshes by the slices of the modifier meshes
-# 5) Applies size compensation (offsets the slices in XY plane)
-# 6) Replaces bad slices by the slices reconstructed from the upper/lower layer
-# Resulting expolygons of layer regions are marked as Internal.
-#
-# this should be idempotent
-sub slice {
-    my $self = shift;
-    
-    return if $self->step_done(STEP_SLICE);
-    $self->set_step_started(STEP_SLICE);
-    $self->print->status_cb->(10, "Processing triangulated mesh");
-
-    $self->_slice;
-
-    # detect slicing errors
-    my $warning_thrown = 0;
-    for my $i (0 .. ($self->layer_count - 1)) {
-        my $layer = $self->get_layer($i);
-        next unless $layer->slicing_errors;
-        if (!$warning_thrown) {
-            warn "The model has overlapping or self-intersecting facets. I tried to repair it, "
-                . "however you might want to check the results or repair the input file and retry.\n";
-            $warning_thrown = 1;
-        }
-        
-        # try to repair the layer surfaces by merging all contours and all holes from
-        # neighbor layers
-        Slic3r::debugf "Attempting to repair layer %d\n", $i;
-        
-        foreach my $region_id (0 .. ($layer->region_count - 1)) {
-            my $layerm = $layer->region($region_id);
-            
-            my (@upper_surfaces, @lower_surfaces);
-            for (my $j = $i+1; $j < $self->layer_count; $j++) {
-                if (!$self->get_layer($j)->slicing_errors) {
-                    @upper_surfaces = @{$self->get_layer($j)->region($region_id)->slices};
-                    last;
-                }
-            }
-            for (my $j = $i-1; $j >= 0; $j--) {
-                if (!$self->get_layer($j)->slicing_errors) {
-                    @lower_surfaces = @{$self->get_layer($j)->region($region_id)->slices};
-                    last;
-                }
-            }
-            
-            my $union = union_ex([
-                map $_->expolygon->contour, @upper_surfaces, @lower_surfaces,
-            ]);
-            my $diff = diff_ex(
-                [ map @$_, @$union ],
-                [ map @{$_->expolygon->holes}, @upper_surfaces, @lower_surfaces, ],
-            );
-            
-            $layerm->slices->clear;
-            $layerm->slices->append($_)
-                for map Slic3r::Surface->new
-                    (expolygon => $_, surface_type => S_TYPE_INTERNAL),
-                    @$diff;
-        }
-            
-        # update layer slices after repairing the single regions
-        $layer->make_slices;
-    }
-    
-    # remove empty layers from bottom
-    while (@{$self->layers} && !@{$self->get_layer(0)->slices}) {
-        $self->delete_layer(0);
-        for (my $i = 0; $i <= $#{$self->layers}; $i++) {
-            $self->get_layer($i)->set_id( $self->get_layer($i)->id-1 );
-        }
-    }
-    
-    # simplify slices if required
-    if ($self->print->config->resolution) {
-        $self->_simplify_slices(scale($self->print->config->resolution));
-    }
-    
-    die "No layers were detected. You might want to repair your STL file(s) or check their size or thickness and retry.\n"
-        if !@{$self->layers};
-    
-    $self->set_typed_slices(0);
-    $self->set_step_done(STEP_SLICE);
-}
-
 sub make_perimeters {
     my ($self) = @_;
     

xs/src/libslic3r/ExPolygonCollection.hpp

@@ -41,6 +41,7 @@ class ExPolygonCollection
     /// ExPolygons and check if at least one contains the point.
     bool contains(const Point &point) const;
 
+    bool empty() const { return expolygons.empty(); }
     size_t size() const { return expolygons.size(); }
     ExPolygons::iterator begin() { return expolygons.begin(); }
     ExPolygons::iterator end() { return expolygons.end(); }

xs/src/libslic3r/PrintObject.cpp

@@ -956,6 +956,17 @@ PrintObject::make_perimeters()
     this->_make_perimeters();
 }
 
+/*
+    1) Decides Z positions of the layers,
+    2) Initializes layers and their regions
+    3) Slices the object meshes
+    4) Slices the modifier meshes and reclassifies the slices of the object meshes by the slices of the modifier meshes
+    5) Applies size compensation (offsets the slices in XY plane)
+    6) Replaces bad slices by the slices reconstructed from the upper/lower layer
+    Resulting expolygons of layer regions are marked as Internal.
+
+    This should be idempotent.
+*/
 void
 PrintObject::slice()
 {
@@ -964,8 +975,7 @@ PrintObject::slice()
     if (_print->status_cb != nullptr) {
         _print->status_cb(10, "Processing triangulated mesh");
     }
-
+    
-
     this->_slice(); 
 
     // detect slicing errors
@@ -975,12 +985,75 @@ PrintObject::slice()
                                          << "I tried to repair it, however you might want to check " 
                                          << "the results or repair the input file and retry.\n";
     
-    if (this->layers.size() == 0) {
+    bool warning_thrown = false;
+    for (size_t i = 0; i < this->layer_count(); ++i) {
+        Layer* layer{ this->get_layer(i) };
+        if (!layer->slicing_errors) continue;
+        if (!warning_thrown) {
+            Slic3r::Log::warn("PrintObject") << "The model has overlapping or self-intersecting facets. " 
+                                             << "I tried to repair it, however you might want to check " 
+                                             << "the results or repair the input file and retry.\n";
+            warning_thrown = true;
+        }
+        
+        // try to repair the layer surfaces by merging all contours and all holes from
+        // neighbor layers
+        #ifdef SLIC3R_DEBUG
+        std::cout << "Attempting to repair layer " << i << std::endl;
+        #endif
+        
+        for (size_t region_id = 0; region_id < layer->region_count(); ++region_id) {
+            LayerRegion* layerm{ layer->get_region(region_id) };
+            
+            ExPolygons slices;
+            for (size_t j = i+1; j < this->layer_count(); ++j) {
+                const Layer* upper = this->get_layer(j);
+                if (!upper->slicing_errors) {
+                    append_to(slices, (ExPolygons)upper->get_region(region_id)->slices);
+                    break;
+                }
+            }
+            for (int j = i-1; j >= 0; --j) {
+                const Layer* lower = this->get_layer(j);
+                if (!lower->slicing_errors) {
+                    append_to(slices, (ExPolygons)lower->get_region(region_id)->slices);
+                    break;
+                }
+            }
+            
+            // TODO: do we actually need to split contours and holes before performing the diff?
+            Polygons contours, holes;
+            for (ExPolygon ex : slices)
+                contours.push_back(ex.contour);
+            for (ExPolygon ex : slices)
+                append_to(holes, ex.holes);
+            
+            const ExPolygons diff = diff_ex(contours, holes);
+            
+            layerm->slices.clear();
+            layerm->slices.append(diff, stInternal);
+        }
+            
+        // update layer slices after repairing the single regions
+        layer->make_slices();
+    }
+    
+    // remove empty layers from bottom
+    while (!this->layers.empty() && this->get_layer(0)->slices.empty()) {
+        this->delete_layer(0);
+        for (Layer* layer : this->layers)
+            layer->set_id(layer->id()-1);
+    }
+    
+    // simplify slices if required
+    if (this->_print->config.resolution() > 0)
+        this->_simplify_slices(scale_(this->_print->config.resolution()));
+    
+    if (this->layers.empty()) {
         Slic3r::Log::error("PrintObject") << "slice(): " << "No layers were detected. You might want to repair your STL file(s) or check their size or thickness and retry.\n";
         return; // make this throw an exception instead?
     }
-
+    
-
     this->typed_slices = false;
     this->state.set_done(posSlice);
 }

xs/xsp/Print.xsp

@@ -132,6 +132,7 @@ _constant()
     void combine_infill();
     void discover_horizontal_shells();
     void clip_fill_surfaces();
+    void slice();
     void _slice();
     SV* _slice_region(size_t region_id, std::vector<double> z, bool modifier)
         %code%{