Collect the perimeter surfaces when generating perimeters.

The perimeter surfaces are later used for performing infill
below overhangs and to maintan configured vertical wall thickness
at sloping surfaces.

7 files changed, 226 insertions, 22 deletions

diff --git a/xs/src/libslic3r/Layer.cpp b/xs/src/libslic3r/Layer.cpp
index a392f732e..1d5e6562d 100644
--- a/xs/src/libslic3r/Layer.cpp
+++ b/xs/src/libslic3r/Layer.cpp
@@ -2,7 +2,7 @@
 #include "ClipperUtils.hpp"
 #include "Geometry.hpp"
 #include "Print.hpp"
-
+#include "SVG.hpp"
 
 namespace Slic3r {
 
@@ -204,7 +204,11 @@ Layer::make_perimeters()
         
         if (layerms.size() == 1) {  // optimization
             (*layerm)->fill_surfaces.surfaces.clear();
-            (*layerm)->make_perimeters((*layerm)->slices, &(*layerm)->fill_surfaces);
+            (*layerm)->perimeter_surfaces.surfaces.clear();
+            (*layerm)->make_perimeters((*layerm)->slices, &(*layerm)->perimeter_surfaces, &(*layerm)->fill_surfaces);
+            this->perimeter_expolygons.expolygons.clear();
+            for (Surfaces::const_iterator it = (*layerm)->perimeter_surfaces.surfaces.begin(); it != (*layerm)->perimeter_surfaces.surfaces.end(); ++ it)
+                this->perimeter_expolygons.expolygons.push_back(it->expolygon);
         } else {
             // group slices (surfaces) according to number of extra perimeters
             std::map<unsigned short,Surfaces> slices;  // extra_perimeters => [ surface, surface... ]
@@ -226,12 +230,18 @@ Layer::make_perimeters()
             }
             
             // make perimeters
+            SurfaceCollection perimeter_surfaces;
             SurfaceCollection fill_surfaces;
-            (*layerm)->make_perimeters(new_slices, &fill_surfaces);
-            
+            (*layerm)->make_perimeters(new_slices, &perimeter_surfaces, &fill_surfaces);
+            // Copy the perimeter surfaces to the layer's surfaces before splitting them into the regions.
+            this->perimeter_expolygons.expolygons.clear();
+            for (Surfaces::const_iterator it = perimeter_surfaces.surfaces.begin(); it != perimeter_surfaces.surfaces.end(); ++ it)
+                this->perimeter_expolygons.expolygons.push_back(it->expolygon);
+
             // assign fill_surfaces to each layer
-            if (!fill_surfaces.surfaces.empty()) {
+            if (!fill_surfaces.surfaces.empty()) { 
                 for (LayerRegionPtrs::iterator l = layerms.begin(); l != layerms.end(); ++l) {
+                    // Separate the fill surfaces.
                     ExPolygons expp = intersection_ex(
                         fill_surfaces,
                         (*l)->slices
@@ -243,12 +253,80 @@ Layer::make_perimeters()
                         s.expolygon = *ex;
                         (*l)->fill_surfaces.surfaces.push_back(s);
                     }
+
+                    // Separate the perimeter surfaces.
+                    expp = intersection_ex(
+                        perimeter_surfaces,
+                        (*l)->slices
+                    );
+                    (*l)->perimeter_surfaces.surfaces.clear();
+                    
+                    for (ExPolygons::iterator ex = expp.begin(); ex != expp.end(); ++ex) {
+                        Surface s = fill_surfaces.surfaces.front();  // clone type and extra_perimeters
+                        s.expolygon = *ex; 
+                        (*l)->perimeter_surfaces.surfaces.push_back(s);
+                    }
                 }
             }
         }
     }
 }
 
+void Layer::export_region_slices_to_svg(const char *path)
+{
+    BoundingBox bbox;
+    for (LayerRegionPtrs::const_iterator region = this->regions.begin(); region != this->regions.end(); ++region)
+        for (Surfaces::const_iterator surface = (*region)->slices.surfaces.begin(); surface != (*region)->slices.surfaces.end(); ++surface)
+            bbox.merge(get_extents(surface->expolygon));
+    Point legend_size = export_surface_type_legend_to_svg_box_size();
+    Point legend_pos(bbox.min.x, bbox.max.y);
+    bbox.merge(Point(std::max(bbox.min.x + legend_size.x, bbox.max.x), bbox.max.y + legend_size.y));
+
+    SVG svg(path, bbox);
+    const float transparency = 0.5f;
+    for (LayerRegionPtrs::const_iterator region = this->regions.begin(); region != this->regions.end(); ++region)
+        for (Surfaces::const_iterator surface = (*region)->slices.surfaces.begin(); surface != (*region)->slices.surfaces.end(); ++surface)
+            svg.draw(surface->expolygon, surface_type_to_color_name(surface->surface_type), transparency);
+    export_surface_type_legend_to_svg(svg, legend_pos);
+    svg.Close(); 
+}
+
+// Export to "out/LayerRegion-name-%d.svg" with an increasing index with every export.
+void Layer::export_region_slices_to_svg_debug(const char *name)
+{
+    static size_t idx = 0;
+    char path[2048];
+    sprintf(path, "out\\Layer-slices-%s-%d.svg", name, idx ++);
+    this->export_region_slices_to_svg(path);
+}
+
+void Layer::export_region_fill_surfaces_to_svg(const char *path)
+{
+    BoundingBox bbox;
+    for (LayerRegionPtrs::const_iterator region = this->regions.begin(); region != this->regions.end(); ++region)
+        for (Surfaces::const_iterator surface = (*region)->fill_surfaces.surfaces.begin(); surface != (*region)->fill_surfaces.surfaces.end(); ++surface)
+            bbox.merge(get_extents(surface->expolygon));
+    Point legend_size = export_surface_type_legend_to_svg_box_size();
+    Point legend_pos(bbox.min.x, bbox.max.y);
+    bbox.merge(Point(std::max(bbox.min.x + legend_size.x, bbox.max.x), bbox.max.y + legend_size.y));
+
+    SVG svg(path, bbox);
+    const float transparency = 0.5f;
+    for (LayerRegionPtrs::const_iterator region = this->regions.begin(); region != this->regions.end(); ++region)
+        for (Surfaces::const_iterator surface = (*region)->fill_surfaces.surfaces.begin(); surface != (*region)->fill_surfaces.surfaces.end(); ++surface)
+            svg.draw(surface->expolygon, surface_type_to_color_name(surface->surface_type), transparency);
+    export_surface_type_legend_to_svg(svg, legend_pos);
+    svg.Close();
+}
+
+// Export to "out/LayerRegion-name-%d.svg" with an increasing index with every export.
+void Layer::export_region_fill_surfaces_to_svg_debug(const char *name)
+{
+    static size_t idx = 0;
+    char path[2048];
+    sprintf(path, "out\\Layer-fill_surfaces-%s-%d.svg", name, idx ++);
+    this->export_region_fill_surfaces_to_svg(path);
+}
 
 SupportLayer::SupportLayer(size_t id, PrintObject *object, coordf_t height,
         coordf_t print_z, coordf_t slice_z)
diff --git a/xs/src/libslic3r/Layer.hpp b/xs/src/libslic3r/Layer.hpp
index 4badb8374..23bc84e90 100644
--- a/xs/src/libslic3r/Layer.hpp
+++ b/xs/src/libslic3r/Layer.hpp
@@ -38,6 +38,11 @@ class LayerRegion
     // collection of surfaces for infill generation
     SurfaceCollection fill_surfaces;
 
+    // Collection of perimeter surfaces. This is a cached result of diff(slices, fill_surfaces).
+    // While not necessary, the memory consumption is meager and it speeds up calculation.
+    // The perimeter_surfaces keep the IDs of the slices (top/bottom/)
+    SurfaceCollection perimeter_surfaces;
+
     // collection of expolygons representing the bridged areas (thus not
     // needing support material)
     Polygons bridged;
@@ -56,10 +61,16 @@ class LayerRegion
     Flow flow(FlowRole role, bool bridge = false, double width = -1) const;
     void merge_slices();
     void prepare_fill_surfaces();
-    void make_perimeters(const SurfaceCollection &slices, SurfaceCollection* fill_surfaces);
+    void make_perimeters(const SurfaceCollection &slices, SurfaceCollection* perimeter_surfaces, SurfaceCollection* fill_surfaces);
     void process_external_surfaces(const Layer* lower_layer);
     double infill_area_threshold() const;
-    
+
+    void export_region_slices_to_svg(const char *path);
+    void export_region_fill_surfaces_to_svg(const char *path);
+    // Export to "out/LayerRegion-name-%d.svg" with an increasing index with every export.
+    void export_region_slices_to_svg_debug(const char *name);
+    void export_region_fill_surfaces_to_svg_debug(const char *name);
+
     private:
     Layer *_layer;
     PrintRegion *_region;
@@ -74,7 +85,7 @@ typedef std::vector<LayerRegion*> LayerRegionPtrs;
 class Layer {
     friend class PrintObject;
 
-    public:
+public:
     size_t id() const;
     void set_id(size_t id);
     PrintObject* object();
@@ -91,6 +102,8 @@ class Layer {
     // collection of expolygons generated by slicing the original geometry;
     // also known as 'islands' (all regions and surface types are merged here)
     ExPolygonCollection slices;
+    // Surfaces of the perimeters including their gap fill.
+    ExPolygonCollection perimeter_expolygons;
 
 
     size_t region_count() const;
@@ -102,8 +115,14 @@ class Layer {
     template <class T> bool any_internal_region_slice_contains(const T &item) const;
     template <class T> bool any_bottom_region_slice_contains(const T &item) const;
     void make_perimeters();
+
+    void export_region_slices_to_svg(const char *path);
+    void export_region_fill_surfaces_to_svg(const char *path);
+    // Export to "out/LayerRegion-name-%d.svg" with an increasing index with every export.
+    void export_region_slices_to_svg_debug(const char *name);
+    void export_region_fill_surfaces_to_svg_debug(const char *name);
     
-    protected:
+protected:
     size_t _id;     // sequential number of layer, 0-based
     PrintObject *_object;
 
diff --git a/xs/src/libslic3r/LayerRegion.cpp b/xs/src/libslic3r/LayerRegion.cpp
index d713b7c1f..fe35fd04b 100644
--- a/xs/src/libslic3r/LayerRegion.cpp
+++ b/xs/src/libslic3r/LayerRegion.cpp
@@ -4,6 +4,10 @@
 #include "PerimeterGenerator.hpp"
 #include "Print.hpp"
 #include "Surface.hpp"
+#include "SVG.hpp"
+
+#include <string>
+#include <map>
 
 namespace Slic3r {
 
@@ -56,7 +60,7 @@ LayerRegion::merge_slices()
 }
 
 void
-LayerRegion::make_perimeters(const SurfaceCollection &slices, SurfaceCollection* fill_surfaces)
+LayerRegion::make_perimeters(const SurfaceCollection &slices, SurfaceCollection* perimeter_surfaces, SurfaceCollection* fill_surfaces)
 {
     this->perimeters.clear();
     this->thin_fills.clear();
@@ -73,6 +77,7 @@ LayerRegion::make_perimeters(const SurfaceCollection &slices, SurfaceCollection*
         // output:
         &this->perimeters,
         &this->thin_fills,
+        perimeter_surfaces, 
         fill_surfaces
     );
     
@@ -94,10 +99,15 @@ LayerRegion::process_external_surfaces(const Layer* lower_layer)
     const Surfaces &surfaces = this->fill_surfaces.surfaces;
     const double margin = scale_(EXTERNAL_INFILL_MARGIN);
     
+#ifdef SLIC3R_DEBUG_SLICE_PROCESSING
+    export_region_fill_surfaces_to_svg_debug("3_process_external_surfaces-initial");
+#endif /* SLIC3R_DEBUG_SLICE_PROCESSING */
+
     SurfaceCollection bottom;
+    // For all stBottom && stBottomBridge surfaces:
     for (Surfaces::const_iterator surface = surfaces.begin(); surface != surfaces.end(); ++surface) {
         if (!surface->is_bottom()) continue;
-        
+        // Grown by 3mm.
         ExPolygons grown = offset_ex(surface->expolygon, +margin);
         
         /*  detect bridge direction before merging grown surfaces otherwise adjacent bridges
@@ -109,6 +119,7 @@ LayerRegion::process_external_surfaces(const Layer* lower_layer)
             BridgeDetector bd(
                 surface->expolygon,
                 lower_layer->slices,
+                // Using extrusion width of an infill.
                 this->flow(frInfill, this->layer()->height, true).scaled_width()
             );
             
@@ -118,10 +129,12 @@ LayerRegion::process_external_surfaces(const Layer* lower_layer)
             
             if (bd.detect_angle()) {
                 angle = bd.angle;
-            
+                // Are supports enabled?
                 if (this->layer()->object()->config.support_material) {
                     Polygons coverage = bd.coverage();
+                    // Bridged polygons do not require supports.
                     this->bridged.insert(this->bridged.end(), coverage.begin(), coverage.end());
+                    // Unsupported edges of the infill.
                     this->unsupported_bridge_edges.append(bd.unsupported_edges()); 
                 }
             }
@@ -228,6 +241,10 @@ LayerRegion::process_external_surfaces(const Layer* lower_layer)
     }
     
     this->fill_surfaces = new_surfaces;
+
+#ifdef SLIC3R_DEBUG_SLICE_PROCESSING
+    export_region_fill_surfaces_to_svg_debug("3_process_external_surfaces-final");
+#endif /* SLIC3R_DEBUG_SLICE_PROCESSING */
 }
 
 void
@@ -265,6 +282,10 @@ LayerRegion::prepare_fill_surfaces()
                 surface->surface_type = stInternalSolid;
         }
     }
+
+#ifdef SLIC3R_DEBUG_SLICE_PROCESSING
+    export_region_slices_to_svg_debug("2_prepare_fill_surfaces");
+#endif /* SLIC3R_DEBUG_SLICE_PROCESSING */
 }
 
 double
@@ -274,4 +295,62 @@ LayerRegion::infill_area_threshold() const
     return ss*ss;
 }
 
+
+void LayerRegion::export_region_slices_to_svg(const char *path)
+{
+    BoundingBox bbox;
+    for (Surfaces::const_iterator surface = this->slices.surfaces.begin(); surface != this->slices.surfaces.end(); ++surface)
+        bbox.merge(get_extents(surface->expolygon));
+    Point legend_size = export_surface_type_legend_to_svg_box_size();
+    Point legend_pos(bbox.min.x, bbox.max.y);
+    bbox.merge(Point(std::max(bbox.min.x + legend_size.x, bbox.max.x), bbox.max.y + legend_size.y));
+
+    SVG svg(path, bbox);
+    const float transparency = 0.5f;
+    for (Surfaces::const_iterator surface = this->slices.surfaces.begin(); surface != this->slices.surfaces.end(); ++surface)
+        svg.draw(surface->expolygon, surface_type_to_color_name(surface->surface_type), transparency);
+    for (Surfaces::const_iterator surface = this->fill_surfaces.surfaces.begin(); surface != this->fill_surfaces.surfaces.end(); ++surface)
+        svg.draw(surface->expolygon.lines(), surface_type_to_color_name(surface->surface_type));
+    export_surface_type_legend_to_svg(svg, legend_pos);
+    svg.Close();
+}
+
+// Export to "out/LayerRegion-name-%d.svg" with an increasing index with every export.
+void LayerRegion::export_region_slices_to_svg_debug(const char *name)
+{
+    static std::map<std::string, size_t> idx_map;
+    size_t &idx = idx_map[name];
+    char path[2048];
+    sprintf(path, "out\\LayerRegion-slices-%s-%d.svg", name, idx ++);
+    this->export_region_slices_to_svg(path);
+}
+
+void LayerRegion::export_region_fill_surfaces_to_svg(const char *path) 
+{
+    BoundingBox bbox;
+    for (Surfaces::const_iterator surface = this->fill_surfaces.surfaces.begin(); surface != this->fill_surfaces.surfaces.end(); ++surface)
+        bbox.merge(get_extents(surface->expolygon));
+    Point legend_size = export_surface_type_legend_to_svg_box_size();
+    Point legend_pos(bbox.min.x, bbox.max.y);
+    bbox.merge(Point(std::max(bbox.min.x + legend_size.x, bbox.max.x), bbox.max.y + legend_size.y));
+
+    SVG svg(path, bbox);
+    const float transparency = 0.5f;
+    for (Surfaces::const_iterator surface = this->fill_surfaces.surfaces.begin(); surface != this->fill_surfaces.surfaces.end(); ++surface)
+        svg.draw(surface->expolygon, surface_type_to_color_name(surface->surface_type), transparency);
+    export_surface_type_legend_to_svg(svg, legend_pos);
+    svg.Close();
+}
+
+// Export to "out/LayerRegion-name-%d.svg" with an increasing index with every export.
+void LayerRegion::export_region_fill_surfaces_to_svg_debug(const char *name)
+{
+    static std::map<std::string, size_t> idx_map;
+    size_t &idx = idx_map[name];
+    char path[2048];
+    sprintf(path, "out\\LayerRegion-fill_surfaces-%s-%d.svg", name, idx ++);
+    this->export_region_fill_surfaces_to_svg(path);
+}
+
 }
+ 
\ No newline at end of file
diff --git a/xs/src/libslic3r/PerimeterGenerator.cpp b/xs/src/libslic3r/PerimeterGenerator.cpp
index aa0b2600f..d0cec1167 100644
--- a/xs/src/libslic3r/PerimeterGenerator.cpp
+++ b/xs/src/libslic3r/PerimeterGenerator.cpp
@@ -239,6 +239,15 @@ PerimeterGenerator::process()
                 this->loops->append(entities);
         } // for each loop of an island
         
+        {
+            //FIXME how about the gaps?
+            // Calculate the region of surface->expolygon covered by the perimeters and their gap fills.
+            // The perimeters will later be used to calculate the object skin.
+            ExPolygons expp = diff_ex((Polygons)surface->expolygon, last, true);
+            for (ExPolygons::const_iterator ex = expp.begin(); ex != expp.end(); ++ex)
+                this->perimeter_surfaces->surfaces.push_back(Surface(stPerimeter, *ex));
+        }
+
         // fill gaps
         if (!gaps.empty()) {
             /*
@@ -275,7 +284,7 @@ PerimeterGenerator::process()
                 last = diff(last, gap_fill.grow());
             }
         }
-        
+
         // create one more offset to be used as boundary for fill
         // we offset by half the perimeter spacing (to get to the actual infill boundary)
         // and then we offset back and forth by half the infill spacing to only consider the
diff --git a/xs/src/libslic3r/PerimeterGenerator.hpp b/xs/src/libslic3r/PerimeterGenerator.hpp
index 0e7fbd3e4..09289a2d4 100644
--- a/xs/src/libslic3r/PerimeterGenerator.hpp
+++ b/xs/src/libslic3r/PerimeterGenerator.hpp
@@ -52,6 +52,7 @@ public:
     // Outputs:
     ExtrusionEntityCollection* loops;
     ExtrusionEntityCollection* gap_fill;
+    SurfaceCollection* perimeter_surfaces;
     SurfaceCollection* fill_surfaces;
     
     PerimeterGenerator(
@@ -67,13 +68,15 @@ public:
         ExtrusionEntityCollection*  loops,
         // Gaps without the thin walls
         ExtrusionEntityCollection*  gap_fill,
+        // Perimeters including their gap fills
+        SurfaceCollection*          perimeter_surfaces,
         // Infills without the gap fills
         SurfaceCollection*          fill_surfaces)
         : slices(slices), lower_slices(NULL), layer_height(layer_height),
             layer_id(-1), perimeter_flow(flow), ext_perimeter_flow(flow),
             overhang_flow(flow), solid_infill_flow(flow),
             config(config), object_config(object_config), print_config(print_config),
-            loops(loops), gap_fill(gap_fill), fill_surfaces(fill_surfaces),
+            loops(loops), gap_fill(gap_fill), perimeter_surfaces(perimeter_surfaces), fill_surfaces(fill_surfaces),
             _ext_mm3_per_mm(-1), _mm3_per_mm(-1), _mm3_per_mm_overhang(-1)
         {};
     void process();
diff --git a/xs/xsp/Layer.xsp b/xs/xsp/Layer.xsp
index e5697ce89..c4490cf71 100644
--- a/xs/xsp/Layer.xsp
+++ b/xs/xsp/Layer.xsp
@@ -17,6 +17,8 @@
         %code%{ RETVAL = &THIS->thin_fills; %};
     Ref<SurfaceCollection> fill_surfaces()
         %code%{ RETVAL = &THIS->fill_surfaces; %};
+    Ref<SurfaceCollection> perimeter_surfaces()
+        %code%{ RETVAL = &THIS->perimeter_surfaces; %};
     Polygons bridged()
         %code%{ RETVAL = THIS->bridged; %};
     Ref<PolylineCollection> unsupported_bridge_edges()
@@ -30,9 +32,14 @@
         %code%{ RETVAL = THIS->flow(role, bridge, width); %};
     void merge_slices();
     void prepare_fill_surfaces();
-    void make_perimeters(SurfaceCollection* slices, SurfaceCollection* fill_surfaces)
-        %code%{ THIS->make_perimeters(*slices, fill_surfaces); %};
+    void make_perimeters(SurfaceCollection* slices, SurfaceCollection* perimeter_surfaces, SurfaceCollection* fill_surfaces)
+        %code%{ THIS->make_perimeters(*slices, perimeter_surfaces, fill_surfaces); %};
     double infill_area_threshold();
+
+    void export_region_slices_to_svg(const char *path);
+    void export_region_fill_surfaces_to_svg(const char *path);
+    void export_region_slices_to_svg_debug(const char *name);
+    void export_region_fill_surfaces_to_svg_debug(const char *name);
 };
 
 %name{Slic3r::Layer} class Layer {
@@ -72,6 +79,9 @@
 
     Ref<ExPolygonCollection> slices()
         %code%{ RETVAL = &THIS->slices; %};
+
+    Ref<ExPolygonCollection> perimeter_expolygons()
+        %code%{ RETVAL = &THIS->perimeter_expolygons; %};
     
     int ptr()
         %code%{ RETVAL = (int)(intptr_t)THIS; %};
@@ -86,6 +96,11 @@
     bool any_bottom_region_slice_contains_polyline(Polyline* polyline)
         %code%{ RETVAL = THIS->any_bottom_region_slice_contains(*polyline); %};
     void make_perimeters();
+
+    void export_region_slices_to_svg(const char *path);
+    void export_region_fill_surfaces_to_svg(const char *path);
+    void export_region_slices_to_svg_debug(const char *name);
+    void export_region_fill_surfaces_to_svg_debug(const char *name);
 };
 
 %name{Slic3r::Layer::Support} class SupportLayer {
@@ -136,8 +151,8 @@
     Ref<ExPolygonCollection> slices()
         %code%{ RETVAL = &THIS->slices; %};
     
-    bool any_internal_region_slice_contains_polyline(Polyline* polyline)
-        %code%{ RETVAL = THIS->any_internal_region_slice_contains(*polyline); %};
-    bool any_bottom_region_slice_contains_polyline(Polyline* polyline)
-        %code%{ RETVAL = THIS->any_bottom_region_slice_contains(*polyline); %};
+    void export_region_slices_to_svg(const char *path);
+    void export_region_fill_surfaces_to_svg(const char *path);
+    void export_region_slices_to_svg_debug(const char *name);
+    void export_region_fill_surfaces_to_svg_debug(const char *name);
 };
diff --git a/xs/xsp/PerimeterGenerator.xsp b/xs/xsp/PerimeterGenerator.xsp
index b4d1d94ec..b8c3edf69 100644
--- a/xs/xsp/PerimeterGenerator.xsp
+++ b/xs/xsp/PerimeterGenerator.xsp
@@ -9,12 +9,13 @@
     PerimeterGenerator(SurfaceCollection* slices, double layer_height, Flow* flow,
         StaticPrintConfig* region_config, StaticPrintConfig* object_config, 
         StaticPrintConfig* print_config, ExtrusionEntityCollection* loops, 
-        ExtrusionEntityCollection* gap_fill, SurfaceCollection* fill_surfaces)
+        ExtrusionEntityCollection* gap_fill, 
+        SurfaceCollection* perimeter_surfaces, SurfaceCollection* fill_surfaces)
         %code{% RETVAL = new PerimeterGenerator(slices, layer_height, *flow,
             dynamic_cast<PrintRegionConfig*>(region_config),
             dynamic_cast<PrintObjectConfig*>(object_config),
             dynamic_cast<PrintConfig*>(print_config),
-            loops, gap_fill, fill_surfaces); %};
+            loops, gap_fill, perimeter_surfaces, fill_surfaces); %};
     ~PerimeterGenerator();
     
     void set_lower_slices(ExPolygonCollection* lower_slices)