WIP: first_layer_print_min/max, first_layer_print_convex_hull

placeholders for the G-code export.

src/libslic3r/GCode.cpp

@@ -1298,7 +1298,21 @@ void GCode::_do_export(Print& print, FILE* file, ThumbnailsGeneratorCallback thu
     m_placeholder_parser.set("has_wipe_tower", has_wipe_tower);
     m_placeholder_parser.set("has_single_extruder_multi_material_priming", has_wipe_tower && print.config().single_extruder_multi_material_priming);
     m_placeholder_parser.set("total_toolchanges", std::max(0, print.wipe_tower_data().number_of_toolchanges)); // Check for negative toolchanges (single extruder mode) and set to 0 (no tool change).
-
+    {
+        // Convex hull of the 1st layer extrusions, for bed leveling and placing the initial purge line.
+        // It encompasses the object extrusions, support extrusions, skirt, brim, wipe tower.
+        // It does NOT encompass user extrusions generated by custom G-code,
+        // therefore it does NOT encompass the initial purge line.
+        // It does NOT encompass MMU/MMU2 starting (wipe) areas.
+        auto pts = std::make_unique<ConfigOptionPoints>();
+        pts->values.reserve(print.first_layer_convex_hull().size());
+        for (const Point &pt : print.first_layer_convex_hull().points)
+            pts->values.emplace_back(unscale(pt));
+        BoundingBoxf bbox(pts->values);
+        m_placeholder_parser.set("first_layer_print_convex_hull", pts.release());
+        m_placeholder_parser.set("first_layer_print_min", new ConfigOptionFloats({ bbox.min.x(), bbox.min.y() }));
+        m_placeholder_parser.set("first_layer_print_max", new ConfigOptionFloats({ bbox.max.x(), bbox.max.y() }));
+    }
     std::string start_gcode = this->placeholder_parser_process("start_gcode", print.config().start_gcode.value, initial_extruder_id);
     // Set bed temperature if the start G-code does not contain any bed temp control G-codes.
     this->_print_first_layer_bed_temperature(file, print, start_gcode, initial_extruder_id, true);

src/libslic3r/Layer.hpp

@@ -166,6 +166,7 @@ class SupportLayer : public Layer
 {
 public:
     // Polygons covered by the supports: base, interface and contact areas.
+    // Used to suppress retraction if moving for a support extrusion over these support_islands.
     ExPolygonCollection         support_islands;
     // Extrusion paths for the support base and for the support interface and contacts.
     ExtrusionEntityCollection   support_fills;

src/libslic3r/Print.cpp

@@ -244,7 +244,6 @@ bool Print::invalidate_step(PrintStep step)
 {
 	bool invalidated = Inherited::invalidate_step(step);
     // Propagate to dependent steps.
-    //FIXME Why should skirt invalidate brim? Shouldn't it be vice versa?
     if (step == psSkirt)
 		invalidated |= Inherited::invalidate_step(psBrim);
     if (step != psGCodeExport)
@@ -1606,6 +1605,8 @@ void Print::process()
     }
     if (this->set_started(psSkirt)) {
         m_skirt.clear();
+        m_skirt_convex_hull.clear();
+        m_first_layer_convex_hull.points.clear();
         if (this->has_skirt()) {
             this->set_status(88, L("Generating skirt"));
             this->_make_skirt();
@@ -1614,11 +1615,15 @@ void Print::process()
     }
 	if (this->set_started(psBrim)) {
         m_brim.clear();
+        m_first_layer_convex_hull.points.clear();
         if (m_config.brim_width > 0) {
             this->set_status(88, L("Generating brim"));
             this->_make_brim();
         }
-       this->set_done(psBrim);
+        // Brim depends on skirt (brim lines are trimmed by the skirt lines), therefore if
+        // the skirt gets invalidated, brim gets invalidated as well and the following line is called.
+        this->finalize_first_layer_convex_hull();
+        this->set_done(psBrim);
     }
     BOOST_LOG_TRIVIAL(info) << "Slicing process finished." << log_memory_info();
 }
@@ -1697,22 +1702,7 @@ void Print::_make_skirt()
     }
 
     // Include the wipe tower.
-    if (has_wipe_tower() && ! m_wipe_tower_data.tool_changes.empty()) {
+    append(points, this->first_layer_wipe_tower_corners());
-        double width = m_config.wipe_tower_width + 2*m_wipe_tower_data.brim_width;
-        double depth = m_wipe_tower_data.depth + 2*m_wipe_tower_data.brim_width;
-        Vec2d pt = Vec2d(-m_wipe_tower_data.brim_width, -m_wipe_tower_data.brim_width);
-
-        std::vector<Vec2d> pts;
-        pts.push_back(Vec2d(pt.x(), pt.y()));
-        pts.push_back(Vec2d(pt.x()+width, pt.y()));
-        pts.push_back(Vec2d(pt.x()+width, pt.y()+depth));
-        pts.push_back(Vec2d(pt.x(), pt.y()+depth));
-        for (Vec2d& pt : pts) {
-            pt = Eigen::Rotation2Dd(Geometry::deg2rad(m_config.wipe_tower_rotation_angle.value)) * pt;
-            pt += Vec2d(m_config.wipe_tower_x.value, m_config.wipe_tower_y.value);
-            points.push_back(Point(scale_(pt.x()), scale_(pt.y())));
-        }
-    }
 
     if (points.size() < 3)
         // At least three points required for a convex hull.
@@ -1796,28 +1786,19 @@ void Print::_make_skirt()
     }
     // Brims were generated inside out, reverse to print the outmost contour first.
     m_skirt.reverse();
+
+    // Remember the outer edge of the last skirt line extruded as m_skirt_convex_hull.
+    for (Polygon &poly : offset(convex_hull, distance + 0.5f * float(scale_(spacing)), ClipperLib::jtRound, float(scale_(0.1))))
+        append(m_skirt_convex_hull, std::move(poly.points));
 }
 
 void Print::_make_brim()
 {
     // Brim is only printed on first layer and uses perimeter extruder.
+    Polygons    islands = this->first_layer_islands();
+    Polygons    loops;
     Flow        flow = this->brim_flow();
-    Polygons    islands;
+    size_t      num_loops = size_t(floor(m_config.brim_width.value / flow.spacing()));
-    for (PrintObject *object : m_objects) {
-        Polygons object_islands;
-        for (ExPolygon &expoly : object->m_layers.front()->lslices)
-            object_islands.push_back(expoly.contour);
-        if (! object->support_layers().empty())
-            object->support_layers().front()->support_fills.polygons_covered_by_spacing(object_islands, float(SCALED_EPSILON));
-        islands.reserve(islands.size() + object_islands.size() * object->instances().size());
-        for (const PrintInstance &instance : object->instances())
-            for (Polygon &poly : object_islands) {
-                islands.push_back(poly);
-                islands.back().translate(instance.shift);
-            }
-    }
-    Polygons loops;
-    size_t num_loops = size_t(floor(m_config.brim_width.value / flow.spacing()));
     for (size_t i = 0; i < num_loops; ++ i) {
         this->throw_if_canceled();
         islands = offset(islands, float(flow.scaled_spacing()), jtSquare);
@@ -1828,6 +1809,11 @@ void Print::_make_brim()
             p.pop_back();
             poly.points = std::move(p);
         }
+        if (i + 1 == num_loops) {
+            // Remember the outer edge of the last brim line extruded as m_first_layer_convex_hull.
+            for (Polygon &poly : islands)
+                append(m_first_layer_convex_hull.points, poly.points);
+        }
         polygons_append(loops, offset(islands, -0.5f * float(flow.scaled_spacing())));
     }
     loops = union_pt_chained(loops, false);
@@ -1967,6 +1953,58 @@ void Print::_make_brim()
     }
 }
 
+Polygons Print::first_layer_islands() const
+{
+    Polygons islands;
+    for (PrintObject *object : m_objects) {
+        Polygons object_islands;
+        for (ExPolygon &expoly : object->m_layers.front()->lslices)
+            object_islands.push_back(expoly.contour);
+        if (! object->support_layers().empty())
+            object->support_layers().front()->support_fills.polygons_covered_by_spacing(object_islands, float(SCALED_EPSILON));
+        islands.reserve(islands.size() + object_islands.size() * object->instances().size());
+        for (const PrintInstance &instance : object->instances())
+            for (Polygon &poly : object_islands) {
+                islands.push_back(poly);
+                islands.back().translate(instance.shift);
+            }
+    }
+    return islands;
+}
+
+std::vector<Point> Print::first_layer_wipe_tower_corners() const
+{
+    std::vector<Point> corners;
+    if (has_wipe_tower() && ! m_wipe_tower_data.tool_changes.empty()) {
+        double width = m_config.wipe_tower_width + 2*m_wipe_tower_data.brim_width;
+        double depth = m_wipe_tower_data.depth + 2*m_wipe_tower_data.brim_width;
+        Vec2d pt0(-m_wipe_tower_data.brim_width, -m_wipe_tower_data.brim_width);
+        for (Vec2d pt : {
+                pt0,
+                Vec2d(pt0.x()+width, pt0.y()      ),
+                Vec2d(pt0.x()+width, pt0.y()+depth),
+                Vec2d(pt0.x(),       pt0.y()+depth)
+            }) {
+            pt = Eigen::Rotation2Dd(Geometry::deg2rad(m_config.wipe_tower_rotation_angle.value)) * pt;
+            pt += Vec2d(m_config.wipe_tower_x.value, m_config.wipe_tower_y.value);
+            corners.emplace_back(Point(scale_(pt.x()), scale_(pt.y())));
+        }
+    }
+    return corners;
+}
+
+void Print::finalize_first_layer_convex_hull()
+{
+    append(m_first_layer_convex_hull.points, m_skirt_convex_hull);
+    if (m_first_layer_convex_hull.empty()) {
+        // Neither skirt nor brim was extruded. Collect points of printed objects from 1st layer.
+        for (Polygon &poly : this->first_layer_islands())
+            append(m_first_layer_convex_hull.points, std::move(poly.points));
+    }
+    append(m_first_layer_convex_hull.points, this->first_layer_wipe_tower_corners());
+    m_first_layer_convex_hull = Geometry::convex_hull(m_first_layer_convex_hull.points);
+}
+
 // Wipe tower support.
 bool Print::has_wipe_tower() const
 {
@@ -1991,7 +2029,6 @@ const WipeTowerData& Print::wipe_tower_data(size_t extruders_cnt, double first_l
     return m_wipe_tower_data;
 }
 
-
 void Print::_make_wipe_tower()
 {
     m_wipe_tower_data.clear();

src/libslic3r/Print.hpp

@@ -402,6 +402,12 @@ public:
 
     const ExtrusionEntityCollection& skirt() const { return m_skirt; }
     const ExtrusionEntityCollection& brim() const { return m_brim; }
+    // Convex hull of the 1st layer extrusions, for bed leveling and placing the initial purge line.
+    // It encompasses the object extrusions, support extrusions, skirt, brim, wipe tower.
+    // It does NOT encompass user extrusions generated by custom G-code,
+    // therefore it does NOT encompass the initial purge line.
+    // It does NOT encompass MMU/MMU2 starting (wipe) areas.
+    const Polygon&                   first_layer_convex_hull() const { return m_first_layer_convex_hull; }
 
     const PrintStatistics&      print_statistics() const { return m_print_statistics; }
 
@@ -437,6 +443,12 @@ private:
     void                _make_skirt();
     void                _make_brim();
     void                _make_wipe_tower();
+    void                finalize_first_layer_convex_hull();
+
+    // Islands of objects and their supports extruded at the 1st layer.
+    Polygons            first_layer_islands() const;
+    // Return 4 wipe tower corners in the world coordinates (shifted and rotated), including the wipe tower brim.
+    std::vector<Point>  first_layer_wipe_tower_corners() const;
 
     // Declared here to have access to Model / ModelObject / ModelInstance
     static void         model_volume_list_update_supports(ModelObject &model_object_dst, const ModelObject &model_object_src);
@@ -450,6 +462,13 @@ private:
     // Ordered collections of extrusion paths to build skirt loops and brim.
     ExtrusionEntityCollection               m_skirt;
     ExtrusionEntityCollection               m_brim;
+    // Convex hull of the 1st layer extrusions.
+    // It encompasses the object extrusions, support extrusions, skirt, brim, wipe tower.
+    // It does NOT encompass user extrusions generated by custom G-code,
+    // therefore it does NOT encompass the initial purge line.
+    // It does NOT encompass MMU/MMU2 starting (wipe) areas.
+    Polygon                                 m_first_layer_convex_hull;
+    Points                                  m_skirt_convex_hull;
 
     // Following section will be consumed by the GCodeGenerator.
     ToolOrdering 							m_tool_ordering;