Implemented priming of all the filaments of the Prusa Multi Material.

slic3r.sublime-project

@@ -26,7 +26,7 @@
   			"file_regex": "^(..[^:]*)\\(([0-9]+)\\)(.*)$",
   			// For GCC:
 // 			"file_regex": "^(..[^:]*):([0-9]+):?([0-9]+)?:? (.*)$",
-			"shell_cmd": "chdir & ninja -j 6",
+			"shell_cmd": "chdir & ninja -j 6 -v",
 			"env": {
 //				"PATH": "C:\\Program Files (x86)\\MSBuild\\12.0\\bin\\amd64;C:\\Program Files (x86)\\Microsoft Visual Studio 12.0\\VC\\BIN\\amd64;C:\\Program Files (x86)\\Microsoft Visual Studio 12.0\\Common7\\IDE;C:\\Program Files (x86)\\Microsoft Visual Studio 12.0\\Common7\\Tools;%PATH%;c:\\wperl64d\\site\\bin;c:\\wperl64d\\bin",
 //				"PERL_CPANM_HOME": "c:\\wperl64d\\cpanm",

xs/CMakeLists.txt

@@ -394,8 +394,15 @@ target_compile_options(XS PRIVATE ${PerlEmbed_CCFLAGS})
 # If the Perl is compiled with optimization off, disable optimization over the whole project.
 if (WIN32 AND ";${PerlEmbed_CCFLAGS};" MATCHES ";[-/]Od;")
     message(STATUS "Perl compiled without optimization. Disabling optimization for the Slic3r build.")
-    set(CMAKE_CXX_FLAGS_RELEASE /Od /Zi)
+    message("Old CMAKE_CXX_FLAGS_RELEASE: ${CMAKE_CXX_FLAGS_RELEASE}")
-    set(CMAKE_C_FLAGS_RELEASE /Od /Zi)
+    message("Old CMAKE_CXX_FLAGS_RELWITHDEBINFO: ${CMAKE_CXX_FLAGS_RELEASE}")
+    message("Old CMAKE_CXX_FLAGS: ${CMAKE_CXX_FLAGS_RELEASE}")
+    set(CMAKE_CXX_FLAGS_RELEASE "/MD /Od /Zi /EHsc /DNDEBUG")
+    set(CMAKE_C_FLAGS_RELEASE "/MD /Od /Zi /DNDEBUG")
+    set(CMAKE_CXX_FLAGS_RELWITHDEBINFO "/MD /Od /Zi /EHsc /DNDEBUG")
+    set(CMAKE_C_FLAGS_RELWITHDEBINFO "/MD /Od /Zi /DNDEBUG")
+    set(CMAKE_CXX_FLAGS "/MD /Od /Zi /EHsc /DNDEBUG")
+    set(CMAKE_C_FLAGS "/MD /Od /Zi /DNDEBUG")
 endif()
 # The following line will add -fPIC on Linux to make the XS.so rellocable.
 add_definitions(${PerlEmbed_CCCDLFLAGS})
@@ -437,6 +444,8 @@ if(MSVC)
     # Suppress implicit linking of the TBB libraries by the Visual Studio compiler.
     add_definitions(-D__TBB_NO_IMPLICIT_LINKAGE)
 endif()
+# The Intel TBB library will use the std::exception_ptr feature of C++11.
+add_definitions(-DTBB_USE_CAPTURED_EXCEPTION=0)
 target_link_libraries(XS ${TBB_LIBRARIES})
 
 # Find and configure wxWidgets

xs/src/libslic3r/GCode.cpp

@@ -192,6 +192,33 @@ std::string WipeTowerIntegration::append_tcr(GCode &gcodegen, const WipeTower::T
     return gcode;
 }
 
+std::string WipeTowerIntegration::prime(GCode &gcodegen)
+{
+    assert(m_layer_idx == 0);
+    std::string gcode;
+
+    if (&m_priming != nullptr && ! m_priming.extrusions.empty()) {
+        // Let the tool change be executed by the wipe tower class.
+        // Inform the G-code writer about the changes done behind its back.
+        gcode += m_priming.gcode;
+        // Let the m_writer know the current extruder_id, but ignore the generated G-code.
+        gcodegen.writer().toolchange(m_priming.extrusions.back().tool);
+        // A phony move to the end position at the wipe tower.
+        gcodegen.writer().travel_to_xy(Pointf(m_priming.end_pos.x, m_priming.end_pos.y));
+        gcodegen.set_last_pos(wipe_tower_point_to_object_point(gcodegen, m_priming.end_pos));
+
+        // Prepare a future wipe.
+        gcodegen.m_wipe.path.points.clear();
+        // Start the wipe at the current position.
+        gcodegen.m_wipe.path.points.emplace_back(wipe_tower_point_to_object_point(gcodegen, m_priming.end_pos));
+        // Wipe end point: Wipe direction away from the closer tower edge to the further tower edge.
+        gcodegen.m_wipe.path.points.emplace_back(wipe_tower_point_to_object_point(gcodegen, 
+            WipeTower::xy((std::abs(m_left - m_priming.end_pos.x) < std::abs(m_right - m_priming.end_pos.x)) ? m_right : m_left,
+            m_priming.end_pos.y)));
+    }
+    return gcode;
+}
+
 std::string WipeTowerIntegration::tool_change(GCode &gcodegen, int extruder_id, bool finish_layer)
 {
     std::string gcode;
@@ -522,7 +549,7 @@ bool GCode::_do_export(Print &print, FILE *file)
     writeln(file, m_placeholder_parser.process(print.config.start_gcode.value, initial_extruder_id));
     // Process filament-specific gcode in extruder order.
     for (const std::string &start_gcode : print.config.start_filament_gcode.values)
-        writeln(file, m_placeholder_parser.process(start_gcode, &start_gcode - &print.config.start_filament_gcode.values.front()));
+        writeln(file, m_placeholder_parser.process(start_gcode, (unsigned int)(&start_gcode - &print.config.start_filament_gcode.values.front())));
     this->_print_first_layer_extruder_temperatures(file, print, initial_extruder_id, true);
     
     // Set other general things.
@@ -647,8 +674,10 @@ bool GCode::_do_export(Print &print, FILE *file)
         std::vector<std::pair<coordf_t, std::vector<LayerToPrint>>> layers_to_print = collect_layers_to_print(print);
         // Prusa Multi-Material wipe tower.
         if (print.has_wipe_tower() && 
-            ! tool_ordering.empty() && tool_ordering.front().wipe_tower_partitions > 0)
+            ! tool_ordering.empty() && tool_ordering.front().wipe_tower_partitions > 0) {
-            m_wipe_tower.reset(new WipeTowerIntegration(print.config, print.m_wipe_tower_tool_changes, *print.m_wipe_tower_final_purge.get()));
+            m_wipe_tower.reset(new WipeTowerIntegration(print.config, *print.m_wipe_tower_priming.get(), print.m_wipe_tower_tool_changes, *print.m_wipe_tower_final_purge.get()));
+			write(file, m_wipe_tower->prime(*this));
+        }
         // Extrude the layers.
         for (auto &layer : layers_to_print) {
             const ToolOrdering::LayerTools &layer_tools = tool_ordering.tools_for_layer(layer.first);
@@ -668,7 +697,7 @@ bool GCode::_do_export(Print &print, FILE *file)
     write(file, m_writer.set_fan(false));
     // Process filament-specific gcode in extruder order.
     for (const std::string &end_gcode : print.config.end_filament_gcode.values)
-        writeln(file, m_placeholder_parser.process(end_gcode, &end_gcode - &print.config.end_filament_gcode.values.front()));
+        writeln(file, m_placeholder_parser.process(end_gcode, (unsigned int)(&end_gcode - &print.config.end_filament_gcode.values.front())));
     writeln(file, m_placeholder_parser.process(print.config.end_gcode, m_writer.extruder()->id()));
     write(file, m_writer.update_progress(m_layer_count, m_layer_count, true)); // 100%
     write(file, m_writer.postamble());
@@ -1471,7 +1500,7 @@ std::string GCode::extrude_loop(ExtrusionLoop loop, std::string description, dou
     } else if (seam_position == spNearest || seam_position == spAligned || seam_position == spRear) {
         Polygon        polygon    = loop.polygon();
         const coordf_t nozzle_dmr = EXTRUDER_CONFIG(nozzle_diameter);
-        const coord_t  nozzle_r   = scale_(0.5*nozzle_dmr);
+        const coord_t  nozzle_r   = coord_t(scale_(0.5 * nozzle_dmr) + 0.5);
 
         // Retrieve the last start position for this object.
         float last_pos_weight = 1.f;
@@ -1524,11 +1553,11 @@ std::string GCode::extrude_loop(ExtrusionLoop loop, std::string description, dou
                 penalty = penaltyConvexVertex;
             else if (ccwAngle < 0.f) {
                 // Interpolate penalty between maximum and zero.
-                penalty = penaltyFlatSurface * bspline_kernel(ccwAngle * (PI * 2. / 3.));
+                penalty = penaltyFlatSurface * bspline_kernel(ccwAngle * float(PI * 2. / 3.));
             } else {
                 assert(ccwAngle >= 0.f);
                 // Interpolate penalty between maximum and the penalty for a convex vertex.
-                penalty = penaltyConvexVertex + (penaltyFlatSurface - penaltyConvexVertex) * bspline_kernel(ccwAngle * (PI * 2. / 3.));
+                penalty = penaltyConvexVertex + (penaltyFlatSurface - penaltyConvexVertex) * bspline_kernel(ccwAngle * float(PI * 2. / 3.));
             }
             // Give a negative penalty for points close to the last point or the prefered seam location.
             //float dist_to_last_pos_proj = last_pos_proj.distance_to(polygon.points[i]);
@@ -1543,8 +1572,8 @@ std::string GCode::extrude_loop(ExtrusionLoop loop, std::string description, dou
         // Penalty for overhangs.
         if (lower_layer_edge_grid && (*lower_layer_edge_grid)) {
             // Use the edge grid distance field structure over the lower layer to calculate overhangs.
-            coord_t nozzle_r = scale_(0.5*nozzle_dmr);
+            coord_t nozzle_r = coord_t(floor(scale_(0.5 * nozzle_dmr) + 0.5));
-            coord_t search_r = scale_(0.8*nozzle_dmr);
+            coord_t search_r = coord_t(floor(scale_(0.8 * nozzle_dmr) + 0.5));
             for (size_t i = 0; i < polygon.points.size(); ++ i) {
                 const Point &p = polygon.points[i];
                 coordf_t dist;
@@ -1555,7 +1584,7 @@ std::string GCode::extrude_loop(ExtrusionLoop loop, std::string description, dou
                 // If the approximate Signed Distance Field was initialized over lower_layer_edge_grid,
                 // then the signed distnace shall always be known.
                 assert(found);
-                penalties[i] += extrudate_overlap_penalty(nozzle_r, penaltyOverhangHalf, dist);
+                penalties[i] += extrudate_overlap_penalty(float(nozzle_r), penaltyOverhangHalf, float(dist));
             }
         }
 
@@ -1651,7 +1680,7 @@ std::string GCode::extrude_loop(ExtrusionLoop loop, std::string description, dou
     }
     
     // reset acceleration
-    gcode += m_writer.set_acceleration(m_config.default_acceleration.value);
+    gcode += m_writer.set_acceleration((unsigned int)(m_config.default_acceleration.value + 0.5));
     
     if (m_wipe.enable)
         m_wipe.path = paths.front().polyline;  // TODO: don't limit wipe to last path
@@ -1708,7 +1737,7 @@ std::string GCode::extrude_multi_path(ExtrusionMultiPath multipath, std::string
         m_wipe.path.reverse();
     }
     // reset acceleration
-    gcode += m_writer.set_acceleration(m_config.default_acceleration.value);
+    gcode += m_writer.set_acceleration((unsigned int)floor(m_config.default_acceleration.value + 0.5));
     return gcode;
 }
 

xs/src/libslic3r/GCode.hpp

@@ -77,16 +77,19 @@ class WipeTowerIntegration {
 public:
     WipeTowerIntegration(
         const PrintConfig                                           &print_config,
+        const WipeTower::ToolChangeResult                           &priming,
         const std::vector<std::vector<WipeTower::ToolChangeResult>> &tool_changes,
         const WipeTower::ToolChangeResult                           &final_purge) :
         m_left(float(print_config.wipe_tower_x.value)),
         m_right(float(print_config.wipe_tower_x.value + print_config.wipe_tower_width.value)),
+        m_priming(priming),
         m_tool_changes(tool_changes),
         m_final_purge(final_purge),
         m_layer_idx(-1),
         m_tool_change_idx(0),
         m_brim_done(false) {}
 
+    std::string prime(GCode &gcodegen);
     void next_layer() { ++ m_layer_idx; m_tool_change_idx = 0; }
     std::string tool_change(GCode &gcodegen, int extruder_id, bool finish_layer);
     std::string finalize(GCode &gcodegen);
@@ -99,6 +102,7 @@ private:
     const float                                                  m_left;
     const float                                                  m_right;
     // Reference to cached values at the Printer class.
+    const WipeTower::ToolChangeResult                           &m_priming;
     const std::vector<std::vector<WipeTower::ToolChangeResult>> &m_tool_changes;
     const WipeTower::ToolChangeResult                           &m_final_purge;
     // Current layer index.

xs/src/libslic3r/GCode/ToolOrdering.cpp

@@ -8,7 +8,7 @@ namespace Slic3r {
 
 // For the use case when each object is printed separately
 // (print.config.complete_objects is true).
-ToolOrdering::ToolOrdering(const PrintObject &object, unsigned int first_extruder)
+ToolOrdering::ToolOrdering(const PrintObject &object, unsigned int first_extruder, bool prime_multi_material)
 {
     if (object.layers.empty())
         return;
@@ -31,11 +31,13 @@ ToolOrdering::ToolOrdering(const PrintObject &object, unsigned int first_extrude
     this->reorder_extruders(first_extruder);
 
     this->fill_wipe_tower_partitions(object.print()->config, object.layers.front()->print_z - object.layers.front()->height);
+
+    this->collect_extruder_statistics(prime_multi_material);
 }
 
 // For the use case when all objects are printed at once.
 // (print.config.complete_objects is false).
-ToolOrdering::ToolOrdering(const Print &print, unsigned int first_extruder)
+ToolOrdering::ToolOrdering(const Print &print, unsigned int first_extruder, bool prime_multi_material)
 {
     // Initialize the print layers for all objects and all layers.
     coordf_t object_bottom_z = 0.;
@@ -61,22 +63,8 @@ ToolOrdering::ToolOrdering(const Print &print, unsigned int first_extruder)
     this->reorder_extruders(first_extruder);
 
     this->fill_wipe_tower_partitions(print.config, object_bottom_z);
-}
 
-unsigned int ToolOrdering::first_extruder() const
+    this->collect_extruder_statistics(prime_multi_material);
-{
-    for (const auto &lt : m_layer_tools)
-        if (! lt.extruders.empty())
-            return lt.extruders.front();
-    return (unsigned int)-1;
-}
-
-unsigned int ToolOrdering::last_extruder() const
-{
-    for (auto lt_it = m_layer_tools.rbegin(); lt_it != m_layer_tools.rend(); ++ lt_it)
-        if (! lt_it->extruders.empty())
-            return lt_it->extruders.back();
-    return (unsigned int)-1;
 }
 
 ToolOrdering::LayerTools&  ToolOrdering::tools_for_layer(coordf_t print_z)
@@ -289,4 +277,38 @@ void ToolOrdering::fill_wipe_tower_partitions(const PrintConfig &config, coordf_
         }
 }
 
+void ToolOrdering::collect_extruder_statistics(bool prime_multi_material)
+{
+    m_first_printing_extruder = (unsigned int)-1;
+    for (const auto &lt : m_layer_tools)
+        if (! lt.extruders.empty()) {
+            m_first_printing_extruder = lt.extruders.front();
+            break;
+        }
+
+    m_last_printing_extruder = (unsigned int)-1;
+    for (auto lt_it = m_layer_tools.rbegin(); lt_it != m_layer_tools.rend(); ++ lt_it)
+        if (! lt_it->extruders.empty()) {
+            m_last_printing_extruder = lt_it->extruders.back();
+            break;
+        }
+
+    m_all_printing_extruders.clear();
+    for (const auto &lt : m_layer_tools) {
+        append(m_all_printing_extruders, lt.extruders);
+        sort_remove_duplicates(m_all_printing_extruders);
+    }
+
+    if (prime_multi_material && ! m_all_printing_extruders.empty()) {
+        // Reorder m_all_printing_extruders in the sequence they will be primed, the last one will be m_first_printing_extruder.
+        // Then set m_first_printing_extruder to the 1st extruder primed.
+        m_all_printing_extruders.erase(
+            std::remove_if(m_all_printing_extruders.begin(), m_all_printing_extruders.end(), 
+                [ this ](const unsigned int eid) { return eid == m_first_printing_extruder; }),
+            m_all_printing_extruders.end());
+        m_all_printing_extruders.emplace_back(m_first_printing_extruder);
+        m_first_printing_extruder = m_all_printing_extruders.front();
+    }
+}
+
 } // namespace Slic3r

xs/src/libslic3r/GCode/ToolOrdering.hpp

@@ -45,19 +45,22 @@ public:
 
 	// For the use case when each object is printed separately
 	// (print.config.complete_objects is true).
-	ToolOrdering(const PrintObject &object, unsigned int first_extruder = (unsigned int)-1);
+	ToolOrdering(const PrintObject &object, unsigned int first_extruder = (unsigned int)-1, bool prime_multi_material = false);
 
 	// For the use case when all objects are printed at once.
 	// (print.config.complete_objects is false).
-	ToolOrdering(const Print &print, unsigned int first_extruder = (unsigned int)-1);
+	ToolOrdering(const Print &print, unsigned int first_extruder = (unsigned int)-1, bool prime_multi_material = false);
 
 	void 				clear() { m_layer_tools.clear(); }
 
 	// Get the first extruder printing the layer_tools, returns -1 if there is no layer printed.
-	unsigned int   		first_extruder() const;
+	unsigned int   		first_extruder() const { return m_first_printing_extruder; }
 
 	// Get the first extruder printing the layer_tools, returns -1 if there is no layer printed.
-	unsigned int   		last_extruder() const;
+	unsigned int   		last_extruder() const { return m_last_printing_extruder; }
+
+	// For a multi-material print, the printing extruders are ordered in the order they shall be primed.
+	std::vector<unsigned int> all_extruders() const { return m_all_printing_extruders; }
 
 	// Find LayerTools with the closest print_z.
 	LayerTools&			tools_for_layer(coordf_t print_z);
@@ -74,8 +77,15 @@ private:
 	void 				collect_extruders(const PrintObject &object);
 	void				reorder_extruders(unsigned int last_extruder_id);
 	void 				fill_wipe_tower_partitions(const PrintConfig &config, coordf_t object_bottom_z);
+	void 				collect_extruder_statistics(bool prime_multi_material);
 
-	std::vector<LayerTools> m_layer_tools;
+	std::vector<LayerTools> 	m_layer_tools;
+	// First printing extruder, including the multi-material priming sequence.
+	unsigned int 				m_first_printing_extruder;
+	// Final printing extruder.
+	unsigned int 				m_last_printing_extruder;
+	// All extruders, which extrude some material over m_layer_tools.
+    std::vector<unsigned int> 	m_all_printing_extruders;
 };
 
 } // namespace SLic3r

xs/src/libslic3r/GCode/WipeTower.hpp

@@ -89,11 +89,27 @@ public:
 		// Time elapsed over this tool change.
 		// This is useful not only for the print time estimation, but also for the control of layer cooling.
 		float  				    elapsed_time;
+
+		// Sum the total length of the extrusion.
+		float total_extrusion_length_in_plane() {
+			float e_length = 0.f;
+			for (size_t i = 1; i < this->extrusions.size(); ++ i) {
+				const Extrusion &e = this->extrusions[i];
+				if (e.width > 0) {
+					xy v = e.pos - (&e - 1)->pos;
+					e_length += sqrt(v.x*v.x+v.y*v.y);
+				}
+			}
+			return e_length;
+		}
 	};
 
+	// Returns gcode to prime the nozzles at the front edge of the print bed.
+	virtual ToolChangeResult prime(float first_layer_height, std::vector<unsigned int> tools, Purpose purpose = PURPOSE_MOVE_TO_TOWER_AND_EXTRUDE) = 0;
+
 	// Returns gcode for toolchange and the end position.
 	// if new_tool == -1, just unload the current filament over the wipe tower.
-	virtual ToolChangeResult tool_change(int new_tool, bool last_in_layer, Purpose purpose = PURPOSE_MOVE_TO_TOWER_AND_EXTRUDE) = 0;
+	virtual ToolChangeResult tool_change(unsigned int new_tool, bool last_in_layer, Purpose purpose = PURPOSE_MOVE_TO_TOWER_AND_EXTRUDE) = 0;
 
 	// Close the current wipe tower layer with a perimeter and possibly fill the unfilled space with a zig-zag.
 	// Call this method only if layer_finished() is false.

xs/src/libslic3r/GCode/WipeTowerPrusaMM.cpp

@@ -315,6 +315,29 @@ private:
 	Writer& operator=(const Writer &rhs);
 };
 
+/*
+class Material
+{
+public:
+	std::string 				name;
+	std::string 				type;
+
+	struct RammingStep {
+//		float length;
+		float extrusion_multiplier; // sirka linky
+		float extrusion;
+		float speed;
+	};
+	std::vector<RammingStep> 			ramming_sequence;
+
+	// Number and speed of the cooling moves.
+	std::vector<float>					cooling_moves;
+
+	// Percentage of the speed overide, in pairs of <z, percentage>
+	std::vector<std::pair<float, int>> 	speed_override;
+};
+*/
+
 } // namespace PrusaMultiMaterial
 
 WipeTowerPrusaMM::material_type WipeTowerPrusaMM::parse_material(const char *name)
@@ -340,7 +363,92 @@ WipeTowerPrusaMM::material_type WipeTowerPrusaMM::parse_material(const char *nam
 	return INVALID;
 }
 
-WipeTower::ToolChangeResult WipeTowerPrusaMM::tool_change(int tool, bool last_in_layer, Purpose purpose)
+// Returns gcode to prime the nozzles at the front edge of the print bed.
+WipeTower::ToolChangeResult WipeTowerPrusaMM::prime(float first_layer_height, std::vector<unsigned int> tools, Purpose purpose)
+{
+	this->set_layer(first_layer_height, first_layer_height, tools.size(), true, false);
+
+	float wipe_area = m_wipe_area;
+	// Calculate the amount of wipe over the wipe tower brim following the prime, decrease wipe_area
+	// with the amount of material extruded over the brim.
+	{
+		// Simulate the brim extrusions, summ the length of the extrusion.
+		float e_length = this->tool_change(0, false, PURPOSE_EXTRUDE).total_extrusion_length_in_plane();
+		// Shrink wipe_area by the amount of extrusion extruded by the finish_layer().
+		// Y stepping of the wipe extrusions.
+		float dy = m_perimeter_width * 0.8f;
+		// Number of whole wipe lines, that would be extruded to wipe as much material as the finish_layer().
+		// Minimum wipe area is 5mm wide.
+		//FIXME calculate the purge_lines_width precisely.
+		float purge_lines_width = 1.3f;
+		wipe_area = std::max(5.f, m_wipe_area - floor(e_length / m_wipe_tower_width) * dy - purge_lines_width);
+	}
+
+	this->set_layer(first_layer_height, first_layer_height, tools.size(), true, false);
+	this->m_num_layer_changes 	= 0;
+	this->m_current_tool 		= tools.front();
+
+	box_coordinates cleaning_box(xy(0.f, - 4.0f), m_wipe_tower_width, wipe_area);
+
+	PrusaMultiMaterial::Writer writer;
+	writer.set_extrusion_flow(m_extrusion_flow)
+		  .set_z(m_z_pos)
+		  .set_layer_height(m_layer_height)
+		  .set_initial_tool(m_current_tool)
+		  .append(";--------------------\n"
+			 	  "; CP PRIMING START\n")
+		  .append(";--------------------\n")
+		  .speed_override(100);
+
+	// Always move to the starting position.
+	writer.travel(cleaning_box.ld, 7200);
+	// Increase the extruder driver current to allow fast ramming.
+	writer.set_extruder_trimpot(750);
+
+	if (purpose == PURPOSE_EXTRUDE || purpose == PURPOSE_MOVE_TO_TOWER_AND_EXTRUDE) {
+		for (size_t idx_tool = 0; idx_tool < tools.size(); ++ idx_tool) {
+			unsigned int tool = tools[idx_tool];
+			// Select the tool, set a speed override for soluble and flex materials.
+			toolchange_Change(writer, tool, m_material[tool]);
+			// Prime the tool.
+			toolchange_Load(writer, cleaning_box);
+			if (idx_tool + 1 == tools.size()) {
+				// Last tool should not be unloaded, but it should be wiped enough to become of a pure color.
+				toolchange_Wipe(writer, cleaning_box);
+			} else {
+				// Ram the hot material out of the melt zone, retract the filament into the cooling tubes and let it cool.
+				toolchange_Unload(writer, cleaning_box, m_material[m_current_tool], m_first_layer_temperature[tool]);
+			    cleaning_box.translate(m_wipe_tower_width, 0.f);
+				writer.travel(cleaning_box.ld, 7200);
+			}
+		    ++ m_num_tool_changes;
+		}
+	}
+
+	// Reset the extruder current to a normal value.
+	writer.set_extruder_trimpot(550)
+		  .feedrate(6000)
+		  .flush_planner_queue()
+		  .reset_extruder()
+		  .append("; CP PRIMING END\n"
+	 		      ";------------------\n"
+				  "\n\n");
+
+	// Force m_idx_tool_change_in_layer to -1, so that tool_change() will know to extrude the wipe tower brim.
+	m_idx_tool_change_in_layer = (unsigned int)(-1);
+
+	ToolChangeResult result;
+	result.print_z 	  	= this->m_z_pos;
+	result.layer_height = this->m_layer_height;
+	result.gcode   	  	= writer.gcode();
+	result.elapsed_time = writer.elapsed_time();
+	result.extrusions 	= writer.extrusions();
+	result.start_pos  	= writer.start_pos();
+	result.end_pos 	  	= writer.pos();
+	return result;
+}
+
+WipeTower::ToolChangeResult WipeTowerPrusaMM::tool_change(unsigned int tool, bool last_in_layer, Purpose purpose)
 {
 	// Either it is the last tool unload,
 	// or there must be a nonzero wipe tower partitions available.
@@ -363,14 +471,7 @@ WipeTower::ToolChangeResult WipeTowerPrusaMM::tool_change(int tool, bool last_in
 				unsigned int old_idx_tool_change = m_idx_tool_change_in_layer;
 			    float old_wipe_start_y = m_current_wipe_start_y;
 			    m_current_wipe_start_y += wipe_area;
-				ToolChangeResult tcr = this->finish_layer(PURPOSE_EXTRUDE);
+				e_length = this->finish_layer(PURPOSE_EXTRUDE).total_extrusion_length_in_plane();
-				for (size_t i = 1; i < tcr.extrusions.size(); ++ i) {
-					const Extrusion &e = tcr.extrusions[i];
-					if (e.width > 0) {
-						xy v = e.pos - (&e - 1)->pos;
-						e_length += sqrt(v.x*v.x+v.y*v.y);
-					}
-				}
 				m_idx_tool_change_in_layer = old_idx_tool_change;
 				m_current_wipe_start_y = old_wipe_start_y;
 			}
@@ -431,10 +532,10 @@ WipeTower::ToolChangeResult WipeTowerPrusaMM::tool_change(int tool, bool last_in
 		// Increase the extruder driver current to allow fast ramming.
 		writer.set_extruder_trimpot(750);
 		// Ram the hot material out of the melt zone, retract the filament into the cooling tubes and let it cool.
-		toolchange_Unload(writer, cleaning_box, m_material[m_current_tool],
-			m_is_first_layer ? m_first_layer_temperature[tool]  : m_temperature[tool]);
 
-		if (tool >= 0) {
+		if (tool != (unsigned int)-1) {
+			toolchange_Unload(writer, cleaning_box, m_material[m_current_tool],
+				m_is_first_layer ? m_first_layer_temperature[tool] : m_temperature[tool]);
 			// This is not the last change.
 			// Change the tool, set a speed override for soluble and flex materials.
 			toolchange_Change(writer, tool, m_material[tool]);
@@ -455,7 +556,8 @@ WipeTower::ToolChangeResult WipeTowerPrusaMM::tool_change(int tool, bool last_in
 			if (purpose == PURPOSE_MOVE_TO_TOWER_AND_EXTRUDE)
 				writer.travel(box.ru, 7200)
 			  		  .travel(box.lu);
-		}
+		} else
+			toolchange_Unload(writer, cleaning_box, m_material[m_current_tool], m_temperature[m_current_tool]);
 
 		// Reset the extruder current to a normal value.
 		writer.set_extruder_trimpot(550)
@@ -587,24 +689,27 @@ void WipeTowerPrusaMM::toolchange_Unload(
 	{
 	case ABS:
    		// ramming          start                    end                  y increment     amount feedrate
-		writer.ram(xl + m_perimeter_width * 2, xr - m_perimeter_width,     y_step * 0.2f, 0,  1.2f * e,  4000)
+		writer.ram(xl + m_perimeter_width * 2, xr - m_perimeter_width,     y_step * 0.2f, 0,  1.2f  * e, 4000)
-			  .ram(xr - m_perimeter_width,     xl + m_perimeter_width,     y_step * 1.2f, e0, 1.6f * e,  4600)
+			  .ram(xr - m_perimeter_width,     xl + m_perimeter_width,     y_step * 1.2f, e0, 1.6f  * e, 4600)
-			  .ram(xl + m_perimeter_width * 2, xr - m_perimeter_width * 2, y_step * 1.2f, e0, 1.8f * e,  5000)
+			  .ram(xl + m_perimeter_width * 2, xr - m_perimeter_width * 2, y_step * 1.2f, e0, 1.8f  * e, 5000)
-			  .ram(xr - m_perimeter_width * 2, xl + m_perimeter_width * 2, y_step * 1.2f, e0, 1.8f * e,  5000);
+			  .ram(xr - m_perimeter_width * 2, xl + m_perimeter_width * 2, y_step * 1.2f, e0, 1.8f  * e, 5000);
 		break;
 	case PVA:
-		writer.ram(xl + m_perimeter_width * 2, xr - m_perimeter_width,     y_step * 0.2f, 0,  3,     4000)
+		// Used for the PrimaSelect PVA
-			  .ram(xr - m_perimeter_width,     xl + m_perimeter_width,     y_step * 1.5f, 0,  3,     4500)
+		writer.ram(xl + m_perimeter_width * 2, xr - m_perimeter_width,     y_step * 0.2f, 0,  1.75f * e, 4000)
-			  .ram(xl + m_perimeter_width * 2, xr - m_perimeter_width * 2, y_step * 1.5f, 0,  3,     4800)
+			  .ram(xr - m_perimeter_width,     xl + m_perimeter_width,     y_step * 1.5f, 0,  1.75f * e, 4500)
-			  .ram(xr - m_perimeter_width,     xl + m_perimeter_width,     y_step * 1.5f, 0,  3,     5000);
+			  .ram(xl + m_perimeter_width * 2, xr - m_perimeter_width * 2, y_step * 1.5f, 0,  1.75f * e, 4800)
+			  .ram(xr - m_perimeter_width,     xl + m_perimeter_width,     y_step * 1.5f, 0,  1.75f * e, 5000);
 		break;
 	case SCAFF:
-		writer.ram(xl + m_perimeter_width * 2, xr - m_perimeter_width,     y_step * 2.f,  0,  3,     4000)
+		writer.ram(xl + m_perimeter_width * 2, xr - m_perimeter_width,     y_step * 2.f,  0,  1.75f * e, 4000)
-			  .ram(xr - m_perimeter_width,     xl + m_perimeter_width,     y_step * 3.f,  0,  4,     4600)
+			  .ram(xr - m_perimeter_width,     xl + m_perimeter_width,     y_step * 3.f,  0,  2.34f * e, 4600)
-			  .ram(xl + m_perimeter_width * 2, xr - m_perimeter_width * 2, y_step * 3.f,  0,  4.5,   5200);
+			  .ram(xl + m_perimeter_width * 2, xr - m_perimeter_width * 2, y_step * 3.f,  0,  2.63f * e, 5200);
 		break;
 	default:
-		writer.ram(xl + m_perimeter_width * 2, xr - m_perimeter_width,     y_step * 0.2f, 0,  1.6f  * e, 4000)
+		// PLA, PLA/PHA and others
+		// Used for the Verbatim BVOH, PET, NGEN, co-polyesters
+		writer.ram(xl + m_perimeter_width * 2, xr - m_perimeter_width,     y_step * 0.2f, 0,  1.60f * e, 4000)
 			  .ram(xr - m_perimeter_width,     xl + m_perimeter_width,     y_step * 1.2f, e0, 1.65f * e, 4600)
 			  .ram(xl + m_perimeter_width * 2, xr - m_perimeter_width * 2, y_step * 1.2f, e0, 1.74f * e, 5200);
 	}
@@ -624,12 +729,6 @@ void WipeTowerPrusaMM::toolchange_Unload(
 		  .suppress_preview();
 	switch (current_material)
 	{
-	case ABS:
-		writer.cool(xl, xr, 3, -5, 1600)
-			  .cool(xl, xr, 5, -5, 2000)
-			  .cool(xl, xr, 5, -5, 2400)
-			  .cool(xl, xr, 5, -3, 2400);
-		break;
 	case PVA:
 		writer.cool(xl, xr, 3, -5, 1600)
 			  .cool(xl, xr, 5, -5, 2000)
@@ -659,8 +758,8 @@ void WipeTowerPrusaMM::toolchange_Unload(
 // Change the tool, set a speed override for solube and flex materials.
 void WipeTowerPrusaMM::toolchange_Change(
 	PrusaMultiMaterial::Writer &writer,
-	const int 		new_tool, 
+	const unsigned int 	new_tool, 
-	material_type 	new_material)
+	material_type 		new_material)
 {
 	// Speed override for the material. Go slow for flex and soluble materials.
 	int speed_override;
@@ -687,8 +786,11 @@ void WipeTowerPrusaMM::toolchange_Load(
 	// Load the filament while moving left / right,
 	// so the excess material will not create a blob at a single position.
 		  .suppress_preview()
+		  // Accelerate the filament loading
 		  .load_move_x(xr, 20, 1400)
+		  // Fast loading phase
 		  .load_move_x(xl, 40, 3000)
+		  // Slowing down
 		  .load_move_x(xr, 20, 1600)
 		  .load_move_x(xl, 10, 1000)
 		  .resume_preview();

xs/src/libslic3r/GCode/WipeTowerPrusaMM.hpp

@@ -107,9 +107,12 @@ public:
 	// The wipe tower is finished, there should be no more tool changes or wipe tower prints.
 	virtual bool 	  		 finished() const { return m_max_color_changes == 0; }
 
+	// Returns gcode to prime the nozzles at the front edge of the print bed.
+	virtual ToolChangeResult prime(float first_layer_height, std::vector<unsigned int> tools, Purpose purpose = PURPOSE_MOVE_TO_TOWER_AND_EXTRUDE);
+
 	// Returns gcode for a toolchange and a final print head position.
 	// On the first layer, extrude a brim around the future wipe tower first.
-	virtual ToolChangeResult tool_change(int new_tool, bool last_in_layer, Purpose purpose);
+	virtual ToolChangeResult tool_change(unsigned int new_tool, bool last_in_layer, Purpose purpose);
 
 	// Close the current wipe tower layer with a perimeter and possibly fill the unfilled space with a zig-zag.
 	// Call this method only if layer_finished() is false.
@@ -218,7 +221,7 @@ private:
 
 	void toolchange_Change(
 		PrusaMultiMaterial::Writer &writer,
-		int 					new_tool,
+		const unsigned int		new_tool,
 		material_type 			new_material);
 	
 	void toolchange_Load(

xs/src/libslic3r/Print.cpp

@@ -54,6 +54,10 @@ void Print::reload_object(size_t /* idx */)
         this->add_model_object(mo);
 }
 
+// Reloads the model instances into the print class.
+// The slicing shall not be running as the modified model instances at the print
+// are used for the brim & skirt calculation.
+// Returns true if the brim or skirt have been invalidated.
 bool Print::reload_model_instances()
 {
     bool invalidated = false;
@@ -461,7 +465,7 @@ bool Print::apply_config(DynamicPrintConfig config)
                         if (region_id < object->region_volumes.size() && ! object->region_volumes[region_id].empty())
                             invalidated |= object->invalidate_state_by_config_options(diff);
                 }
-                other_region_configs.emplace_back(this_region_config);
+                other_region_configs.emplace_back(std::move(this_region_config));
             }
         }
     }
@@ -953,6 +957,7 @@ bool Print::has_wipe_tower() const
 void Print::_clear_wipe_tower()
 {
     m_tool_ordering.clear();
+    m_wipe_tower_priming.reset(nullptr);
     m_wipe_tower_tool_changes.clear();
     m_wipe_tower_final_purge.reset(nullptr);
 }
@@ -963,7 +968,8 @@ void Print::_make_wipe_tower()
     if (! this->has_wipe_tower())
         return;
 
-    m_tool_ordering = ToolOrdering(*this, (unsigned int)-1);
+    // Let the ToolOrdering class know there will be initial priming extrusions at the start of the print.
+    m_tool_ordering = ToolOrdering(*this, (unsigned int)-1, true);
     unsigned int initial_extruder_id = m_tool_ordering.first_extruder();
     if (initial_extruder_id == (unsigned int)-1 || m_tool_ordering.front().wipe_tower_partitions == 0)
         // Don't generate any wipe tower.
@@ -977,7 +983,6 @@ void Print::_make_wipe_tower()
     
     //wipe_tower.set_retract();
     //wipe_tower.set_zhop();
-    //wipe_tower.set_zhop();
 
     // Set the extruder & material properties at the wipe tower object.
     for (size_t i = 0; i < 4; ++ i)
@@ -987,6 +992,9 @@ void Print::_make_wipe_tower()
             this->config.temperature.get_at(i),
             this->config.first_layer_temperature.get_at(i));
 
+    m_wipe_tower_priming = Slic3r::make_unique<WipeTower::ToolChangeResult>(
+        wipe_tower.prime(this->skirt_first_layer_height(), m_tool_ordering.all_extruders(), WipeTower::PURPOSE_EXTRUDE));
+
     // Generate the wipe tower layers.
     m_wipe_tower_tool_changes.reserve(m_tool_ordering.layer_tools().size());
     unsigned int current_extruder_id = initial_extruder_id;
@@ -1048,7 +1056,7 @@ void Print::_make_wipe_tower()
         wipe_tower.set_layer(float(m_tool_ordering.back().print_z), float(layer_height), 0, false, true);
     }
     m_wipe_tower_final_purge = Slic3r::make_unique<WipeTower::ToolChangeResult>(
-        wipe_tower.tool_change(-1, false, WipeTower::PURPOSE_EXTRUDE));
+		wipe_tower.tool_change((unsigned int)-1, false, WipeTower::PURPOSE_EXTRUDE));
 }
 
 std::string Print::output_filename()
@@ -1080,4 +1088,9 @@ std::string Print::output_filepath(const std::string &path)
     return path;
 }
 
+void Print::set_status(int percent, const std::string &message)
+{
+    printf("Print::status %d => %s\n", percent, message.c_str());
+}
+
 }

xs/src/libslic3r/Print.hpp

@@ -16,6 +16,8 @@
 #include "GCode/ToolOrdering.hpp"
 #include "GCode/WipeTower.hpp"
 
+#include "tbb/atomic.h"
+
 namespace Slic3r {
 
 class Print;
@@ -125,9 +127,9 @@ public:
     // Slic3r::Point objects in scaled G-code coordinates in our coordinates
     Points _shifted_copies;
 
-    LayerPtrs layers;
+    LayerPtrs                               layers;
-    SupportLayerPtrs support_layers;
+    SupportLayerPtrs                        support_layers;
-    PrintState<PrintObjectStep, posCount> state;
+    PrintState<PrintObjectStep, posCount>   state;
 
     Print*              print()                 { return this->_print; }
     const Print*        print() const           { return this->_print; }
@@ -231,14 +233,14 @@ public:
     PrintRegionPtrs regions;
     PlaceholderParser placeholder_parser;
     // TODO: status_cb
-    double total_used_filament, total_extruded_volume, total_cost, total_weight;
+    double                          total_used_filament, total_extruded_volume, total_cost, total_weight;
-    std::map<size_t,float> filament_stats;
+    std::map<size_t,float>          filament_stats;
-    PrintState<PrintStep, psCount> state;
+    PrintState<PrintStep, psCount>  state;
 
     // ordered collections of extrusion paths to build skirt loops and brim
     ExtrusionEntityCollection skirt, brim;
 
-    Print() : total_used_filament(0), total_extruded_volume(0) {}
+    Print() : total_used_filament(0), total_extruded_volume(0) { restart(); }
     ~Print() { clear_objects(); }
     
     // methods for handling objects
@@ -291,15 +293,28 @@ public:
     // Cache it here, so it does not need to be recalculated during the G-code generation.
     ToolOrdering m_tool_ordering;
     // Cache of tool changes per print layer.
+    std::unique_ptr<WipeTower::ToolChangeResult>          m_wipe_tower_priming;
     std::vector<std::vector<WipeTower::ToolChangeResult>> m_wipe_tower_tool_changes;
     std::unique_ptr<WipeTower::ToolChangeResult>          m_wipe_tower_final_purge;
 
     std::string output_filename();
     std::string output_filepath(const std::string &path);
 
+    // Calls a registered callback to update the status.
+    void set_status(int percent, const std::string &message);
+    // Cancel the running computation. Stop execution of all the background threads.
+    void cancel() { m_canceled = true; }
+    // Cancel the running computation. Stop execution of all the background threads.
+    void restart() { m_canceled = false; }
+    // Has the calculation been canceled?
+    bool canceled() { return m_canceled; }
+    
 private:
     bool invalidate_state_by_config_options(const std::vector<t_config_option_key> &opt_keys);
     PrintRegionConfig _region_config_from_model_volume(const ModelVolume &volume);
+
+    // Has the calculation been canceled?
+    tbb::atomic<bool>   m_canceled;
 };
 
 #define FOREACH_BASE(type, container, iterator) for (type::const_iterator iterator = (container).begin(); iterator != (container).end(); ++iterator)

xs/src/slic3r/GUI/3DScene.cpp

@@ -969,16 +969,23 @@ void _3DScene::_load_wipe_tower_toolpaths(
         const float*                 color_tool(size_t tool) const { return tool_colors->data() + tool * 4; }
         int                          volume_idx(int tool, int feature) const 
             { return this->color_by_tool() ? std::min<int>(this->number_tools() - 1, std::max<int>(tool, 0)) : feature; }
+
+        const std::vector<WipeTower::ToolChangeResult>& tool_change(size_t idx) 
+            { return (idx == 0) ? priming : (idx == print->m_wipe_tower_tool_changes.size() + 1) ? final : print->m_wipe_tower_tool_changes[idx - 1]; }
+        std::vector<WipeTower::ToolChangeResult> priming;
+        std::vector<WipeTower::ToolChangeResult> final;
     } ctxt;
 
     ctxt.print          = print;
     ctxt.tool_colors    = tool_colors.empty() ? nullptr : &tool_colors;
+    ctxt.priming.emplace_back(*print->m_wipe_tower_priming.get());
+    ctxt.final.emplace_back(*print->m_wipe_tower_final_purge.get());
     
     BOOST_LOG_TRIVIAL(debug) << "Loading wipe tower toolpaths in parallel - start";
 
     //FIXME Improve the heuristics for a grain size.
-    size_t          n_layers   = print->m_wipe_tower_tool_changes.size();
+    size_t          n_items    = print->m_wipe_tower_tool_changes.size() + 1;
-    size_t          grain_size = std::max(n_layers / 128, size_t(1));
+    size_t          grain_size = std::max(n_items / 128, size_t(1));
     tbb::spin_mutex new_volume_mutex;
     auto            new_volume = [volumes, &new_volume_mutex](const float *color) -> GLVolume* {
         auto *volume = new GLVolume(color);
@@ -988,21 +995,21 @@ void _3DScene::_load_wipe_tower_toolpaths(
         return volume;
     };
     const size_t   volumes_cnt_initial = volumes->volumes.size();
-    std::vector<GLVolumeCollection> volumes_per_thread(n_layers);
+    std::vector<GLVolumeCollection> volumes_per_thread(n_items);
     tbb::parallel_for(
-        tbb::blocked_range<size_t>(0, n_layers, grain_size),
+        tbb::blocked_range<size_t>(0, n_items, grain_size),
         [&ctxt, &new_volume](const tbb::blocked_range<size_t>& range) {
             // Bounding box of this slab of a wipe tower.
             BoundingBoxf3 bbox;
             bbox.min = Pointf3(
                 ctxt.print->config.wipe_tower_x.value - 10.,
                 ctxt.print->config.wipe_tower_y.value - 10., 
-                ctxt.print->m_wipe_tower_tool_changes[range.begin()].front().print_z - 3.);
+                ctxt.tool_change(range.begin()).front().print_z - 3.);
             bbox.max = Pointf3(
                 ctxt.print->config.wipe_tower_x.value + ctxt.print->config.wipe_tower_width.value + 10.,
                 ctxt.print->config.wipe_tower_y.value + ctxt.print->config.wipe_tower_per_color_wipe.value * 
                     ctxt.print->m_tool_ordering.layer_tools()[range.begin()].wipe_tower_partitions + 10., 
-                ctxt.print->m_wipe_tower_tool_changes[range.end() - 1].front().print_z + 0.1);
+                ctxt.tool_change(range.end() - 1).front().print_z + 0.1);
             std::vector<GLVolume*> vols;
             if (ctxt.color_by_tool()) {
                 for (size_t i = 0; i < ctxt.number_tools(); ++ i)
@@ -1015,7 +1022,7 @@ void _3DScene::_load_wipe_tower_toolpaths(
                 volume.indexed_vertex_array.reserve(ctxt.alloc_size_reserve());
             }
             for (size_t idx_layer = range.begin(); idx_layer < range.end(); ++ idx_layer) {
-                const std::vector<WipeTower::ToolChangeResult> &layer = ctxt.print->m_wipe_tower_tool_changes[idx_layer];
+                const std::vector<WipeTower::ToolChangeResult> &layer = ctxt.tool_change(idx_layer);
                 for (size_t i = 0; i < vols.size(); ++ i) {
                     GLVolume &vol = *vols[i];
                     if (vol.print_zs.empty() || vol.print_zs.back() != layer.front().print_z) {

xs/src/xsinit.h

@@ -31,6 +31,7 @@
 #undef socketpair
 #undef recvfrom
 #undef sendto
+#undef pause
 
 // these need to be included early for Win32 (listing it in Build.PL is not enough)
 #include <ostream>