Set a minimum length on extrusion. Also improve the comment with the …

…type of extrusion.

resources/ui_layout/printer_fff.ui

@@ -20,6 +20,7 @@ group:Advanced
 	setting:use_relative_e_distances
 	setting:use_firmware_retraction
 	setting:use_volumetric_e
+	setting:min_length
 	setting:variable_layer_height
 
 page:Custom G-code:cog

src/libslic3r/GCode.cpp

@@ -3540,11 +3540,59 @@ void GCode::use(const ExtrusionEntityCollection &collection) {
     }
 }
 
+std::string extrusion_role_2_string(const ExtrusionRole &er) {
+    switch (er) {
+        case erNone: return " none";
+        case erPerimeter: return " perimeter";
+        case erExternalPerimeter: return " external_perimeter";
+        case erOverhangPerimeter: return " overhang_perimeter";
+        case erInternalInfill: return " internal_infill";
+        case erSolidInfill: return " solid_infill";
+        case erTopSolidInfill: return " top_solid_infill";
+        case erBridgeInfill: return " bridge_infill";
+        case erThinWall: return " thin_wall";
+        case erGapFill: return " gap_fill";
+        case erSkirt: return " skirt";
+        case erSupportMaterial: return " support_material";
+        case erSupportMaterialInterface: return " support_material_interface";
+        case erWipeTower: return " wipe_tower";
+        case erMilling: return " milling";
+        case erCustom: return " custom";
+        case erMixed: return " mixed";
+        case erCount: return " count";
+    }
+    return " unkown";
+}
+
 std::string GCode::extrude_path(const ExtrusionPath &path, const std::string &description, double speed) {
-    //    description += ExtrusionRole2String(path.role());
+
+    std::string descr = extrusion_role_2_string(path.role());
     ExtrusionPath simplifed_path = path;
-    simplifed_path.simplify(SCALED_RESOLUTION);
-    std::string gcode = this->_extrude(simplifed_path, description, speed);
+    if (this->config().min_length.value != 0 && !m_last_too_small.empty()) {
+        //descr += " trys fusion " + std::to_string(unscaled(m_last_too_small.last_point().x())) + " , " + std::to_string(unscaled(path.first_point().x()));
+        //ensure that it's a continous thing
+        if (m_last_too_small.last_point().distance_to_square(path.first_point()) < scale_(this->config().min_length)) {
+            //descr += " ! fusion " + std::to_string(simplifed_path.polyline.points.size());
+            simplifed_path.height = (m_last_too_small.height * m_last_too_small.length() + path.height * path.length()) / (m_last_too_small.length() + path.length());
+            simplifed_path.mm3_per_mm = (m_last_too_small.mm3_per_mm * m_last_too_small.length() + path.mm3_per_mm * path.length()) / (m_last_too_small.length() + path.length());
+            simplifed_path.polyline.points.insert(simplifed_path.polyline.points.begin(), m_last_too_small.polyline.points.begin(), m_last_too_small.polyline.points.end()-1);
+        }
+        m_last_too_small.polyline.points.clear();
+    }
+    simplifed_path.simplify(this->config().min_length.value != 0 ? scale_(this->config().min_length) : SCALED_RESOLUTION);
+    if (this->config().min_length.value != 0 && simplifed_path.length() < scale_(this->config().min_length)) {
+        m_last_too_small = simplifed_path;
+        return "";
+            //"; "+ descr+" .... too small for extrude: "+std::to_string(simplifed_path.length())+" < "+ std::to_string(scale_(this->config().min_length))
+            //+ " ; " + std::to_string(unscaled(path.first_point().x())) + " : " + std::to_string(unscaled(path.last_point().x()))
+            //+" =;=> " + std::to_string(unscaled(simplifed_path.first_point().x())) + " : " + std::to_string(unscaled(simplifed_path.last_point().x()))
+            //+ "\n";
+    }
+
+    std::string gcode = this->_extrude(simplifed_path, description + descr, speed);
+
+    //gcode += " ; " + std::to_string(unscaled(path.first_point().x())) + " : " + std::to_string(unscaled(path.last_point().x()));
+    //gcode += " =;=> " + std::to_string(unscaled(simplifed_path.first_point().x())) + " : " + std::to_string(unscaled(simplifed_path.last_point().x()));
 
     if (m_wipe.enable) {
         m_wipe.path = std::move(simplifed_path.polyline);
@@ -3556,9 +3604,9 @@ std::string GCode::extrude_path(const ExtrusionPath &path, const std::string &de
 }
 
 std::string GCode::extrude_path_3D(const ExtrusionPath3D &path, const std::string &description, double speed) {
-    //    description += ExtrusionRole2String(path.role());
+    std::string descr = extrusion_role_2_string(path.role());
     //path.simplify(SCALED_RESOLUTION);
-    std::string gcode = this->_before_extrude(path, description, speed);
+    std::string gcode = this->_before_extrude(path, description + descr, speed);
 
     // calculate extrusion length per distance unit
     double e_per_mm = path.mm3_per_mm

src/libslic3r/GCode.hpp

@@ -161,7 +161,8 @@ class GCode : ExtrusionVisitorConst {
         m_normal_time_estimator(GCodeTimeEstimator::Normal),
         m_silent_time_estimator(GCodeTimeEstimator::Silent),
         m_silent_time_estimator_enabled(false),
-        m_last_obj_copy(nullptr, Point(std::numeric_limits<coord_t>::max(), std::numeric_limits<coord_t>::max()))
+        m_last_obj_copy(nullptr, Point(std::numeric_limits<coord_t>::max(), std::numeric_limits<coord_t>::max())),
+        m_last_too_small(ExtrusionRole::erNone)
         {}
     ~GCode() {}
 
@@ -380,6 +381,9 @@ class GCode : ExtrusionVisitorConst {
     Point                               m_last_pos;
     bool                                m_last_pos_defined;
 
+    // a previous extrusion path that is too small to be extruded, have to fusion it into the next call.
+    ExtrusionPath                       m_last_too_small;
+
     std::unique_ptr<CoolingBuffer>      m_cooling_buffer;
     std::unique_ptr<SpiralVase>         m_spiral_vase;
 #ifdef HAS_PRESSURE_EQUALIZER

src/libslic3r/PrintConfig.cpp

@@ -2061,6 +2061,16 @@ void PrintConfigDef::init_fff_params()
     def->mode = comSimple;
     def->set_default_value(new ConfigOptionFloats { 0.07 });
 
+    def = this->add("min_length", coFloat);
+    def->label = L("minimum extrusion length");
+    def->category = OptionCategory::speed;
+    def->tooltip = L("Too many too small commands may overload the firmware / connection. Put a higher value here if you see strange slowdown."
+                     "\n0 to disable.");
+    def->sidetext = L("mm");
+    def->min = 0;
+    def->mode = comExpert;
+    def->set_default_value(new ConfigOptionFloat(0.035));
+
     def = this->add("min_width_top_surface", coFloatOrPercent);
     def->label = L("minimum top width for infill");
     def->category = OptionCategory::speed;

src/libslic3r/PrintConfig.hpp

@@ -886,11 +886,12 @@ class GCodeConfig : public StaticPrintConfig
     ConfigOptionString              feature_gcode;
     ConfigOptionFloat               max_print_speed;
     ConfigOptionFloat               max_volumetric_speed;
-    ConfigOptionFloats              milling_z_lift;
 #ifdef HAS_PRESSURE_EQUALIZER
     ConfigOptionFloat               max_volumetric_extrusion_rate_slope_positive;
     ConfigOptionFloat               max_volumetric_extrusion_rate_slope_negative;
 #endif
+    ConfigOptionFloats              milling_z_lift;
+    ConfigOptionFloat               min_length;
     ConfigOptionPercents            retract_before_wipe;
     ConfigOptionFloats              retract_length;
     ConfigOptionFloats              retract_length_toolchange;
@@ -983,6 +984,7 @@ class GCodeConfig : public StaticPrintConfig
         OPT_PTR(max_print_speed);
         OPT_PTR(max_volumetric_speed);
         OPT_PTR(milling_z_lift);
+        OPT_PTR(min_length);
 #ifdef HAS_PRESSURE_EQUALIZER
         OPT_PTR(max_volumetric_extrusion_rate_slope_positive);
         OPT_PTR(max_volumetric_extrusion_rate_slope_negative);

src/slic3r/GUI/Preset.cpp

@@ -596,6 +596,7 @@ const std::vector<std::string>& Preset::printer_options()
             "printer_technology",
             "bed_shape", "bed_custom_texture", "bed_custom_model", "z_offset", "gcode_flavor", "use_relative_e_distances", "serial_port", "serial_speed",
             "use_firmware_retraction", "use_volumetric_e", "variable_layer_height",
+            "min_length",
             "host_type", "print_host", "printhost_apikey", "printhost_cafile",
             "single_extruder_multi_material", "start_gcode", "end_gcode", "before_layer_gcode", "layer_gcode", "toolchange_gcode",
             "feature_gcode",