ENH: Polynomial fitting via Gaussian regression for determining the filament_max_volumetric_speed

Jira: none
Change-Id: Iab1ef65f0546884c60d2a9e39213a07d76a1f483
(cherry picked from commit 186948cc91b12d547b7168104ba629d40c333d1b)

src/libslic3r/GCode.cpp

@@ -5797,6 +5797,28 @@ bool GCode::_needSAFC(const ExtrusionPath &path)
     });
 }
 
+double GCode::calc_max_volumetric_speed(const double layer_height, const double line_width, const std::string co_str)
+{
+    std::vector<double> cs;
+    std::stringstream   ss(co_str);
+    std::string         token;
+
+    while (std::getline(ss, token, ';')) {
+        try {
+            cs.push_back(std::stod(token));
+        } catch (...) {
+            std::cerr << "Transformation failed: " << token << std::endl;
+        }
+    }
+    if (cs.size() != 6 || std::all_of(cs.begin(), cs.end(), [](double v) { return v == 0; })) return std::numeric_limits<double>::max();
+
+    const double x = layer_height;
+    const double y = line_width;
+
+    double res = cs[0] * x * x + cs[1] * y * y + cs[2] * x * y + cs[3] * x + cs[4] * y + cs[5];
+    return res;
+}
+
 std::string GCode::_extrude(const ExtrusionPath &path, std::string description, double speed)
 {
     std::string gcode;
@@ -5959,8 +5981,10 @@ std::string GCode::_extrude(const ExtrusionPath &path, std::string description,
         }
     }
     //BBS: if not set the speed, then use the filament_max_volumetric_speed directly
+    double filament_max_volumetric_speed = calc_max_volumetric_speed(path.height, path.width, FILAMENT_CONFIG(volumetric_speed_coefficients));
+    filament_max_volumetric_speed        = std::min(filament_max_volumetric_speed, FILAMENT_CONFIG(filament_max_volumetric_speed));
     if (speed == 0)
-        speed = FILAMENT_CONFIG(filament_max_volumetric_speed) / _mm3_per_mm;
+        speed = filament_max_volumetric_speed / _mm3_per_mm;
     if (this->on_first_layer()) {
         //BBS: for solid infill of initial layer, speed can be higher as long as
         //wall lines have be attached

src/libslic3r/GCode.hpp

@@ -634,6 +634,7 @@ private:
     int get_bed_temperature(const int extruder_id, const bool is_first_layer, const BedType bed_type) const;
     int get_highest_bed_temperature(const bool is_first_layer,const Print &print) const;
 
+    double      calc_max_volumetric_speed(const double layer_height, const double line_width, const std::string co_str);
     std::string _extrude(const ExtrusionPath &path, std::string description = "", double speed = -1);
     bool _needSAFC(const ExtrusionPath &path);
     void print_machine_envelope(GCodeOutputStream& file, Print& print, int extruder_id);

src/libslic3r/Preset.cpp

@@ -947,7 +947,7 @@ static std::vector<std::string> s_Preset_print_options {
      "interlocking_beam", "interlocking_orientation", "interlocking_beam_layer_count", "interlocking_depth", "interlocking_boundary_avoidance", "interlocking_beam_width","calib_flowrate_topinfill_special_order",
 };
 
-static std::vector<std::string> s_Preset_filament_options {/*"filament_colour", */ "default_filament_colour", "required_nozzle_HRC", "filament_diameter", "pellet_flow_coefficient", "filament_type",
+static std::vector<std::string> s_Preset_filament_options {/*"filament_colour", */ "default_filament_colour", "required_nozzle_HRC", "filament_diameter", "pellet_flow_coefficient", "volumetric_speed_coefficients", "filament_type",
                                                           "filament_soluble", "filament_is_support", "filament_printable",
     "filament_max_volumetric_speed",
     "filament_flow_ratio", "filament_density", "filament_adhesiveness_category", "filament_cost", "filament_minimal_purge_on_wipe_tower",

src/libslic3r/Print.cpp

@@ -130,6 +130,7 @@ bool Print::invalidate_state_by_config_options(const ConfigOptionResolver & /* n
         "filament_colour",
         "default_filament_colour",
         "filament_diameter",
+         "volumetric_speed_coefficients",
         "filament_density",
         "filament_cost",
         "filament_notes",

src/libslic3r/PrintConfig.cpp

@@ -2320,6 +2320,10 @@ void PrintConfigDef::init_fff_params()
     def->min = 0;
     def->set_default_value(new ConfigOptionFloats{ 0.4157 });
 
+    def        = this->add("volumetric_speed_coefficients", coStrings);
+    def->label = L("Max volumetric speed multinomial coefficients");
+    def->set_default_value(new ConfigOptionStrings{""});
+
     def = this->add("filament_shrink", coPercents);
     def->label = L("Shrinkage (XY)");
     // xgettext:no-c-format, no-boost-format
@@ -6521,7 +6525,7 @@ void PrintConfigDef::init_extruder_option_keys()
 void PrintConfigDef::init_filament_option_keys()
 {
     m_filament_option_keys = {
-        "filament_diameter", "min_layer_height", "max_layer_height",
+        "filament_diameter", "min_layer_height", "max_layer_height","volumetric_speed_coefficients",
         "retraction_length", "z_hop", "z_hop_types", "retract_lift_above", "retract_lift_below", "retract_lift_enforce", "retraction_speed", "deretraction_speed",
         "retract_before_wipe", "retract_restart_extra", "retraction_minimum_travel", "wipe", "wipe_distance",
         "retract_when_changing_layer", "retract_length_toolchange", "retract_restart_extra_toolchange", "filament_colour",
@@ -7518,7 +7522,8 @@ std::set<std::string> filament_options_with_variant = {
     "nozzle_temperature_initial_layer",
     "nozzle_temperature",
     "filament_flush_volumetric_speed",
-    "filament_flush_temp"
+    "filament_flush_temp",
+    "volumetric_speed_coefficients"
 };
 
 // Parameters that are the same as the number of extruders

src/libslic3r/PrintConfig.hpp

@@ -1224,6 +1224,7 @@ PRINT_CONFIG_CLASS_DEFINE(
     ((ConfigOptionBool,                fan_speedup_overhangs))
     ((ConfigOptionFloat,               fan_speedup_time))
     ((ConfigOptionFloats,              filament_diameter))
+    ((ConfigOptionStrings,             volumetric_speed_coefficients))
     ((ConfigOptionInts,              filament_adhesiveness_category))
     ((ConfigOptionFloats,              filament_density))
     ((ConfigOptionStrings,             filament_type))