ENH: enable arachne for wall

Refer to prusa and enable arachne for wall.

Arachne also has corner case and cause strange
slicing result and bad quality when print, while
class engine is much better for these cases.

Provide option for user to choose.

Signed-off-by: salt.wei <salt.wei@bambulab.com>
Change-Id: Ieb3a1c6a457ca610561f8734de4a122d74165afd

src/libslic3r/PrintConfig.cpp

@@ -283,6 +283,12 @@ static t_config_enum_values s_keys_map_NozzleType {
 };
 CONFIG_OPTION_ENUM_DEFINE_STATIC_MAPS(NozzleType)
 
+static t_config_enum_values s_keys_map_PerimeterGeneratorType{
+    { "classic", int(PerimeterGeneratorType::Classic) },
+    { "arachne", int(PerimeterGeneratorType::Arachne) }
+};
+CONFIG_OPTION_ENUM_DEFINE_STATIC_MAPS(PerimeterGeneratorType)
+
 static void assign_printer_technology_to_unknown(t_optiondef_map &options, PrinterTechnology printer_technology)
 {
     for (std::pair<const t_config_option_key, ConfigOptionDef> &kvp : options)
@@ -2940,6 +2946,92 @@ void PrintConfigDef::init_fff_params()
     def->mode = comAdvanced;
     def->set_default_value(new ConfigOptionFloat(0));
 
+    def = this->add("wall_generator", coEnum);
+    def->label = L("Wall generator");
+    def->category = L("Quality");
+    def->tooltip = L("Classic wall generator produces walls with constant extrusion width and for "
+        "very thin areas is used gap-fill. "
+        "Arachne engine produces walls with variable extrusion width");
+    def->enum_keys_map = &ConfigOptionEnum<PerimeterGeneratorType>::get_enum_values();
+    def->enum_values.push_back("classic");
+    def->enum_values.push_back("arachne");
+    def->enum_labels.push_back(L("Classic"));
+    def->enum_labels.push_back(L("Arachne"));
+    def->mode = comAdvanced;
+    def->set_default_value(new ConfigOptionEnum<PerimeterGeneratorType>(PerimeterGeneratorType::Classic));
+
+    def = this->add("wall_transition_length", coPercent);
+    def->label = L("Wall transition length");
+    def->category = L("Quality");
+    def->tooltip = L("When transitioning between different numbers of walls as the part becomes "
+        "thinner, a certain amount of space is allotted to split or join the wall segments. "
+        "It's expressed as a percentage over nozzle diameter");
+    def->sidetext = L("%");
+    def->mode = comAdvanced;
+    def->min = 0;
+    def->set_default_value(new ConfigOptionPercent(100));
+
+    def = this->add("wall_transition_filter_deviation", coPercent);
+    def->label = L("Wall transitioning filter margin");
+    def->category = L("Quality");
+    def->tooltip = L("Prevent transitioning back and forth between one extra wall and one less. This "
+        "margin extends the range of extrusion widths which follow to [Minimum perimeter width "
+        "- margin, 2 * Minimum perimeter width + margin]. Increasing this margin "
+        "reduces the number of transitions, which reduces the number of extrusion "
+        "starts/stops and travel time. However, large extrusion width variation can lead to "
+        "under- or overextrusion problems. "
+        "It's expressed as a percentage over nozzle diameter");
+    def->sidetext = L("%");
+    def->mode = comAdvanced;
+    def->min = 0;
+    def->set_default_value(new ConfigOptionPercent(25));
+
+    def = this->add("wall_transition_angle", coFloat);
+    def->label = L("Perimeter transitioning threshold angle");
+    def->category = L("Quality");
+    def->tooltip = L("When to create transitions between even and odd numbers of perimeters. A wedge shape with"
+        " an angle greater than this setting will not have transitions and no perimeters will be "
+        "printed in the center to fill the remaining space. Reducing this setting reduces "
+        "the number and length of these center perimeters, but may leave gaps or overextrude");
+    def->sidetext = L("°");
+    def->mode = comAdvanced;
+    def->min = 1.;
+    def->max = 59.;
+    def->set_default_value(new ConfigOptionFloat(10.));
+
+    def = this->add("wall_distribution_count", coInt);
+    def->label = L("Perimeter distribution count");
+    def->category = L("Quality");
+    def->tooltip = L("The number of perimeters, counted from the center, over which the variation needs to be "
+        "spread. Lower values mean that the outer perimeters don't change in width");
+    def->mode = comAdvanced;
+    def->min = 1;
+    def->set_default_value(new ConfigOptionInt(1));
+
+    def = this->add("min_feature_size", coPercent);
+    def->label = L("Minimum feature size");
+    def->category = L("Quality");
+    def->tooltip = L("Minimum thickness of thin features. Model features that are thinner than this value will "
+        "not be printed, while features thicker than the Minimum feature size will be widened to "
+        "the Minimum perimeter width. "
+        "It's expressed as a percentage over nozzle diameter");
+    def->sidetext = L("%");
+    def->mode = comAdvanced;
+    def->min = 0;
+    def->set_default_value(new ConfigOptionPercent(25));
+
+    def = this->add("min_bead_width", coPercent);
+    def->label = L("Minimum perimeter width");
+    def->category = L("Quality");
+    def->tooltip = L("Width of the perimeter that will replace thin features (according to the Minimum feature size) "
+        "of the model. If the Minimum perimeter width is thinner than the thickness of the feature,"
+        " the perimeter will become as thick as the feature itself. "
+        "It's expressed as a percentage over nozzle diameter");
+    def->sidetext = L("%");
+    def->mode = comAdvanced;
+    def->min = 0;
+    def->set_default_value(new ConfigOptionPercent(85));
+
     // Declare retract values for filament profile, overriding the printer's extruder profile.
     for (const char *opt_key : {
         // floats