add "first layer flow" setting, for fuck sake first layer width isn't enough with a cheap printer like an ender3 that can have his bed damaged so easily.

resources/ui_layout/print.ui

@@ -216,6 +216,7 @@ group:Flow
 		setting:bridge_flow_ratio
 		setting:over_bridge_flow_ratio
 		setting:fill_top_flow_ratio
+		setting:first_layer_flow_ratio
 	end_line
 
 page:Multiple extruders:funnel

src/libslic3r/GCode.cpp

@@ -3350,6 +3350,7 @@ std::string GCode::_extrude(const ExtrusionPath &path, const std::string &descri
 
     // calculate extrusion length per distance unit
     double e_per_mm = m_writer.extruder()->e_per_mm3() * path.mm3_per_mm;
+    if (this->m_layer_index <= 0) e_per_mm *= this->config().first_layer_flow_ratio.get_abs_value(1);
     if (m_writer.extrusion_axis().empty()) e_per_mm = 0;
     double path_length = 0.;
     {

src/libslic3r/Print.cpp

@@ -102,6 +102,7 @@ bool Print::invalidate_state_by_config_options(const std::vector<t_config_option
         "filament_cost",
         "first_layer_acceleration",
         "first_layer_bed_temperature",
+        "first_layer_flow_ratio",
         "first_layer_speed",
         "first_layer_infill_speed",
         "gcode_comments",

src/libslic3r/PrintConfig.cpp

@@ -1244,7 +1244,16 @@ void PrintConfigDef::init_fff_params()
     def->label = L("Top fill");
     def->full_label = L("Top fill flow ratio");
     def->category = OptionCategory::width;
-    def->tooltip = L("You can increase this to over-extrude on the top layer if there are not enough plastic to makle a good fill.");
+    def->tooltip = L("You can increase this to over-extrude on the top layer if there are not enough plastic to make a good fill.");
+    def->min = 0;
+    def->mode = comExpert;
+    def->set_default_value(new ConfigOptionFloatOrPercent(100, true));
+
+    def = this->add("first_layer_flow_ratio", coFloatOrPercent);
+    def->label = L("First layer");
+    def->full_label = L("First layer flow ratio");
+    def->category = OptionCategory::width;
+    def->tooltip = L("You can increase this to over-extrude on the first layer if there are not enough plastic because your bed isn't levelled.");
     def->min = 0;
     def->mode = comExpert;
     def->set_default_value(new ConfigOptionFloatOrPercent(100, true));

src/libslic3r/PrintConfig.hpp

@@ -1007,6 +1007,7 @@ public:
     ConfigOptionFloat               first_layer_acceleration;
     ConfigOptionInts                first_layer_bed_temperature;
     ConfigOptionFloatOrPercent      first_layer_extrusion_width;
+    ConfigOptionFloatOrPercent      first_layer_flow_ratio;
     ConfigOptionFloatOrPercent      first_layer_speed;
     ConfigOptionFloatOrPercent      first_layer_infill_speed;
     ConfigOptionInts                first_layer_temperature;
@@ -1085,6 +1086,7 @@ protected:
         OPT_PTR(first_layer_acceleration);
         OPT_PTR(first_layer_bed_temperature);
         OPT_PTR(first_layer_extrusion_width);
+        OPT_PTR(first_layer_flow_ratio);
         OPT_PTR(first_layer_speed);
         OPT_PTR(first_layer_infill_speed);
         OPT_PTR(first_layer_temperature);

src/slic3r/GUI/Preset.cpp

@@ -452,6 +452,7 @@ const std::vector<std::string>& Preset::print_options()
         "clip_multipart_objects",
         "over_bridge_flow_ratio",
         "bridge_overlap",
+        "first_layer_flow_ratio",
         "clip_multipart_objects", "enforce_full_fill_volume", "external_infill_margin", "bridged_infill_margin",
         "elefant_foot_compensation", "xy_size_compensation", "hole_size_compensation", 
         "hole_to_polyhole",

src/slic3r/GUI/Tab.cpp

@@ -1746,6 +1746,7 @@ void TabPrint::build()
         line.append_option(optgroup->get_option("bridge_overlap"));
         line.append_option(optgroup->get_option("over_bridge_flow_ratio"));
         line.append_option(optgroup->get_option("fill_top_flow_ratio"));
+        line.append_option(optgroup->get_option("first_layer_flow_ratio"));
         optgroup->append_line(line);
 
     page = add_options_page(_(L(toString(OptionCategory::extruders))), "funnel");