add start_gcode_manual to disable automatic 'start gcode' output

supermerill/SuperSlicer#875

resources/ui_layout/printer_fff.ui

@@ -41,6 +41,8 @@ group:Advanced
 	setting:variable_layer_height
 
 page:Custom G-code:cog
+group: 
+	setting:start_gcode_manual
 height:15
 group:nolabel:Start G-code
 	setting:full_width:start_gcode

src/libslic3r/GCode.cpp

@@ -1323,14 +1323,15 @@ void GCode::_do_export(Print& print, FILE* file, ThumbnailsGeneratorCallback thu
 
     std::string start_gcode = this->placeholder_parser_process("start_gcode", print.config().start_gcode.value, initial_extruder_id);
     // Set bed temperature if the start G-code does not contain any bed temp control G-codes.
-    if(this->config().gcode_flavor != gcfKlipper && print.config().first_layer_bed_temperature.get_at(initial_extruder_id) != 0)
+    if( !this->config().start_gcode_manual && this->config().gcode_flavor != gcfKlipper && print.config().first_layer_bed_temperature.get_at(initial_extruder_id) != 0)
         this->_print_first_layer_bed_temperature(file, print, start_gcode, initial_extruder_id, false);
 
     //init extruders
+    if (!this->config().start_gcode_manual)
         this->_init_multiextruders(file, print, m_writer, tool_ordering, start_gcode);
 
     // Set extruder(s) temperature before and after start G-code.
-    if ((this->config().gcode_flavor != gcfKlipper || print.config().start_gcode.value.empty()) && print.config().first_layer_temperature.get_at(initial_extruder_id) != 0)
+    if (!this->config().start_gcode_manual && (this->config().gcode_flavor != gcfKlipper || print.config().start_gcode.value.empty()) && print.config().first_layer_temperature.get_at(initial_extruder_id) != 0)
         this->_print_first_layer_extruder_temperatures(file, print, start_gcode, initial_extruder_id, false);
 
     // adds tag for processor
@@ -1350,7 +1351,7 @@ void GCode::_do_export(Print& print, FILE* file, ThumbnailsGeneratorCallback thu
 */
 
     // Disable fan.
-    if (print.config().disable_fan_first_layers.get_at(initial_extruder_id))
+    if (!this->config().start_gcode_manual && print.config().disable_fan_first_layers.get_at(initial_extruder_id))
         _write(file, m_writer.set_fan(0, true, initial_extruder_id));
     //ensure fan is at the right speed
 
@@ -1367,6 +1368,7 @@ void GCode::_do_export(Print& print, FILE* file, ThumbnailsGeneratorCallback thu
     m_seam_placer.init(print);
 
     //activate first extruder is multi-extruder and not in start-gcode
+    if (!this->config().start_gcode_manual) {
         if (m_writer.multiple_extruders) {
             //if not in gcode
             bool find = false;
@@ -1408,11 +1410,15 @@ void GCode::_do_export(Print& print, FILE* file, ThumbnailsGeneratorCallback thu
             // if we are running a single-extruder setup, just set the extruder and "return nothing"
             _write(file, this->set_extruder(initial_extruder_id, 0.));
         }
+    } else {
+        // the right tool should have been set by the user.
+        m_writer.toolchange(initial_extruder_id);
+    }
 
     //write temps after custom gcodes to ensure the temperature are good. (after tool selection)
-    if(print.config().first_layer_temperature.get_at(initial_extruder_id) != 0)
+    if (!this->config().start_gcode_manual && print.config().first_layer_temperature.get_at(initial_extruder_id) != 0)
         this->_print_first_layer_extruder_temperatures(file, print, start_gcode, initial_extruder_id, true);
-    if (print.config().first_layer_bed_temperature.get_at(initial_extruder_id) != 0)
+    if (!this->config().start_gcode_manual && print.config().first_layer_bed_temperature.get_at(initial_extruder_id) != 0)
         this->_print_first_layer_bed_temperature(file, print, start_gcode, initial_extruder_id, true);
 
     // Do all objects for each layer.
@@ -2699,7 +2705,10 @@ void GCode::set_origin(const Vec2d &pointf)
 
 std::string GCode::preamble()
 {
-    std::string gcode = m_writer.preamble();
+    std::string gcode;
+    
+    if (!this->config().start_gcode_manual)
+        gcode = m_writer.preamble();
 
     /*  Perform a *silent* move to z_offset: we need this to initialize the Z
         position of our writer object so that any initial lift taking place

src/libslic3r/Preset.cpp

@@ -692,8 +692,13 @@ const std::vector<std::string>& Preset::printer_options()
             "min_length",
             //FIXME the print host keys are left here just for conversion from the Printer preset to Physical Printer preset.
             "host_type", "print_host", "printhost_apikey", "printhost_cafile", "printhost_port",
-            "single_extruder_multi_material", "start_gcode", "end_gcode", "before_layer_gcode", "layer_gcode", "toolchange_gcode",
-
+            "single_extruder_multi_material", 
+            "start_gcode",
+            "start_gcode_manual",
+            "end_gcode",
+            "before_layer_gcode",
+            "layer_gcode",
+            "toolchange_gcode",
             "color_change_gcode", "pause_print_gcode", "template_custom_gcode",            "feature_gcode",
             "between_objects_gcode", "printer_vendor", "printer_model", "printer_variant", "printer_notes", "cooling_tube_retraction",
             "cooling_tube_length", "high_current_on_filament_swap", "parking_pos_retraction", "extra_loading_move", "max_print_height", 

src/libslic3r/Print.cpp

@@ -164,6 +164,7 @@ bool Print::invalidate_state_by_config_options(const std::vector<t_config_option
         "slowdown_below_layer_time",
         "standby_temperature_delta",
         "start_gcode",
+        "start_gcode_manual",
         "start_filament_gcode",
         "thin_walls_speed",
         "time_estimation_compensation",

src/libslic3r/PrintConfig.cpp

@@ -3475,6 +3475,14 @@ void PrintConfigDef::init_fff_params()
     def->mode = comExpert;
     def->set_default_value(new ConfigOptionString("G28 ; home all axes\nG1 Z5 F5000 ; lift nozzle\n"));
 
+    def = this->add("start_gcode_manual", coBool);
+    def->label = L("Only custom Start G-code");
+    def->category = OptionCategory::customgcode;
+    def->tooltip = L("Ensure that the slicer won't add heating, fan, extruder... commands before or just after your start-gcode."
+                    "If set to true, you have to write a good and complete start_gcode, as no checks are made anymore.");
+    def->mode = comExpert;
+    def->set_default_value(new ConfigOptionBool(false));
+
     def = this->add("start_filament_gcode", coStrings);
     def->label = L("Start G-code");
     def->full_label = ("Filament start G-code");
@@ -5437,7 +5445,8 @@ void PrintConfigDef::to_prusa(t_config_option_key& opt_key, std::string& value,
 "external_perimeter_extrusion_spacing",
 "infill_extrusion_spacing",
 "solid_infill_extrusion_spacing",
-"top_infill_extrusion_spacing"
+"top_infill_extrusion_spacing",
+"start_gcode_manual",
 
     };
     //looks if it's to be removed, or have to be transformed

src/libslic3r/PrintConfig.hpp

@@ -1089,6 +1089,7 @@ public:
     ConfigOptionFloats              retract_speed;
     ConfigOptionStrings             start_filament_gcode;
     ConfigOptionString              start_gcode;
+    ConfigOptionBool                start_gcode_manual;
     ConfigOptionBool                single_extruder_multi_material;
     ConfigOptionBool                single_extruder_multi_material_priming;
     ConfigOptionBool                wipe_tower_no_sparse_layers;
@@ -1202,6 +1203,7 @@ protected:
         OPT_PTR(single_extruder_multi_material_priming);
         OPT_PTR(wipe_tower_no_sparse_layers);
         OPT_PTR(start_gcode);
+        OPT_PTR(start_gcode_manual);
         OPT_PTR(start_filament_gcode);
         OPT_PTR(tool_name);
         OPT_PTR(toolchange_gcode);