feat: Add File header G-code option and print_time_sec/filament_length_m placeholders (#12186)

## Problem Some Creality printers (e.g. Ender-3 V3 SE) rely on metadata comments in the first lines of G-code files to display print info on the screen (estimated time, filament usage, layer height). This follows a format originally used by Cura/Creality Print: ``` ;FLAVOR:Marlin ;TIME:3708.97 ;Filament used:6.21m ;Layer height:0.2 ``` OrcaSlicer currently has no way to write content before the `HEADER_BLOCK` in the G-code output, and does not expose `print_time_sec` or `filament_length_m` as usable placeholders. As a result, these printers show zeroed-out print info on screen. ## Changes ### 1. New placeholders (post-processing) Added two new G-code placeholders resolved during post-processing: - `{print_time_sec}` — total estimated print time in seconds (double) - `{filament_length_m}` — total filament length in meters (double) These values are only available after G-code generation, so they use inline marker replacement (`@PRINT_TIME_SEC@`, `@FILAMENT_LENGTH_M@`) that `GCodeProcessor::run_post_process()` substitutes with actual computed values — the same pattern used by existing M73 and layer count placeholders. ### 2. New "File header G-code" option (`machine_top_gcode`) Added a new G-code field in **Printer Settings > Machine G-code** that writes content at the very top of the output file, before `HEADER_BLOCK_START`. This allows users to add firmware-specific metadata that must appear in the first lines. ### 3. Creality Ender-3 V3 SE profile update Pre-configured the Ender-3 V3 SE profiles (all 4 nozzle variants) with a default `machine_top_gcode` value matching the Cura-compatible header format, so print info displays correctly out of the box. # Screenshots | Before (current OrcaSlicer) | After (this PR) | |---|---| | ![IMG_5285](https://github.com/user-attachments/assets/fdd2cc96-6593-4108-83f4-e272d5547467) | ![IMG_5286](https://github.com/user-attachments/assets/6cb4091a-4560-4596-93d9-49f2ff8f0a2b) | ## Tests - Sliced test model with Ender-3 V3 SE profile - Verified G-code output contains correct values in first lines: - `;TIME:` with actual print time in seconds - `;Filament used:` with filament length in meters - `;Layer height:` with correct layer height - Verified `{print_time_sec}` and `{filament_length_m}` work in both Machine Start G-code and File header G-code fields - Verified empty `machine_top_gcode` produces no extra output - Built and tested on macOS (arm64)
2026-04-06 00:32:05 +02:00 · 2026-02-08 12:56:28 -03:00
parent 1663dab6ff
commit 2f2f0df6af
11 changed files with 99 additions and 3 deletions
--- a/resources/profiles/Creality/machine/Creality
+++ b/resources/profiles/Creality/machine/Creality
@@ -116,6 +116,7 @@
    "default_filament_profile": [
        "Creality Generic PLA @Ender-3V3-all"
    ],
+    "file_start_gcode": ";FLAVOR:Marlin\\n;TIME:{print_time_sec}\\n;Filament used:{used_filament_length}m\\n;Layer height:{layer_height}",
    "machine_start_gcode": "M220 S100 ;Reset Feedrate \nM221 S100 ;Reset Flowrate \n \nM104 S[nozzle_temperature_initial_layer] ;Set final nozzle temp \nM190 S[bed_temperature_initial_layer_single] ;Set and wait for bed temp to stabilize \nG28 ;Home \nG92 E0 ;Reset Extruder \nG1 Z2.0 F3000 ;Move Z Axis up \nG1 X-2.1 Y20 Z0.28 F5000.0 ;Move to start position \nM109 S[nozzle_temperature_initial_layer] ;Wait for nozzle temp to stabilize \nG1 X-2.1 Y145.0 Z0.28 F1500.0 E15 ;Draw the first line \nG1 X-2.4 Y145.0 Z0.28 F5000.0 ;Move to side a little \nG1 X-2.4 Y20 Z0.28 F1500.0 E30 ;Draw the second line \nG92 E0  ;Reset Extruder \nG1 E-1.0000 F1800 ;Retract a bit \nG1 Z2.0 F3000 ;Move Z Axis up \nG1 E0.0000 F1800",
    "machine_end_gcode": "G91 ;Relative positionning \nG1 E-2 F2700 ;Retract a bit \nG1 E-2 Z0.2 F2400 ;Retract and raise Z \nG1 X5 Y5 F3000 ;Wipe out \nG1 Z10 ;Raise Z more \nG90 ;Absolute positionning \n \nG1 X0 Y220 ;Present print \nM106 S0 ;Turn-off fan \nM104 S0 ;Turn-off hotend \nM140 S0 ;Turn-off bed \n \nM84 X Y E ;Disable all steppers but Z",
    "scan_first_layer": "0",
--- a/resources/profiles/Creality/machine/Creality
+++ b/resources/profiles/Creality/machine/Creality
@@ -116,6 +116,7 @@
    "default_filament_profile": [
        "Creality Generic PLA @Ender-3V3-all"
    ],
+    "file_start_gcode": ";FLAVOR:Marlin\\n;TIME:{print_time_sec}\\n;Filament used:{used_filament_length}m\\n;Layer height:{layer_height}",
    "machine_start_gcode": "M220 S100 ;Reset Feedrate \nM221 S100 ;Reset Flowrate \n \nM104 S[nozzle_temperature_initial_layer] ;Set final nozzle temp \nM190 S[bed_temperature_initial_layer_single] ;Set and wait for bed temp to stabilize \nG28 ;Home \nG92 E0 ;Reset Extruder \nG1 Z2.0 F3000 ;Move Z Axis up \nG1 X-2.1 Y20 Z0.28 F5000.0 ;Move to start position \nM109 S[nozzle_temperature_initial_layer] ;Wait for nozzle temp to stabilize \nG1 X-2.1 Y145.0 Z0.28 F1500.0 E15 ;Draw the first line \nG1 X-2.4 Y145.0 Z0.28 F5000.0 ;Move to side a little \nG1 X-2.4 Y20 Z0.28 F1500.0 E30 ;Draw the second line \nG92 E0  ;Reset Extruder \nG1 E-1.0000 F1800 ;Retract a bit \nG1 Z2.0 F3000 ;Move Z Axis up \nG1 E0.0000 F1800",
    "machine_end_gcode": "G91 ;Relative positionning \nG1 E-2 F2700 ;Retract a bit \nG1 E-2 Z0.2 F2400 ;Retract and raise Z \nG1 X5 Y5 F3000 ;Wipe out \nG1 Z10 ;Raise Z more \nG90 ;Absolute positionning \n \nG1 X0 Y220 ;Present print \nM106 S0 ;Turn-off fan \nM104 S0 ;Turn-off hotend \nM140 S0 ;Turn-off bed \n \nM84 X Y E ;Disable all steppers but Z",
    "scan_first_layer": "0",
--- a/resources/profiles/Creality/machine/Creality
+++ b/resources/profiles/Creality/machine/Creality
@@ -116,6 +116,7 @@
    "default_filament_profile": [
        "Creality Generic PLA @Ender-3V3-all"
    ],
+    "file_start_gcode": ";FLAVOR:Marlin\\n;TIME:{print_time_sec}\\n;Filament used:{used_filament_length}m\\n;Layer height:{layer_height}",
    "machine_start_gcode": "M220 S100 ;Reset Feedrate \nM221 S100 ;Reset Flowrate \n \nM104 S[nozzle_temperature_initial_layer] ;Set final nozzle temp \nM190 S[bed_temperature_initial_layer_single] ;Set and wait for bed temp to stabilize \nG28 ;Home \nG92 E0 ;Reset Extruder \nG1 Z2.0 F3000 ;Move Z Axis up \nG1 X-2.1 Y20 Z0.28 F5000.0 ;Move to start position \nM109 S[nozzle_temperature_initial_layer] ;Wait for nozzle temp to stabilize \nG1 X-2.1 Y145.0 Z0.28 F1500.0 E15 ;Draw the first line \nG1 X-2.4 Y145.0 Z0.28 F5000.0 ;Move to side a little \nG1 X-2.4 Y20 Z0.28 F1500.0 E30 ;Draw the second line \nG92 E0  ;Reset Extruder \nG1 E-1.0000 F1800 ;Retract a bit \nG1 Z2.0 F3000 ;Move Z Axis up \nG1 E0.0000 F1800",
    "machine_end_gcode": "G91 ;Relative positionning \nG1 E-2 F2700 ;Retract a bit \nG1 E-2 Z0.2 F2400 ;Retract and raise Z \nG1 X5 Y5 F3000 ;Wipe out \nG1 Z10 ;Raise Z more \nG90 ;Absolute positionning \n \nG1 X0 Y220 ;Present print \nM106 S0 ;Turn-off fan \nM104 S0 ;Turn-off hotend \nM140 S0 ;Turn-off bed \n \nM84 X Y E ;Disable all steppers but Z",
    "scan_first_layer": "0",
--- a/resources/profiles/Creality/machine/Creality
+++ b/resources/profiles/Creality/machine/Creality
@@ -116,6 +116,7 @@
    "default_filament_profile": [
        "Creality Generic PLA @Ender-3V3-all"
    ],
+    "file_start_gcode": ";FLAVOR:Marlin\\n;TIME:{print_time_sec}\\n;Filament used:{used_filament_length}m\\n;Layer height:{layer_height}",
    "machine_start_gcode": "M220 S100 ;Reset Feedrate \nM221 S100 ;Reset Flowrate \n \nM104 S[nozzle_temperature_initial_layer] ;Set final nozzle temp \nM190 S[bed_temperature_initial_layer_single] ;Set and wait for bed temp to stabilize \nG28 ;Home \nG92 E0 ;Reset Extruder \nG1 Z2.0 F3000 ;Move Z Axis up \nG1 X-2.1 Y20 Z0.28 F5000.0 ;Move to start position \nM109 S[nozzle_temperature_initial_layer] ;Wait for nozzle temp to stabilize \nG1 X-2.1 Y145.0 Z0.28 F1500.0 E15 ;Draw the first line \nG1 X-2.4 Y145.0 Z0.28 F5000.0 ;Move to side a little \nG1 X-2.4 Y20 Z0.28 F1500.0 E30 ;Draw the second line \nG92 E0  ;Reset Extruder \nG1 E-1.0000 F1800 ;Retract a bit \nG1 Z2.0 F3000 ;Move Z Axis up \nG1 E0.0000 F1800",
    "machine_end_gcode": "G91 ;Relative positionning \nG1 E-2 F2700 ;Retract a bit \nG1 E-2 Z0.2 F2400 ;Retract and raise Z \nG1 X5 Y5 F3000 ;Wipe out \nG1 Z10 ;Raise Z more \nG90 ;Absolute positionning \n \nG1 X0 Y220 ;Present print \nM106 S0 ;Turn-off fan \nM104 S0 ;Turn-off hotend \nM140 S0 ;Turn-off bed \n \nM84 X Y E ;Disable all steppers but Z",
    "scan_first_layer": "0",
--- a/src/libslic3r/GCode.cpp
+++ b/src/libslic3r/GCode.cpp
@@ -2313,6 +2313,19 @@ void GCode::_do_export(Print& print, GCodeOutputStream &file, ThumbnailsGenerato
    if (!print.config().small_area_infill_flow_compensation_model.empty())
        m_small_area_infill_flow_compensator = make_unique<SmallAreaInfillFlowCompensator>(print.config());
    
+    // Process file_start_gcode - written at the very top of the file, before any header
+    {
+        std::string top_gcode_template = print.config().file_start_gcode.value;
+        if (!top_gcode_template.empty()) {
+            DynamicConfig top_config;
+            top_config.set_key_value("print_time_sec", new ConfigOptionString(GCodeProcessor::reserved_tag(GCodeProcessor::ETags::Print_Time_Sec_Placeholder)));
+            top_config.set_key_value("used_filament_length", new ConfigOptionString(GCodeProcessor::reserved_tag(GCodeProcessor::ETags::Used_Filament_Length_Placeholder)));
+            std::string top_gcode = print.placeholder_parser().process(top_gcode_template, 0, &top_config);
+            if (!top_gcode.empty())
+                file.writeln(top_gcode);
+        }
+    }
+
    // Orca: Don't output Header block if BTT thumbnail is identified in the list
    // Get the thumbnails value as a string
    std::string thumbnails_value = print.config().option<ConfigOptionString>("thumbnails")->value;
@@ -2854,6 +2867,8 @@ void GCode::_do_export(Print& print, GCodeOutputStream &file, ThumbnailsGenerato
        this->placeholder_parser().set("hold_chamber_temp_for_flat_print", new ConfigOptionBool(hold_chamber_temp_for_flat_print));
    }

+    this->placeholder_parser().set("print_time_sec", new ConfigOptionString(GCodeProcessor::reserved_tag(GCodeProcessor::ETags::Print_Time_Sec_Placeholder)));
+    this->placeholder_parser().set("used_filament_length", new ConfigOptionString(GCodeProcessor::reserved_tag(GCodeProcessor::ETags::Used_Filament_Length_Placeholder)));

    std::string machine_start_gcode = this->placeholder_parser_process("machine_start_gcode", print.config().machine_start_gcode.value, initial_extruder_id);
    if (print.config().gcode_flavor != gcfKlipper) {
--- a/src/libslic3r/GCode/GCodeProcessor.cpp
+++ b/src/libslic3r/GCode/GCodeProcessor.cpp
@@ -73,7 +73,9 @@ const std::vector<std::string> GCodeProcessor::Reserved_Tags = {
    "_DURING_PRINT_EXHAUST_FAN",
    " WIPE_TOWER_START",
    " WIPE_TOWER_END",
-    " PA_CHANGE:"
+    " PA_CHANGE:",
+    "@PRINT_TIME_SEC@",
+    "@USED_FILAMENT_LENGTH@"
 };

 const std::vector<std::string> GCodeProcessor::Reserved_Tags_compatible = {
@@ -94,7 +96,9 @@ const std::vector<std::string> GCodeProcessor::Reserved_Tags_compatible = {
    "_DURING_PRINT_EXHAUST_FAN",
    " WIPE_TOWER_START",
    " WIPE_TOWER_END",
-    " PA_CHANGE:"
+    " PA_CHANGE:",
+    "@PRINT_TIME_SEC@",
+    "@USED_FILAMENT_LENGTH@"
 };


@@ -1101,6 +1105,42 @@ void GCodeProcessor::run_post_process()
        return ret;
    };

+    // Process inline placeholders (print_time_sec and used_filament_length)
+    auto process_inline_placeholders = [&](std::string& gcode_line) {
+        bool processed = false;
+
+        const std::string& print_time_placeholder = reserved_tag(ETags::Print_Time_Sec_Placeholder);
+        const std::string& used_filament_placeholder = reserved_tag(ETags::Used_Filament_Length_Placeholder);
+
+        // Replace print_time_sec
+        size_t pos = gcode_line.find(print_time_placeholder);
+        while (pos != std::string::npos) {
+            double print_time_sec = m_time_processor.machines[static_cast<size_t>(PrintEstimatedStatistics::ETimeMode::Normal)].time;
+            char buf[64];
+            sprintf(buf, "%.2f", print_time_sec);
+            gcode_line.replace(pos, print_time_placeholder.length(), buf);
+            processed = true;
+            pos = gcode_line.find(print_time_placeholder, pos + strlen(buf));
+        }
+
+        // Replace used_filament_length
+        pos = gcode_line.find(used_filament_placeholder);
+        while (pos != std::string::npos) {
+            double total_filament_mm = 0.0;
+            for (const auto& mm : filament_mm) {
+                total_filament_mm += mm;
+            }
+            double used_filament_length = total_filament_mm / 1000.0; // Convert mm to m
+            char buf[64];
+            sprintf(buf, "%.2f", used_filament_length);
+            gcode_line.replace(pos, used_filament_placeholder.length(), buf);
+            processed = true;
+            pos = gcode_line.find(used_filament_placeholder, pos + strlen(buf));
+        }
+
+        return processed;
+    };
+
    // check for temporary lines
    auto is_temporary_decoration = [](const std::string_view gcode_line) {
        // remove trailing '\n'
@@ -1317,6 +1357,8 @@ void GCodeProcessor::run_post_process()
                        gcode_line.clear();
                    if (!processed)
                        processed = process_used_filament(gcode_line);
+                    if (!gcode_line.empty())
+                        process_inline_placeholders(gcode_line);
                    if (!processed && !is_temporary_decoration(gcode_line)) {
                        if (GCodeReader::GCodeLine::cmd_is(gcode_line, "G0") || GCodeReader::GCodeLine::cmd_is(gcode_line, "G1")) {
                            export_line.append_line(gcode_line);
--- a/src/libslic3r/GCode/GCodeProcessor.hpp
+++ b/src/libslic3r/GCode/GCodeProcessor.hpp
@@ -342,6 +342,8 @@ class Print;
            Wipe_Tower_Start,
            Wipe_Tower_End,
            PA_Change,
+            Print_Time_Sec_Placeholder,
+            Used_Filament_Length_Placeholder,
        };

        static const std::string& reserved_tag(ETags tag) { return s_IsBBLPrinter ? Reserved_Tags[static_cast<unsigned char>(tag)] : Reserved_Tags_compatible[static_cast<unsigned char>(tag)]; }
--- a/src/libslic3r/Preset.cpp
+++ b/src/libslic3r/Preset.cpp
@@ -1008,7 +1008,7 @@ static std::vector<std::string> s_Preset_printer_options {
    "printer_technology",
    "printable_area", "extruder_printable_area", "bed_exclude_area","bed_custom_texture", "bed_custom_model", "gcode_flavor",
    "fan_kickstart", "fan_speedup_time", "fan_speedup_overhangs",
-    "single_extruder_multi_material", "manual_filament_change", "machine_start_gcode", "machine_end_gcode", "before_layer_change_gcode", "printing_by_object_gcode", "layer_change_gcode", "time_lapse_gcode", "wrapping_detection_gcode", "change_filament_gcode", "change_extrusion_role_gcode",
+    "single_extruder_multi_material", "manual_filament_change", "file_start_gcode", "machine_start_gcode", "machine_end_gcode", "before_layer_change_gcode", "printing_by_object_gcode", "layer_change_gcode", "time_lapse_gcode", "wrapping_detection_gcode", "change_filament_gcode", "change_extrusion_role_gcode",
    "printer_model", "printer_variant", "printer_extruder_id", "printer_extruder_variant", "extruder_variant_list", "default_nozzle_volume_type",
    "printable_height", "extruder_printable_height", "extruder_clearance_radius", "extruder_clearance_height_to_lid", "extruder_clearance_height_to_rod",
    "nozzle_height", "master_extruder_id",
--- a/src/libslic3r/PrintConfig.cpp
+++ b/src/libslic3r/PrintConfig.cpp
@@ -5398,6 +5398,18 @@ void PrintConfigDef::init_fff_params()
    def->set_default_value(new ConfigOptionInt(1));


+    def = this->add("file_start_gcode", coString);
+    def->label = L("File header G-code");
+    def->tooltip = L("G-code written at the very top of the output file, before any other content. "
+                     "Useful for adding metadata that printer firmware reads from the first lines of the file "
+                     "(e.g. estimated print time, filament usage). "
+                     "Supports placeholders like {print_time_sec} and {used_filament_length}.");
+    def->multiline = true;
+    def->full_width = true;
+    def->height = 8;
+    def->mode = comAdvanced;
+    def->set_default_value(new ConfigOptionString(""));
+
    def = this->add("machine_start_gcode", coString);
    def->label = L("Start G-code");
    def->tooltip = L("Start G-code when starting the entire print.");
@@ -10299,6 +10311,14 @@ PrintStatisticsConfigDef::PrintStatisticsConfigDef()
    def = this->add("used_filament", coFloat);
    def->label = L("Used filament");
    def->tooltip = L("Total length of filament used in the print.");
+
+    def = this->add("print_time_sec", coString);
+    def->label = L("Print time (seconds)");
+    def->tooltip = L("Total estimated print time in seconds. Replaced with actual value during post-processing.");
+
+    def = this->add("used_filament_length", coString);
+    def->label = L("Filament length (meters)");
+    def->tooltip = L("Total filament length used in meters. Replaced with actual value during post-processing.");
 }

 ObjectsInfoConfigDef::ObjectsInfoConfigDef()
@@ -10433,6 +10453,7 @@ OtherPresetsConfigDef::OtherPresetsConfigDef()

 static std::map<t_custom_gcode_key, t_config_option_keys> s_CustomGcodeSpecificPlaceholders{
    // Machine G-code
+    {"file_start_gcode",           {}},
    {"machine_start_gcode",         {}},
    {"machine_end_gcode",           {"layer_num", "layer_z", "max_layer_z", "filament_extruder_id"}},
    {"before_layer_change_gcode",   {"layer_num", "layer_z", "max_layer_z"}},
--- a/src/libslic3r/PrintConfig.hpp
+++ b/src/libslic3r/PrintConfig.hpp
@@ -1321,6 +1321,7 @@ PRINT_CONFIG_CLASS_DEFINE(
    ((ConfigOptionFloats,              retract_restart_extra))
    ((ConfigOptionFloats,              retract_restart_extra_toolchange))
    ((ConfigOptionFloats,              retraction_speed))
+    ((ConfigOptionString,              file_start_gcode))
    ((ConfigOptionString,              machine_start_gcode))
    ((ConfigOptionStrings,             filament_start_gcode))
    ((ConfigOptionBool,                single_extruder_multi_material))
--- a/src/slic3r/GUI/Tab.cpp
+++ b/src/slic3r/GUI/Tab.cpp
@@ -4434,6 +4434,17 @@ void TabPrinter::build_fff()
    const int gcode_field_height = 15; // 150
    const int notes_field_height = 25; // 250
    page = add_options_page(L("Machine G-code"), "custom-gcode_gcode"); // ORCA: icon only visible on placeholders
+        optgroup = page->new_optgroup(L("File header G-code"), L"param_gcode", 0);
+        optgroup->m_on_change = [this, &optgroup_title = optgroup->title](const t_config_option_key& opt_key, const boost::any& value) {
+            validate_custom_gcode_cb(this, optgroup_title, opt_key, value);
+        };
+        optgroup->edit_custom_gcode = edit_custom_gcode_fn;
+        option = optgroup->get_option("file_start_gcode");
+        option.opt.full_width = true;
+        option.opt.is_code = true;
+        option.opt.height = 8;
+        optgroup->append_single_option_line(option);
+
        optgroup = page->new_optgroup(L("Machine start G-code"), L"param_gcode", 0);
        optgroup->m_on_change = [this, &optgroup_title = optgroup->title](const t_config_option_key& opt_key, const boost::any& value) {
            validate_custom_gcode_cb(this, optgroup_title, opt_key, value);