CURA-13249 Merge header with first GCode part

include/gcode_export/FixedGCodePart.h

@@ -15,7 +15,7 @@ namespace cura
 class FixedGCodePart : public GCodePart
 {
 public:
-    explicit FixedGCodePart();
+    explicit FixedGCodePart(const GCodePartType type);
 
     /*! \brief Gets the full piece of GCode to be exported */
     std::string str() const override;

include/gcode_export/GCodePart.h

@@ -6,6 +6,8 @@
 
 #include <string>
 
+#include "gcode_export/GCodePartType.h"
+
 namespace cura
 {
 
@@ -18,8 +20,19 @@ class GCodePart
     /*! \brief Gets the full piece of GCode to be exported */
     virtual std::string str() const = 0;
 
+    GCodePartType type() const
+    {
+        return type_;
+    }
+
 protected:
-    explicit GCodePart() = default;
+    explicit GCodePart(const GCodePartType type = GCodePartType::Management)
+        : type_(type)
+    {
+    }
+
+private:
+    const GCodePartType type_;
 };
 
 } // namespace cura

include/gcode_export/GCodePartType.h

@@ -0,0 +1,20 @@
+// Copyright (c) 2026 UltiMaker
+// CuraEngine is released under the terms of the AGPLv3 or higher
+
+#ifndef GCODEEXPORT_GCODEPARTTYPE_H
+#define GCODEEXPORT_GCODEPARTTYPE_H
+
+namespace cura
+{
+
+enum class GCodePartType
+{
+    Header, // The header, only made of useful comments
+    Management, // Management commands, like heating, extruder switching, custom gcode, ...
+    Print, // Actual model print commands
+
+};
+
+} // namespace cura
+
+#endif

include/gcode_export/gcodeExport.h

@@ -15,6 +15,7 @@
 
 #include "PrintInformation.h"
 #include "TravelAntiOozing.h"
+#include "gcode_export/GCodePartType.h"
 #include "gcode_export/ResolvingExtruderContext.h"
 #include "geometry/Point2LL.h"
 #include "settings/EnumSettings.h"
@@ -409,13 +410,11 @@ class GCodeExport : public NoCopy
      */
     bool needPrimeBlob() const;
 
-    /*
-     *  Function is used to write the content of output_stream to the gcode file
+    /*!
+     * \brief Creates a new instance of fixed GCode part and sets it as the current container for fixed GCode parts.
+     * \param print_code Whether the GCode actually contains print instructions, or management commands (heating, extruder switch, ...)
      */
-    void flushOutputStream();
-
-    /*! \brief Creates a new instance of fixed GCode part and sets it as the current container for fixed GCode parts. */
-    void prepareNewFixedGCodePart();
+    void prepareNewFixedGCodePart(const GCodePartType type = GCodePartType::Management);
 
     /*!
      * \brief Write a piece of resolvable GCode
@@ -556,9 +555,6 @@ class GCodeExport : public NoCopy
     static PrintFeatureType
         sendTravel(const Point3LL& p, const Velocity& speed, const ExtruderTrainAttributes& extruder_attr, const std::optional<RetractionAmounts>& retraction_amounts);
 
-    /*! \brief Resolves and sends all the pieces of GCode that have been created during slicing */
-    void sendFinalGCode();
-
     /*! \brief Calculates the end-of-print data about material consumption */
     std::vector<std::optional<ExtruderPrintInformation>> calculateMaterialPrintInformation() const;
 
@@ -775,6 +771,9 @@ class GCodeExport : public NoCopy
      * Indicates whether the printer handles the retraction/priming, totally or with specific commands
      */
     bool machineHandlesRetraction() const;
+
+    /*! \brief Resolves and sends all the pieces of GCode that have been created during slicing */
+    void sendFinalGCode();
 };
 
 } // namespace cura

src/FffGcodeWriter.cpp

@@ -4288,7 +4288,7 @@ void FffGcodeWriter::finalize()
     }
 
     gcode.writeComment("End of Gcode");
-    gcode.flushOutputStream();
+    gcode.sendFinalGCode();
     /*
     the profile string below can be executed since the M25 doesn't end the gcode on an UMO and when printing via USB.
     gcode.writeCode("M25 ;Stop reading from this point on.");

src/gcode_export/FixedGCodePart.cpp

@@ -7,7 +7,8 @@
 namespace cura
 {
 
-FixedGCodePart::FixedGCodePart()
+FixedGCodePart::FixedGCodePart(const GCodePartType type)
+    : GCodePart(type)
 {
     stream_ << std::fixed;
 }

src/gcode_export/gcodeExport.cpp

@@ -12,6 +12,7 @@
 #include <regex>
 
 #include <fmt/chrono.h>
+#include <range/v3/algorithm/find_if.hpp>
 #include <spdlog/spdlog.h>
 
 #include "Application.h" //To send layer view data.
@@ -354,7 +355,9 @@ std::string GCodeExport::getFileHeader(const std::vector<bool>& extruder_is_used
 void GCodeExport::setLayerNr(const LayerIndex& layer_nr)
 {
     layer_nr_ = layer_nr;
-    prepareNewFixedGCodePart(); // Now is a good time to switch to a new buffer
+
+    constexpr GCodePartType type = GCodePartType::Print; // Now we are actually going to send print commands
+    prepareNewFixedGCodePart(type); // Now is a good time to switch to a new buffer
 }
 
 bool GCodeExport::getExtruderIsUsed(const int extruder_nr) const
@@ -1423,8 +1426,55 @@ PrintFeatureType
 
 void GCodeExport::sendFinalGCode()
 {
-    std::shared_ptr<Communication> communication = Application::getInstance().communication_;
+    {
+        // For retro-compatibility with the post-processing plugins, merge all the initial gcode parts into a single one
+        const auto iterator_first_init_part = ranges::find_if(
+            gcode_parts_,
+            [](const std::shared_ptr<GCodePart>& part)
+            {
+                return part->type() != GCodePartType::Header;
+            });
+        const auto iterator_first_print_part = ranges::find_if(
+            iterator_first_init_part,
+            gcode_parts_.end(),
+            [](const std::shared_ptr<GCodePart>& part)
+            {
+                return part->type() == GCodePartType::Print;
+            });
+        if (std::distance(iterator_first_init_part, iterator_first_print_part) > 1) // If there is none or a single init part, we can skip
+        {
+            constexpr auto type = GCodePartType::Management;
+            auto init_part = std::make_shared<FixedGCodePart>(type);
+            for (auto iterator = iterator_first_init_part; iterator != iterator_first_print_part; ++iterator)
+            {
+                init_part->stream() << (*iterator)->str();
+            }
+
+            // To avoid invalidating iterators, replace the first init part and erase the rest
+            *iterator_first_init_part = init_part;
+            gcode_parts_.erase(iterator_first_init_part + 1, iterator_first_print_part);
+        }
+    }
+
+    {
+        // For retro-compatibility with the post-processing plugins, merge all the end gcode parts into a single one
+        auto iterator_last_print_part = gcode_parts_.end() - 1;
+        while (iterator_last_print_part != gcode_parts_.begin() && (*iterator_last_print_part)->type() != GCodePartType::Print)
+        {
+            --iterator_last_print_part;
+        }
 
+        constexpr auto type = GCodePartType::Management;
+        auto end_part = std::make_shared<FixedGCodePart>(type);
+        for (auto iterator = iterator_last_print_part + 1; iterator != gcode_parts_.end(); ++iterator)
+        {
+            end_part->stream() << (*iterator)->str();
+        }
+        gcode_parts_.erase(iterator_last_print_part + 1, gcode_parts_.end());
+        gcode_parts_.push_back(end_part);
+    }
+
+    std::shared_ptr<Communication> communication = Application::getInstance().communication_;
     run_multiple_producers_ordered_consumer(
         0,
         gcode_parts_.size(),
@@ -2027,13 +2077,15 @@ void GCodeExport::finalize(const std::string& end_code, PrintInformation& print_
 
     template_resolver_->prepareForResolving(print_info.initial_extruder_nr.value_or(0), extra_global_settings);
 
-    std::shared_ptr<Communication> communication = Application::getInstance().communication_;
-
-    communication->sendGCodePart(getFileHeader(is_extruder_used_bool, filaments_volumes, materials_ids));
-
-    sendFinalGCode();
+    {
+        // Prepend the header as a full separate part
+        constexpr GCodePartType type = GCodePartType::Header;
+        auto header_part = std::make_shared<FixedGCodePart>(type);
+        header_part->stream() << getFileHeader(is_extruder_used_bool, filaments_volumes, materials_ids);
+        gcode_parts_.insert(gcode_parts_.begin(), header_part);
+    }
 
-    communication->sendPrintInformation(total_print_times_, print_info);
+    Application::getInstance().communication_->sendPrintInformation(total_print_times_, print_info);
 }
 
 void GCodeExport::finalizeExtruder(const std::string& extruder_end_code)
@@ -2043,14 +2095,9 @@ void GCodeExport::finalizeExtruder(const std::string& extruder_end_code)
     writeCodeWithAbsoluteExtrusion(extruder_end_code, getExtruderNr(), extra_settings);
 }
 
-void GCodeExport::flushOutputStream()
-{
-    prepareNewFixedGCodePart();
-}
-
-void GCodeExport::prepareNewFixedGCodePart()
+void GCodeExport::prepareNewFixedGCodePart(const GCodePartType type)
 {
-    auto fixed_gcode_part = std::make_shared<FixedGCodePart>();
+    const auto fixed_gcode_part = std::make_shared<FixedGCodePart>(type);
     gcode_parts_.push_back(fixed_gcode_part);
     output_stream_ = &fixed_gcode_part->stream();
 }