ENH: save filament sequences in gcode result

jira: NONE

Signed-off-by: xun.zhang <xun.zhang@bambulab.com>
Change-Id: I79c2eb4002c72568d487df417c914ab0b8a14a67
(cherry picked from commit a289370b19e78693698db388d4057e25ba285d6b)

src/libslic3r/GCode.hpp

@@ -200,6 +200,7 @@ public:
     // throws std::runtime_exception on error,
     // throws CanceledException through print->throw_if_canceled().
     void            do_export(Print* print, const char* path, GCodeProcessorResult* result = nullptr, ThumbnailsGeneratorCallback thumbnail_cb = nullptr);
+    void            export_layer_filaments(GCodeProcessorResult* result);
     //BBS: set offset for gcode writer
     void set_gcode_offset(double x, double y) { m_writer.set_xy_offset(x, y); m_processor.set_xy_offset(x, y);}
 
@@ -608,6 +609,7 @@ private:
     int m_start_gcode_filament = -1;
 
     std::set<unsigned int>                  m_initial_layer_extruders;
+    std::vector<std::vector<unsigned int>>  m_sorted_layer_filaments;
     // BBS
     int get_bed_temperature(const int extruder_id, const bool is_first_layer, const BedType bed_type) const;