Fix duplicate G29 preparation time (#15274)

The time estimate added 260 s for every G29 on non-Bambu printers. Prusa MK4, MK4S and CORE One start G-code splits bed leveling across six G29 commands, so those printers showed about 26 extra minutes. The 260 s is now added once per G-code processing run. Bambu printers still only count a G29 inside an M622 J1 block, and their estimates are unchanged.

Fixes #15088

src/libslic3r/GCode/GCodeProcessor.cpp

@@ -3730,6 +3730,7 @@ void GCodeProcessor::reset()
     m_detect_layer_based_on_tag = false;
 
     m_seams_count = 0;
+    m_g29_time_added = false;
     m_preheat_time = 0.f;
     m_preheat_steps = 1;
 }
@@ -6131,15 +6132,12 @@ void GCodeProcessor::process_G4(const GCodeReader::GCodeLine& line)
 //BBS
 void GCodeProcessor::process_G29(const GCodeReader::GCodeLine& line)
 {
-    //BBS: hardcode 260 seconds for G29
-    //Todo: use a machine related setting when we have second kind of BBL printer
-    const float value_s = 260.0;
-    if (s_IsBBLPrinter){
-        if(m_measure_g29_time)
-            simulate_st_synchronize(value_s);
-    }
-    else{
-        simulate_st_synchronize(value_s);
+    // Firmware may split one bed-leveling sequence across multiple G29 subcommands.
+    constexpr float g29_time = 260.0f;
+    const bool should_add_time = !s_IsBBLPrinter || m_measure_g29_time;
+    if (should_add_time && !m_g29_time_added) {
+        simulate_st_synchronize(g29_time);
+        m_g29_time_added = true;
     }
 }
 

src/libslic3r/GCode/GCodeProcessor.hpp

@@ -1280,6 +1280,7 @@ inline constexpr float DEFAULT_FILAMENT_DENSITY = 1.245f;
         bool m_detect_layer_based_on_tag {false};
         int m_seams_count;
         bool m_measure_g29_time {false};
+        bool m_g29_time_added {false};
         bool m_single_extruder_multi_material;
         float m_preheat_time;
         int m_preheat_steps;

tests/fff_print/test_gcode_timing.cpp

@@ -7,6 +7,7 @@
 #include "libslic3r/GCode/GCodeProcessor.hpp"
 #include "libslic3r/MultiNozzleUtils.hpp"
 #include "libslic3r/PrintConfig.hpp"
+#include "libslic3r/Utils.hpp"
 
 #include "test_utils.hpp"
 
@@ -21,6 +22,7 @@
 #include <memory>
 #include <sstream>
 #include <string>
+#include <utility>
 #include <vector>
 #include "libslic3r/Config.hpp"
 
@@ -52,12 +54,16 @@ FullPrintConfig make_config(double load_time, double unload_time, double tool_ch
     return config;
 }
 
-void run_processor(GCodeProcessor& proc, const FullPrintConfig& config, const char* gcode)
+void run_processor(GCodeProcessor& proc, const FullPrintConfig& config, const char* gcode, bool is_bbl_printer = true)
 {
     // reserved_tag() selects between two tag tables based on this shared static, and
-    // other tests in the binary mutate it -- pin it so our "; FEATURE:" role tags are
-    // parsed deterministically regardless of test execution order.
-    GCodeProcessor::s_IsBBLPrinter = true;
+    // other tests in the binary mutate it -- pin it so role tags are parsed
+    // deterministically regardless of test execution order.
+    const bool previous_is_bbl_printer = GCodeProcessor::s_IsBBLPrinter;
+    GCodeProcessor::s_IsBBLPrinter = is_bbl_printer;
+    const ScopeGuard restore_flag([previous_is_bbl_printer] {
+        GCodeProcessor::s_IsBBLPrinter = previous_is_bbl_printer;
+    });
     ScopedTemporaryFile temp(".gcode");
     {
         std::ofstream os(temp.string());
@@ -99,6 +105,45 @@ double filament_change_delay(const GCodeProcessorResult& r)
 
 } // namespace
 
+TEST_CASE("G29 preparation time is added only once", "[GCodeTiming][Regression]")
+{
+    const FullPrintConfig config = make_config(0.0, 0.0, 0.0);
+    auto estimate = [&config](bool is_bbl_printer, const char* commands) {
+        const auto mode = PrintEstimatedStatistics::ETimeMode::Normal;
+        std::string gcode = is_bbl_printer ? "; FEATURE: Custom\n" : ";TYPE:Custom\n";
+        gcode += "G1 X10 Y10 Z0.2 F600\nG1 X20 Y10 F600\n";
+        if (is_bbl_printer)
+            gcode += "M622 J1\n";
+        gcode += commands;
+        if (is_bbl_printer)
+            gcode += "M623\n";
+        gcode += "G1 X20 Y20 F600\nG1 X10 Y20 F600\n";
+
+        GCodeProcessor processor;
+        run_processor(processor, config, gcode.c_str(), is_bbl_printer);
+        return std::make_pair(processor.get_time(mode), processor.get_prepare_time(mode));
+    };
+
+    const auto [baseline_time, baseline_prepare] = estimate(false, "G4 S0\n");
+    const auto [one_time, one_prepare] = estimate(false, "G29\n");
+    const auto [repeated_time, repeated_prepare] = estimate(false,
+        "G29 P9 X10 Y-4 W32 H4\nG29 P1\nG29 P1 X0 Y0 W50 H20 C\nG29 P3.2\nG29 P3.13\nG29 A\n");
+
+    REQUIRE_THAT(one_time - baseline_time, WithinAbs(260.0, 1e-2));
+    REQUIRE_THAT(one_prepare - baseline_prepare, WithinAbs(260.0, 1e-2));
+    REQUIRE_THAT(repeated_time, WithinAbs(one_time, 1e-2));
+    REQUIRE_THAT(repeated_prepare, WithinAbs(one_prepare, 1e-2));
+
+    const auto [baseline_bbl_time, baseline_bbl_prepare] = estimate(true, "G4 S0\n");
+    const auto [one_bbl_time, one_bbl_prepare] = estimate(true, "G29\n");
+    const auto [repeated_bbl_time, repeated_bbl_prepare] = estimate(true, "G29\nG29\n");
+
+    REQUIRE_THAT(one_bbl_time - baseline_bbl_time, WithinAbs(260.0, 1e-2));
+    REQUIRE_THAT(one_bbl_prepare - baseline_bbl_prepare, WithinAbs(260.0, 1e-2));
+    REQUIRE_THAT(repeated_bbl_time, WithinAbs(one_bbl_time, 1e-2));
+    REQUIRE_THAT(repeated_bbl_prepare, WithinAbs(one_bbl_prepare, 1e-2));
+}
+
 TEST_CASE("Filament-change time is attributed to tool-change moves, not extrusion roles", "[GCodeTiming]")
 {
     // Relative extrusion (M83) so every "E5" is a real 5mm extrusion move rather