Implemented clamping of the acceleration when extruding for the Marlin

firmware, both for the G-code export and the time estimator.

xs/src/libslic3r/GCode.cpp

@@ -412,7 +412,7 @@ void GCode::_do_export(Print &print, FILE *file, GCodePreviewData *preview_data)
     // resets time estimators
     m_normal_time_estimator.reset();
     m_normal_time_estimator.set_dialect(print.config.gcode_flavor);
-    m_normal_time_estimator.set_acceleration(print.config.machine_max_acceleration_extruding.values[0]);
+    m_normal_time_estimator.set_max_acceleration(print.config.machine_max_acceleration_extruding.values[0]);
     m_normal_time_estimator.set_retract_acceleration(print.config.machine_max_acceleration_retracting.values[0]);
     m_normal_time_estimator.set_minimum_feedrate(print.config.machine_min_extruding_rate.values[0]);
     m_normal_time_estimator.set_minimum_travel_feedrate(print.config.machine_min_travel_rate.values[0]);
@@ -434,7 +434,7 @@ void GCode::_do_export(Print &print, FILE *file, GCodePreviewData *preview_data)
     {
         m_silent_time_estimator.reset();
         m_silent_time_estimator.set_dialect(print.config.gcode_flavor);
-        m_silent_time_estimator.set_acceleration(print.config.machine_max_acceleration_extruding.values[1]);
+        m_silent_time_estimator.set_max_acceleration(print.config.machine_max_acceleration_extruding.values[1]);
         m_silent_time_estimator.set_retract_acceleration(print.config.machine_max_acceleration_retracting.values[1]);
         m_silent_time_estimator.set_minimum_feedrate(print.config.machine_min_extruding_rate.values[1]);
         m_silent_time_estimator.set_minimum_travel_feedrate(print.config.machine_min_travel_rate.values[1]);

xs/src/libslic3r/GCodeTimeEstimator.cpp

@@ -414,7 +414,7 @@ namespace Slic3r {
 
     void GCodeTimeEstimator::set_acceleration(float acceleration_mm_sec2)
     {
-        _state.acceleration = acceleration_mm_sec2;
+        _state.acceleration = std::min(_state.max_acceleration, acceleration_mm_sec2);
     }
 
     float GCodeTimeEstimator::get_acceleration() const
@@ -422,6 +422,17 @@ namespace Slic3r {
         return _state.acceleration;
     }
 
+    void GCodeTimeEstimator::set_max_acceleration(float acceleration_mm_sec2)
+    {
+        _state.max_acceleration = acceleration_mm_sec2;
+        _state.acceleration = acceleration_mm_sec2;
+    }
+
+    float GCodeTimeEstimator::get_max_acceleration() const
+    {
+        return _state.max_acceleration;
+    }
+
     void GCodeTimeEstimator::set_retract_acceleration(float acceleration_mm_sec2)
     {
         _state.retract_acceleration = acceleration_mm_sec2;
@@ -540,7 +551,7 @@ namespace Slic3r {
         set_e_local_positioning_type(Absolute);
 
         set_feedrate(DEFAULT_FEEDRATE);
-        set_acceleration(DEFAULT_ACCELERATION);
+        set_max_acceleration(DEFAULT_ACCELERATION);
         set_retract_acceleration(DEFAULT_RETRACT_ACCELERATION);
         set_minimum_feedrate(DEFAULT_MINIMUM_FEEDRATE);
         set_minimum_travel_feedrate(DEFAULT_MINIMUM_TRAVEL_FEEDRATE);

xs/src/libslic3r/GCodeTimeEstimator.hpp

@@ -72,6 +72,8 @@ namespace Slic3r {
             Axis axis[Num_Axis];
             float feedrate;                     // mm/s
             float acceleration;                 // mm/s^2
+            // hard limit for the acceleration, to which the firmware will clamp.
+            float max_acceleration;             // mm/s^2
             float retract_acceleration;         // mm/s^2
             float additional_time;              // s
             float minimum_feedrate;             // mm/s
@@ -263,6 +265,10 @@ namespace Slic3r {
         void set_acceleration(float acceleration_mm_sec2);
         float get_acceleration() const;
 
+        // Maximum acceleration for the machine. The firmware simulator will clamp the M204 Sxxx to this maximum.
+        void set_max_acceleration(float acceleration_mm_sec2);
+        float get_max_acceleration() const;
+
         void set_retract_acceleration(float acceleration_mm_sec2);
         float get_retract_acceleration() const;
 

xs/src/libslic3r/GCodeWriter.cpp

@@ -18,7 +18,9 @@ void GCodeWriter::apply_print_config(const PrintConfig &print_config)
 {
     this->config.apply(print_config, true);
     m_extrusion_axis = this->config.get_extrusion_axis();
-    this->m_single_extruder_multi_material = print_config.single_extruder_multi_material.value;
+    m_single_extruder_multi_material = print_config.single_extruder_multi_material.value;
+    m_max_acceleration = (print_config.gcode_flavor.value == gcfMarlin) ?
+        print_config.machine_max_acceleration_extruding.value : 0;
 }
 
 void GCodeWriter::set_extruders(const std::vector<unsigned int> &extruder_ids)
@@ -85,7 +87,7 @@ std::string GCodeWriter::set_temperature(unsigned int temperature, bool wait, in
     }
     gcode << temperature;
     if (tool != -1 && 
-        ( (this->multiple_extruders && ! this->m_single_extruder_multi_material) ||
+        ( (this->multiple_extruders && ! m_single_extruder_multi_material) ||
           FLAVOR_IS(gcfMakerWare) || FLAVOR_IS(gcfSailfish)) ) {
         gcode << " T" << tool;
     }
@@ -170,6 +172,10 @@ std::string GCodeWriter::set_fan(unsigned int speed, bool dont_save)
 
 std::string GCodeWriter::set_acceleration(unsigned int acceleration)
 {
+    // Clamp the acceleration to the allowed maximum.
+    if (m_max_acceleration > 0 && acceleration > m_max_acceleration)
+        acceleration = m_max_acceleration;
+
     if (acceleration == 0 || acceleration == m_last_acceleration)
         return std::string();
     

xs/src/libslic3r/GCodeWriter.hpp

@@ -18,7 +18,7 @@ public:
     GCodeWriter() : 
         multiple_extruders(false), m_extrusion_axis("E"), m_extruder(nullptr),
         m_single_extruder_multi_material(false),
-        m_last_acceleration(0), m_last_fan_speed(0), 
+        m_last_acceleration(0), m_max_acceleration(0), m_last_fan_speed(0), 
         m_last_bed_temperature(0), m_last_bed_temperature_reached(true), 
         m_lifted(0)
         {}
@@ -74,6 +74,9 @@ private:
     bool            m_single_extruder_multi_material;
     Extruder*       m_extruder;
     unsigned int    m_last_acceleration;
+    // Limit for setting the acceleration, to respect the machine limits set for the Marlin firmware.
+    // If set to zero, the limit is not in action.
+    unsigned int    m_max_acceleration;
     unsigned int    m_last_fan_speed;
     unsigned int    m_last_bed_temperature;
     bool            m_last_bed_temperature_reached;