Use different minimum layer time when layer has an overhang

CURA-12352

include/FanSpeedLayerTime.h

@@ -1,5 +1,5 @@
-//Copyright (c) 2020 Ultimaker B.V.
-//CuraEngine is released under the terms of the AGPLv3 or higher.
+// Copyright (c) 2020 Ultimaker B.V.
+// CuraEngine is released under the terms of the AGPLv3 or higher.
 
 #ifndef FAN_SPEED_LAYER_TIME_H
 #define FAN_SPEED_LAYER_TIME_H
@@ -8,7 +8,7 @@
 #include "settings/types/LayerIndex.h"
 #include "settings/types/Velocity.h"
 
-namespace cura 
+namespace cura
 {
 
 /*!
@@ -19,7 +19,7 @@ namespace cura
  * store these settings over and over again for each part, even though the
  * settings may be different for each part on a layer.
  */
-struct FanSpeedLayerTimeSettings 
+struct FanSpeedLayerTimeSettings
 {
 public:
     /*!
@@ -28,6 +28,11 @@ struct FanSpeedLayerTimeSettings
      */
     Duration cool_min_layer_time;
 
+    /*!
+     * Similar to Minimum layer time, but to be applied for layers that contain overhanging extrusion.
+     */
+    Duration cool_min_layer_time_overhang;
+
     /*!
      * "Regular/Maximum Fan Speed Threshold". If the layers take longer to print
      * than this, they'll use the regular fan speed. If they take shorter, we'll

include/LayerPlan.h

@@ -124,6 +124,7 @@ class LayerPlan : public NoCopy
     std::vector<OverhangMask> overhang_masks_; //!< The regions of a layer part where the walls overhang, calculated for multiple overhang angles. The latter is the most
                                                //!< overhanging. For a visual explanation of the result, see doc/gradual_overhang_speed.svg
     Shape seam_overhang_mask_; //!< The regions of a layer part where the walls overhang, specifically as defined for the seam
+    bool contains_overhang_{ false }; //!< Indicates whether this plan contains any overhanging extrusion
     Shape roofing_mask_; //!< The regions of a layer part where the walls are exposed to the air
 
     bool min_layer_time_used = false; //!< Wether or not the minimum layer time (cool_min_layer_time) was actually used in this layerplan.

src/FffGcodeWriter.cpp

@@ -318,6 +318,7 @@ void FffGcodeWriter::setConfigFanSpeedLayerTime()
         fan_speed_layer_time_settings_per_extruder.emplace_back();
         FanSpeedLayerTimeSettings& fan_speed_layer_time_settings = fan_speed_layer_time_settings_per_extruder.back();
         fan_speed_layer_time_settings.cool_min_layer_time = train.settings_.get<Duration>("cool_min_layer_time");
+        fan_speed_layer_time_settings.cool_min_layer_time_overhang = train.settings_.get<Duration>("cool_min_layer_time_overhang");
         fan_speed_layer_time_settings.cool_min_layer_time_fan_speed_max = train.settings_.get<Duration>("cool_min_layer_time_fan_speed_max");
         fan_speed_layer_time_settings.cool_fan_speed_0 = train.settings_.get<Ratio>("cool_fan_speed_0") * 100.0;
         fan_speed_layer_time_settings.cool_fan_speed_min = train.settings_.get<Ratio>("cool_fan_speed_min") * 100.0;

src/LayerPlan.cpp

@@ -569,8 +569,13 @@ void LayerPlan::addExtrusionMoveWithGradualOverhang(
     const double fan_speed,
     const bool travel_to_z)
 {
-    const auto add_extrusion_move = [&](const Point3LL& target, const Ratio& overhang_speed_factor = 1.0_r)
+    const auto add_extrusion_move = [&](const Point3LL& target, const std::optional<size_t> speed_region_index = std::nullopt)
     {
+        const Ratio overhang_speed_factor = speed_region_index.has_value() ? overhang_masks_[speed_region_index.value()].speed_ratio : 1.0_r;
+        if (speed_region_index.has_value() && speed_region_index.value() > 0)
+        {
+            contains_overhang_ = true;
+        }
         addExtrusionMove(target, config, space_fill_type, flow, width_factor, spiralize, speed_factor * overhang_speed_factor, fan_speed, travel_to_z);
     };
 
@@ -659,7 +664,7 @@ void LayerPlan::addExtrusionMoveWithGradualOverhang(
 
             // Move to intersection at current region speed
             const Point2LL split_position = start + vector * intersection_parameter;
-            add_extrusion_move(split_position, overhang_masks_[actual_speed_region_index].speed_ratio);
+            add_extrusion_move(split_position, actual_speed_region_index);
 
             // Prepare for next move in different region
             actual_speed_region_index = next_speed_region_index;
@@ -668,7 +673,7 @@ void LayerPlan::addExtrusionMoveWithGradualOverhang(
         else
         {
             // We cross no border, which means we can reach the end of the segment within the current speed region, so we are done
-            add_extrusion_move(p, overhang_masks_[actual_speed_region_index].speed_ratio);
+            add_extrusion_move(p, actual_speed_region_index);
             return;
         }
     }
@@ -2562,7 +2567,9 @@ void LayerPlan::processFanSpeedAndMinimalLayerTime(Point2LL starting_position)
             {
                 other_extr_plan_time += extruder_plan.estimates_.getTotalTime();
             }
-            maximum_cool_min_layer_time = std::max(maximum_cool_min_layer_time, extruder_plan.fan_speed_layer_time_settings_.cool_min_layer_time);
+
+            const FanSpeedLayerTimeSettings& settings = extruder_plan.fan_speed_layer_time_settings_;
+            maximum_cool_min_layer_time = std::max(maximum_cool_min_layer_time, contains_overhang_ ? settings.cool_min_layer_time_overhang : settings.cool_min_layer_time);
 
             // Modify fan speeds for the first layer(s)
             extruder_plan.processFanSpeedForFirstLayers();