fix and integrate with CoolingBuffer

src/libslic3r/GCode.cpp

@@ -25,6 +25,7 @@
 #include <cstdlib>
 #include <chrono>
 #include <math.h>
+#include <string>
 #include <string_view>
 
 #include <boost/algorithm/string.hpp>
@@ -2989,7 +2990,7 @@ std::string GCode::_extrude(const ExtrusionPath &path, const std::string_view de
         double last_set_speed     = new_points[0].speed * 60.0;
         double last_set_fan_speed = new_points[0].fan_speed;
         gcode += m_writer.set_speed(last_set_speed, "", cooling_marker_setspeed_comments);
-        gcode += m_writer.set_fan(last_set_fan_speed);
+        gcode += ";_SET_FAN_SPEED" + std::to_string(int(last_set_fan_speed)) + "\n";
         Vec2d prev = this->point_to_gcode_quantized(new_points[0].p);
         for (size_t i = 1; i < new_points.size(); i++) {
             const ProcessedPoint &processed_point = new_points[i];
@@ -3003,10 +3004,11 @@ std::string GCode::_extrude(const ExtrusionPath &path, const std::string_view de
                 last_set_speed = new_speed;
             }
             if (last_set_fan_speed != processed_point.fan_speed) {
-                gcode += m_writer.set_fan(processed_point.fan_speed);
                 last_set_fan_speed = processed_point.fan_speed;
+                gcode += ";_SET_FAN_SPEED" + std::to_string(int(last_set_fan_speed)) + "\n";
             }
         }
+        gcode += ";_RESET_FAN_SPEED\n";
     }
 
     if (m_enable_cooling_markers)

src/libslic3r/GCode/CoolingBuffer.cpp

@@ -1,5 +1,6 @@
 #include "../GCode.hpp"
 #include "CoolingBuffer.hpp"
+#include <algorithm>
 #include <boost/algorithm/string/predicate.hpp>
 #include <boost/algorithm/string/replace.hpp>
 #include <boost/log/trivial.hpp>
@@ -59,6 +60,9 @@ struct CoolingLine
         // Would be TYPE_ADJUSTABLE, but the block of G-code lines has zero extrusion length, thus the block
         // cannot have its speed adjusted. This should not happen (sic!).
         TYPE_ADJUSTABLE_EMPTY   = 1 << 12,
+        // Custom fan speed (introduced for overhang fan speed)
+        TYPE_SET_FAN_SPEED      = 1 << 13,
+        TYPE_RESET_FAN_SPEED    = 1 << 14,
     };
 
     CoolingLine(unsigned int type, size_t  line_start, size_t  line_end) :
@@ -88,6 +92,8 @@ struct CoolingLine
     float   time;
     // Maximum duration of this segment.
     float   time_max;
+    // Requested fan speed
+    int     fan_speed;
     // If marked with the "slowdown" flag, the line has been slowed down.
     bool    slowdown;
 };
@@ -497,7 +503,18 @@ std::vector<PerExtruderAdjustments> CoolingBuffer::parse_layer_gcode(const std::
             } else
                 line.time = 0;
             line.time_max = line.time;
+        } else if (boost::contains(sline, ";_SET_FAN_SPEED")) {
+            auto speed_start = sline.find_last_of('D');
+            int  speed       = 0;
+            for (char num : sline.substr(speed_start + 1)) {
+                speed = speed * 10 + (num - '0');
             }
+            line.type = CoolingLine::TYPE_SET_FAN_SPEED;
+            line.fan_speed = speed;
+        } else if (boost::contains(sline, ";_RESET_FAN_SPEED")) {
+            line.type = CoolingLine::TYPE_RESET_FAN_SPEED;
+        }
+
         if (line.type != 0)
             adjustment->lines.emplace_back(std::move(line));
     }
@@ -734,6 +751,7 @@ std::string CoolingBuffer::apply_layer_cooldown(
 #define EXTRUDER_CONFIG(OPT) m_config.OPT.get_at(m_current_extruder)
         int min_fan_speed = EXTRUDER_CONFIG(min_fan_speed);
         int fan_speed_new = EXTRUDER_CONFIG(fan_always_on) ? min_fan_speed : 0;
+        std::pair<int, int> custom_fan_speed_limits{fan_speed_new, EXTRUDER_CONFIG(cooling) ? EXTRUDER_CONFIG(max_fan_speed) : 100 };
         int disable_fan_first_layers = EXTRUDER_CONFIG(disable_fan_first_layers);
         // Is the fan speed ramp enabled?
         int full_fan_speed_layer = EXTRUDER_CONFIG(full_fan_speed_layer);
@@ -750,11 +768,13 @@ std::string CoolingBuffer::apply_layer_cooldown(
                 if (layer_time < slowdown_below_layer_time) {
                     // Layer time very short. Enable the fan to a full throttle.
                     fan_speed_new = max_fan_speed;
+                    custom_fan_speed_limits.first = fan_speed_new;
                 } else if (layer_time < fan_below_layer_time) {
                     // Layer time quite short. Enable the fan proportionally according to the current layer time.
                     assert(layer_time >= slowdown_below_layer_time);
                     double t = (layer_time - slowdown_below_layer_time) / (fan_below_layer_time - slowdown_below_layer_time);
                     fan_speed_new = int(floor(t * min_fan_speed + (1. - t) * max_fan_speed) + 0.5);
+                    custom_fan_speed_limits.first = fan_speed_new;
                 }
             }
             bridge_fan_speed   = EXTRUDER_CONFIG(bridge_fan_speed);
@@ -763,6 +783,7 @@ std::string CoolingBuffer::apply_layer_cooldown(
                 float factor = float(int(layer_id + 1) - disable_fan_first_layers) / float(full_fan_speed_layer - disable_fan_first_layers);
                 fan_speed_new    = std::clamp(int(float(fan_speed_new) * factor + 0.5f), 0, 255);
                 bridge_fan_speed = std::clamp(int(float(bridge_fan_speed) * factor + 0.5f), 0, 255);
+                custom_fan_speed_limits.second = fan_speed_new;
             }
 #undef EXTRUDER_CONFIG
             bridge_fan_control = bridge_fan_speed > fan_speed_new;
@@ -775,11 +796,12 @@ std::string CoolingBuffer::apply_layer_cooldown(
             m_fan_speed = fan_speed_new;
             new_gcode  += GCodeWriter::set_fan(m_config.gcode_flavor, m_config.gcode_comments, m_fan_speed);
         }
+        return custom_fan_speed_limits;
     };
 
     const char         *pos               = gcode.c_str();
     int                 current_feedrate  = 0;
-    change_extruder_set_fan();
+    std::pair<int,int> fan_speed_limits = change_extruder_set_fan();
     for (const CoolingLine *line : lines) {
         const char *line_start  = gcode.c_str() + line->line_start;
         const char *line_end    = gcode.c_str() + line->line_end;
@@ -790,9 +812,17 @@ std::string CoolingBuffer::apply_layer_cooldown(
             auto res = std::from_chars(line_start + m_toolchange_prefix.size(), line_end, new_extruder);
             if (res.ec != std::errc::invalid_argument && new_extruder != m_current_extruder) {
                 m_current_extruder = new_extruder;
-                change_extruder_set_fan();
+                fan_speed_limits = change_extruder_set_fan();
             }
             new_gcode.append(line_start, line_end - line_start);
+        } else if (line->type & CoolingLine::TYPE_SET_FAN_SPEED) {
+            int new_speed = std::clamp(line->fan_speed, fan_speed_limits.first, fan_speed_limits.second);
+            if (m_fan_speed != new_speed) {
+                new_gcode += GCodeWriter::set_fan(m_config.gcode_flavor, m_config.gcode_comments, new_speed);
+                m_fan_speed = new_speed;
+            }
+        } else if (line->type & CoolingLine::TYPE_RESET_FAN_SPEED){
+            fan_speed_limits = change_extruder_set_fan();
         } else if (line->type & CoolingLine::TYPE_BRIDGE_FAN_START) {
             if (bridge_fan_control)
                 new_gcode += GCodeWriter::set_fan(m_config.gcode_flavor, m_config.gcode_comments, bridge_fan_speed);