change print flow ratio to float.

Also fixed an issue that maximum volumetric speed is not respected
#93 #103

src/libslic3r/GCode.cpp

@@ -3699,7 +3699,8 @@ std::string GCode::_extrude(const ExtrusionPath &path, std::string description,
     }
 
     // calculate extrusion length per distance unit
-    double e_per_mm = m_writer.extruder()->e_per_mm3() * path.mm3_per_mm * this->config().print_flow_ratio.get_abs_value(1);
+    const auto _mm3_per_mm = path.mm3_per_mm * this->config().print_flow_ratio;
+    double e_per_mm = m_writer.extruder()->e_per_mm3() * _mm3_per_mm;
 
     double min_speed = double(m_config.slow_down_min_speed.get_at(m_writer.extruder()->id()));
     // set speed
@@ -3743,7 +3744,7 @@ std::string GCode::_extrude(const ExtrusionPath &path, std::string description,
     }
     //BBS: if not set the speed, then use the filament_max_volumetric_speed directly
     if (speed == 0)
-        speed = EXTRUDER_CONFIG(filament_max_volumetric_speed) / path.mm3_per_mm;
+        speed = EXTRUDER_CONFIG(filament_max_volumetric_speed) / _mm3_per_mm;
     if (this->on_first_layer()) {
         //BBS: for solid infill of initial layer, speed can be higher as long as
         //wall lines have be attached
@@ -3757,14 +3758,14 @@ std::string GCode::_extrude(const ExtrusionPath &path, std::string description,
     //    // cap speed with max_volumetric_speed anyway (even if user is not using autospeed)
     //    speed = std::min(
     //        speed,
-    //        m_config.max_volumetric_speed.value / path.mm3_per_mm
+    //        m_config.max_volumetric_speed.value / _mm3_per_mm
     //    );
     //}
     if (EXTRUDER_CONFIG(filament_max_volumetric_speed) > 0) {
         // cap speed with max_volumetric_speed anyway (even if user is not using autospeed)
         speed = std::min(
             speed,
-            EXTRUDER_CONFIG(filament_max_volumetric_speed) / path.mm3_per_mm
+            EXTRUDER_CONFIG(filament_max_volumetric_speed) / _mm3_per_mm
         );
     }
     double F = speed * 60;  // convert mm/sec to mm/min

src/libslic3r/PrintConfig.cpp

@@ -1152,16 +1152,16 @@ void PrintConfigDef::init_fff_params()
     def->mode = comAdvanced;
     def->set_default_value(new ConfigOptionFloats { 1. });
 
-    def = this->add("print_flow_ratio", coPercent);
+    def = this->add("print_flow_ratio", coFloat);
     def->label = L("Flow ratio");
     def->tooltip = L("The material may have volumetric change after switching between molten state and crystalline state. "
                      "This setting changes all extrusion flow of this filament in gcode proportionally. "
                      "Recommended value range is between 0.95 and 1.05. "
                      "Maybe you can tune this value to get nice flat surface when there has slight overflow or underflow");
-    def->sidetext = L("%");
     def->mode = comAdvanced;
-    def->min = 2;
-    def->set_default_value(new ConfigOptionPercent(100));
+    def->max = 2;
+    def->min = 0.01;
+    def->set_default_value(new ConfigOptionFloat(1));
 
     def = this->add("enable_pressure_advance", coBools);
     def->label = L("Enable pressure advance");

src/libslic3r/PrintConfig.hpp

@@ -755,7 +755,7 @@ PRINT_CONFIG_CLASS_DEFINE(
     ((ConfigOptionBool,                 only_one_wall_top))
     ((ConfigOptionBool,                 only_one_wall_first_layer))
     //SoftFever
-    ((ConfigOptionPercent,              print_flow_ratio))
+    ((ConfigOptionFloat,                print_flow_ratio))
 )
 
 PRINT_CONFIG_CLASS_DEFINE(

src/slic3r/GUI/Plater.cpp

@@ -8014,7 +8014,7 @@ void Plater::calib_flowrate(int pass) {
         if (obj_name[0] == 'm')
             obj_name[0] = '-';
         auto modifier = stof(obj_name);
-        _obj->config.set_key_value("print_flow_ratio", new ConfigOptionPercent(100 + modifier));
+        _obj->config.set_key_value("print_flow_ratio", new ConfigOptionFloat(1.0f + modifier/100.f));
     }
 
     print_config->set_key_value("layer_height", new ConfigOptionFloat(layer_height));