Rework calculation of min/max flow rates for simulation view colour scheme.

The max value was being calculated as the product of the max line width, max layer thickness
and max feedrate but it should be calculated as the maximum of the products of the width,
thickness and feedrate for each individual line. i.e. calculate the flow for each line
and use the min and max values of the flows.

plugins/SimulationView/SimulationView.py

@@ -90,11 +90,12 @@ class SimulationView(CuraView):
 
         self._max_feedrate = sys.float_info.min
         self._min_feedrate = sys.float_info.max
-        self._max_feedrate_with_extrusion = sys.float_info.min
         self._max_thickness = sys.float_info.min
         self._min_thickness = sys.float_info.max
         self._max_line_width = sys.float_info.min
         self._min_line_width = sys.float_info.max
+        self._min_flow_rate = sys.float_info.max
+        self._max_flow_rate = sys.float_info.min
 
         self._global_container_stack = None  # type: Optional[ContainerStack]
         self._proxy = None
@@ -413,10 +414,10 @@ class SimulationView(CuraView):
         return self._min_line_width
 
     def getMaxFlowRate(self) -> float:
-        return self._max_line_width * self._max_thickness * self._max_feedrate_with_extrusion
+        return self._max_flow_rate
 
     def getMinFlowRate(self) -> float:
-        min_flow_rate = self._min_line_width * self._min_thickness * self._min_feedrate
+        min_flow_rate = self._min_flow_rate
         if abs(min_flow_rate - sys.float_info.max) < 10:  # Some lenience due to floating point rounding.
             return 0.0  # If it's still max-float, there are no measurements. Use 0 then.
         return min_flow_rate
@@ -474,7 +475,6 @@ class SimulationView(CuraView):
         # Before we start, save the old values so that we can tell if any of the spectrums need to change.
         old_min_feedrate = self._min_feedrate
         old_max_feedrate = self._max_feedrate
-        old_max_feedrate_with_extrusion = self._max_feedrate_with_extrusion
         old_min_linewidth = self._min_line_width
         old_max_linewidth = self._max_line_width
         old_min_thickness = self._min_thickness
@@ -482,7 +482,6 @@ class SimulationView(CuraView):
 
         self._min_feedrate = sys.float_info.max
         self._max_feedrate = sys.float_info.min
-        self._max_feedrate_with_extrusion = sys.float_info.min
         self._min_line_width = sys.float_info.max
         self._max_line_width = sys.float_info.min
         self._min_thickness = sys.float_info.max
@@ -522,10 +521,13 @@ class SimulationView(CuraView):
                     visible_feedrates = numpy.take(polyline.lineFeedrates, visible_indices)
                     visible_feedrates_with_extrusion = numpy.take(polyline.lineFeedrates, visible_indicies_with_extrusion)
                     visible_linewidths = numpy.take(polyline.lineWidths, visible_indices)
+                    visible_linewidths_with_extrusion = numpy.take(polyline.lineWidths, visible_indicies_with_extrusion)
                     visible_thicknesses = numpy.take(polyline.lineThicknesses, visible_indices)
+                    visible_thicknesses_with_extrusion = numpy.take(polyline.lineThicknesses, visible_indicies_with_extrusion)
                     self._max_feedrate = max(float(visible_feedrates.max()), self._max_feedrate)
-                    if visible_feedrates_with_extrusion.size != 0:
-                        self._max_feedrate_with_extrusion = max(float(visible_feedrates_with_extrusion.max()), self._max_feedrate_with_extrusion)
+                    flow_rates = visible_feedrates_with_extrusion * visible_linewidths_with_extrusion * visible_thicknesses_with_extrusion
+                    self._min_flow_rate = min(float(flow_rates.min()), self._min_flow_rate)
+                    self._max_flow_rate = max(float(flow_rates.max()), self._max_flow_rate)
                     self._min_feedrate = min(float(visible_feedrates.min()), self._min_feedrate)
                     self._max_line_width = max(float(visible_linewidths.max()), self._max_line_width)
                     self._min_line_width = min(float(visible_linewidths.min()), self._min_line_width)
@@ -538,8 +540,7 @@ class SimulationView(CuraView):
 
         if old_min_feedrate != self._min_feedrate or old_max_feedrate != self._max_feedrate \
                 or old_min_linewidth != self._min_line_width or old_max_linewidth != self._max_line_width \
-                or old_min_thickness != self._min_thickness or old_max_thickness != self._max_thickness \
-                or old_max_feedrate_with_extrusion != self._max_feedrate_with_extrusion:
+                or old_min_thickness != self._min_thickness or old_max_thickness != self._max_thickness:
             self.colorSchemeLimitsChanged.emit()
 
     def calculateMaxPathsOnLayer(self, layer_num: int) -> None: