Refactor bridge flow to Slic3r::Flow::Bridge class

lib/Slic3r/Extruder.pm

@@ -13,12 +13,18 @@ use constant OPTIONS => [qw(
 has 'id'    => (is => 'rw', required => 1);
 has $_      => (is => 'ro', required => 1) for @{&OPTIONS};
 
+has 'bridge_flow'               => (is => 'lazy');
 has 'retracted'                 => (is => 'rw', default => sub {0} );
 has 'restart_extra'             => (is => 'rw', default => sub {0} );
 has 'e_per_mm3'                 => (is => 'lazy');
 has 'retract_speed_mm_min'      => (is => 'lazy');
 has '_mm3_per_mm_cache'         => (is => 'ro', default => sub {{}});
 
+sub _build_bridge_flow {
+    my $self = shift;
+    return Slic3r::Flow::Bridge->new(nozzle_diameter => $self->nozzle_diameter);
+}
+
 sub _build_e_per_mm3 {
     my $self = shift;
     return $self->extrusion_multiplier * (4 / (($self->filament_diameter ** 2) * PI));

lib/Slic3r/Fill.pm

@@ -135,7 +135,7 @@ sub make_fill {
             $filler = $Slic3r::Config->solid_fill_pattern;
             if ($is_bridge) {
                 $filler = 'rectilinear';
-                $flow_spacing = $layer->infill_flow->bridge_spacing;
+                $flow_spacing = $layer->extruders->{infill}->bridge_flow->spacing;
             } elsif ($surface->surface_type == S_TYPE_INTERNALSOLID) {
                 $filler = 'rectilinear';
             }
@@ -157,7 +157,7 @@ sub make_fill {
         my $params = shift @paths;
         
         # ugly hack(tm) to get the right amount of flow (GCode.pm should be fixed)
-        $params->{flow_spacing} = $layer->infill_flow->bridge_width if $is_bridge;
+        $params->{flow_spacing} = $layer->extruders->{infill}->bridge_flow->width if $is_bridge;
         
         # save into layer
         next unless @paths;

lib/Slic3r/Flow.pm

@@ -9,8 +9,6 @@ has 'layer_height'      => (is => 'ro', default => sub { $Slic3r::Config->layer_
 
 has 'width'             => (is => 'rwp', builder => 1);
 has 'spacing'           => (is => 'lazy');
-has 'bridge_width'      => (is => 'lazy');
-has 'bridge_spacing'    => (is => 'lazy');
 has 'scaled_width'      => (is => 'lazy');
 has 'scaled_spacing'    => (is => 'lazy');
 
@@ -73,17 +71,6 @@ sub clone {
     );
 }
 
-sub _build_bridge_width {
-    my $self = shift;
-    return sqrt($Slic3r::Config->bridge_flow_ratio * ($self->nozzle_diameter**2));
-}
-
-sub _build_bridge_spacing {
-    my $self = shift;
-    my $width = $self->bridge_width;
-    return $width + &Slic3r::OVERLAP_FACTOR * ($width * PI / 4 - $width);
-}
-
 sub _build_scaled_width {
     my $self = shift;
     return scale $self->width;
@@ -94,4 +81,22 @@ sub _build_scaled_spacing {
     return scale $self->spacing;
 }
 
+
+package Slic3r::Flow::Bridge;
+use Moo;
+extends 'Slic3r::Flow';
+
+use Slic3r::Geometry qw(PI);
+
+sub _build_width {
+    my $self = shift;
+    return sqrt($Slic3r::Config->bridge_flow_ratio * ($self->nozzle_diameter**2));
+}
+
+sub _build_spacing {
+    my $self = shift;
+    my $width = $self->width;
+    return $width + &Slic3r::OVERLAP_FACTOR * ($width * PI / 4 - $width);
+}
+
 1;

lib/Slic3r/Layer.pm

@@ -64,7 +64,7 @@ sub support_material_contact_height {
     
     # TODO: check what upper region applies instead of considering the first one
     my $upper_layer = $self->object->layers->[ $self->id + 1 ] // $self;
-    my $h = ($self->height + $upper_layer->height) - $upper_layer->regions->[0]->infill_flow->bridge_width;
+    my $h = ($self->height + $upper_layer->height) - $upper_layer->regions->[0]->extruders->{infill}->bridge_flow->width;
     
     # If layer height is less than half the bridge width then we'll get a negative height for contact area.
     # The optimal solution would be to skip some layers during support material generation, but for now

lib/Slic3r/Layer/Region.pm

@@ -13,7 +13,7 @@ has 'layer' => (
     trigger     => 1,
     handles     => [qw(id slice_z print_z height flow)],
 );
-has 'region'            => (is => 'ro', required => 1);
+has 'region'            => (is => 'ro', required => 1, handles => [qw(extruders)]);
 has 'perimeter_flow'    => (is => 'rw');
 has 'infill_flow'       => (is => 'rw');
 has 'infill_area_threshold' => (is => 'lazy');

lib/Slic3r/Print/Object.pm

@@ -473,7 +473,7 @@ sub bridge_over_infill {
             # exclude infill from the layers below if needed
             # see discussion at https://github.com/alexrj/Slic3r/issues/240
             {
-                my $excess = $layerm->infill_flow->bridge_width - $layerm->height;
+                my $excess = $layerm->extruders->{infill}->bridge_flow->width - $layerm->height;
                 for (my $i = $layer_id-1; $excess >= $self->layers->[$i]->height; $i--) {
                     Slic3r::debugf "  skipping infill below those areas at layer %d\n", $i;
                     foreach my $lower_layerm (@{$self->layers->[$i]->regions}) {