From 6194cbf530e427da4aa884d17469de2c3b13ff63 Mon Sep 17 00:00:00 2001
From: Alessandro Ranellucci <aar@cpan.org>
Date: Thu, 12 Jun 2014 09:15:40 +0200
Subject: [PATCH] Refactoring: new method in Flow for calculating spacing
 between extrusions having different width

---
 lib/Slic3r/Layer/Region.pm | 16 +++++++---------
 xs/src/Flow.cpp            | 17 ++++++++++++++++-
 xs/src/Flow.hpp            |  1 +
 xs/xsp/Flow.xsp            |  2 ++
 4 files changed, 26 insertions(+), 10 deletions(-)

diff --git a/lib/Slic3r/Layer/Region.pm b/lib/Slic3r/Layer/Region.pm
index bf6e639e..976b049f 100644
--- a/lib/Slic3r/Layer/Region.pm
+++ b/lib/Slic3r/Layer/Region.pm
@@ -41,18 +41,18 @@ sub flow {
 sub make_perimeters {
     my $self = shift;
     
-    # external perimeters
-    my $ext_perimeter_flow  = $self->flow(FLOW_ROLE_EXTERNAL_PERIMETER);
-    my $ext_mm3_per_mm      = $ext_perimeter_flow->mm3_per_mm;
-    my $ext_pwidth          = $ext_perimeter_flow->scaled_width;
-    my $ext_pspacing        = $ext_perimeter_flow->scaled_spacing;
-    
     # other perimeters
     my $perimeter_flow      = $self->flow(FLOW_ROLE_PERIMETER);
     my $mm3_per_mm          = $perimeter_flow->mm3_per_mm;
     my $pwidth              = $perimeter_flow->scaled_width;
     my $pspacing            = $perimeter_flow->scaled_spacing;
     
+    # external perimeters
+    my $ext_perimeter_flow  = $self->flow(FLOW_ROLE_EXTERNAL_PERIMETER);
+    my $ext_mm3_per_mm      = $ext_perimeter_flow->mm3_per_mm;
+    my $ext_pwidth          = $ext_perimeter_flow->scaled_width;
+    my $ext_pspacing        = scale($ext_perimeter_flow->spacing_to($perimeter_flow));
+    
     # overhang perimeters
     my $overhang_flow       = $self->region->flow(FLOW_ROLE_PERIMETER, -1, 1, 0, undef, $self->layer->object);
     my $mm3_per_mm_overhang = $overhang_flow->mm3_per_mm;
@@ -109,9 +109,7 @@ sub make_perimeters {
                         push @thin_walls, @$diff;
                     }
                 } else {
-                    my $distance = ($i == 2)
-                        ? (0.5*$ext_pspacing + 0.5*$pspacing)
-                        : (1.0*$pspacing);
+                    my $distance = ($i == 2) ? $ext_pspacing : $pspacing;
                     
                     @offsets = @{offset2(
                         \@last,
diff --git a/xs/src/Flow.cpp b/xs/src/Flow.cpp
index ba828aff..00c6cdc9 100644
--- a/xs/src/Flow.cpp
+++ b/xs/src/Flow.cpp
@@ -40,7 +40,7 @@ Flow::new_from_spacing(float spacing, float nozzle_diameter, float height, bool
 float
 Flow::spacing() const {
     if (this->bridge) {
-        return width + BRIDGE_EXTRA_SPACING;
+        return this->width + BRIDGE_EXTRA_SPACING;
     }
     
     float min_flow_spacing;
@@ -54,6 +54,21 @@ Flow::spacing() const {
     return this->width - OVERLAP_FACTOR * (this->width - min_flow_spacing);
 }
 
+/* This method returns the centerline spacing between an extrusion using this
+   flow and another one using another flow.
+   this->spacing(other) shall return the same value as other.spacing(*this) */
+float
+Flow::spacing(const Flow &other) const {
+    assert(this->height == other.height);
+    assert(this->bridge == other.bridge);
+    
+    if (this->bridge) {
+        return this->width/2 + other.width/2 + BRIDGE_EXTRA_SPACING;
+    }
+    
+    return this->spacing()/2 + other.spacing()/2;
+}
+
 /* This method returns extrusion volume per head move unit. */
 double
 Flow::mm3_per_mm() const {
diff --git a/xs/src/Flow.hpp b/xs/src/Flow.hpp
index aeb87183..88cae247 100644
--- a/xs/src/Flow.hpp
+++ b/xs/src/Flow.hpp
@@ -29,6 +29,7 @@ class Flow
     Flow(float _w, float _h, float _nd, bool _bridge = false)
         : width(_w), height(_h), nozzle_diameter(_nd), bridge(_bridge) {};
     float spacing() const;
+    float spacing(const Flow &other) const;
     double mm3_per_mm() const;
     coord_t scaled_width() const {
         return scale_(this->width);
diff --git a/xs/xsp/Flow.xsp b/xs/xsp/Flow.xsp
index 7c494314..09c6fd57 100644
--- a/xs/xsp/Flow.xsp
+++ b/xs/xsp/Flow.xsp
@@ -24,6 +24,8 @@
     bool bridge()
         %code{% RETVAL = THIS->bridge; %};
     float spacing();
+    float spacing_to(Flow* other)
+        %code{% RETVAL = THIS->spacing(*other); %};
     long scaled_width();
     long scaled_spacing();
     double mm3_per_mm();