From bd3daeed5adfa5922668390ae460d85402ee5455 Mon Sep 17 00:00:00 2001
From: bubnikv <bubnikv@gmail.com>
Date: Wed, 11 Jan 2017 13:43:33 +0100
Subject: [PATCH] Slightly more efficient PrintObject Layer destruction.

---
 xs/src/libslic3r/Layer.cpp       |  5 -----
 xs/src/libslic3r/Layer.hpp       |  2 +-
 xs/src/libslic3r/PrintObject.cpp | 16 ++++++++++++----
 3 files changed, 13 insertions(+), 10 deletions(-)

diff --git a/xs/src/libslic3r/Layer.cpp b/xs/src/libslic3r/Layer.cpp
index 929460169c..c40c036e7d 100644
--- a/xs/src/libslic3r/Layer.cpp
+++ b/xs/src/libslic3r/Layer.cpp
@@ -313,9 +313,4 @@ SupportLayer::SupportLayer(size_t id, PrintObject *object, coordf_t height,
 {
 }
 
-SupportLayer::~SupportLayer()
-{
-}
-
-
 }
diff --git a/xs/src/libslic3r/Layer.hpp b/xs/src/libslic3r/Layer.hpp
index a5ba3f804b..02cb196553 100644
--- a/xs/src/libslic3r/Layer.hpp
+++ b/xs/src/libslic3r/Layer.hpp
@@ -152,7 +152,7 @@ public:
 protected:
     SupportLayer(size_t id, PrintObject *object, coordf_t height, coordf_t print_z,
         coordf_t slice_z);
-    virtual ~SupportLayer();
+    virtual ~SupportLayer() {}
 };
 
 
diff --git a/xs/src/libslic3r/PrintObject.cpp b/xs/src/libslic3r/PrintObject.cpp
index c323f5d9db..56a45613f3 100644
--- a/xs/src/libslic3r/PrintObject.cpp
+++ b/xs/src/libslic3r/PrintObject.cpp
@@ -133,8 +133,12 @@ PrintObject::layer_count() const
 void
 PrintObject::clear_layers()
 {
-    for (int i = this->layers.size()-1; i >= 0; --i)
-        this->delete_layer(i);
+    for (size_t i = 0; i < this->layers.size(); ++ i) {
+        Layer *layer = this->layers[i];
+        layer->upper_layer = layer->lower_layer = nullptr;
+        delete layer;
+    }
+    this->layers.clear();
 }
 
 Layer*
@@ -162,8 +166,12 @@ PrintObject::support_layer_count() const
 void
 PrintObject::clear_support_layers()
 {
-    for (int i = this->support_layers.size()-1; i >= 0; --i)
-        this->delete_support_layer(i);
+    for (size_t i = 0; i < this->support_layers.size(); ++ i) {
+        Layer *layer = this->support_layers[i];
+        layer->upper_layer = layer->lower_layer = nullptr;
+        delete layer;
+    }
+    this->support_layers.clear();
 }
 
 SupportLayer*