From 5d1e01839cdd956db28c6c70a69837329753ef17 Mon Sep 17 00:00:00 2001
From: supermerill <merill@fr.fr>
Date: Thu, 29 Nov 2018 16:43:41 +0100
Subject: [PATCH] remove bad algo from keep_types

---
 xs/src/libslic3r/PrintObject.cpp       |  2 +-
 xs/src/libslic3r/SurfaceCollection.cpp | 23 +++++++++++++++++------
 2 files changed, 18 insertions(+), 7 deletions(-)

diff --git a/xs/src/libslic3r/PrintObject.cpp b/xs/src/libslic3r/PrintObject.cpp
index e4604782e..bcce57559 100644
--- a/xs/src/libslic3r/PrintObject.cpp
+++ b/xs/src/libslic3r/PrintObject.cpp
@@ -1641,7 +1641,7 @@ PrintObject::_discover_neighbor_horizontal_shells(LayerRegion* layerm, const siz
         // assign top and bottom surfaces to layer
         SurfaceCollection tmp_coll;
         for (const auto& s : neighbor_fill_surfaces.surfaces)
-            if (s.surface_type == stTop || s.is_bottom())
+            if (s.is_top() || s.is_bottom())
                 tmp_coll.append(s);
         
         for (auto s : tmp_coll.group()) {
diff --git a/xs/src/libslic3r/SurfaceCollection.cpp b/xs/src/libslic3r/SurfaceCollection.cpp
index 1fb15d023..04f449dc2 100644
--- a/xs/src/libslic3r/SurfaceCollection.cpp
+++ b/xs/src/libslic3r/SurfaceCollection.cpp
@@ -200,12 +200,23 @@ SurfaceCollection::keep_type(const SurfaceType type)
 void
 SurfaceCollection::keep_types(const SurfaceType *types, size_t ntypes) 
 {
-    size_t n {0};
-    for (size_t i = 0; i < ntypes; ++i)
-        n |= types[i]; // form bitmask.
-    // Use stl remove_if to remove 
-    auto ptr = std::remove_if(surfaces.begin(), surfaces.end(),[n] (const Surface& s) { return (s.surface_type & n) != s.surface_type; });
-    surfaces.erase(ptr, surfaces.cend());
+    size_t j = 0;
+    for (size_t i = 0; i < surfaces.size(); ++ i) {
+        bool keep = false;
+        for (int k = 0; k < ntypes; ++ k) {
+            if (surfaces[i].surface_type == types[k]) {
+                keep = true;
+                break;
+            }
+        }
+        if (keep) {
+            if (j < i)
+                std::swap(surfaces[i], surfaces[j]);
+            ++ j;
+        }
+    }
+    if (j < surfaces.size())
+        surfaces.erase(surfaces.begin() + j, surfaces.end());
 }
 
 void