Add disallowed areas

include/libnest2d/nester.hpp

@@ -71,6 +71,15 @@ class _Item {
     int binid_{BIN_ID_UNSET}, priority_{0};
     bool fixed_{false};
 
+    /**
+     * \brief If this is a fixed area, indicates whether it is a disallowed area
+     * or a previously placed item.
+     *
+     * If this is a disallowed area, other objects will not get packed close
+     * together with this item. It only blocks other items in its area.
+     */
+    bool disallowed_{false};
+
 public:
 
     /// The type of the shape which was handed over as the template argument.
@@ -129,10 +138,18 @@ class _Item {
         sh_(sl::create<RawShape>(std::move(contour), std::move(holes))) {}
 
     inline bool isFixed() const noexcept { return fixed_; }
+    inline bool isDisallowedArea() const noexcept { return disallowed_; }
     inline void markAsFixedInBin(int binid)
     {
         fixed_ = binid >= 0;
         binid_ = binid;
+        disallowed_ = false;
+    }
+    inline void markAsDisallowedAreaInBin(int binid)
+    {
+        fixed_ = binid >= 0;
+        binid_ = binid;
+        disallowed_ = fixed_;
     }
 
     inline void binId(int idx) { binid_ = idx; }

include/libnest2d/placers/nfpplacer.hpp

@@ -101,7 +101,7 @@ struct NfpPConfig {
      * alignment with the candidate item or do anything else.
      *
      * \param remaining A container with the remaining items waiting to be
-     * placed. You can use some features about the remaining items to alter to
+     * placed. You can use some features about the remaining items to alter the
      * score of the current placement. If you know that you have to leave place
      * for other items as well, that might influence your decision about where
      * the current candidate should be placed. E.g. imagine three big circles
@@ -735,7 +735,8 @@ class _NofitPolyPlacer: public PlacerBoilerplate<_NofitPolyPlacer<RawShape, TBin
             remlist.insert(remlist.end(), remaining.from, remaining.to);
         }
 
-        if(items_.empty()) {
+        if(std::all_of(items_.begin(), items_.end(),
+                [](const Item& item) { return item.isDisallowedArea(); })) {
             setInitialPosition(item);
             best_overfit = overfit(item.transformedShape(), bin_);
             can_pack = best_overfit <= 0;