--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/OrthancStone/Sources/Toolbox/Internals/OrientedIntegerLine2D.h	Tue Jan 11 18:58:37 2022 +0100
@@ -0,0 +1,98 @@
+/**
+ * Stone of Orthanc
+ * Copyright (C) 2012-2016 Sebastien Jodogne, Medical Physics
+ * Department, University Hospital of Liege, Belgium
+ * Copyright (C) 2017-2022 Osimis S.A., Belgium
+ * Copyright (C) 2021-2022 Sebastien Jodogne, ICTEAM UCLouvain, Belgium
+ *
+ * This program is free software: you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public License
+ * as published by the Free Software Foundation, either version 3 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this program. If not, see
+ * <http://www.gnu.org/licenses/>.
+ **/
+
+
+#pragma once
+
+#include <vector>
+#include <list>
+
+
+namespace OrthancStone
+{
+  namespace Internals
+  {
+    /**
+     * This is an oriented 2D line with unsigned integer coordinates.
+     **/
+    class OrientedIntegerLine2D
+    {
+    private:
+      size_t  x1_;
+      size_t  y1_;
+      size_t  x2_;
+      size_t  y2_;
+
+    public:
+      OrientedIntegerLine2D(size_t x1,
+                            size_t y1,
+                            size_t x2,
+                            size_t y2);
+
+      bool IsVertical() const
+      {
+        return (x1_ == x2_);
+      }
+
+      bool IsHorizontal() const
+      {
+        return (y1_ == y2_);
+      }
+
+      bool IsEmpty() const
+      {
+        return (x1_ == x2_ &&
+                y1_ == y2_);
+      }
+
+      size_t GetX1() const
+      {
+        return x1_;
+      }
+
+      size_t GetY1() const
+      {
+        return y1_;
+      }
+
+      size_t GetX2() const
+      {
+        return x2_;
+      }
+
+      size_t GetY2() const
+      {
+        return y2_;
+      }
+
+      bool IsDownward() const
+      {
+        return (y1_ < y2_);
+      }
+
+      typedef std::list< std::pair<size_t, size_t> >  Chain;
+      
+      static void ExtractChains(std::list<Chain>& chains,
+                                const std::vector<OrientedIntegerLine2D>& edges);
+    };
+  }
+}