--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Framework/Toolbox/Extent.cpp	Tue May 30 14:09:11 2017 +0200
@@ -0,0 +1,86 @@
+/**
+ * Stone of Orthanc
+ * Copyright (C) 2012-2016 Sebastien Jodogne, Medical Physics
+ * Department, University Hospital of Liege, Belgium
+ * Copyright (C) 2017 Osimis, Belgium
+ *
+ * This program is free software: you can redistribute it and/or
+ * modify it under the terms of the GNU Affero 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
+ * Affero General Public License for more details.
+ * 
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ **/
+
+
+#include "Extent.h"
+
+#include <algorithm>
+#include <cassert>
+
+namespace OrthancStone
+{
+  void Extent::Reset()
+  {
+    empty_ = true;
+    x1_ = 0;
+    y1_ = 0;
+    x2_ = 0;
+    y2_ = 0;      
+  }
+
+  void Extent::AddPoint(double x,
+                        double y)
+  {
+    if (empty_)
+    {
+      x1_ = x;
+      y1_ = y;
+      x2_ = x;
+      y2_ = y;
+      empty_ = false;
+    }
+    else
+    {
+      x1_ = std::min(x1_, x);
+      y1_ = std::min(y1_, y);
+      x2_ = std::max(x2_, x);
+      y2_ = std::max(y2_, y);
+    }
+
+    assert(x1_ <= x2_ &&
+           y1_ <= y2_);    // This is the invariant of the structure
+  }
+
+
+  void Extent::Union(const Extent& other)
+  {
+    if (other.IsEmpty())
+    {
+      return;
+    }
+
+    if (IsEmpty())
+    {
+      *this = other;
+      return;
+    }
+
+    assert(!IsEmpty());
+
+    x1_ = std::min(x1_, other.x1_);
+    y1_ = std::min(y1_, other.y1_);
+    x2_ = std::min(x2_, other.x2_);
+    y2_ = std::min(y2_, other.y2_);
+
+    assert(x1_ <= x2_ &&
+           y1_ <= y2_);    // This is the invariant of the structure
+  }
+
+}