--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/OrthancStone/Sources/Scene2D/Internals/FixedPointAligner.cpp	Tue Jul 07 16:21:02 2020 +0200
@@ -0,0 +1,52 @@
+/**
+ * Stone of Orthanc
+ * Copyright (C) 2012-2016 Sebastien Jodogne, Medical Physics
+ * Department, University Hospital of Liege, Belgium
+ * Copyright (C) 2017-2020 Osimis S.A., 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 "../../Scene2DViewport/ViewportController.h"
+#include "FixedPointAligner.h"
+
+namespace OrthancStone
+{
+  namespace Internals
+  {
+    FixedPointAligner::FixedPointAligner(boost::shared_ptr<IViewport> viewport,
+                                         const ScenePoint2D& p) 
+      : viewport_(viewport)
+      , canvas_(p)
+    {
+      std::unique_ptr<IViewport::ILock> lock(viewport_->Lock());
+      pivot_ = canvas_.Apply(lock->GetController().GetCanvasToSceneTransform());
+    }
+
+    
+    void FixedPointAligner::Apply()
+    {
+      std::unique_ptr<IViewport::ILock> lock(viewport_->Lock());
+      ScenePoint2D p = canvas_.Apply(
+        lock->GetController().GetCanvasToSceneTransform());
+
+      lock->GetController().SetSceneToCanvasTransform(
+        AffineTransform2D::Combine(
+          lock->GetController().GetSceneToCanvasTransform(),
+          AffineTransform2D::CreateOffset(p.GetX() - pivot_.GetX(),
+                                          p.GetY() - pivot_.GetY())));
+      lock->Invalidate();
+    }
+  }
+}