--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/OrthancStone/Sources/Scene2D/GrayscaleWindowingSceneTracker.cpp	Fri Aug 07 15:55:59 2020 +0200
@@ -0,0 +1,161 @@
+/**
+ * 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 "GrayscaleWindowingSceneTracker.h"
+
+#include "../Scene2DViewport/ViewportController.h"
+#include "FloatTextureSceneLayer.h"
+
+#include <OrthancException.h>
+
+namespace OrthancStone
+{
+  namespace
+  {
+    class GrayscaleLayerAccessor : public boost::noncopyable
+    {
+    private:
+      std::unique_ptr<IViewport::ILock>   lock_;
+      FloatTextureSceneLayer*             layer_;
+
+    public:
+      GrayscaleLayerAccessor(boost::shared_ptr<IViewport> viewport,
+                             int layerIndex) :
+        layer_(NULL)
+      {
+        if (viewport != NULL)
+        {
+          lock_.reset(viewport->Lock());
+
+          if (lock_->GetController().GetScene().HasLayer(layerIndex))
+          {
+            ISceneLayer& layer = lock_->GetController().GetScene().GetLayer(layerIndex);
+            if (layer.GetType() == ISceneLayer::Type_FloatTexture)
+            {
+              layer_ = &dynamic_cast<FloatTextureSceneLayer&>(layer);
+            }
+          }
+        }
+      }
+
+      bool IsValid() const
+      {
+        return layer_ != NULL;
+      }
+
+      FloatTextureSceneLayer& GetLayer() const
+      {
+        if (layer_ == NULL)
+        {
+          throw Orthanc::OrthancException(Orthanc::ErrorCode_BadSequenceOfCalls);
+        }
+        else
+        {
+          return *layer_;
+        }
+      }
+
+      void Invalidate()
+      {
+        if (lock_.get() != NULL)
+        {
+          lock_->Invalidate();
+        }
+      }
+    };
+  }
+  
+  void GrayscaleWindowingSceneTracker::SetWindowing(float center,
+                                                    float width)
+  {
+    if (active_)
+    {
+      GrayscaleLayerAccessor accessor(viewport_, layerIndex_);
+      
+      if (accessor.IsValid())
+      {
+        accessor.GetLayer().SetCustomWindowing(center, width);
+        accessor.Invalidate();
+      }
+    }      
+  }
+    
+
+  GrayscaleWindowingSceneTracker::GrayscaleWindowingSceneTracker(boost::shared_ptr<IViewport> viewport,
+                                                                 int layerIndex,
+                                                                 const PointerEvent& event,
+                                                                 unsigned int canvasWidth,
+                                                                 unsigned int canvasHeight) :
+    OneGesturePointerTracker(viewport),
+    layerIndex_(layerIndex),
+    clickX_(event.GetMainPosition().GetX()),
+    clickY_(event.GetMainPosition().GetY())
+  {
+    active_ = false;
+
+    if (canvasWidth > 3 &&
+        canvasHeight > 3)
+    {
+      GrayscaleLayerAccessor accessor(viewport_, layerIndex_);
+      
+      if (accessor.IsValid())
+      {
+        FloatTextureSceneLayer& layer = accessor.GetLayer();
+        
+        layer.GetWindowing(originalCenter_, originalWidth_);
+        
+        float minValue, maxValue;
+        layer.GetRange(minValue, maxValue);
+        
+        normalization_ = (maxValue - minValue) / static_cast<double>(std::min(canvasWidth, canvasHeight) - 1);
+        active_ = true;
+      }
+      else
+      {
+        LOG(INFO) << "Cannot create GrayscaleWindowingSceneTracker on a non-float texture";
+      }
+    }
+  }
+  
+  void GrayscaleWindowingSceneTracker::PointerMove(const PointerEvent& event)
+  {
+    if (active_)
+    {
+      const double x = event.GetMainPosition().GetX();
+      const double y = event.GetMainPosition().GetY();
+
+      float center = originalCenter_ + (x - clickX_) * normalization_;
+      float width = originalWidth_ + (y - clickY_) * normalization_;
+
+      if (width <= 1)
+      {
+        width = 1;
+      }
+      
+      SetWindowing(center, width);
+    }
+  }
+
+  void GrayscaleWindowingSceneTracker::Cancel()
+  {
+    SetWindowing(originalCenter_, originalWidth_);
+  }
+}