--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Framework/Radiography/RadiographyWindowingTracker.cpp	Tue Nov 13 10:36:53 2018 +0100
@@ -0,0 +1,195 @@
+/**
+ * Stone of Orthanc
+ * Copyright (C) 2012-2016 Sebastien Jodogne, Medical Physics
+ * Department, University Hospital of Liege, Belgium
+ * Copyright (C) 2017-2018 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 "RadiographyWindowingTracker.h"
+
+#include <Core/OrthancException.h>
+
+
+namespace OrthancStone
+{
+  class RadiographyWindowingTracker::UndoRedoCommand : public UndoRedoStack::ICommand
+  {
+  private:
+    RadiographyScene&  scene_;
+    float              sourceCenter_;
+    float              sourceWidth_;
+    float              targetCenter_;
+    float              targetWidth_;
+
+  public:
+    UndoRedoCommand(const RadiographyWindowingTracker& tracker) :
+      scene_(tracker.scene_),
+      sourceCenter_(tracker.sourceCenter_),
+      sourceWidth_(tracker.sourceWidth_)
+    {
+      scene_.GetWindowingWithDefault(targetCenter_, targetWidth_);
+    }
+
+    virtual void Undo() const
+    {
+      scene_.SetWindowing(sourceCenter_, sourceWidth_);
+    }
+      
+    virtual void Redo() const
+    {
+      scene_.SetWindowing(targetCenter_, targetWidth_);
+    }
+  };
+
+
+  void RadiographyWindowingTracker::ComputeAxisEffect(int& deltaCenter,
+                                                      int& deltaWidth,
+                                                      int delta,
+                                                      Action actionNegative,
+                                                      Action actionPositive)
+  {
+    if (delta < 0)
+    {
+      switch (actionNegative)
+      {
+        case Action_IncreaseWidth:
+          deltaWidth = -delta;
+          break;
+
+        case Action_DecreaseWidth:
+          deltaWidth = delta;
+          break;
+
+        case Action_IncreaseCenter:
+          deltaCenter = -delta;
+          break;
+
+        case Action_DecreaseCenter:
+          deltaCenter = delta;
+          break;
+
+        default:
+          throw Orthanc::OrthancException(Orthanc::ErrorCode_InternalError);
+      }
+    }
+    else if (delta > 0)
+    {
+      switch (actionPositive)
+      {
+        case Action_IncreaseWidth:
+          deltaWidth = delta;
+          break;
+
+        case Action_DecreaseWidth:
+          deltaWidth = -delta;
+          break;
+
+        case Action_IncreaseCenter:
+          deltaCenter = delta;
+          break;
+
+        case Action_DecreaseCenter:
+          deltaCenter = -delta;
+          break;
+
+        default:
+          throw Orthanc::OrthancException(Orthanc::ErrorCode_InternalError);
+      }
+    }
+  }
+    
+    
+  RadiographyWindowingTracker::RadiographyWindowingTracker(UndoRedoStack& undoRedoStack,
+                                                           RadiographyScene& scene,
+                                                           int x,
+                                                           int y,
+                                                           Action leftAction,
+                                                           Action rightAction,
+                                                           Action upAction,
+                                                           Action downAction) :
+    undoRedoStack_(undoRedoStack),
+    scene_(scene),
+    clickX_(x),
+    clickY_(y),
+    leftAction_(leftAction),
+    rightAction_(rightAction),
+    upAction_(upAction),
+    downAction_(downAction)
+  {
+    scene_.GetWindowingWithDefault(sourceCenter_, sourceWidth_);
+
+    float minValue, maxValue;
+    scene.GetRange(minValue, maxValue);
+
+    assert(minValue <= maxValue);
+
+    float tmp;
+      
+    float delta = (maxValue - minValue);
+    if (delta <= 1)
+    {
+      tmp = 0;
+    }
+    else
+    {
+      // NB: Visual Studio 2008 does not provide "log2f()", so we
+      // implement it by ourselves
+      tmp = logf(delta) / logf(2.0f);
+    }
+
+    strength_ = tmp - 7;
+    if (strength_ < 1)
+    {
+      strength_ = 1;
+    }
+  }
+
+
+  void RadiographyWindowingTracker::Render(CairoContext& context,
+                                           double zoom)
+  {
+    throw Orthanc::OrthancException(Orthanc::ErrorCode_InternalError);
+  }
+  
+
+  void RadiographyWindowingTracker::MouseUp()
+  {
+    undoRedoStack_.Add(new UndoRedoCommand(*this));
+  }
+
+
+  void RadiographyWindowingTracker::MouseMove(int displayX,
+                                              int displayY,
+                                              double sceneX,
+                                              double sceneY)
+  {
+    // This follows the behavior of the Osimis Web viewer:
+    // https://bitbucket.org/osimis/osimis-webviewer-plugin/src/master/frontend/src/app/viewport/image-plugins/windowing-viewport-tool.class.js
+
+    static const float SCALE = 1.0;
+      
+    int deltaCenter = 0;
+    int deltaWidth = 0;
+
+    ComputeAxisEffect(deltaCenter, deltaWidth, displayX - clickX_, leftAction_, rightAction_);
+    ComputeAxisEffect(deltaCenter, deltaWidth, displayY - clickY_, upAction_, downAction_);
+
+    float newCenter = sourceCenter_ + (deltaCenter / SCALE * strength_);
+    float newWidth = sourceWidth_ + (deltaWidth / SCALE * strength_);
+    scene_.SetWindowing(newCenter, newWidth);
+  }
+}