/*==========================================================================

  Portions (c) Copyright 2008-2009 Brigham and Women's Hospital (BWH) All Rights Reserved.

  See Doc/copyright/copyright.txt
  or http://www.slicer.org/copyright/copyright.txt for details.

  Program:   3D Slicer
  Module:    $HeadURL$
  Date:      $Date$
  Version:   $Revision$

==========================================================================*/

#include "vtkObjectFactory.h"
#include "vtkCallbackCommand.h"
#include "vtkTransformPolyDataFilter.h"
#include "vtkTransform.h"

#include "vtkOpenIGTLinkIFLogic.h"

#include "vtkMRMLModelDisplayNode.h"
#include "vtkMRMLScalarVolumeNode.h"
#include "vtkMRMLLinearTransformNode.h"
#include "vtkSlicerApplication.h"
#include "vtkSlicerApplicationGUI.h"
#include "vtkSlicerColorLogic.h"

#include "vtkCylinderSource.h"
#include "vtkSphereSource.h"
#include "vtkAppendPolyData.h"


#include "vtkMultiThreader.h"

#include "vtkMRMLIGTLConnectorNode.h"
#include "vtkIGTLCircularBuffer.h"

vtkCxxRevisionMacro(vtkOpenIGTLinkIFLogic, "$Revision$");
vtkStandardNewMacro(vtkOpenIGTLinkIFLogic);

//---------------------------------------------------------------------------
vtkOpenIGTLinkIFLogic::vtkOpenIGTLinkIFLogic()
{
  // initialize slice driver information
  for (int i = 0; i < 3; i ++)
    {
    this->SliceDriver[i] = vtkOpenIGTLinkIFLogic::SLICE_DRIVER_USER;
    }

  this->LocatorDriverFlag = 0;
  //this->LocatorDriver = NULL;
  this->LocatorDriverNodeID = "";
  this->RealTimeImageSourceNodeID = "";

  // If the following code doesn't work, slice nodes should be obtained from application GUI
  this->SliceNode[0] = NULL;
  this->SliceNode[1] = NULL;
  this->SliceNode[2] = NULL;

  this->SliceOrientation[0] = SLICE_RTIMAGE_PERP;
  this->SliceOrientation[1] = SLICE_RTIMAGE_INPLANE;
  this->SliceOrientation[2] = SLICE_RTIMAGE_INPLANE90;

  // Timer Handling

  this->DataCallbackCommand = vtkCallbackCommand::New();
  this->DataCallbackCommand->SetClientData( reinterpret_cast<void *> (this) );
  this->DataCallbackCommand->SetCallback(vtkOpenIGTLinkIFLogic::DataCallback);

  this->EnableOblique = false;
  this->FreezePlane   = false;

  this->Initialized   = 0;
  this->RestrictDeviceName = 0;
  
  this->MessageConverterList.clear();

  // register default data types
  this->LinearTransformConverter = vtkIGTLToMRMLLinearTransform::New();
  this->ImageConverter           = vtkIGTLToMRMLImage::New();
  this->PositionConverter        = vtkIGTLToMRMLPosition::New();

  RegisterMessageConverter(this->LinearTransformConverter);
  RegisterMessageConverter(this->ImageConverter);
  RegisterMessageConverter(this->PositionConverter);

}


//---------------------------------------------------------------------------
vtkOpenIGTLinkIFLogic::~vtkOpenIGTLinkIFLogic()
{
  if (this->LinearTransformConverter)
    {
    UnregisterMessageConverter(this->LinearTransformConverter);
    this->LinearTransformConverter->Delete();
    }

  if (this->ImageConverter)
    {
    UnregisterMessageConverter(this->ImageConverter);
    this->ImageConverter->Delete();
    }

  if (this->PositionConverter)
    {
    UnregisterMessageConverter(this->PositionConverter);

    this->PositionConverter->Delete();
    }

  if (this->DataCallbackCommand)
    {
    this->DataCallbackCommand->Delete();
    }

}


//---------------------------------------------------------------------------
void vtkOpenIGTLinkIFLogic::PrintSelf(ostream& os, vtkIndent indent)
{
  this->vtkObject::PrintSelf(os, indent);

  os << indent << "vtkOpenIGTLinkIFLogic:             " << this->GetClassName() << "\n";

}


//---------------------------------------------------------------------------
int vtkOpenIGTLinkIFLogic::Initialize()
{

  // -----------------------------------------
  // Register MRML event handler
  
  if (this->Initialized == 0)
    {
    // MRML Event Handling
    vtkIntArray* events = vtkIntArray::New();
    //events->InsertNextValue(vtkMRMLScene::NodeAddedEvent);
    //events->InsertNextValue(vtkMRMLScene::NodeRemovedEvent);
    //events->InsertNextValue(vtkMRMLScene::SceneCloseEvent);
    //events->InsertNextValue(vtkMRMLScene::Node
    if (this->GetMRMLScene() != NULL)
      {
      //this->SetAndObserveMRMLSceneEvents(this->GetMRMLScene(), events);
      }

    events->Delete();
    this->Initialized = 1;

    }

  return 1;

}


//---------------------------------------------------------------------------
void vtkOpenIGTLinkIFLogic::DataCallback(vtkObject *caller, 
                                       unsigned long eid, void *clientData, void *callData)
{
  vtkOpenIGTLinkIFLogic *self = reinterpret_cast<vtkOpenIGTLinkIFLogic *>(clientData);
  vtkDebugWithObjectMacro(self, "In vtkOpenIGTLinkIFLogic DataCallback");
  self->UpdateAll();
}


//---------------------------------------------------------------------------
void vtkOpenIGTLinkIFLogic::UpdateAll()
{

}


//---------------------------------------------------------------------------
vtkMRMLIGTLConnectorNode* vtkOpenIGTLinkIFLogic::GetConnector(const char* conID)
{

  vtkMRMLNode* node = this->GetMRMLScene()->GetNodeByID(conID);
  if (node)
    {
    vtkMRMLIGTLConnectorNode* conNode = vtkMRMLIGTLConnectorNode::SafeDownCast(node);
    return conNode;
    }
  else
    {
    return NULL;
    }

}


//---------------------------------------------------------------------------
void vtkOpenIGTLinkIFLogic::ImportFromCircularBuffers()
{
  //ConnectorMapType::iterator cmiter;
  std::vector<vtkMRMLNode*> nodes;
  const char* className = this->GetMRMLScene()->GetClassNameByTag("IGTLConnector");
  this->GetMRMLScene()->GetNodesByClass(className, nodes);

  std::vector<vtkMRMLNode*>::iterator iter;
  
  //for (cmiter = this->ConnectorMap.begin(); cmiter != this->ConnectorMap.end(); cmiter ++)
  for (iter = nodes.begin(); iter != nodes.end(); iter ++)
    {
    vtkMRMLIGTLConnectorNode* connector = vtkMRMLIGTLConnectorNode::SafeDownCast(*iter);
    if (connector == NULL)
      {
      continue;
      }

    connector->ImportDataFromCircularBuffer();
    }
}

//---------------------------------------------------------------------------
void vtkOpenIGTLinkIFLogic::ImportEvents()
{
  //ConnectorMapType::iterator cmiter;
  std::vector<vtkMRMLNode*> nodes;
  const char* className = this->GetMRMLScene()->GetClassNameByTag("IGTLConnector");
  this->GetMRMLScene()->GetNodesByClass(className, nodes);

  std::vector<vtkMRMLNode*>::iterator iter;
  
  //for (cmiter = this->ConnectorMap.begin(); cmiter != this->ConnectorMap.end(); cmiter ++)
  for (iter = nodes.begin(); iter != nodes.end(); iter ++)
    {
    vtkMRMLIGTLConnectorNode* connector = vtkMRMLIGTLConnectorNode::SafeDownCast(*iter);
    if (connector == NULL)
      {
      continue;
      }

    connector->ImportEventsFromEventBuffer();
    }
}

//---------------------------------------------------------------------------
int vtkOpenIGTLinkIFLogic::SetLocatorDriver(const char* nodeID)
{
  vtkMRMLLinearTransformNode* node =
    vtkMRMLLinearTransformNode::SafeDownCast(this->GetMRMLScene()->GetNodeByID(nodeID));

  if (node && strcmp(node->GetNodeTagName(), "LinearTransform") == 0)
    {
    this->LocatorDriverNodeID = nodeID;
    if (this->LocatorDriverFlag)
      {
      EnableLocatorDriver(1);
      }
    return 1;
    }

  return 0;
}


//---------------------------------------------------------------------------
int vtkOpenIGTLinkIFLogic::EnableLocatorDriver(int sw)
{
  if (sw == 1)  // turn on
    {
    this->LocatorDriverFlag = 1;
    vtkMRMLModelNode* mnode = 
      SetVisibilityOfLocatorModel("IGTLLocator", 1);
    vtkMRMLLinearTransformNode *tnode = 
      vtkMRMLLinearTransformNode::SafeDownCast(this->GetMRMLScene()->GetNodeByID(this->LocatorDriverNodeID));
    if (!tnode)
      {
      return 0;
      }
    mnode->SetAndObserveTransformNodeID(tnode->GetID());
    mnode->InvokeEvent(vtkMRMLTransformableNode::TransformModifiedEvent);
    }
  else  // turn off
    {
    this->LocatorDriverFlag = 0;
    //vtkMRMLModelNode* mnode = 
    //  SetVisibilityOfLocatorModel("IGTLLocator", 0);
    //mnode->SetAndObserveTransformNodeID(NULL);
    SetVisibilityOfLocatorModel("IGTLLocator", 0);
    }
  return 1;

}


//---------------------------------------------------------------------------
int vtkOpenIGTLinkIFLogic::SetRealTimeImageSource(const char* nodeID)
{
  vtkMRMLVolumeNode* volNode =
    vtkMRMLVolumeNode::SafeDownCast(this->GetMRMLScene()->GetNodeByID(nodeID));

  if (volNode && strcmp(volNode->GetNodeTagName(), "Volume") == 0)
    {
    // register the volume node in event observer
    vtkMRMLNode *node = NULL; // TODO: is this OK?
    vtkIntArray* nodeEvents = vtkIntArray::New();
    nodeEvents->InsertNextValue(vtkMRMLVolumeNode::ImageDataModifiedEvent); 
    vtkSetAndObserveMRMLNodeEventsMacro(node,volNode,nodeEvents);
    nodeEvents->Delete();
    this->RealTimeImageSourceNodeID = nodeID;
    return 1;
    }

  return 0;
  
}


//---------------------------------------------------------------------------
int vtkOpenIGTLinkIFLogic::SetSliceDriver(int index, int v)
{
  if (index < 0 || index >= 3)
    {
    return 0;
    }

  this->SliceDriver[index] = v;
  if (v == SLICE_DRIVER_LOCATOR)
    {
    vtkMRMLLinearTransformNode* transNode =
      vtkMRMLLinearTransformNode::SafeDownCast(this->GetMRMLScene()->GetNodeByID(this->LocatorDriverNodeID));
    if (transNode)
      {
      vtkMRMLNode *node = NULL; // TODO: is this OK?
      vtkIntArray* nodeEvents = vtkIntArray::New();
      nodeEvents->InsertNextValue(vtkMRMLTransformableNode::TransformModifiedEvent);
      vtkSetAndObserveMRMLNodeEventsMacro(node,transNode,nodeEvents);
      nodeEvents->Delete();
      transNode->InvokeEvent(vtkMRMLTransformableNode::TransformModifiedEvent);
      }
    }

  return 1;
}


//---------------------------------------------------------------------------
int vtkOpenIGTLinkIFLogic::GetSliceDriver(int index)
{
  if (index < 0 || index >= 3)
    {
    return -1;
    }

  return this->SliceDriver[index];
    
}

//---------------------------------------------------------------------------
int vtkOpenIGTLinkIFLogic::SetRestrictDeviceName(int f)
{

  if (f != 0) f = 1; // make sure that f is either 0 or 1.
  this->RestrictDeviceName = f;

  std::vector<vtkMRMLNode*> nodes;
  const char* className = this->GetMRMLScene()->GetClassNameByTag("IGTLConnector");
  this->GetMRMLScene()->GetNodesByClass(className, nodes);

  std::vector<vtkMRMLNode*>::iterator iter;
  
  for (iter = nodes.begin(); iter != nodes.end(); iter ++)
    {
    vtkMRMLIGTLConnectorNode* connector = vtkMRMLIGTLConnectorNode::SafeDownCast(*iter);
    if (connector)
      {
      connector->SetRestrictDeviceName(f);
      }
    }

  return this->RestrictDeviceName;
}


//---------------------------------------------------------------------------
int vtkOpenIGTLinkIFLogic::RegisterMessageConverter(vtkIGTLToMRMLBase* converter)
{
  if (converter == NULL)
    {
    return 0;
    }

  // Search the list and check if the same converter has already been registered.
  int found = 0;

  MessageConverterListType::iterator iter;
  for (iter = this->MessageConverterList.begin();
       iter != this->MessageConverterList.end();
       iter ++)
    {
    if ((converter->GetIGTLName() && strcmp(converter->GetIGTLName(), (*iter)->GetIGTLName()) == 0) &&
        (converter->GetMRMLName() && strcmp(converter->GetMRMLName(), (*iter)->GetMRMLName()) == 0))
      {
      found = 1;
      }
    }
  if (found)
    {
    return 0;
    }
  
  if (converter->GetIGTLName() && converter->GetMRMLName())
    // TODO: is this correct? Shouldn't it be "&&"
    {
    this->MessageConverterList.push_back(converter);
    }
  else
    {
    return 0;
    }

  // Add the converter to the existing connectors
  if (this->GetMRMLScene())
    {
    std::vector<vtkMRMLNode*> nodes;
    const char* className = this->GetMRMLScene()->GetClassNameByTag("IGTLConnector");
    this->GetMRMLScene()->GetNodesByClass(className, nodes);
    
    std::vector<vtkMRMLNode*>::iterator niter;
    for (niter = nodes.begin(); niter != nodes.end(); niter ++)
      {
      vtkMRMLIGTLConnectorNode* connector = vtkMRMLIGTLConnectorNode::SafeDownCast(*niter);
      if (connector)
        {
        connector->RegisterMessageConverter(converter);
        }
      }
    }

  return 1;
}


//---------------------------------------------------------------------------
int vtkOpenIGTLinkIFLogic::UnregisterMessageConverter(vtkIGTLToMRMLBase* converter)
{
  if (converter == NULL)
    {
    return 0;
    }

  // Look up the message converter list
  MessageConverterListType::iterator iter;
  iter = this->MessageConverterList.begin();
  while ((*iter) != converter) iter ++;

  if (iter != this->MessageConverterList.end())
    // if the converter is on the list
    {
    this->MessageConverterList.erase(iter);
    // Remove the converter from the existing connectors
    std::vector<vtkMRMLNode*> nodes;
    if (this->GetMRMLScene())
      {
      const char* className = this->GetMRMLScene()->GetClassNameByTag("IGTLConnector");
      this->GetMRMLScene()->GetNodesByClass(className, nodes);
    
      std::vector<vtkMRMLNode*>::iterator iter;
      for (iter = nodes.begin(); iter != nodes.end(); iter ++)
        {
        vtkMRMLIGTLConnectorNode* connector = vtkMRMLIGTLConnectorNode::SafeDownCast(*iter);
        if (connector)
          {
          connector->UnregisterMessageConverter(converter);
          }
        }
      }
    return 1;
    }         
  else
    {
    return 0;
    }
}

//---------------------------------------------------------------------------
unsigned int vtkOpenIGTLinkIFLogic::GetNumberOfConverters()
{
  return this->MessageConverterList.size();
}


//---------------------------------------------------------------------------
vtkIGTLToMRMLBase* vtkOpenIGTLinkIFLogic::GetConverter(unsigned int i)
{

  if (i < this->MessageConverterList.size())
    {
    return this->MessageConverterList[i];
    }
  else
    {
    return NULL;
    }

}


//---------------------------------------------------------------------------
vtkIGTLToMRMLBase* vtkOpenIGTLinkIFLogic::GetConverterByDeviceType(const char* deviceType)
{
  vtkIGTLToMRMLBase* converter = NULL;

  MessageConverterListType::iterator iter;
  for (iter = this->MessageConverterList.begin();
       iter != this->MessageConverterList.end();
       iter ++)
    {
    if ((*iter)->GetConverterType() == vtkIGTLToMRMLBase::TYPE_NORMAL)
      {
      if (strcmp((*iter)->GetIGTLName(), deviceType) == 0)
        {
        converter = *iter;
        break;
        }
      }
    else
      {
      int n = (*iter)->GetNumberOfIGTLNames();
      for (int i = 0; i < n; i ++)
        {
        if (strcmp((*iter)->GetIGTLName(i), deviceType) == 0)
          {
          converter = *iter;
          break;
          }
        }
      }
    }

  return converter;
}



//---------------------------------------------------------------------------
void vtkOpenIGTLinkIFLogic::ProcessMRMLEvents(vtkObject * caller, unsigned long event, void * callData)
{
  if (caller != NULL)
    {
    vtkMRMLNode* node = vtkMRMLNode::SafeDownCast(caller);

    ////---------------------------------------------------------------------------
    //// Outgoing data
    //// TODO: should check the type of the node here
    //ConnectorListType* list = &MRMLEventConnectorMap[node];
    //ConnectorListType::iterator cliter;
    //for (cliter = list->begin(); cliter != list->end(); cliter ++)
    //  {
    //  vtkMRMLIGTLConnectorNode* connector = 
    //    vtkMRMLIGTLConnectorNode::SafeDownCast(this->GetMRMLScene()->GetNodeByID(*cliter));
    //  if (connector == NULL)
    //    {
    //    return;
    //    }
    //
    //  MessageConverterListType::iterator iter;
    //  for (iter = this->MessageConverterList.begin();
    //       iter != this->MessageConverterList.end();
    //       iter ++)
    //    {
    //    if ((*iter)->GetMRMLName() && strcmp(node->GetNodeTagName(), (*iter)->GetMRMLName()) == 0)
    //      {
    //      // check if the name-type combination is on the list
    //      if (connector->GetDeviceID(node->GetName(), (*iter)->GetIGTLName()) >= 0)
    //        {
    //        int size;
    //        void* igtlMsg;
    //        (*iter)->MRMLToIGTL(event, node, &size, &igtlMsg);
    //        int r = connector->SendData(size, (unsigned char*)igtlMsg);
    //        if (r == 0)
    //          {
    //          // TODO: error handling
    //          //std::cerr << "ERROR: send data." << std::endl;
    //          }
    //        }
    //      }
    //    } // for (iter)
    //  } // for (cliter)

    //---------------------------------------------------------------------------
    // Slice Driven by Locator
    if (node && strcmp(node->GetID(), this->LocatorDriverNodeID.c_str()) == 0)
      {
      vtkMatrix4x4* transform = NULL;
      for (int i = 0; i < 3; i ++)
        {
        if (this->SliceDriver[i] == SLICE_DRIVER_LOCATOR)
          {
          if (!transform)
            {
            vtkMRMLLinearTransformNode* transNode =    
              vtkMRMLLinearTransformNode::SafeDownCast(this->GetMRMLScene()->GetNodeByID(this->LocatorDriverNodeID));
            if (transNode)
              {
              transform = transNode->GetMatrixTransformToParent();
              }
            }
          if (transform)
            {
            UpdateSliceNode(i, transform);
            }
          }
        }
      }

      
    //---------------------------------------------------------------------------
    // Slice Driven by Real-time image
    if (strcmp(node->GetID(), this->RealTimeImageSourceNodeID.c_str()) == 0)
      {
      for (int i = 0; i < 3; i ++)
        {
        if (this->SliceDriver[i] == SLICE_DRIVER_RTIMAGE)
          {
          UpdateSliceNodeByImage(i);
          }
        }
      }
    }
}


//---------------------------------------------------------------------------
void vtkOpenIGTLinkIFLogic::UpdateSliceNode(int sliceNodeNumber, vtkMatrix4x4* transform)
{

  // NOTES: In Slicer3 ver. 3.2 and higher, a slice orientation information in
  // a slice nodes classes are automaticall set to "Reformat", whenever
  // SetSliceToRASByNTP() function is called.
  // The OpenIGTLinkIF module saves the slice orientations in SliceOrientation[]
  // before the slice nodes update slice orientation information.

  if (this->FreezePlane)
    {
    return;
    }

  CheckSliceNode();

  float tx = transform->GetElement(0, 0);
  float ty = transform->GetElement(1, 0);
  float tz = transform->GetElement(2, 0);
  /*
  float sx = transform->GetElement(0, 1);
  float sy = transform->GetElement(1, 1);
  float sz = transform->GetElement(2, 1);
  */
  float nx = transform->GetElement(0, 2);
  float ny = transform->GetElement(1, 2);
  float nz = transform->GetElement(2, 2);
  float px = transform->GetElement(0, 3);
  float py = transform->GetElement(1, 3);
  float pz = transform->GetElement(2, 3);

  if (strcmp(this->SliceNode[sliceNodeNumber]->GetOrientationString(), "Axial") == 0)
    {
    if (this->EnableOblique) // perpendicular
      {
      //this->SliceOrientation[sliceNodeNumber] = SLICE_RTIMAGE_PERP;
      this->SliceNode[sliceNodeNumber]->SetSliceToRASByNTP(nx, ny, nz, tx, ty, tz, px, py, pz, sliceNodeNumber);
      }
    else
      {
      this->SliceNode[sliceNodeNumber]->SetOrientationToAxial();
      this->SliceNode[sliceNodeNumber]->JumpSlice(px, py, pz);
      }
    }
  else if (strcmp(this->SliceNode[sliceNodeNumber]->GetOrientationString(), "Sagittal") == 0)
    {
    if (this->EnableOblique) // In-Plane
      {
      //this->SliceOrientation[sliceNodeNumber] = SLICE_RTIMAGE_INPLANE;
      this->SliceNode[sliceNodeNumber]->SetSliceToRASByNTP(nx, ny, nz, tx, ty, tz, px, py, pz, sliceNodeNumber);
      }
    else
      {
      this->SliceNode[sliceNodeNumber]->SetOrientationToSagittal();
      this->SliceNode[sliceNodeNumber]->JumpSlice(px, py, pz);
      }
    }
  else if (strcmp(this->SliceNode[sliceNodeNumber]->GetOrientationString(), "Coronal") == 0)
    {
    if (this->EnableOblique)  // In-Plane 90
      {
       //this->SliceOrientation[sliceNodeNumber] = SLICE_RTIMAGE_INPLANE90;
      this->SliceNode[sliceNodeNumber]->SetSliceToRASByNTP(nx, ny, nz, tx, ty, tz, px, py, pz, sliceNodeNumber);
      }
    else
      {
      this->SliceNode[sliceNodeNumber]->SetOrientationToCoronal();
      this->SliceNode[sliceNodeNumber]->JumpSlice(px, py, pz);
      }
    }

  else if (strcmp(this->SliceNode[sliceNodeNumber]->GetOrientationString(), "Reformat") == 0)
    {
    if (this->EnableOblique)  // In-Plane 90
      {
      if (this->SliceOrientation[sliceNodeNumber] == SLICE_RTIMAGE_PERP)
        {
        this->SliceNode[sliceNodeNumber]->SetSliceToRASByNTP(nx, ny, nz, tx, ty, tz, px, py, pz, 0);
        }
      else if (this->SliceOrientation[sliceNodeNumber] == SLICE_RTIMAGE_INPLANE)
        {
        this->SliceNode[sliceNodeNumber]->SetSliceToRASByNTP(nx, ny, nz, tx, ty, tz, px, py, pz, 1);
        }
      else if (this->SliceOrientation[sliceNodeNumber] == SLICE_RTIMAGE_INPLANE90)
        {
        this->SliceNode[sliceNodeNumber]->SetSliceToRASByNTP(nx, ny, nz, tx, ty, tz, px, py, pz, 2);
        }
      }
    else
      {
      if (this->SliceOrientation[sliceNodeNumber] == SLICE_RTIMAGE_PERP)
        {
        this->SliceNode[sliceNodeNumber]->SetOrientationToAxial();
        }
      else if (this->SliceOrientation[sliceNodeNumber] == SLICE_RTIMAGE_INPLANE)
        {
        this->SliceNode[sliceNodeNumber]->SetOrientationToSagittal();
        }
      else if (this->SliceOrientation[sliceNodeNumber] == SLICE_RTIMAGE_INPLANE90)
        {
        this->SliceNode[sliceNodeNumber]->SetOrientationToCoronal();
        }

      this->SliceNode[sliceNodeNumber]->JumpSlice(px, py, pz);
      }
    }

  this->SliceNode[sliceNodeNumber]->UpdateMatrices();
}


//---------------------------------------------------------------------------
void vtkOpenIGTLinkIFLogic::UpdateSliceNodeByImage(int sliceNodeNumber)
{

  vtkMRMLVolumeNode* volumeNode =
    vtkMRMLVolumeNode::SafeDownCast(this->GetMRMLScene()->GetNodeByID(this->RealTimeImageSourceNodeID));

  if (volumeNode == NULL)
    {
    return;
    }

  vtkMatrix4x4* rtimgTransform = vtkMatrix4x4::New();
  //volumeNode->GetRASToIJKMatrix(rtimgTransform);
  volumeNode->GetIJKToRASMatrix(rtimgTransform);
  //rtimgTransform->Invert();
  
  float tx = rtimgTransform->GetElement(0, 0);
  float ty = rtimgTransform->GetElement(1, 0);
  float tz = rtimgTransform->GetElement(2, 0);
  float sx = rtimgTransform->GetElement(0, 1);
  float sy = rtimgTransform->GetElement(1, 1);
  float sz = rtimgTransform->GetElement(2, 1);
  float nx = rtimgTransform->GetElement(0, 2);
  float ny = rtimgTransform->GetElement(1, 2);
  float nz = rtimgTransform->GetElement(2, 2);
  float px = rtimgTransform->GetElement(0, 3);
  float py = rtimgTransform->GetElement(1, 3);
  float pz = rtimgTransform->GetElement(2, 3);

  vtkImageData* imageData;
  imageData = volumeNode->GetImageData();
  int size[3];
  imageData->GetDimensions(size);
  
  // normalize
  float psi = sqrt(tx*tx + ty*ty + tz*tz);
  float psj = sqrt(sx*sx + sy*sy + sz*sz);
  float psk = sqrt(nx*nx + ny*ny + nz*nz);
  float ntx = tx / psi;
  float nty = ty / psi;
  float ntz = tz / psi;
  float nsx = sx / psj;
  float nsy = sy / psj;
  float nsz = sz / psj;
  float nnx = nx / psk;
  float nny = ny / psk;
  float nnz = nz / psk;

  // Shift the center
  // NOTE: The center of the image should be shifted due to different
  // definitions of image origin between VTK (Slicer) and OpenIGTLink;
  // OpenIGTLink image has its origin at the center, while VTK image
  // has one at the corner.

  float hfovi = psi * size[0] / 2.0;
  float hfovj = psj * size[1] / 2.0;
  //float hfovk = psk * imgheader->size[2] / 2.0;
  float hfovk = 0;

  float cx = ntx * hfovi + nsx * hfovj + nnx * hfovk;
  float cy = nty * hfovi + nsy * hfovj + nny * hfovk;
  float cz = ntz * hfovi + nsz * hfovj + nnz * hfovk;

  rtimgTransform->SetElement(0, 0, ntx);
  rtimgTransform->SetElement(1, 0, nty);
  rtimgTransform->SetElement(2, 0, ntz);
  rtimgTransform->SetElement(0, 1, nsx);
  rtimgTransform->SetElement(1, 1, nsy);
  rtimgTransform->SetElement(2, 1, nsz);
  rtimgTransform->SetElement(0, 2, nnx);
  rtimgTransform->SetElement(1, 2, nny);
  rtimgTransform->SetElement(2, 2, nnz);
  rtimgTransform->SetElement(0, 3, px + cx);
  rtimgTransform->SetElement(1, 3, py + cy);
  rtimgTransform->SetElement(2, 3, pz + cz);
  
  UpdateSliceNode(sliceNodeNumber, rtimgTransform);

  rtimgTransform->Delete();
  //volumeNode->Delete();

} 


//---------------------------------------------------------------------------
void vtkOpenIGTLinkIFLogic::CheckSliceNode()
{
  
  if (this->SliceNode[0] == NULL)
    {
    this->SliceNode[0] = this->GetApplicationLogic()
      ->GetSliceLogic("Red")->GetSliceNode();
    }
  if (this->SliceNode[1] == NULL)
    {
    this->SliceNode[1] = this->GetApplicationLogic()
      ->GetSliceLogic("Yellow")->GetSliceNode();
    }
  if (this->SliceNode[2] == NULL)
    {
    this->SliceNode[2] = this->GetApplicationLogic()
      ->GetSliceLogic("Green")->GetSliceNode();
    }
}


//---------------------------------------------------------------------------
vtkMRMLModelNode* vtkOpenIGTLinkIFLogic::SetVisibilityOfLocatorModel(const char* nodeName, int v)
{
  vtkMRMLModelNode*   locatorModel;
  vtkMRMLDisplayNode* locatorDisp;

  // Check if any node with the specified name exists
  vtkMRMLScene*  scene = this->GetApplicationLogic()->GetMRMLScene();
  vtkCollection* collection = scene->GetNodesByName(nodeName);

  if (collection != NULL && collection->GetNumberOfItems() == 0)
    {
    // if a node doesn't exist
    locatorModel = AddLocatorModel(nodeName, 0.0, 1.0, 1.0);
    }
  else
    {
    locatorModel = vtkMRMLModelNode::SafeDownCast(collection->GetItemAsObject(0));
    }

  if (locatorModel)
    {
    locatorDisp = locatorModel->GetDisplayNode();
    locatorDisp->SetVisibility(v);
    locatorModel->Modified();
    this->GetApplicationLogic()->GetMRMLScene()->Modified();
    }

  return locatorModel;
}


//---------------------------------------------------------------------------
vtkMRMLModelNode* vtkOpenIGTLinkIFLogic::AddLocatorModel(const char* nodeName, double r, double g, double b)
{

  vtkMRMLModelNode           *locatorModel;
  vtkMRMLModelDisplayNode    *locatorDisp;

  locatorModel = vtkMRMLModelNode::New();
  locatorDisp = vtkMRMLModelDisplayNode::New();
  
  GetMRMLScene()->SaveStateForUndo();
  GetMRMLScene()->AddNode(locatorDisp);
  GetMRMLScene()->AddNode(locatorModel);  
  
  locatorDisp->SetScene(this->GetMRMLScene());
  
  locatorModel->SetName(nodeName);
  locatorModel->SetScene(this->GetMRMLScene());
  locatorModel->SetAndObserveDisplayNodeID(locatorDisp->GetID());
  locatorModel->SetHideFromEditors(0);
  
  // Cylinder represents the locator stick
  vtkCylinderSource *cylinder = vtkCylinderSource::New();
  cylinder->SetRadius(1.5);
  cylinder->SetHeight(100);
  cylinder->SetCenter(0, 0, 0);
  cylinder->Update();

  // Rotate cylinder
  vtkTransformPolyDataFilter *tfilter = vtkTransformPolyDataFilter::New();
  vtkTransform* trans =   vtkTransform::New();
  trans->RotateX(90.0);
  trans->Translate(0.0, -50.0, 0.0);
  trans->Update();
  tfilter->SetInput(cylinder->GetOutput());
  tfilter->SetTransform(trans);
  tfilter->Update();
  
  // Sphere represents the locator tip 
  vtkSphereSource *sphere = vtkSphereSource::New();
  sphere->SetRadius(3.0);
  sphere->SetCenter(0, 0, 0);
  sphere->Update();
  
  vtkAppendPolyData *apd = vtkAppendPolyData::New();
  apd->AddInput(sphere->GetOutput());
  //apd->AddInput(cylinder->GetOutput());
  apd->AddInput(tfilter->GetOutput());
  apd->Update();
  
  locatorModel->SetAndObservePolyData(apd->GetOutput());
  
  double color[3];
  color[0] = r;
  color[1] = g;
  color[2] = b;
  locatorDisp->SetPolyData(locatorModel->GetPolyData());
  locatorDisp->SetColor(color);
  
  trans->Delete();
  tfilter->Delete();
  cylinder->Delete();
  sphere->Delete();
  apd->Delete();

  //locatorModel->Delete();
  locatorDisp->Delete();

  return locatorModel;
}


//---------------------------------------------------------------------------
void vtkOpenIGTLinkIFLogic::ProcCommand(const char* nodeName, int size, unsigned char* data)
{
}

//---------------------------------------------------------------------------
void vtkOpenIGTLinkIFLogic::GetDeviceNamesFromMrml(IGTLMrmlNodeListType &list)
{

  list.clear();

  MessageConverterListType::iterator mcliter;
  for (mcliter = this->MessageConverterList.begin();
       mcliter != this->MessageConverterList.end();
       mcliter ++)
    {
    if ((*mcliter)->GetMRMLName())
      {
      std::string className = this->GetMRMLScene()->GetClassNameByTag((*mcliter)->GetMRMLName());
      std::string deviceTypeName;
      if ((*mcliter)->GetIGTLName() != NULL)
        {
        deviceTypeName = (*mcliter)->GetIGTLName();
        }
      else
        {
        deviceTypeName = (*mcliter)->GetMRMLName();
        }
      std::vector<vtkMRMLNode*> nodes;
      this->GetApplicationLogic()->GetMRMLScene()->GetNodesByClass(className.c_str(), nodes);
      std::vector<vtkMRMLNode*>::iterator iter;
      for (iter = nodes.begin(); iter != nodes.end(); iter ++)
        {
        IGTLMrmlNodeInfoType nodeInfo;
        nodeInfo.name   = (*iter)->GetName();
        nodeInfo.type   = deviceTypeName.c_str();
        nodeInfo.io     = vtkMRMLIGTLConnectorNode::IO_UNSPECIFIED;
        nodeInfo.nodeID = (*iter)->GetID();
        list.push_back(nodeInfo);
        }
      }
    }

}


//---------------------------------------------------------------------------
void vtkOpenIGTLinkIFLogic::GetDeviceNamesFromMrml(IGTLMrmlNodeListType &list, const char* mrmlTagName)
{

  list.clear();

  MessageConverterListType::iterator mcliter;
  for (mcliter = this->MessageConverterList.begin();
       mcliter != this->MessageConverterList.end();
       mcliter ++)
    {
    if ((*mcliter)->GetMRMLName() && strcmp(mrmlTagName, (*mcliter)->GetMRMLName()) == 0)
      {
      const char* className = this->GetMRMLScene()->GetClassNameByTag(mrmlTagName);
      const char* deviceTypeName = (*mcliter)->GetIGTLName();
      std::vector<vtkMRMLNode*> nodes;
      this->GetMRMLScene()->GetNodesByClass(className, nodes);
      std::vector<vtkMRMLNode*>::iterator iter;
      for (iter = nodes.begin(); iter != nodes.end(); iter ++)
        {
        IGTLMrmlNodeInfoType nodeInfo;
        nodeInfo.name = (*iter)->GetName();
        nodeInfo.type = deviceTypeName;
        nodeInfo.io   = vtkMRMLIGTLConnectorNode::IO_UNSPECIFIED;
        nodeInfo.nodeID = (*iter)->GetID();
        list.push_back(nodeInfo);
        }
      }
    }

}


////---------------------------------------------------------------------------
//const char* vtkOpenIGTLinkIFLogic::MRMLTagToIGTLName(const char* mrmlTagName);
//{
//  
//}
