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

  Program:   Visualization Toolkit
  Module:    $RCSfile: vtkImagePlaneWidget.cxx,v $
  Language:  C++
  Date:      $Date: 2003/09/23 15:02:08 $
  Version:   $Revision: 1.66 $

  Copyright (c) 1993-2002 Ken Martin, Will Schroeder, Bill Lorensen
  All rights reserved.
  See Copyright.txt or http://www.kitware.com/Copyright.htm for details.

     This software is distributed WITHOUT ANY WARRANTY; without even
     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
     PURPOSE.  See the above copyright notice for more information.

=========================================================================*/
#include "vtkImagePlaneWidget.h"

#include "vtkActor.h"
#include "vtkAssemblyNode.h"
#include "vtkAssemblyPath.h"
#include "vtkCallbackCommand.h"
#include "vtkCamera.h"
#include "vtkCellArray.h"
#include "vtkCellPicker.h"
#include "vtkDataSetMapper.h"
#include "vtkImageData.h"
#include "vtkImageMapToColors.h"
#include "vtkImageReslice.h"
#include "vtkLookupTable.h"
#include "vtkMath.h"
#include "vtkMatrix4x4.h"
#include "vtkObjectFactory.h"
#include "vtkPlaneSource.h"
#include "vtkPolyData.h"
#include "vtkPolyDataMapper.h"
#include "vtkProperty.h"
#include "vtkRenderWindowInteractor.h"
#include "vtkRenderer.h"
#include "vtkTextActor.h"
#include "vtkTextProperty.h"
#include "vtkTexture.h"
#include "vtkTextureMapToPlane.h"
#include "vtkTransform.h"

vtkCxxRevisionMacro(vtkImagePlaneWidget, "$Revision: 1.66 $");
vtkStandardNewMacro(vtkImagePlaneWidget);

vtkCxxSetObjectMacro(vtkImagePlaneWidget, PlaneProperty, vtkProperty);
vtkCxxSetObjectMacro(vtkImagePlaneWidget, SelectedPlaneProperty, vtkProperty);
vtkCxxSetObjectMacro(vtkImagePlaneWidget, CursorProperty, vtkProperty);
vtkCxxSetObjectMacro(vtkImagePlaneWidget, MarginProperty, vtkProperty);
vtkCxxSetObjectMacro(vtkImagePlaneWidget, TexturePlaneProperty, vtkProperty);

vtkImagePlaneWidget::vtkImagePlaneWidget() : vtkPolyDataSourceWidget()
{
  this->State = vtkImagePlaneWidget::Start;
  this->EventCallbackCommand->SetCallback(vtkImagePlaneWidget::ProcessEvents);

  this->Interaction              = 1;
  this->PlaneOrientation         = 0;
  this->RestrictPlaneToVolume    = 1;
  this->OriginalWindow           = 1.0;
  this->OriginalLevel            = 0.5;
  this->CurrentWindow            = 1.0;
  this->CurrentLevel             = 0.5;
  this->TextureInterpolate       = 1;
  this->ResliceInterpolate       = VTK_LINEAR_RESLICE;
  this->UserControlledLookupTable= 0;
  this->DisplayText              = 0;
  this->CurrentCursorPosition[0] = 0;
  this->CurrentCursorPosition[1] = 0;
  this->CurrentCursorPosition[2] = 0;
  this->CurrentImageValue        = VTK_FLOAT_MAX;
  this->MarginSelectMode         = 8;

  // Represent the plane's outline
  //
  this->PlaneSource = vtkPlaneSource::New();
  this->PlaneSource->SetXResolution(1);
  this->PlaneSource->SetYResolution(1);
  this->PlaneOutlinePolyData = vtkPolyData::New();
  this->PlaneOutlineMapper   = vtkPolyDataMapper::New();
  this->PlaneOutlineActor    = vtkActor::New();

  // Represent the resliced image plane
  //
  this->ColorMap           = vtkImageMapToColors::New();
  this->Reslice            = vtkImageReslice::New();
  this->ResliceAxes        = vtkMatrix4x4::New();
  this->Texture            = vtkTexture::New();
  this->TexturePlaneCoords = vtkTextureMapToPlane::New();
  this->TexturePlaneMapper = vtkDataSetMapper::New();
  this->TexturePlaneActor  = vtkActor::New();
  this->Transform          = vtkTransform::New();
  this->ImageData          = 0;
  this->LookupTable        = 0;

  // Represent the cross hair cursor
  //
  this->CursorPolyData = vtkPolyData::New();
  this->CursorMapper   = vtkPolyDataMapper::New();
  this->CursorActor    = vtkActor::New();

  // Represent the oblique positioning margins
  //
  this->MarginPolyData = vtkPolyData::New();
  this->MarginMapper   = vtkPolyDataMapper::New();
  this->MarginActor    = vtkActor::New();

  // Represent the text: annotation for cursor position and W/L
  //
  this->TextActor = vtkTextActor::New();

  this->GeneratePlaneOutline();

  // Define some default point coordinates
  //
  float bounds[6];
  bounds[0] = -0.5;
  bounds[1] =  0.5;
  bounds[2] = -0.5;
  bounds[3] =  0.5;
  bounds[4] = -0.5;
  bounds[5] =  0.5;

  // Initial creation of the widget, serves to initialize it
  //
  this->PlaceWidget(bounds);

  this->GenerateTexturePlane();
  this->GenerateCursor();
  this->GenerateMargins();
  this->GenerateText();

  // Manage the picking stuff
  //
  this->PlanePicker = vtkCellPicker::New();
  this->PlanePicker->SetTolerance(0.005); //need some fluff
  this->PlanePicker->AddPickList(this->TexturePlaneActor);
  this->PlanePicker->PickFromListOn();
  this->PlanePicker->Register(this);
  this->PlanePicker->Delete();

  // Set up the initial properties
  //
  this->PlaneProperty         = 0;
  this->SelectedPlaneProperty = 0;
  this->TexturePlaneProperty  = 0;
  this->CursorProperty        = 0;
  this->MarginProperty        = 0;
  this->CreateDefaultProperties();
}

vtkImagePlaneWidget::~vtkImagePlaneWidget()
{
  this->PlaneOutlineActor->Delete();
  this->PlaneOutlineMapper->Delete();
  this->PlaneOutlinePolyData->Delete();
  this->PlaneSource->Delete();

  if ( this->PlanePicker )
    {
    this->PlanePicker->UnRegister(this);
    }

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

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

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

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

  this->ResliceAxes->Delete();
  this->Transform->Delete();
  this->Reslice->Delete();

  if ( this->LookupTable )
    {
    this->LookupTable->UnRegister(this);
    }

  this->TexturePlaneCoords->Delete();
  this->TexturePlaneMapper->Delete();
  this->TexturePlaneActor->Delete();
  this->ColorMap->Delete();
  this->Texture->Delete();

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

  if ( this->ImageData )
    {
    this->ImageData = 0;
    }

  this->CursorActor->Delete();
  this->CursorMapper->Delete();
  this->CursorPolyData->Delete();

  this->MarginActor->Delete();
  this->MarginMapper->Delete();
  this->MarginPolyData->Delete();

  this->TextActor->Delete();
}

void vtkImagePlaneWidget::SetEnabled(int enabling)
{

  if ( ! this->Interactor )
    {
    vtkErrorMacro(<<"The interactor must be set prior to enabling/disabling widget");
    return;
    }

  if ( enabling ) //----------------------------------------------------------
    {
    vtkDebugMacro(<<"Enabling plane widget");

    if ( this->Enabled ) //already enabled, just return
      {
      return;
      }
    
    if ( ! this->CurrentRenderer )
      {
      this->SetCurrentRenderer(this->Interactor->FindPokedRenderer(
        this->Interactor->GetLastEventPosition()[0],
        this->Interactor->GetLastEventPosition()[1]));
      if (this->CurrentRenderer == NULL)
        {
        return;
        }
      }

    this->Enabled = 1;

    // we have to honour this ivar: it could be that this->Interaction was
    // set to off when we were disabled
    if (this->Interaction)
    {
      this->AddObservers();
    }

    // Add the plane
    this->CurrentRenderer->AddProp(this->PlaneOutlineActor);
    this->PlaneOutlineActor->SetProperty(this->PlaneProperty);

    //add the TexturePlaneActor
    this->CurrentRenderer->AddProp(this->TexturePlaneActor);
    this->TexturePlaneActor->SetProperty(this->TexturePlaneProperty);

    // Add the cross-hair cursor
    this->CurrentRenderer->AddProp(this->CursorActor);
    this->CursorActor->SetProperty(this->CursorProperty);

    // Add the margins
    this->CurrentRenderer->AddProp(this->MarginActor);
    this->MarginActor->SetProperty(this->MarginProperty);

    // Add the image data annotation
    this->CurrentRenderer->AddProp(this->TextActor);

    if ( this->PlanePicker )
      {
      this->TexturePlaneActor->PickableOn();
      }

    this->InvokeEvent(vtkCommand::EnableEvent,0);

    }

  else //disabling----------------------------------------------------------
    {
    vtkDebugMacro(<<"Disabling plane widget");

    if ( ! this->Enabled ) //already disabled, just return
      {
      return;
      }

    this->Enabled = 0;

    // don't listen for events any more
    this->Interactor->RemoveObserver(this->EventCallbackCommand);

    // turn off the plane
    this->CurrentRenderer->RemoveProp(this->PlaneOutlineActor);

    //turn off the texture plane
    this->CurrentRenderer->RemoveProp(this->TexturePlaneActor);

    //turn off the cursor
    this->CurrentRenderer->RemoveProp(this->CursorActor);

    //turn off the margins
    this->CurrentRenderer->RemoveProp(this->MarginActor);    

    //turn off the image data annotation
    this->CurrentRenderer->RemoveProp(this->TextActor);

    if ( this->PlanePicker )
      {
      this->TexturePlaneActor->PickableOff();
      }

    this->InvokeEvent(vtkCommand::DisableEvent,0);
    this->SetCurrentRenderer(NULL);
    }

  this->Interactor->Render();
}

void vtkImagePlaneWidget::ProcessEvents(vtkObject* vtkNotUsed(object),
                                        unsigned long event,
                                        void* clientdata,
                                        void* vtkNotUsed(calldata))
{
  vtkImagePlaneWidget* self =
    reinterpret_cast<vtkImagePlaneWidget *>( clientdata );

  //okay, let's do the right thing
  switch ( event )
    {
    case vtkCommand::LeftButtonPressEvent:
      self->OnLeftButtonDown();
      break;
    case vtkCommand::LeftButtonReleaseEvent:
      self->OnLeftButtonUp();
      break;
    case vtkCommand::MiddleButtonPressEvent:
      self->OnMiddleButtonDown();
      break;
    case vtkCommand::MiddleButtonReleaseEvent:
      self->OnMiddleButtonUp();
      break;
    case vtkCommand::RightButtonPressEvent:
      self->OnRightButtonDown();
      break;
    case vtkCommand::RightButtonReleaseEvent:
      self->OnRightButtonUp();
      break;
    case vtkCommand::MouseMoveEvent:
      self->OnMouseMove();
      break;
    }
}

void vtkImagePlaneWidget::AddObservers(void)
{
    // listen for the following events
    vtkRenderWindowInteractor *i = this->Interactor;
    if (i)
    {
        i->AddObserver(vtkCommand::MouseMoveEvent, this->EventCallbackCommand,
                       this->Priority);
        i->AddObserver(vtkCommand::LeftButtonPressEvent,
                       this->EventCallbackCommand, this->Priority);
        i->AddObserver(vtkCommand::LeftButtonReleaseEvent,
                       this->EventCallbackCommand, this->Priority);
        i->AddObserver(vtkCommand::MiddleButtonPressEvent,
                       this->EventCallbackCommand, this->Priority);
        i->AddObserver(vtkCommand::MiddleButtonReleaseEvent,
                       this->EventCallbackCommand, this->Priority);
        i->AddObserver(vtkCommand::RightButtonPressEvent,
                       this->EventCallbackCommand, this->Priority);
        i->AddObserver(vtkCommand::RightButtonReleaseEvent,
                       this->EventCallbackCommand, this->Priority);
    }
}

void vtkImagePlaneWidget::SetInteraction(int interact)
{
  if (this->Interactor && this->Enabled)
    {
    if (this->Interaction == interact)
      {
      return;
      }
    if (interact == 0)
      {
      this->Interactor->RemoveObserver(this->EventCallbackCommand);
      }
    else
      {
        this->AddObservers();
      }
    this->Interaction = interact;
    }
  else
    {
    vtkGenericWarningMacro(<<"set interactor and Enabled before changing interaction...");
    }
}

void vtkImagePlaneWidget::PrintSelf(ostream& os, vtkIndent indent)
{
  this->Superclass::PrintSelf(os,indent);

  if ( this->PlaneProperty )
    {
    os << indent << "Plane Property:\n";
    this->PlaneProperty->PrintSelf(os,indent.GetNextIndent());
    }
  else
    {
    os << indent << "Plane Property: (none)\n";
    }

  if ( this->SelectedPlaneProperty )
    {
    os << indent << "Selected Plane Property:\n";
    this->SelectedPlaneProperty->PrintSelf(os,indent.GetNextIndent());
    }
  else
    {
    os << indent << "Selected Plane Property: (none)\n";
    }

  if ( this->LookupTable )
    {
    os << indent << "LookupTable:\n";
    this->LookupTable->PrintSelf(os,indent.GetNextIndent());
    }
  else
    {
    os << indent << "LookupTable: (none)\n";
    }

  if ( this->CursorProperty )
    {
    os << indent << "Cursor Property:\n";
    this->CursorProperty->PrintSelf(os,indent.GetNextIndent());
    }
  else
    {
    os << indent << "Cursor Property: (none)\n";
    }

  if ( this->MarginProperty )
    {
    os << indent << "Margin Property:\n";
    this->MarginProperty->PrintSelf(os,indent.GetNextIndent());
    }
  else
    {
    os << indent << "Margin Property: (none)\n";
    }

  if ( this->TexturePlaneProperty )
    {
    os << indent << "TexturePlane Property:\n";
    this->TexturePlaneProperty->PrintSelf(os,indent.GetNextIndent());
    }
  else
    {
    os << indent << "TexturePlane Property: (none)\n";
    }

  float *o = this->PlaneSource->GetOrigin();
  float *pt1 = this->PlaneSource->GetPoint1();
  float *pt2 = this->PlaneSource->GetPoint2();

  os << indent << "Origin: (" << o[0] << ", "
     << o[1] << ", "
     << o[2] << ")\n";
  os << indent << "Point 1: (" << pt1[0] << ", "
     << pt1[1] << ", "
     << pt1[2] << ")\n";
  os << indent << "Point 2: (" << pt2[0] << ", "
     << pt2[1] << ", "
     << pt2[2] << ")\n";

  os << indent << "Plane Orientation: " << this->PlaneOrientation << "\n";
  os << indent << "Reslice Interpolate: " << this->ResliceInterpolate << "\n";
  os << indent << "Texture Interpolate: "
     << (this->TextureInterpolate ? "On\n" : "Off\n") ;
  os << indent << "Restrict Plane To Volume: "
     << (this->RestrictPlaneToVolume ? "On\n" : "Off\n") ;
  os << indent << "Display Text: "
     << (this->DisplayText ? "On\n" : "Off\n") ;
  os << indent << "Interaction: "
     << (this->Interaction ? "On\n" : "Off\n") ;
  os << indent << "User Controlled Lookup Table: "
     << (this->UserControlledLookupTable ? "On\n" : "Off\n") ;
}

void vtkImagePlaneWidget::BuildRepresentation()
{
  float *o = this->PlaneSource->GetOrigin();
  float *pt1 = this->PlaneSource->GetPoint1();
  float *pt2 = this->PlaneSource->GetPoint2();

  float x[3];
  x[0] = o[0] + (pt1[0]-o[0]) + (pt2[0]-o[0]);
  x[1] = o[1] + (pt1[1]-o[1]) + (pt2[1]-o[1]);
  x[2] = o[2] + (pt1[2]-o[2]) + (pt2[2]-o[2]);

  vtkPoints* points = this->PlaneOutlinePolyData->GetPoints();
  points->SetPoint(0,o);
  points->SetPoint(1,pt1);
  points->SetPoint(2,x);
  points->SetPoint(3,pt2);
  this->PlaneOutlineMapper->Modified();

  this->PlaneSource->GetNormal(this->Normal);
  vtkMath::Normalize(this->Normal);
}

void vtkImagePlaneWidget::HighlightPlane(int highlight)
{
  if ( highlight )
    {
    this->PlaneOutlineActor->SetProperty(this->SelectedPlaneProperty);
    this->PlanePicker->GetPickPosition(this->LastPickPosition);
    }
  else
    {
    this->PlaneOutlineActor->SetProperty(this->PlaneProperty);
    }
}

void vtkImagePlaneWidget::OnLeftButtonDown()
{
  int X = this->Interactor->GetEventPosition()[0];
  int Y = this->Interactor->GetEventPosition()[1];

  // Okay, make sure that the pick is in the current renderer
  vtkRenderer *ren = this->Interactor->FindPokedRenderer(X,Y);
  if ( ren != this->CurrentRenderer )
    {
    this->State = vtkImagePlaneWidget::Outside;
    return;
    }

  // Okay, we can process this. If anything is picked, then we
  // can start pushing the plane.
  vtkAssemblyPath *path;
  this->PlanePicker->Pick(X,Y,0.0,this->CurrentRenderer);
  path = this->PlanePicker->GetPath();

  int found = 0;
  int i;
  if ( path != 0 )
    {
// Deal with the possibility that we may be using a shared picker
    path->InitTraversal();
    vtkAssemblyNode *node;
    for ( i = 0; i < path->GetNumberOfItems() && !found ; i++ )
      {
      node = path->GetNextNode();
      if ( node->GetProp() == vtkProp::SafeDownCast(this->TexturePlaneActor) )
        {
        found = 1;
        }
      }
    }

  if( ! found || path == 0 )
    {
    this->State = vtkImagePlaneWidget::Outside;
    this->HighlightPlane(0);
    this->ActivateCursor(0);
    this->ActivateText(0);
    return;
    }
  else
    {
    this->State = vtkImagePlaneWidget::Cursoring;
    this->HighlightPlane(1);
    this->ActivateCursor(1);
    this->ActivateText(1);
    this->UpdateCursor(X,Y);
    this->ManageTextDisplay();
    }

  this->EventCallbackCommand->SetAbortFlag(1);
  this->StartInteraction();
  this->InvokeEvent(vtkCommand::StartInteractionEvent,0);
  this->Interactor->Render();
}

void vtkImagePlaneWidget::OnLeftButtonUp()
{
  if ( this->State == vtkImagePlaneWidget::Outside ||
       this->State == vtkImagePlaneWidget::Start )
    {
    return;
    }

  this->State = vtkImagePlaneWidget::Start;
  this->HighlightPlane(0);
  this->ActivateCursor(0);
  this->ActivateText(0);

  this->EventCallbackCommand->SetAbortFlag(1);
  this->EndInteraction();
  this->InvokeEvent(vtkCommand::EndInteractionEvent,0);
  this->Interactor->Render();
}

void vtkImagePlaneWidget::OnMiddleButtonDown()
{
  int X = this->Interactor->GetEventPosition()[0];
  int Y = this->Interactor->GetEventPosition()[1];

  // Okay, make sure that the pick is in the current renderer
  vtkRenderer *ren = this->Interactor->FindPokedRenderer(X,Y);
  if ( ren != this->CurrentRenderer )
    {
    this->State = vtkImagePlaneWidget::Outside;
    return;
    }

  // Okay, we can process this. If anything is picked, then we
  // can start pushing or check for adjusted states.
  vtkAssemblyPath *path;
  this->PlanePicker->Pick(X,Y,0.0,this->CurrentRenderer);
  path = this->PlanePicker->GetPath();

  int found = 0;
  int i;
  if ( path != 0 )
    {
// Deal with the possibility that we may be using a shared picker
    path->InitTraversal();
    vtkAssemblyNode *node;
    for(i = 0; i< path->GetNumberOfItems() && !found ;i++)
      {
      node = path->GetNextNode();
      if(node->GetProp() == vtkProp::SafeDownCast(this->TexturePlaneActor) )
        {
        found = 1;
        }
      }
    }

  if ( !found || path == 0 )
    {
    this->State = vtkImagePlaneWidget::Outside;
    this->HighlightPlane(0);
    this->ActivateMargins(0);
    return;
    }
  else
    {
    this->State = vtkImagePlaneWidget::Pushing;
    this->HighlightPlane(1);
    this->ActivateMargins(1);
    this->AdjustState();
    this->UpdateMargins();
    }

  this->EventCallbackCommand->SetAbortFlag(1);
  this->StartInteraction();
  this->InvokeEvent(vtkCommand::StartInteractionEvent,0);
  this->Interactor->Render();
}

void vtkImagePlaneWidget::OnMiddleButtonUp()
{
  if ( this->State == vtkImagePlaneWidget::Outside ||
       this->State == vtkImagePlaneWidget::Start )
    {
    return;
    }

  this->State = vtkImagePlaneWidget::Start;
  this->HighlightPlane(0);
  this->ActivateMargins(0);

  this->EventCallbackCommand->SetAbortFlag(1);
  this->EndInteraction();
  this->InvokeEvent(vtkCommand::EndInteractionEvent,0);
  this->Interactor->Render();
}

void vtkImagePlaneWidget::OnRightButtonDown()
{
  int X = this->Interactor->GetEventPosition()[0];
  int Y = this->Interactor->GetEventPosition()[1];

  // Okay, make sure that the pick is in the current renderer
  vtkRenderer *ren = this->Interactor->FindPokedRenderer(X,Y);
  if ( ren != this->CurrentRenderer )
    {
    this->State = vtkImagePlaneWidget::Outside;
    return;
    }

  // Okay, we can process this. If anything is picked, then we
  // can start window-levelling.
  vtkAssemblyPath *path;
  this->PlanePicker->Pick(X,Y,0.0,this->CurrentRenderer);
  path = this->PlanePicker->GetPath();

  int found = 0;
  int i;
  if ( path != 0 )
    {
// Deal with the possibility that we may be using a shared picker
    path->InitTraversal();
    vtkAssemblyNode *node;
    for ( i = 0; i < path->GetNumberOfItems() && !found ; i++ )
      {
      node = path->GetNextNode();
      if ( node->GetProp() == vtkProp::SafeDownCast(this->TexturePlaneActor) )
        {
        found = 1;
        }
      }
    }

  if( ! found || path == 0 )
    {
    this->State = vtkImagePlaneWidget::Outside;
    this->HighlightPlane(0);
    this->ActivateText(0);
    return;
    }
  else
    {
    this->State = vtkImagePlaneWidget::WindowLevelling;
    this->HighlightPlane(1);
    this->ActivateText(1);
    this->WindowLevel(X,Y);
    this->ManageTextDisplay();
    }

  this->EventCallbackCommand->SetAbortFlag(1);
  this->StartInteraction();
  this->InvokeEvent(vtkCommand::StartInteractionEvent,0);
  this->Interactor->Render();
}

void vtkImagePlaneWidget::OnRightButtonUp()
{
  if ( this->State == vtkImagePlaneWidget::Outside ||
       this->State == vtkImagePlaneWidget::Start )
    {
    return;
    }

  this->State = vtkImagePlaneWidget::Start;
  this->HighlightPlane(0);
  this->ActivateText(0);

  this->EventCallbackCommand->SetAbortFlag(1);
  this->EndInteraction();
  this->InvokeEvent(vtkCommand::EndInteractionEvent,0);
  this->Interactor->Render();
}

void vtkImagePlaneWidget::OnMouseMove()
{
  // See whether we're active
  //
  if ( this->State == vtkImagePlaneWidget::Outside ||
       this->State == vtkImagePlaneWidget::Start )
    {
    return;
    }

  int X = this->Interactor->GetEventPosition()[0];
  int Y = this->Interactor->GetEventPosition()[1];

  // Do different things depending on state
  // Calculations everybody does
  //
  double focalPoint[4], pickPoint[4], prevPickPoint[4];
  double z, vpn[3];

  vtkRenderer *renderer = this->Interactor->FindPokedRenderer(X,Y);
  vtkCamera *camera = renderer->GetActiveCamera();
  if ( ! camera )
    {
    return;
    }

  // Compute the two points defining the motion vector
  //
  this->ComputeWorldToDisplay(this->LastPickPosition[0], this->LastPickPosition[1],
                              this->LastPickPosition[2], focalPoint);
  z = focalPoint[2];

  this->ComputeDisplayToWorld(double(this->Interactor->GetLastEventPosition()[0]),
                              double(this->Interactor->GetLastEventPosition()[1]),
                              z, prevPickPoint);

  this->ComputeDisplayToWorld(double(X), double(Y), z, pickPoint);

  if ( this->State == vtkImagePlaneWidget::WindowLevelling )
    {
    this->WindowLevel(X,Y);
    this->ManageTextDisplay();
    }
  else if ( this->State == vtkImagePlaneWidget::Pushing )
    {
    this->Push(prevPickPoint, pickPoint);
    this->UpdateNormal();
    this->UpdateOrigin();
    this->UpdateMargins();
    }
  else if ( this->State == vtkImagePlaneWidget::Spinning )
    {
    this->Spin(prevPickPoint, pickPoint);
    this->UpdateNormal();
    this->UpdateOrigin();
    this->UpdateMargins();
    }
  else if ( this->State == vtkImagePlaneWidget::Rotating )
    {
    camera->GetViewPlaneNormal(vpn);
    this->Rotate(prevPickPoint, pickPoint, vpn);
    this->UpdateNormal();
    this->UpdateOrigin();
    this->UpdateMargins();
    }
  else if ( this->State == vtkImagePlaneWidget::Scaling )
    {
    this->Scale(prevPickPoint, pickPoint, X, Y);
    this->UpdateNormal();
    this->UpdateOrigin();
    this->UpdateMargins();
    }
  else if ( this->State == vtkImagePlaneWidget::Moving )
    {
    this->Translate(prevPickPoint, pickPoint);
    this->UpdateNormal();
    this->UpdateOrigin();
    this->UpdateMargins();
    }
  else if ( this->State == vtkImagePlaneWidget::Cursoring )
    {
    this->UpdateCursor(X,Y);
    this->ManageTextDisplay();
    }

  // Interact, if desired
  //
  this->EventCallbackCommand->SetAbortFlag(1);
  this->InvokeEvent(vtkCommand::InteractionEvent,0);

  this->Interactor->Render();
}

void vtkImagePlaneWidget::WindowLevel(int X, int Y)
{
  float range[2];
  this->LookupTable->GetTableRange(range);
  float window = range[1] - range[0];
  float level = 0.5*(range[0] + range[1]);

  float owin = this->OriginalWindow;

  level = level + (X - this->Interactor->GetLastEventPosition()[0])*owin/500.0;
  window = window + (this->Interactor->GetLastEventPosition()[1] - Y)*owin/250.0;

  if ( window == 0.0 )
    {
    window = 0.001;
    }

  float rmin = level - window*0.5;
  float rmax = level + window*0.5;

  if( rmin < rmax )
    {
    this->CurrentWindow = window;
    this->CurrentLevel = level;
    if (!this->UserControlledLookupTable)
      {
      this->LookupTable->SetTableRange(rmin,rmax);
      }
    }
}

void vtkImagePlaneWidget::SetWindowLevel(float window, float level)
{
  float rmin = level - window*0.5;
  float rmax = level + window*0.5;
  this->CurrentWindow = window;
  this->OriginalWindow  = window;
  this->CurrentLevel = level;
  this->OriginalLevel  = level;
  this->LookupTable->SetTableRange(rmin,rmax);

  if(this->Enabled)
    {
    this->Interactor->Render();
    }
}

void vtkImagePlaneWidget::GetWindowLevel(float wl[2])
{
  float range[2];
  this->LookupTable->GetTableRange(range);
  wl[0] = range[1] - range[0];
  wl[1] = 0.5*(range[0]+range[1]);
}

int vtkImagePlaneWidget::GetCursorData(float xyzv[4])
{
  if ( this->State != vtkImagePlaneWidget::Cursoring  || \
    this->CurrentImageValue == VTK_FLOAT_MAX )
    {
    return 0;
    }

  xyzv[0] = this->CurrentCursorPosition[0];
  xyzv[1] = this->CurrentCursorPosition[1];
  xyzv[2] = this->CurrentCursorPosition[2];
  xyzv[3] = this->ImageData->GetScalarComponentAsFloat( \
                   this->CurrentCursorPosition[0],
                   this->CurrentCursorPosition[1],
                   this->CurrentCursorPosition[2],0);
  return 1;
}

void vtkImagePlaneWidget::ManageTextDisplay()
{
  if ( !this->DisplayText )
    {
    return;
    }

  if ( this->State == vtkImagePlaneWidget::WindowLevelling )
    {
    sprintf(this->TextBuff,"Window, Level: ( %g, %g )",
            this->CurrentWindow, this->CurrentLevel );
    }
  else if ( this->State == vtkImagePlaneWidget::Cursoring )
    {
    if( this->CurrentImageValue == VTK_FLOAT_MAX )
      {
      sprintf(this->TextBuff,"Off Image");
      }
    else
      {
      float val = this->ImageData->GetScalarComponentAsFloat( \
                   this->CurrentCursorPosition[0],
                   this->CurrentCursorPosition[1],
                   this->CurrentCursorPosition[2],0);
      sprintf(this->TextBuff,"( %3d, %3d, %3d ): %g",
                   this->CurrentCursorPosition[0],
                   this->CurrentCursorPosition[1],
                   this->CurrentCursorPosition[2],val);
      }
    }

  this->TextActor->SetInput(this->TextBuff);
  this->TextActor->Modified();
}

void vtkImagePlaneWidget::Push(double *p1, double *p2)
{
  // Get the motion vector
  //
  float v[3];
  v[0] = p2[0] - p1[0];
  v[1] = p2[1] - p1[1];
  v[2] = p2[2] - p1[2];
  
  this->PlaneSource->Push( vtkMath::Dot(v,this->Normal) );
  this->PlaneSource->Update();
  this->BuildRepresentation();
}

void vtkImagePlaneWidget::CreateDefaultProperties()
{
  if ( ! this->PlaneProperty )
    {
    this->PlaneProperty = vtkProperty::New();
    this->PlaneProperty->SetAmbient(1);
    this->PlaneProperty->SetColor(1,1,1);
    this->PlaneProperty->SetRepresentationToWireframe();
    this->PlaneProperty->SetInterpolationToFlat();
    }

  if ( ! this->SelectedPlaneProperty )
    {
    this->SelectedPlaneProperty = vtkProperty::New();
    this->SelectedPlaneProperty->SetAmbient(1);
    this->SelectedPlaneProperty->SetColor(0,1,0);
    this->SelectedPlaneProperty->SetRepresentationToWireframe();
    this->SelectedPlaneProperty->SetInterpolationToFlat();
    }

  if ( ! this->CursorProperty )
    {
    this->CursorProperty = vtkProperty::New();
    this->CursorProperty->SetAmbient(1);
    this->CursorProperty->SetColor(1,0,0);
    this->CursorProperty->SetRepresentationToWireframe();
    this->CursorProperty->SetInterpolationToFlat();
    }

  if ( ! this->MarginProperty )
    {
    this->MarginProperty = vtkProperty::New();
    this->MarginProperty->SetAmbient(1);
    this->MarginProperty->SetColor(0,0,1);
    this->MarginProperty->SetRepresentationToWireframe();
    this->MarginProperty->SetInterpolationToFlat();
    }

  if ( ! this->TexturePlaneProperty )
    {
    this->TexturePlaneProperty = vtkProperty::New();
    this->TexturePlaneProperty->SetAmbient(1);
    this->TexturePlaneProperty->SetInterpolationToFlat();
    }
}

void vtkImagePlaneWidget::PlaceWidget(float bds[6])
{
  float bounds[6], center[3];

  this->AdjustBounds(bds, bounds, center);

  if ( this->PlaneOrientation == 1 )
    {
    this->PlaneSource->SetOrigin(bounds[0],center[1],bounds[4]);
    this->PlaneSource->SetPoint1(bounds[1],center[1],bounds[4]);
    this->PlaneSource->SetPoint2(bounds[0],center[1],bounds[5]);
    }
  else if ( this->PlaneOrientation == 2 )
    {
    this->PlaneSource->SetOrigin(bounds[0],bounds[2],center[2]);
    this->PlaneSource->SetPoint1(bounds[1],bounds[2],center[2]);
    this->PlaneSource->SetPoint2(bounds[0],bounds[3],center[2]);
    }
  else //default or x-normal
    {
    this->PlaneSource->SetOrigin(center[0],bounds[2],bounds[4]);
    this->PlaneSource->SetPoint1(center[0],bounds[3],bounds[4]);
    this->PlaneSource->SetPoint2(center[0],bounds[2],bounds[5]);
    }
  this->PlaneSource->Update();
  this->BuildRepresentation();
}

void vtkImagePlaneWidget::SetPlaneOrientation(int i)
{
  // Generate a XY plane if i = 2, z-normal
  // or a YZ plane if i = 0, x-normal
  // or a ZX plane if i = 1, y-normal
  //
  this->PlaneOrientation = i;
  this->Modified();

  // This method must be called _after_ SetInput
  //
  this->ImageData = this->Reslice->GetInput();
  if ( !this->ImageData )
    {
    vtkErrorMacro(<<"SetInput() before setting plane orientation.");
    return;
    }

  this->ImageData->UpdateInformation();
  int extent[6];
  this->ImageData->GetWholeExtent(extent);
  float origin[3];
  this->ImageData->GetOrigin(origin);
  float spacing[3];
  this->ImageData->GetSpacing(spacing);

  // Prevent obscuring voxels by offsetting the plane geometry
  //
  float xbounds[] = {origin[0] + spacing[0] * (extent[0] - 0.5),
                     origin[0] + spacing[0] * (extent[1] + 0.5)};
  float ybounds[] = {origin[1] + spacing[1] * (extent[2] - 0.5),
                     origin[1] + spacing[1] * (extent[3] + 0.5)};
  float zbounds[] = {origin[2] + spacing[2] * (extent[4] - 0.5),
                     origin[2] + spacing[2] * (extent[5] + 0.5)};

  if ( spacing[0] < 0.0f )
    {
    float t = xbounds[0];
    xbounds[0] = xbounds[1];
    xbounds[1] = t;
    }
  if ( spacing[1] < 0.0f )
    {
    float t = ybounds[0];
    ybounds[0] = ybounds[1];
    ybounds[1] = t;
    }
  if ( spacing[2] < 0.0f )
    {
    float t = zbounds[0];
    zbounds[0] = zbounds[1];
    zbounds[1] = t;
    }

  if ( i == 2 ) //XY, z-normal
    {
    this->PlaneSource->SetOrigin(xbounds[0],ybounds[0],zbounds[0]);
    this->PlaneSource->SetPoint1(xbounds[1],ybounds[0],zbounds[0]);
    this->PlaneSource->SetPoint2(xbounds[0],ybounds[1],zbounds[0]);
    }
  else if ( i == 0 ) //YZ, x-normal
    {
    this->PlaneSource->SetOrigin(xbounds[0],ybounds[0],zbounds[0]);
    this->PlaneSource->SetPoint1(xbounds[0],ybounds[1],zbounds[0]);
    this->PlaneSource->SetPoint2(xbounds[0],ybounds[0],zbounds[1]);
    }
  else  //ZX, y-normal
    {
    this->PlaneSource->SetOrigin(xbounds[0],ybounds[0],zbounds[0]);
    this->PlaneSource->SetPoint1(xbounds[0],ybounds[0],zbounds[1]);
    this->PlaneSource->SetPoint2(xbounds[1],ybounds[0],zbounds[0]);
    }

  this->PlaneSource->Update();
  this->BuildRepresentation();
  this->UpdateNormal();
  this->UpdateOrigin();
}

void vtkImagePlaneWidget::SetInput(vtkDataSet* input)
{
  this->Superclass::SetInput(input);
  this->ImageData = vtkImageData::SafeDownCast(this->GetInput());

  if( !this->ImageData )
    {
  // If NULL is passed, remove any reference that Reslice had
  // on the old ImageData
  //
    this->Reslice->SetInput(NULL);
    return;
    }

  float range[2];
  this->ImageData->GetScalarRange(range);

  if ( !this->UserControlledLookupTable )
    {
    this->LookupTable->SetTableRange(range[0],range[1]);
    this->LookupTable->Build();
    }

  this->OriginalWindow = range[1] - range[0];
  this->OriginalLevel = 0.5*(range[0] + range[1]);

  this->Reslice->SetInput(this->ImageData);
  this->SetResliceInterpolate(this->ResliceInterpolate);

  this->ColorMap->SetInput(this->Reslice->GetOutput());

  this->Texture->SetInput(this->ColorMap->GetOutput());
  this->Texture->SetInterpolate(this->TextureInterpolate);

  this->SetPlaneOrientation(this->PlaneOrientation);
}

void vtkImagePlaneWidget::UpdateOrigin()
{
  int i;

  if ( this->RestrictPlaneToVolume )
    {
    if ( !this->Reslice )
      {
      return;
      }
    this->ImageData = this->Reslice->GetInput();
    if ( !this->ImageData )
      {
      return;
      }
    this->ImageData->UpdateInformation();
    float origin[3];
    this->ImageData->GetOrigin(origin);
    float spacing[3];
    this->ImageData->GetSpacing(spacing);
    int extent[6];
    this->ImageData->GetWholeExtent(extent);
    float bounds[] = {origin[0] + spacing[0]*extent[0],
                      origin[0] + spacing[0]*extent[1],
                      origin[1] + spacing[1]*extent[2],
                      origin[1] + spacing[1]*extent[3],
                      origin[2] + spacing[2]*extent[4],
                      origin[2] + spacing[2]*extent[5]};

    for ( i = 0; i <= 4; i += 2 ) // reverse bounds if necessary
      {
      if ( bounds[i] > bounds[i+1] )
        {
        float t = bounds[i+1];
        bounds[i+1] = bounds[i];
        bounds[i] = t;
        }
      }

    float abs_normal[3];
    this->PlaneSource->GetNormal(abs_normal);
    float planeCenter[3];
    this->PlaneSource->GetCenter(planeCenter);
    float nmax = 0.0f;
    int k = 0;
    for ( i = 0; i < 3; i++ )
      {
      abs_normal[i] = fabs(abs_normal[i]);
      if ( abs_normal[i]>nmax )
        {
        nmax = abs_normal[i];
        k = i;
        }
      }
  // Force the plane to lie within the true image bounds along its normal
  //
    if ( planeCenter[k] > bounds[2*k+1] )
      {
      planeCenter[k] = bounds[2*k+1];
      this->PlaneSource->SetCenter(planeCenter);
      this->PlaneSource->Update();
      this->BuildRepresentation();
      }
    else if ( planeCenter[k] < bounds[2*k] )
      {
      planeCenter[k] = bounds[2*k];
      this->PlaneSource->SetCenter(planeCenter);
      this->PlaneSource->Update();
      this->BuildRepresentation();
      }
    }

  this->ResliceAxes->DeepCopy(this->Reslice->GetResliceAxes());
  this->ResliceAxes->SetElement(0,3,0);
  this->ResliceAxes->SetElement(1,3,0);
  this->ResliceAxes->SetElement(2,3,0);

  // Transpose is an exact way to invert a pure rotation matrix
  //
  this->ResliceAxes->Transpose();

  float planeOrigin[4];
  this->PlaneSource->GetOrigin(planeOrigin);
  planeOrigin[3] = 1.0;
  float originXYZW[4];
  this->ResliceAxes->MultiplyPoint(planeOrigin,originXYZW);

  this->ResliceAxes->Transpose();
  float neworiginXYZW[4];
  float point[] =  {0.0,0.0,originXYZW[2],1.0};
  this->ResliceAxes->MultiplyPoint(point,neworiginXYZW);

  this->ResliceAxes->SetElement(0,3,neworiginXYZW[0]);
  this->ResliceAxes->SetElement(1,3,neworiginXYZW[1]);
  this->ResliceAxes->SetElement(2,3,neworiginXYZW[2]);

  this->Reslice->SetResliceAxes(this->ResliceAxes);

  float spacingXYZ[3];
  this->Reslice->GetOutputSpacing(spacingXYZ);
  this->Reslice->SetOutputOrigin(0.5*spacingXYZ[0] + originXYZW[0],
                                 0.5*spacingXYZ[1] + originXYZW[1],
                                 0.0);
}

void vtkImagePlaneWidget::UpdateNormal()
{
  float planeAxis1[3];
  float planeAxis2[3];

  this->GetVector1(planeAxis1);
  this->GetVector2(planeAxis2);

  // The x,y dimensions of the plane
  //
  float planeSizeX = vtkMath::Normalize(planeAxis1);
  float planeSizeY = vtkMath::Normalize(planeAxis2);

  this->PlaneSource->GetNormal(this->Normal);

  // Generate the slicing matrix
  //
  int i;
  this->ResliceAxes->Identity();
  for ( i = 0; i < 3; i++ )
     {
     this->ResliceAxes->SetElement(i,0,planeAxis1[i]);
     this->ResliceAxes->SetElement(i,1,planeAxis2[i]);
     this->ResliceAxes->SetElement(i,2,this->Normal[i]);
     }

  // Transpose is an exact way to invert a pure rotation matrix
  //
  this->ResliceAxes->Transpose();

  float planeOrigin[4];
  this->PlaneSource->GetOrigin(planeOrigin);
  planeOrigin[3] = 1.0;
  float originXYZW[4];
  this->ResliceAxes->MultiplyPoint(planeOrigin,originXYZW);

  this->ResliceAxes->Transpose();
  float neworiginXYZW[4];
  float point[] =  {0.0,0.0,originXYZW[2],1.0};
  this->ResliceAxes->MultiplyPoint(point,neworiginXYZW);

  this->ResliceAxes->SetElement(0,3,neworiginXYZW[0]);
  this->ResliceAxes->SetElement(1,3,neworiginXYZW[1]);
  this->ResliceAxes->SetElement(2,3,neworiginXYZW[2]);

  this->Reslice->SetResliceAxes(this->ResliceAxes);

  this->ImageData = this->Reslice->GetInput();

  // Calculate appropriate pixel spacing for the reslicing
  //
  this->ImageData->UpdateInformation();
  float spacing[3];
  this->ImageData->GetSpacing(spacing);

  float spacingX = fabs(planeAxis1[0]*spacing[0])+\
                   fabs(planeAxis1[1]*spacing[1])+\
                   fabs(planeAxis1[2]*spacing[2]);

  float spacingY = fabs(planeAxis2[0]*spacing[0])+\
                   fabs(planeAxis2[1]*spacing[1])+\
                   fabs(planeAxis2[2]*spacing[2]);


  // Pad extent up to a power of two for efficient texture mapping

  // make sure we're working with valid values
  float realExtentX;
  if (spacingX == 0)
    realExtentX = 0;
  else
    realExtentX = planeSizeX / spacingX;

  int extentX;
  // Sanity check the input data:
  // * if realExtentX is too large, extentX will wrap
  // * if spacingX is 0, things will blow up.
  // * if realExtentX is naturally 0 or < 0, the padding will yield an
  //   extentX of 1, which is also not desirable if the input data is invalid.
  if (realExtentX > (VTK_INT_MAX >> 1) || realExtentX < 1)
    {
      vtkErrorMacro(<<"Invalid X extent.  Perhaps the input data is empty?");
      extentX = 0;
    }
  else
    {
      extentX = 1;
      while (extentX < realExtentX)
        {
          extentX = extentX << 1;
        }
    }

  // make sure extentY doesn't wrap during padding
  float realExtentY;
  if (spacingY == 0)
    realExtentY = 0;
  else
    realExtentY = planeSizeY / spacingY;

  int extentY;
  if (realExtentY > (VTK_INT_MAX >> 1) || realExtentY < 1)
    {
      vtkErrorMacro(<<"Invalid Y extent.  Perhaps the input data is empty?");
      extentY = 0;
    }
  else
    {
      extentY = 1;
      while (extentY < realExtentY)
        {
          extentY = extentY << 1;
        }
    }

  this->Reslice->SetOutputSpacing(spacingX,spacingY,1);
  this->Reslice->SetOutputOrigin(0.5*spacingX + originXYZW[0],
                                 0.5*spacingY + originXYZW[1],
                                 0.0);

  this->Reslice->SetOutputExtent(0,extentX-1,0,extentY-1,0,0);

  // Find expansion factor to account for increasing the extent
  // to a power of two
  //
  float expand1 = extentX*spacingX;
  float expand2 = extentY*spacingY;

  // Set the texture coordinates to map the image to the plane
  //
  this->TexturePlaneCoords->SetOrigin(planeOrigin[0],
                                      planeOrigin[1],planeOrigin[2]);
  this->TexturePlaneCoords->SetPoint1(planeOrigin[0] + planeAxis1[0]*expand1,
                                      planeOrigin[1] + planeAxis1[1]*expand1,
                                      planeOrigin[2] + planeAxis1[2]*expand1);
  this->TexturePlaneCoords->SetPoint2(planeOrigin[0] + planeAxis2[0]*expand2,
                                      planeOrigin[1] + planeAxis2[1]*expand2,
                                      planeOrigin[2] + planeAxis2[2]*expand2);
}

vtkImageData* vtkImagePlaneWidget::GetResliceOutput()
{
  if ( ! this->Reslice )
    {
    return 0;
    }
  return this->Reslice->GetOutput();
}

void vtkImagePlaneWidget::SetResliceInterpolate(int i)
{
  if ( this->ResliceInterpolate == i )
    {
    return;
    }
  this->ResliceInterpolate = i;
  this->Modified();

  if ( !this->Reslice )
    {
    return;
    }
  
  if ( i == VTK_NEAREST_RESLICE )
    {
    this->Reslice->SetInterpolationModeToNearestNeighbor();
    }
  else if ( i == VTK_LINEAR_RESLICE)
    {
    this->Reslice->SetInterpolationModeToLinear();
    }
  else
    {
    this->Reslice->SetInterpolationModeToCubic();
    }
  this->Texture->SetInterpolate(this->TextureInterpolate);
}

void vtkImagePlaneWidget::SetPicker(vtkCellPicker* picker)
{
  if (this->PlanePicker != picker)
    {
    // to avoid destructor recursion
    vtkCellPicker *temp = this->PlanePicker;
    this->PlanePicker = picker;
    if (temp != 0)
      {
      temp->UnRegister(this);
      }
    if (this->PlanePicker != 0)
      {
      this->PlanePicker->Register(this);
      this->PlanePicker->SetTolerance(0.005); //need some fluff
      this->PlanePicker->AddPickList(this->TexturePlaneActor);
      this->PlanePicker->PickFromListOn();
      }
    }
}

vtkLookupTable* vtkImagePlaneWidget::CreateDefaultLookupTable()
{
  vtkLookupTable* lut = vtkLookupTable::New();
  lut->Register(this);
  lut->Delete();
  lut->SetNumberOfColors( 256);
  lut->SetHueRange( 0, 0);
  lut->SetSaturationRange( 0, 0);
  lut->SetValueRange( 0 ,1);
  lut->SetAlphaRange( 1, 1);
  lut->Build();
  return lut;
}

void vtkImagePlaneWidget::SetLookupTable(vtkLookupTable* table)
{
  if (this->LookupTable != table)
    {
    // to avoid destructor recursion
    vtkLookupTable *temp = this->LookupTable;
    this->LookupTable = table;
    if (temp != 0)
      {
      temp->UnRegister(this);
      }
    if (this->LookupTable != 0)
      {
      this->LookupTable->Register(this);
      }
    else  //create a default lut
      {
      this->LookupTable = this->CreateDefaultLookupTable();
      }
    }

  this->ColorMap->SetLookupTable(this->LookupTable);
  this->Texture->SetLookupTable(this->LookupTable);

  if( this->ImageData && !this->UserControlledLookupTable)
    {
    float range[2];
    this->ImageData->GetScalarRange(range);

    this->LookupTable->SetTableRange(range[0],range[1]);
    this->LookupTable->Build();

    this->OriginalWindow = range[1] - range[0];
    this->OriginalLevel = 0.5*(range[0] + range[1]);
    }
}

void vtkImagePlaneWidget::SetSlicePosition(float position)
{
  float amount = 0.0f;
  float planeOrigin[3];
  this->PlaneSource->GetOrigin(planeOrigin);

  if ( this->PlaneOrientation == 2 ) // z axis
    {
    amount = position - planeOrigin[2];
    }
  else if ( this->PlaneOrientation == 0 ) // x axis
    {
    amount = position - planeOrigin[0];
    }
  else if ( this->PlaneOrientation == 1 )  //y axis
    {
    amount = position - planeOrigin[1];
    }
  else
    {
    vtkGenericWarningMacro("only works for ortho planes: set plane orientation first");
    return;
    } 

  this->PlaneSource->Push(amount);
  this->PlaneSource->Update();
  this->BuildRepresentation();
  this->UpdateOrigin();
}

float vtkImagePlaneWidget::GetSlicePosition()
{
  float planeOrigin[3];
  this->PlaneSource->GetOrigin(planeOrigin);

  if ( this->PlaneOrientation == 2 )
    {
    return planeOrigin[2];
    }
  else if ( this->PlaneOrientation == 1 )
    { 
    return planeOrigin[1];
    }
  else if ( this->PlaneOrientation == 0 )
    {  
    return planeOrigin[0];
    } 
  else
    {
    vtkGenericWarningMacro("only works for ortho planes: set plane orientation first");
    }

  return 0.0f;
}

void vtkImagePlaneWidget::SetSliceIndex(int index)
{
  if ( !this->Reslice )
    {
      return;
    }
  this->ImageData = this->Reslice->GetInput();
  if ( !this->ImageData )
    {
    return;
    } 
  this->ImageData->UpdateInformation();
  float origin[3];
  this->ImageData->GetOrigin(origin);
  float spacing[3];
  this->ImageData->GetSpacing(spacing);
  float planeOrigin[3];
  this->PlaneSource->GetOrigin(planeOrigin);
  float pt1[3];
  this->PlaneSource->GetPoint1(pt1);
  float pt2[3];
  this->PlaneSource->GetPoint2(pt2);

  if ( this->PlaneOrientation == 2 )
    {
    planeOrigin[2] = origin[2] + index*spacing[2];
    pt1[2] = planeOrigin[2];
    pt2[2] = planeOrigin[2];
    }
  else if ( this->PlaneOrientation == 1 )
    {
    planeOrigin[1] = origin[1] + index*spacing[1]; 
    pt1[1] = planeOrigin[1];
    pt2[1] = planeOrigin[1];
    }
  else if ( this->PlaneOrientation == 0 )
    {
    planeOrigin[0] = origin[0] + index*spacing[0]; 
    pt1[0] = planeOrigin[0];
    pt2[0] = planeOrigin[0];
    }
  else
    {
    vtkGenericWarningMacro("only works for ortho planes: set plane orientation first");
    return; 
    }

  this->PlaneSource->SetOrigin(planeOrigin);
  this->PlaneSource->SetPoint1(pt1);
  this->PlaneSource->SetPoint2(pt2);
  this->PlaneSource->Update();
  this->BuildRepresentation();
  this->UpdateOrigin();
}

int vtkImagePlaneWidget::GetSliceIndex()
{
  if ( ! this->Reslice )
    {
    return 0;
    }
  this->ImageData = this->Reslice->GetInput();
  if ( ! this->ImageData )
    {
    return 0;
    } 
  this->ImageData->UpdateInformation();
  float origin[3];
  this->ImageData->GetOrigin(origin);
  float spacing[3];
  this->ImageData->GetSpacing(spacing);
  float planeOrigin[3];
  this->PlaneSource->GetOrigin(planeOrigin);

  if ( this->PlaneOrientation == 2 )
    {
    return vtkMath::Round((planeOrigin[2]-origin[2])/spacing[2]);
    }
  else if ( this->PlaneOrientation == 1 )
    {
    return vtkMath::Round((planeOrigin[1]-origin[1])/spacing[1]);
    }
  else if ( this->PlaneOrientation == 0 )
    {
    return vtkMath::Round((planeOrigin[0]-origin[0])/spacing[0]);
    }
  else
    {
    vtkGenericWarningMacro("only works for ortho planes: set plane orientation first");
    }

  return 0;
}

void vtkImagePlaneWidget::ActivateCursor(int i)
{

  if( !this->CurrentRenderer )
    {
    return;
    }

  if( i == 0 )
    {
    this->CursorActor->VisibilityOff();
    }
  else
    {
    this->CursorActor->VisibilityOn();
    }
}

void vtkImagePlaneWidget::ActivateMargins(int i)
{

  if( !this->CurrentRenderer )
    {
    return;
    }

  if( i == 0 )
    {
    this->MarginActor->VisibilityOff();
    }
  else
    {
    this->MarginActor->VisibilityOn();
    }
}

void vtkImagePlaneWidget::ActivateText(int i)
{
  if( !this->CurrentRenderer || !this->DisplayText)
    {
    return;
    }

  if( i == 0 )
    {
    this->TextActor->VisibilityOff();
    }
  else
    {
    this->TextActor->VisibilityOn();
    }
}

void vtkImagePlaneWidget::UpdateCursor(int X, int Y )
{
  vtkAssemblyPath *path;
  this->PlanePicker->Pick(X,Y,0.0,this->CurrentRenderer);
  path = this->PlanePicker->GetPath();
  this->CurrentImageValue = VTK_FLOAT_MAX;

  int found = 0;
  int i;
  if ( path != 0 )
    {
  // Deal with the possibility that we may be using a shared picker
  //
    path->InitTraversal();
    vtkAssemblyNode *node;
    for ( i = 0; i< path->GetNumberOfItems() && !found ; i++ )
      {
      node = path->GetNextNode();
      if ( node->GetProp() == vtkProp::SafeDownCast(this->TexturePlaneActor) )
        {
        found = 1;
        }
      }
    }

  if( !found || path == 0 )
    {
    this->CursorActor->VisibilityOff();
    return;
    }
  else
    {
    this->CursorActor->VisibilityOn();
    }

  float q[3];
  this->PlanePicker->GetPickPosition(q);

  // vtkImageData will find the nearest implicit point to q
  //
  vtkIdType ptId = this->ImageData->FindPoint(q);

  if ( ptId == -1 )
    {
    this->CursorActor->VisibilityOff();
    return;
    }

  float closestPt[3];
  this->ImageData->GetPoint(ptId,closestPt);

  float origin[3];
  this->ImageData->GetOrigin(origin);
  float spacing[3];
  this->ImageData->GetSpacing(spacing);
  int extent[6];
  this->ImageData->GetExtent(extent);

  float o[3];
  this->PlaneSource->GetOrigin(o);

  int iq[3];
  int iqtemp;
  float qro[3];
  for (i = 0; i < 3; i++)
    {
  // compute world to image coords
    iqtemp = vtkMath::Round((closestPt[i]-origin[i])/spacing[i]);

  // we have a valid pick already, just enforce bounds check
    iq[i] = (iqtemp < extent[2*i])?extent[2*i]:((iqtemp > extent[2*i+1])?extent[2*i+1]:iqtemp);

  // compute image to world coords
    q[i] = iq[i]*spacing[i] + origin[i];

  // q relative to the plane origin
    qro[i]= q[i] - o[i];
    }

  memcpy(this->CurrentCursorPosition,iq,3*sizeof(int));
  this->CurrentImageValue = 0.0;

  float p1o[3];
  float p2o[3];

  this->GetVector1(p1o);
  this->GetVector2(p2o);

  float Lp1 = vtkMath::Dot(qro,p1o)/vtkMath::Dot(p1o,p1o);
  float Lp2 = vtkMath::Dot(qro,p2o)/vtkMath::Dot(p2o,p2o);

  float p1[3];
  this->PlaneSource->GetPoint1(p1);
  float p2[3];
  this->PlaneSource->GetPoint2(p2);

  float a[3];
  float b[3];
  float c[3];
  float d[3];

  for (i = 0; i < 3; i++)
    {
    a[i] = o[i]  + Lp2*p2o[i];   // left
    b[i] = p1[i] + Lp2*p2o[i];   // right
    c[i] = o[i]  + Lp1*p1o[i];   // bottom
    d[i] = p2[i] + Lp1*p1o[i];   // top
    }

  vtkPoints* cursorPts = this->CursorPolyData->GetPoints();

  cursorPts->SetPoint(0,a);
  cursorPts->SetPoint(1,b);
  cursorPts->SetPoint(2,c);
  cursorPts->SetPoint(3,d);

  this->CursorMapper->Modified();
}

void vtkImagePlaneWidget::SetOrigin(float x, float y, float z)
{
  this->PlaneSource->SetOrigin(x,y,z);
}

void vtkImagePlaneWidget::SetOrigin(float xyz[3])
{
  this->PlaneSource->SetOrigin(xyz);
}

float* vtkImagePlaneWidget::GetOrigin()
{
  return this->PlaneSource->GetOrigin();
}

void vtkImagePlaneWidget::GetOrigin(float xyz[3])
{
  this->PlaneSource->GetOrigin(xyz);
}

void vtkImagePlaneWidget::SetPoint1(float x, float y, float z)
{
  this->PlaneSource->SetPoint1(x,y,z);
}

void vtkImagePlaneWidget::SetPoint1(float xyz[3])
{
  this->PlaneSource->SetPoint1(xyz);
}

float* vtkImagePlaneWidget::GetPoint1()
{
  return this->PlaneSource->GetPoint1();
}

void vtkImagePlaneWidget::GetPoint1(float xyz[3])
{
  this->PlaneSource->GetPoint1(xyz);
}

void vtkImagePlaneWidget::SetPoint2(float x, float y, float z)
{
  this->PlaneSource->SetPoint2(x,y,z);
}

void vtkImagePlaneWidget::SetPoint2(float xyz[3])
{
  this->PlaneSource->SetPoint2(xyz);
}

float* vtkImagePlaneWidget::GetPoint2()
{
  return this->PlaneSource->GetPoint2();
}

void vtkImagePlaneWidget::GetPoint2(float xyz[3])
{
  this->PlaneSource->GetPoint2(xyz);
}

float* vtkImagePlaneWidget::GetCenter() 
{
  return this->PlaneSource->GetCenter();
}

void vtkImagePlaneWidget::GetCenter(float xyz[3]) 
{
  this->PlaneSource->GetCenter(xyz);
}

float* vtkImagePlaneWidget::GetNormal() 
{
  return this->PlaneSource->GetNormal();
}

void vtkImagePlaneWidget::GetNormal(float xyz[3])
{
  this->PlaneSource->GetNormal(xyz);
}

void vtkImagePlaneWidget::GetPolyData(vtkPolyData *pd)
{
  pd->ShallowCopy(this->PlaneSource->GetOutput());
}

vtkPolyDataSource *vtkImagePlaneWidget::GetPolyDataSource()
{
  return this->PlaneSource;
}

void vtkImagePlaneWidget::UpdatePlacement(void)
{
  this->PlaneSource->Update();
  this->BuildRepresentation();
  this->UpdateNormal();
  this->UpdateOrigin();
  this->UpdateMargins();
}

void vtkImagePlaneWidget::SetTextProperty(vtkTextProperty* tprop)
{
  this->TextActor->SetTextProperty(tprop);
}

vtkTextProperty* vtkImagePlaneWidget::GetTextProperty()
{
  return this->TextActor->GetTextProperty();
}

vtkTexture* vtkImagePlaneWidget::GetTexture()
{
  return this->Texture;
}

vtkImageMapToColors* vtkImagePlaneWidget::GetImageMapToColors()
{
  return this->ColorMap;
}

void vtkImagePlaneWidget::GetVector1(float v1[3])
{
  float* p1 = this->PlaneSource->GetPoint1();
  float* o =  this->PlaneSource->GetOrigin();
  v1[0] = p1[0] - o[0];
  v1[1] = p1[1] - o[1];
  v1[2] = p1[2] - o[2];
}

void vtkImagePlaneWidget::GetVector2(float v2[3])
{
  float* p2 = this->PlaneSource->GetPoint2();
  float* o =  this->PlaneSource->GetOrigin();
  v2[0] = p2[0] - o[0];
  v2[1] = p2[1] - o[1];
  v2[2] = p2[2] - o[2];
}

void vtkImagePlaneWidget::AdjustState()
{
  if ( this->Interactor->GetShiftKey() )
    {
    this->State = vtkImagePlaneWidget::Scaling;
    return;
    }

  float v1[3];
  this->GetVector1(v1);
  float v2[3];
  this->GetVector2(v2);
  float planeSize1 = vtkMath::Normalize(v1);
  float planeSize2 = vtkMath::Normalize(v2);
  float* planeOrigin = this->PlaneSource->GetOrigin();

  float ppo[3] = {this->LastPickPosition[0] - planeOrigin[0],
                  this->LastPickPosition[1] - planeOrigin[1],
                  this->LastPickPosition[2] - planeOrigin[2] };

  float x2D = vtkMath::Dot(ppo,v1);
  float y2D = vtkMath::Dot(ppo,v2);

  // Divide plane into three zones for different user interactions:
  // four corners -- spin around the plane's normal at its center
  // four edges   -- rotate around one of the plane's axes at its center
  // center area  -- push
  //
  float marginX = planeSize1 * 0.05;
  float marginY = planeSize2 * 0.05;

  float x0 = marginX;
  float y0 = marginY;
  float x1 = planeSize1 - marginX;
  float y1 = planeSize2 - marginY;

  if ( x2D < x0  )       // left margin
    {
    if (y2D < y0)        // bottom left corner
      {
      this->MarginSelectMode =  0;
      }
    else if (y2D > y1)   // top left corner
      {
      this->MarginSelectMode =  3;
      }
    else                 // left edge
      {
      this->MarginSelectMode =  4;
      }
    }
  else if ( x2D > x1 )   // right margin
    {
    if (y2D < y0)        // bottom right corner
      {
      this->MarginSelectMode =  1;
      }
    else if (y2D > y1)   // top right corner
      {
      this->MarginSelectMode =  2;
      }
    else                 // right edge
      {
      this->MarginSelectMode =  5;
      }
    }
  else                   // middle
    {
    if (y2D < y0)        // bottom edge
      {
      this->MarginSelectMode =  6;
      }
    else if (y2D > y1)   // top edge
      {
      this->MarginSelectMode =  7;
      }
    else                 // central area
      {
      this->MarginSelectMode =  8;
      }
    }

  if ( this->Interactor->GetControlKey() )
    {
    this->State = vtkImagePlaneWidget::Moving;
    }
  else
    {
    if (this->MarginSelectMode >= 0 && this->MarginSelectMode < 4)
      {
      this->State = vtkImagePlaneWidget::Spinning;
      return;
      }
    else if (this->MarginSelectMode == 8)
      {
      this->State = vtkImagePlaneWidget::Pushing;
      return;
      }
    else
      {
      this->State = vtkImagePlaneWidget::Rotating;
      }
    }

  float *raPtr = 0;
  float *rvPtr = 0;
  float rvfac = 1.0;
  float rafac = 1.0;

  switch ( this->MarginSelectMode )
    {
     // left bottom corner
    case 0: raPtr = v2; rvPtr = v1; rvfac = -1.0; rafac = -1.0; break;
     // right bottom corner
    case 1: raPtr = v2; rvPtr = v1;               rafac = -1.0; break;
     // right top corner
    case 2: raPtr = v2; rvPtr = v1;               break;
     // left top corner
    case 3: raPtr = v2; rvPtr = v1; rvfac = -1.0; break;
    case 4: raPtr = v2; rvPtr = v1; rvfac = -1.0; break; // left
    case 5: raPtr = v2; rvPtr = v1;               break; // right
    case 6: raPtr = v1; rvPtr = v2; rvfac = -1.0; break; // bottom
    case 7: raPtr = v1; rvPtr = v2;               break; // top
    default: raPtr = v1; rvPtr = v2; break;
    }

  for (int i = 0; i < 3; i++)
    {
    this->RotateAxis[i] = *raPtr++ * rafac;
    this->RadiusVector[i] = *rvPtr++ * rvfac;
    }
}

void vtkImagePlaneWidget::Spin(double *p1, double *p2)
{
  // Disable cursor snap
  //
  this->PlaneOrientation = 3;
  
  // Get the motion vector, in world coords
  //
  float v[3];
  v[0] = p2[0] - p1[0];
  v[1] = p2[1] - p1[1];
  v[2] = p2[2] - p1[2];

  // Plane center and normal before transform
  //
  float* wc = this->PlaneSource->GetCenter();
  float* wn = this->Normal;

  // Radius vector from center to cursor position
  //
  float rv[3] = {p2[0]-wc[0], p2[1]-wc[1], p2[2]-wc[2]};

  // Distance between center and cursor location
  //
  float rs = vtkMath::Normalize(rv);

  // Spin direction
  //
  float wn_cross_rv[3];
  vtkMath::Cross(wn,rv,wn_cross_rv);

  // Spin angle
  //
  float dw = vtkMath::RadiansToDegrees() * vtkMath::Dot(v,wn_cross_rv) / rs;

  this->Transform->Identity();
  this->Transform->Translate(wc[0],wc[1],wc[2]);
  this->Transform->RotateWXYZ(dw,wn);
  this->Transform->Translate(-wc[0],-wc[1],-wc[2]);

  float newpt[3];
  this->Transform->TransformPoint(this->PlaneSource->GetPoint1(),newpt);
  this->PlaneSource->SetPoint1(newpt);
  this->Transform->TransformPoint(this->PlaneSource->GetPoint2(),newpt);
  this->PlaneSource->SetPoint2(newpt);
  this->Transform->TransformPoint(this->PlaneSource->GetOrigin(),newpt);
  this->PlaneSource->SetOrigin(newpt);

  this->PlaneSource->Update();
  this->BuildRepresentation();
}

void vtkImagePlaneWidget::Rotate(double *p1, double *p2, double *vpn)
{
  // Disable cursor snap
  //
  this->PlaneOrientation = 3;

  // Get the motion vector, in world coords
  //
  float v[3];
  v[0] = p2[0] - p1[0];
  v[1] = p2[1] - p1[1];
  v[2] = p2[2] - p1[2];

  // Plane center and normal
  //
  float* wc = this->PlaneSource->GetCenter();

  // Radius of the rotating circle of the picked point
  //
  float radius = fabs( this->RadiusVector[0]*(p2[0]-wc[0]) +
                       this->RadiusVector[1]*(p2[1]-wc[1]) +
                       this->RadiusVector[2]*(p2[2]-wc[2]) );

  // Rotate direction ra_cross_rv
  //
  float rd[3];
  vtkMath::Cross(this->RotateAxis,this->RadiusVector,rd);

  // Direction cosin between rotating direction and view normal
  //
  float rd_dot_vpn = rd[0]*vpn[0] + rd[1]*vpn[1] + rd[2]*vpn[2];

  // 'push' plane edge when mouse moves away from plane center
  // 'pull' plane edge when mouse moves toward plane center
  //
  float dw = vtkMath::RadiansToDegrees() * (vtkMath::Dot(this->RadiusVector,v))/radius * (-rd_dot_vpn);

  this->Transform->Identity();
  this->Transform->Translate(wc[0],wc[1],wc[2]);
  this->Transform->RotateWXYZ(dw,this->RotateAxis);
  this->Transform->Translate(-wc[0],-wc[1],-wc[2]);

  float newpt[3];
  this->Transform->TransformPoint(this->PlaneSource->GetPoint1(),newpt);
  this->PlaneSource->SetPoint1(newpt);
  this->Transform->TransformPoint(this->PlaneSource->GetPoint2(),newpt);
  this->PlaneSource->SetPoint2(newpt);
  this->Transform->TransformPoint(this->PlaneSource->GetOrigin(),newpt);
  this->PlaneSource->SetOrigin(newpt);

  this->PlaneSource->Update();
  this->BuildRepresentation();
}

void vtkImagePlaneWidget::GeneratePlaneOutline()
{
  vtkPoints* points   = vtkPoints::New(VTK_DOUBLE);
  points->SetNumberOfPoints(4);
  int i;
  for (i = 0; i < 4; i++)
    {
    points->SetPoint(i,0.0,0.0,0.0);
    }

  vtkCellArray *cells = vtkCellArray::New();
  cells->Allocate(cells->EstimateSize(4,2));
  vtkIdType pts[2];
  pts[0] = 3; pts[1] = 2;       // top edge
  cells->InsertNextCell(2,pts);
  pts[0] = 0; pts[1] = 1;       // bottom edge
  cells->InsertNextCell(2,pts);
  pts[0] = 0; pts[1] = 3;       // left edge
  cells->InsertNextCell(2,pts);
  pts[0] = 1; pts[1] = 2;       // right edge
  cells->InsertNextCell(2,pts);

  this->PlaneOutlinePolyData->SetPoints(points);
  points->Delete();
  this->PlaneOutlinePolyData->SetLines(cells);
  cells->Delete();

  this->PlaneOutlineMapper->SetInput( this->PlaneOutlinePolyData );
  this->PlaneOutlineMapper->SetResolveCoincidentTopologyToPolygonOffset();
  this->PlaneOutlineActor->SetMapper(this->PlaneOutlineMapper);
  this->PlaneOutlineActor->PickableOff();
}

void vtkImagePlaneWidget::GenerateTexturePlane()
{
  this->SetResliceInterpolate(this->ResliceInterpolate);

  this->LookupTable = this->CreateDefaultLookupTable();

  this->ColorMap->SetLookupTable(this->LookupTable);
  this->ColorMap->SetOutputFormatToRGBA();
  this->ColorMap->PassAlphaToOutputOn();

  this->TexturePlaneCoords->SetInput(this->PlaneSource->GetOutput());
  this->TexturePlaneCoords->AutomaticPlaneGenerationOff();

  this->TexturePlaneMapper->SetInput(this->TexturePlaneCoords->GetOutput());

  this->Texture->SetQualityTo32Bit();
  this->Texture->MapColorScalarsThroughLookupTableOff();
  this->Texture->SetInterpolate(this->TextureInterpolate);
  this->Texture->RepeatOff();
  this->Texture->SetLookupTable(this->LookupTable);

  this->TexturePlaneActor->SetMapper(this->TexturePlaneMapper);
  this->TexturePlaneActor->SetTexture(this->Texture);
  this->TexturePlaneActor->PickableOn();
}

void vtkImagePlaneWidget::GenerateMargins()
{
  // Construct initial points
  vtkPoints* points = vtkPoints::New(VTK_DOUBLE); 
  points->SetNumberOfPoints(8);
  int i;
  for (i = 0; i < 8; i++)
    {
    points->SetPoint(i,0.0,0.0,0.0);
    }

  vtkCellArray *cells = vtkCellArray::New();
  cells->Allocate(cells->EstimateSize(4,2));
  vtkIdType pts[2];
  pts[0] = 0; pts[1] = 1;       // top margin
  cells->InsertNextCell(2,pts);
  pts[0] = 2; pts[1] = 3;       // bottom margin
  cells->InsertNextCell(2,pts);
  pts[0] = 4; pts[1] = 5;       // left margin
  cells->InsertNextCell(2,pts);
  pts[0] = 6; pts[1] = 7;       // right margin
  cells->InsertNextCell(2,pts);

  this->MarginPolyData->SetPoints(points);
  points->Delete();
  this->MarginPolyData->SetLines(cells);
  cells->Delete();

  this->MarginMapper->SetInput(this->MarginPolyData);
  this->MarginMapper->SetResolveCoincidentTopologyToPolygonOffset();
  this->MarginActor->SetMapper(this->MarginMapper);
  this->MarginActor->PickableOff();
  this->MarginActor->VisibilityOff();
}

void vtkImagePlaneWidget::GenerateCursor()
{
  // Construct initial points
  //
  vtkPoints* points = vtkPoints::New(VTK_DOUBLE);
  points->SetNumberOfPoints(4);
  int i;
  for (i = 0; i < 4; i++)
    {
    points->SetPoint(i,0.0,0.0,0.0);
    }

  vtkCellArray *cells = vtkCellArray::New();
  cells->Allocate(cells->EstimateSize(2,2));
  vtkIdType pts[2];
  pts[0] = 0; pts[1] = 1;       // horizontal segment
  cells->InsertNextCell(2,pts);
  pts[0] = 2; pts[1] = 3;       // vertical segment
  cells->InsertNextCell(2,pts);

  this->CursorPolyData->SetPoints(points);
  points->Delete();
  this->CursorPolyData->SetLines(cells);
  cells->Delete();

  this->CursorMapper->SetInput(this->CursorPolyData);
  this->CursorMapper->SetResolveCoincidentTopologyToPolygonOffset();
  this->CursorActor->SetMapper(this->CursorMapper);
  this->CursorActor->PickableOff();
  this->CursorActor->VisibilityOff();
}

void vtkImagePlaneWidget::GenerateText()
{
  sprintf(this->TextBuff,"NA");
  this->TextActor->SetInput(this->TextBuff);
  this->TextActor->ScaledTextOff();

  vtkTextProperty* textprop = this->TextActor->GetTextProperty();
  textprop->SetColor(1,1,1);
  textprop->SetFontFamilyToArial();
  textprop->SetFontSize(18);
  textprop->BoldOff();
  textprop->ItalicOff();
  textprop->ShadowOff();
  textprop->SetJustificationToLeft();
  textprop->SetVerticalJustificationToBottom();

  vtkCoordinate* coord = this->TextActor->GetPositionCoordinate();
  coord->SetCoordinateSystemToNormalizedViewport();
  coord->SetValue(.01, .01);

  this->TextActor->VisibilityOff();
}

void vtkImagePlaneWidget::UpdateMargins()
{
  float v1[3];
  this->GetVector1(v1);
  float v2[3];
  this->GetVector2(v2);
  float o[3];
  this->PlaneSource->GetOrigin(o);
  float p1[3];
  this->PlaneSource->GetPoint1(p1);
  float p2[3];
  this->PlaneSource->GetPoint2(p2);

  float a[3];
  float b[3];
  float c[3];
  float d[3];

  float s = 0.05;
  float t = 0.05;

  int i;
  for ( i = 0; i < 3; i++)
    {
    a[i] = o[i] + v2[i]*(1-t);
    b[i] = p1[i] + v2[i]*(1-t);
    c[i] = o[i] + v2[i]*t;
    d[i] = p1[i] + v2[i]*t;
    }

  vtkPoints* marginPts = this->MarginPolyData->GetPoints();

  marginPts->SetPoint(0,a);
  marginPts->SetPoint(1,b);
  marginPts->SetPoint(2,c);
  marginPts->SetPoint(3,d);

  for ( i = 0; i < 3; i++)
    {
    a[i] = o[i] + v1[i]*s;
    b[i] = p2[i] + v1[i]*s;
    c[i] = o[i] + v1[i]*(1-s);
    d[i] = p2[i] + v1[i]*(1-s);
    }

  marginPts->SetPoint(4,a);
  marginPts->SetPoint(5,b);
  marginPts->SetPoint(6,c);
  marginPts->SetPoint(7,d);

  this->MarginMapper->Modified();
}

void vtkImagePlaneWidget::Translate(double *p1, double *p2)
{
  // Get the motion vector
  //
  double v[3];
  v[0] = p2[0] - p1[0];
  v[1] = p2[1] - p1[1];
  v[2] = p2[2] - p1[2];

  float *o = this->PlaneSource->GetOrigin();
  float *pt1 = this->PlaneSource->GetPoint1();
  float *pt2 = this->PlaneSource->GetPoint2();
  float origin[3], point1[3], point2[3];

  float vdrv = this->RadiusVector[0]*v[0] + \
               this->RadiusVector[1]*v[1] + \
               this->RadiusVector[2]*v[2];
  float vdra = this->RotateAxis[0]*v[0] + \
               this->RotateAxis[1]*v[1] + \
               this->RotateAxis[2]*v[2];

  int i;
  if ( this->MarginSelectMode == 8 )       // everybody comes along
    {
    for (i=0; i<3; i++)
      {
      origin[i] = o[i] + v[i];
      point1[i] = pt1[i] + v[i];
      point2[i] = pt2[i] + v[i];
      }
    this->PlaneSource->SetOrigin(origin);
    this->PlaneSource->SetPoint1(point1);
    this->PlaneSource->SetPoint2(point2);
    }
  else if ( this->MarginSelectMode == 4 ) // left edge
    {
    for (i=0; i<3; i++)
      {
      origin[i] = o[i]   + vdrv*this->RadiusVector[i];
      point2[i] = pt2[i] + vdrv*this->RadiusVector[i];
      }
    this->PlaneSource->SetOrigin(origin);
    this->PlaneSource->SetPoint2(point2);
    }
  else if ( this->MarginSelectMode == 5 ) // right edge
    {
    for (i=0; i<3; i++)
      {
      point1[i] = pt1[i] + vdrv*this->RadiusVector[i];
      }
    this->PlaneSource->SetPoint1(point1);
    }
  else if ( this->MarginSelectMode == 6 ) // bottom edge
    {
    for (i=0; i<3; i++)
      {
      origin[i] = o[i]   + vdrv*this->RadiusVector[i];
      point1[i] = pt1[i] + vdrv*this->RadiusVector[i];
      }
    this->PlaneSource->SetOrigin(origin);
    this->PlaneSource->SetPoint1(point1);
    }
  else if ( this->MarginSelectMode == 7 ) // top edge
    {
    for (i=0; i<3; i++)
      {
      point2[i] = pt2[i] + vdrv*this->RadiusVector[i];
      }
    this->PlaneSource->SetPoint2(point2);
    }
  else if ( this->MarginSelectMode == 3 ) // top left corner
    {
    for (i=0; i<3; i++)
      {
      origin[i] = o[i]   + vdrv*this->RadiusVector[i];
      point2[i] = pt2[i] + vdrv*this->RadiusVector[i] + vdra*this->RotateAxis[i];
      }
    this->PlaneSource->SetOrigin(origin);
    this->PlaneSource->SetPoint2(point2);
    }
  else if ( this->MarginSelectMode == 0 ) // bottom left corner
    {
    for (i=0; i<3; i++)
      {
      origin[i] = o[i]   + vdrv*this->RadiusVector[i] + vdra*this->RotateAxis[i];
      point1[i] = pt1[i] + vdra*this->RotateAxis[i];
      point2[i] = pt2[i] + vdrv*this->RadiusVector[i];
      }
    this->PlaneSource->SetOrigin(origin);
    this->PlaneSource->SetPoint1(point1);
    this->PlaneSource->SetPoint2(point2);
    }
  else if ( this->MarginSelectMode == 2 ) // top right corner
    {
    for (i=0; i<3; i++)
      {
      point1[i] = pt1[i] + vdrv*this->RadiusVector[i];
      point2[i] = pt2[i] + vdra*this->RotateAxis[i];
      }
    this->PlaneSource->SetPoint1(point1);
    this->PlaneSource->SetPoint2(point2);
    }
  else                                   // bottom right corner
    {
    for (i=0; i<3; i++)
      {
      origin[i] = o[i]   + vdra*this->RotateAxis[i];
      point1[i] = pt1[i] + vdrv*this->RadiusVector[i] + vdra*this->RotateAxis[i];
      }
    this->PlaneSource->SetPoint1(point1);
    this->PlaneSource->SetOrigin(origin);
    }

  this->PlaneSource->Update(); 
  this->BuildRepresentation();
}

void vtkImagePlaneWidget::Scale(double *p1, double *p2, int vtkNotUsed(X), int Y)
{
  // Get the motion vector
  //
  double v[3];
  v[0] = p2[0] - p1[0];
  v[1] = p2[1] - p1[1];
  v[2] = p2[2] - p1[2];

  float *o = this->PlaneSource->GetOrigin();
  float *pt1 = this->PlaneSource->GetPoint1();
  float *pt2 = this->PlaneSource->GetPoint2();

  float center[3];
  center[0] = o[0] + (pt1[0]-o[0])/2.0 + (pt2[0]-o[0])/2.0;
  center[1] = o[1] + (pt1[1]-o[1])/2.0 + (pt2[1]-o[1])/2.0;
  center[2] = o[2] + (pt1[2]-o[2])/2.0 + (pt2[2]-o[2])/2.0;

  // Compute the scale factor
  //
  float sf = vtkMath::Norm(v) / sqrt(vtkMath::Distance2BetweenPoints(pt1,pt2));
  if ( Y > this->Interactor->GetLastEventPosition()[1] )
    {
    sf = 1.0 + sf;
    }
  else
    {
    sf = 1.0 - sf;
    }

  // Move the corner points
  //
  float origin[3], point1[3], point2[3];

  for (int i=0; i<3; i++)
    {
    origin[i] = sf * (o[i] - center[i]) + center[i];
    point1[i] = sf * (pt1[i] - center[i]) + center[i];
    point2[i] = sf * (pt2[i] - center[i]) + center[i];
    }

  this->PlaneSource->SetOrigin(origin);
  this->PlaneSource->SetPoint1(point1);
  this->PlaneSource->SetPoint2(point2);
  this->PlaneSource->Update();
  this->BuildRepresentation();
}


