vtkImagePlaneWidget.cxx

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

  Program:   Visualization Toolkit
  Module:    vtkImagePlaneWidget.cxx

  Copyright (c) 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 "vtkAlgorithmOutput.h"
#include "vtkAssemblyNode.h"
#include "vtkAssemblyPath.h"
#include "vtkCallbackCommand.h"
#include "vtkCamera.h"
#include "vtkCellArray.h"
#include "vtkCellPicker.h"
#include "vtkImageData.h"
#include "vtkImageMapToColors.h"
#include "vtkImageReslice.h"
#include "vtkLookupTable.h"
#include "vtkMath.h"
#include "vtkMatrix4x4.h"
#include "vtkObjectFactory.h"
#include "vtkPickingManager.h"
#include "vtkPlaneSource.h"
#include "vtkPointData.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 "vtkTransform.h"
#include "vtkStreamingDemandDrivenPipeline.h"
#include "vtkInformation.h"

vtkStandardNewMacro(vtkImagePlaneWidget);

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

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

  this->Interaction              = 1;
  this->PlaneOrientation         = 0;
  this->PlaceFactor              = 1.0;
  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_DOUBLE_MAX;
  this->MarginSelectMode         = 8;
  this->UseContinuousCursor      = 0;
  this->MarginSizeX              = 0.05;
  this->MarginSizeY              = 0.05;


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

  // Represent the resliced image plane
  //
  this->ColorMap           = vtkImageMapToColors::New();
  this->Reslice            = vtkImageReslice::New();
  this->Reslice->TransformInputSamplingOff();
  this->ResliceAxes        = vtkMatrix4x4::New();
  this->Texture            = vtkTexture::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->CursorActor    = vtkActor::New();

  // Represent the oblique positioning margins
  //
  this->MarginPolyData = vtkPolyData::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
  //
  double 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 = NULL;
  vtkCellPicker* picker = vtkCellPicker::New();
  picker->SetTolerance(0.005); //need some fluff
  this->SetPicker(picker);
  picker->Delete();

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

  // Set up actions

  this->LeftButtonAction = vtkImagePlaneWidget::VTK_CURSOR_ACTION;
  this->MiddleButtonAction = vtkImagePlaneWidget::VTK_SLICE_MOTION_ACTION;
  this->RightButtonAction = vtkImagePlaneWidget::VTK_WINDOW_LEVEL_ACTION;

  // Set up modifiers

  this->LeftButtonAutoModifier = vtkImagePlaneWidget::VTK_NO_MODIFIER;
  this->MiddleButtonAutoModifier = vtkImagePlaneWidget::VTK_NO_MODIFIER;
  this->RightButtonAutoModifier = vtkImagePlaneWidget::VTK_NO_MODIFIER;

  this->LastButtonPressed = vtkImagePlaneWidget::VTK_NO_BUTTON;

  this->TextureVisibility = 1;
}

//----------------------------------------------------------------------------
vtkImagePlaneWidget::~vtkImagePlaneWidget()
{
  this->PlaneOutlineActor->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->TexturePlaneActor->Delete();
  this->ColorMap->Delete();
  this->Texture->Delete();

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

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

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

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

  this->TextActor->Delete();
}

//----------------------------------------------------------------------------
void vtkImagePlaneWidget::SetTextureVisibility(int vis)
{
  if (this->TextureVisibility == vis)
  {
    return;
  }

  this->TextureVisibility = vis;

  if ( this->Enabled )
  {
    if (this->TextureVisibility && this->ImageData)
    {
      this->CurrentRenderer->AddViewProp(this->TexturePlaneActor);
    }
    else
    {
      this->CurrentRenderer->RemoveViewProp(this->TexturePlaneActor);
    }
  }

  this->Modified();
}


//----------------------------------------------------------------------------
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->AddViewProp(this->PlaneOutlineActor);
    this->PlaneOutlineActor->SetProperty(this->PlaneProperty);

    //add the TexturePlaneActor
    if (this->TextureVisibility && this->ImageData)
    {
      this->CurrentRenderer->AddViewProp(this->TexturePlaneActor);
    }
    this->TexturePlaneActor->SetProperty(this->TexturePlaneProperty);

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

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

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

    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->RemoveViewProp(this->PlaneOutlineActor);

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

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

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

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

    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 );

  self->LastButtonPressed = vtkImagePlaneWidget::VTK_NO_BUTTON;

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

//----------------------------------------------------------------------------
void vtkImagePlaneWidget::OnChar()
{
  vtkRenderWindowInteractor *i = this->Interactor;

  if ( i->GetKeyCode() == 'r' || i->GetKeyCode() == 'R' )
  {
    if ( i->GetShiftKey() || i->GetControlKey() )
    {
      this->SetWindowLevel( this->OriginalWindow, this->OriginalLevel );
      double wl[2] = { this->CurrentWindow, this->CurrentLevel };

      this->EventCallbackCommand->SetAbortFlag(1);
      this->InvokeEvent(vtkCommand::ResetWindowLevelEvent, wl);
    }
    else
    {
      this->Interactor->GetInteractorStyle()->OnChar();
    }
  }
  else
  {
    this->Interactor->GetInteractorStyle()->OnChar();
  }
}

//----------------------------------------------------------------------------
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);
    i->AddObserver(vtkCommand::CharEvent,
                       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";
  }

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

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

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

  double *o = this->PlaneSource->GetOrigin();
  double *pt1 = this->PlaneSource->GetPoint1();
  double *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 << "Current Cursor Position: ("
     << this->CurrentCursorPosition[0] << ", "
     << this->CurrentCursorPosition[1] << ", "
     << this->CurrentCursorPosition[2] << ")\n";

  os << indent << "Current Image Value: "
     << this->CurrentImageValue << "\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 << "Texture Visibility: "
     << (this->TextureVisibility ? "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") ;
  os << indent << "LeftButtonAction: " << this->LeftButtonAction << endl;
  os << indent << "MiddleButtonAction: " << this->MiddleButtonAction << endl;
  os << indent << "RightButtonAction: " << this->RightButtonAction << endl;
  os << indent << "LeftButtonAutoModifier: " <<
    this->LeftButtonAutoModifier << endl;
  os << indent << "MiddleButtonAutoModifier: " <<
    this->MiddleButtonAutoModifier << endl;
  os << indent << "RightButtonAutoModifier: " <<
    this->RightButtonAutoModifier << endl;
  os << indent << "UseContinuousCursor: "
     << (this->UseContinuousCursor ? "On\n" : "Off\n") ;

  os << indent << "MarginSizeX: "
     << this->MarginSizeX << "\n";
  os << indent << "MarginSizeY: "
     << this->MarginSizeY << "\n";
}

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

  double 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);
  points->GetData()->Modified();
  this->PlaneOutlinePolyData->Modified();
}

//----------------------------------------------------------------------------
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()
{
  switch (this->LeftButtonAction)
  {
    case vtkImagePlaneWidget::VTK_CURSOR_ACTION:
      this->StartCursor();
      break;
    case vtkImagePlaneWidget::VTK_SLICE_MOTION_ACTION:
      this->StartSliceMotion();
      break;
    case vtkImagePlaneWidget::VTK_WINDOW_LEVEL_ACTION:
      this->StartWindowLevel();
      break;
  }
}

//----------------------------------------------------------------------------
void vtkImagePlaneWidget::OnLeftButtonUp()
{
  switch (this->LeftButtonAction)
  {
    case vtkImagePlaneWidget::VTK_CURSOR_ACTION:
      this->StopCursor();
      break;
    case vtkImagePlaneWidget::VTK_SLICE_MOTION_ACTION:
      this->StopSliceMotion();
      break;
    case vtkImagePlaneWidget::VTK_WINDOW_LEVEL_ACTION:
      this->StopWindowLevel();
      break;
  }
}

//----------------------------------------------------------------------------
void vtkImagePlaneWidget::OnMiddleButtonDown()
{
  switch (this->MiddleButtonAction)
  {
    case vtkImagePlaneWidget::VTK_CURSOR_ACTION:
      this->StartCursor();
      break;
    case vtkImagePlaneWidget::VTK_SLICE_MOTION_ACTION:
      this->StartSliceMotion();
      break;
    case vtkImagePlaneWidget::VTK_WINDOW_LEVEL_ACTION:
      this->StartWindowLevel();
      break;
  }
}

//----------------------------------------------------------------------------
void vtkImagePlaneWidget::OnMiddleButtonUp()
{
  switch (this->MiddleButtonAction)
  {
    case vtkImagePlaneWidget::VTK_CURSOR_ACTION:
      this->StopCursor();
      break;
    case vtkImagePlaneWidget::VTK_SLICE_MOTION_ACTION:
      this->StopSliceMotion();
      break;
    case vtkImagePlaneWidget::VTK_WINDOW_LEVEL_ACTION:
      this->StopWindowLevel();
      break;
  }
}

//----------------------------------------------------------------------------
void vtkImagePlaneWidget::OnRightButtonDown()
{
  switch (this->RightButtonAction)
  {
    case vtkImagePlaneWidget::VTK_CURSOR_ACTION:
      this->StartCursor();
      break;
    case vtkImagePlaneWidget::VTK_SLICE_MOTION_ACTION:
      this->StartSliceMotion();
      break;
    case vtkImagePlaneWidget::VTK_WINDOW_LEVEL_ACTION:
      this->StartWindowLevel();
      break;
  }
}

//----------------------------------------------------------------------------
void vtkImagePlaneWidget::OnRightButtonUp()
{
  switch (this->RightButtonAction)
  {
    case vtkImagePlaneWidget::VTK_CURSOR_ACTION:
      this->StopCursor();
      break;
    case vtkImagePlaneWidget::VTK_SLICE_MOTION_ACTION:
      this->StopSliceMotion();
      break;
    case vtkImagePlaneWidget::VTK_WINDOW_LEVEL_ACTION:
      this->StopWindowLevel();
      break;
  }
}

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

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

  // Okay, we can process this. If anything is picked, then we
  // can start pushing the plane.
  vtkAssemblyPath* path = this->GetAssemblyPath(X, Y, 0., this->PlanePicker);

  int found = 0;
  int i;
  if ( path != 0 )
  {
    // Deal with the possibility that we may be using a shared picker
    vtkCollectionSimpleIterator sit;
    path->InitTraversal(sit);
    vtkAssemblyNode *node;
    for ( i = 0; i < path->GetNumberOfItems() && !found ; i++ )
    {
      node = path->GetNextNode(sit);
      if ( node->GetViewProp() == 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::StopCursor()
{
  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::StartSliceMotion()
{
  int X = this->Interactor->GetEventPosition()[0];
  int Y = this->Interactor->GetEventPosition()[1];

  // Okay, make sure that the pick is in the current renderer
  if (!this->CurrentRenderer || !this->CurrentRenderer->IsInViewport(X, Y))
  {
    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->GetAssemblyPath(X, Y, 0., this->PlanePicker);

  int found = 0;
  int i;
  if ( path != 0 )
  {
    // Deal with the possibility that we may be using a shared picker
    vtkCollectionSimpleIterator sit;
    path->InitTraversal(sit);
    vtkAssemblyNode *node;
    for(i = 0; i< path->GetNumberOfItems() && !found ;i++)
    {
      node = path->GetNextNode(sit);
      if(node->GetViewProp() == 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::StopSliceMotion()
{
  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::StartWindowLevel()
{
  int X = this->Interactor->GetEventPosition()[0];
  int Y = this->Interactor->GetEventPosition()[1];

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

  // Okay, we can process this. If anything is picked, then we
  // can start window-levelling.
  vtkAssemblyPath* path = this->GetAssemblyPath(X, Y, 0., this->PlanePicker);

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

  this->InitialWindow = this->CurrentWindow;
  this->InitialLevel = this->CurrentLevel;

  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->StartWindowLevelPositionX = X;
    this->StartWindowLevelPositionY = Y;
    this->ManageTextDisplay();
  }

  this->EventCallbackCommand->SetAbortFlag(1);
  this->StartInteraction();

  double wl[2] = { this->CurrentWindow, this->CurrentLevel };
  this->InvokeEvent(vtkCommand::StartWindowLevelEvent,wl);

  this->Interactor->Render();
}

//----------------------------------------------------------------------------
void vtkImagePlaneWidget::StopWindowLevel()
{
  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();

  double wl[2] = { this->CurrentWindow, this->CurrentLevel };
  this->InvokeEvent(vtkCommand::EndWindowLevelEvent,wl);

  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];

  vtkCamera *camera = this->CurrentRenderer->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->UpdatePlane();
    this->UpdateMargins();
    this->BuildRepresentation();
  }
  else if ( this->State == vtkImagePlaneWidget::Spinning )
  {
    this->Spin(prevPickPoint, pickPoint);
    this->UpdatePlane();
    this->UpdateMargins();
    this->BuildRepresentation();
  }
  else if ( this->State == vtkImagePlaneWidget::Rotating )
  {
    camera->GetViewPlaneNormal(vpn);
    this->Rotate(prevPickPoint, pickPoint, vpn);
    this->UpdatePlane();
    this->UpdateMargins();
    this->BuildRepresentation();
  }
  else if ( this->State == vtkImagePlaneWidget::Scaling )
  {
    this->Scale(prevPickPoint, pickPoint, X, Y);
    this->UpdatePlane();
    this->UpdateMargins();
    this->BuildRepresentation();
  }
  else if ( this->State == vtkImagePlaneWidget::Moving )
  {
    this->Translate(prevPickPoint, pickPoint);
    this->UpdatePlane();
    this->UpdateMargins();
    this->BuildRepresentation();
  }
  else if ( this->State == vtkImagePlaneWidget::Cursoring )
  {
    this->UpdateCursor(X,Y);
    this->ManageTextDisplay();
  }

  // Interact, if desired
  //
  this->EventCallbackCommand->SetAbortFlag(1);

  if ( this->State == vtkImagePlaneWidget::WindowLevelling )
  {
    double wl[2] = { this->CurrentWindow, this->CurrentLevel };
    this->InvokeEvent(vtkCommand::WindowLevelEvent,wl);
  }
  else
  {
    this->InvokeEvent(vtkCommand::InteractionEvent,0);
  }

  this->Interactor->Render();
}

//----------------------------------------------------------------------------
void vtkImagePlaneWidget::WindowLevel(int X, int Y)
{
  int *size = this->CurrentRenderer->GetSize();
  double window = this->InitialWindow;
  double level = this->InitialLevel;

  // Compute normalized delta

  double dx = 4.0 * ( X - this->StartWindowLevelPositionX ) / size[0];
  double dy = 4.0 *( this->StartWindowLevelPositionY - Y ) / size[1];

  // Scale by current values

  if ( fabs( window ) > 0.01 )
  {
    dx = dx * window;
  }
  else
  {
    dx = dx * ( window < 0 ? -0.01 : 0.01 );
  }
  if ( fabs( level ) > 0.01 )
  {
    dy = dy * level;
  }
  else
  {
    dy = dy * ( level < 0 ? -0.01 : 0.01 );
  }

  // Abs so that direction does not flip

  if ( window < 0.0 )
  {
    dx = -1 * dx;
  }
  if ( level < 0.0 )
  {
    dy = -1 * dy;
  }

  // Compute new window level

  double newWindow = dx + window;
  double newLevel = level - dy;

  if ( fabs( newWindow ) < 0.01 )
  {
    newWindow = 0.01 * ( newWindow < 0 ? -1 : 1 );
  }
  if ( fabs( newLevel ) < 0.01 )
  {
    newLevel = 0.01 * ( newLevel < 0 ? -1 : 1 );
  }

  if ( !this->UserControlledLookupTable )
  {
    if (( newWindow < 0 && this->CurrentWindow > 0 ) || \
        ( newWindow > 0 && this->CurrentWindow < 0 ))
    {
      this->InvertTable();
    }

    double rmin = newLevel - 0.5*fabs( newWindow );
    double rmax = rmin + fabs( newWindow );
    this->LookupTable->SetTableRange( rmin, rmax );
  }

  this->CurrentWindow = newWindow;
  this->CurrentLevel = newLevel;
}

//----------------------------------------------------------------------------
void vtkImagePlaneWidget::InvertTable()
{
  int index = this->LookupTable->GetNumberOfTableValues();
  unsigned char swap[4];
  size_t num = 4*sizeof(unsigned char);
  vtkUnsignedCharArray* table = this->LookupTable->GetTable();
  for ( int count = 0; count < --index; count++ )
  {
    unsigned char *rgba1 = table->GetPointer(4*count);
    unsigned char *rgba2 = table->GetPointer(4*index);
    memcpy( swap,  rgba1, num );
    memcpy( rgba1, rgba2, num );
    memcpy( rgba2, swap,  num );
  }

  // force the lookuptable to update its InsertTime to avoid
  // rebuilding the array
  this->LookupTable->SetTableValue( 0, this->LookupTable->GetTableValue( 0 ) );
}

//----------------------------------------------------------------------------
void vtkImagePlaneWidget::SetWindowLevel(double window, double level, int copy)
{
  if ( copy )
  {
    this->CurrentWindow = window;
    this->CurrentLevel = level;
    return;
  }

  if ( this->CurrentWindow == window && this->CurrentLevel == level )
  {
    return;
  }

  // if the new window is negative and the old window was positive invert table
  if ( (( window < 0 && this->CurrentWindow > 0 ) ||
        ( window > 0 && this->CurrentWindow < 0 )) &&
        !this->UserControlledLookupTable )
  {
    this->InvertTable();
  }

  this->CurrentWindow = window;
  this->CurrentLevel = level;

  if ( !this->UserControlledLookupTable )
  {
    double rmin = this->CurrentLevel - 0.5*fabs( this->CurrentWindow );
    double rmax = rmin + fabs( this->CurrentWindow );
    this->LookupTable->SetTableRange( rmin, rmax );
  }

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

//----------------------------------------------------------------------------
void vtkImagePlaneWidget::GetWindowLevel(double wl[2])
{
  wl[0] = this->CurrentWindow;
  wl[1] = this->CurrentLevel;
}

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

  xyzv[0] = this->CurrentCursorPosition[0];
  xyzv[1] = this->CurrentCursorPosition[1];
  xyzv[2] = this->CurrentCursorPosition[2];
  xyzv[3] = this->CurrentImageValue;

  return 1;
}

//----------------------------------------------------------------------------
int vtkImagePlaneWidget::GetCursorDataStatus()
{
  if ( this->State != vtkImagePlaneWidget::Cursoring  || \
    this->CurrentImageValue == VTK_DOUBLE_MAX )
  {
    return 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_DOUBLE_MAX )
    {
      sprintf(this->TextBuff,"Off Image");
    }
    else
    {
      sprintf(this->TextBuff,"( %g, %g, %g ): %g",
                   this->CurrentCursorPosition[0],
                   this->CurrentCursorPosition[1],
                   this->CurrentCursorPosition[2],this->CurrentImageValue);
    }
  }

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

//----------------------------------------------------------------------------
void vtkImagePlaneWidget::Push(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];

  this->PlaneSource->Push( vtkMath::Dot( v, this->PlaneSource->GetNormal() ) );
}

//----------------------------------------------------------------------------
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->SetDiffuse(0);
    this->TexturePlaneProperty->SetInterpolationToFlat();
  }
}

//----------------------------------------------------------------------------
void vtkImagePlaneWidget::PlaceWidget(double bds[6])
{
  double 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->UpdatePlane();
  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 method must be called _after_ SetInput
  //
  if ( !this->ImageData )
  {
    vtkErrorMacro(<<"SetInput() before setting plane orientation.");
    return;
  }

  vtkAlgorithm* inpAlg = this->Reslice->GetInputAlgorithm();
  inpAlg->UpdateInformation();
  vtkInformation* outInfo = inpAlg->GetOutputInformation(0);
  int extent[6];
  outInfo->Get(vtkStreamingDemandDrivenPipeline::WHOLE_EXTENT(), extent);
  double origin[3];
  outInfo->Get(vtkDataObject::ORIGIN(), origin);
  double spacing[3];
  outInfo->Get(vtkDataObject::SPACING(), spacing);

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

  if ( spacing[0] < 0.0 )
  {
    double t = xbounds[0];
    xbounds[0] = xbounds[1];
    xbounds[1] = t;
  }
  if ( spacing[1] < 0.0 )
  {
    double t = ybounds[0];
    ybounds[0] = ybounds[1];
    ybounds[1] = t;
  }
  if ( spacing[2] < 0.0 )
  {
    double 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->UpdatePlane();
  this->BuildRepresentation();
  this->Modified();
}

//----------------------------------------------------------------------------
void vtkImagePlaneWidget::SetInputConnection(vtkAlgorithmOutput* aout)
{
  this->Superclass::SetInputConnection(aout);

  this->ImageData = vtkImageData::SafeDownCast(
    aout->GetProducer()->GetOutputDataObject(
      aout->GetIndex()));

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

  double 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]);

  if( fabs( this->OriginalWindow ) < 0.001 )
  {
    this->OriginalWindow = 0.001 * ( this->OriginalWindow < 0.0 ? -1 : 1 );
  }
  if( fabs( this->OriginalLevel ) < 0.001 )
  {
   this->OriginalLevel = 0.001 * ( this->OriginalLevel < 0.0 ? -1 : 1 );
  }

  this->SetWindowLevel(this->OriginalWindow,this->OriginalLevel);

  this->Reslice->SetInputConnection(aout);
  int interpolate = this->ResliceInterpolate;
  this->ResliceInterpolate = -1; // Force change
  this->SetResliceInterpolate(interpolate);

  this->ColorMap->SetInputConnection(this->Reslice->GetOutputPort());

  this->Texture->SetInputConnection(this->ColorMap->GetOutputPort());
  this->Texture->SetInterpolate(this->TextureInterpolate);

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

//----------------------------------------------------------------------------
void vtkImagePlaneWidget::UpdatePlane()
{
  if ( !this->Reslice || !this->ImageData )
  {
    return;
  }

  // Calculate appropriate pixel spacing for the reslicing
  //
  vtkAlgorithm* inpAlg = this->Reslice->GetInputAlgorithm();
  inpAlg->UpdateInformation();
  vtkInformation* outInfo = inpAlg->GetOutputInformation(0);
  double spacing[3];
  outInfo->Get(vtkDataObject::SPACING(), spacing);
  double origin[3];
  outInfo->Get(vtkDataObject::ORIGIN(), origin);
  int extent[6];
  outInfo->Get(vtkStreamingDemandDrivenPipeline::WHOLE_EXTENT(), extent);

  int i;

  for (i = 0; i < 3; i++)
  {
    if (extent[2*i] > extent[2*i + 1])
    {
      vtkErrorMacro("Invalid extent ["
                    << extent[0] << ", " << extent[1] << ", "
                    << extent[2] << ", " << extent[3] << ", "
                    << extent[4] << ", " << extent[5] << "]."
                    << " Perhaps the input data is empty?");
      break;
    }
  }

  if ( this->RestrictPlaneToVolume )
  {
    double bounds[] = {origin[0] + spacing[0]*extent[0], //xmin
                       origin[0] + spacing[0]*extent[1], //xmax
                       origin[1] + spacing[1]*extent[2], //ymin
                       origin[1] + spacing[1]*extent[3], //ymax
                       origin[2] + spacing[2]*extent[4], //zmin
                       origin[2] + spacing[2]*extent[5]};//zmax

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

    double abs_normal[3];
    this->PlaneSource->GetNormal(abs_normal);
    double planeCenter[3];
    this->PlaneSource->GetCenter(planeCenter);
    double nmax = 0.0;
    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];
    }
    else if ( planeCenter[k] < bounds[2*k] )
    {
      planeCenter[k] = bounds[2*k];
    }

    this->PlaneSource->SetCenter(planeCenter);
  }

  double planeAxis1[3];
  double planeAxis2[3];

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

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

  double normal[3];
  this->PlaneSource->GetNormal(normal);

  // Generate the slicing matrix
  //

  this->ResliceAxes->Identity();
  for ( i = 0; i < 3; i++ )
  {
     this->ResliceAxes->SetElement(0,i,planeAxis1[i]);
     this->ResliceAxes->SetElement(1,i,planeAxis2[i]);
     this->ResliceAxes->SetElement(2,i,normal[i]);
  }

  double planeOrigin[4];
  this->PlaneSource->GetOrigin(planeOrigin);

  planeOrigin[3] = 1.0;

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

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

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

  double 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
  double realExtentX = ( spacingX == 0 ) ? VTK_INT_MAX : 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 > (VTK_INT_MAX >> 1))
  {
    vtkErrorMacro(<<"Invalid X extent: " << realExtentX);
    extentX = 0;
  }
  else
  {
    extentX = 1;
    while (extentX < realExtentX)
    {
      extentX = extentX << 1;
    }
  }

  // make sure extentY doesn't wrap during padding
  double realExtentY = ( spacingY == 0 ) ? VTK_INT_MAX : planeSizeY / spacingY;

  int extentY;
  if (realExtentY > (VTK_INT_MAX >> 1))
  {
    vtkErrorMacro(<<"Invalid Y extent: " << realExtentY);
    extentY = 0;
  }
  else
  {
    extentY = 1;
    while (extentY < realExtentY)
    {
      extentY = extentY << 1;
    }
  }

  double outputSpacingX = (extentX == 0) ? 1.0 : planeSizeX/extentX;
  double outputSpacingY = (extentY == 0) ? 1.0 : planeSizeY/extentY;
  this->Reslice->SetOutputSpacing(outputSpacingX, outputSpacingY, 1);
  this->Reslice->SetOutputOrigin(0.5*outputSpacingX, 0.5*outputSpacingY, 0);
  this->Reslice->SetOutputExtent(0, extentX-1, 0, extentY-1, 0, 0);
}

//----------------------------------------------------------------------------
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(vtkAbstractPropPicker* picker)
{
  // we have to have a picker for slice motion, window level and cursor to work
  if (this->PlanePicker != picker)
  {
    // to avoid destructor recursion
    vtkAbstractPropPicker *temp = this->PlanePicker;
    this->PlanePicker = picker;
    if (temp != 0)
    {
      temp->UnRegister(this);
    }

    int delPicker = 0;
    if (this->PlanePicker == 0)
    {
      this->PlanePicker = vtkCellPicker::New();
      vtkCellPicker::SafeDownCast(this->PlanePicker)->SetTolerance(0.005);
      delPicker = 1;
    }

    this->PlanePicker->Register(this);
    this->PlanePicker->AddPickList(this->TexturePlaneActor);
    this->PlanePicker->PickFromListOn();

    if ( delPicker )
    {
      this->PlanePicker->Delete();
    }
  }
}

//------------------------------------------------------------------------------
void vtkImagePlaneWidget::RegisterPickers()
{
  this->Interactor->GetPickingManager()->AddPicker(this->PlanePicker, this);
}

//----------------------------------------------------------------------------
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)
  {
    double 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]);

    if( fabs( this->OriginalWindow ) < 0.001 )
    {
      this->OriginalWindow = 0.001 * ( this->OriginalWindow < 0.0 ? -1 : 1 );
    }
    if( fabs( this->OriginalLevel ) < 0.001 )
    {
      this->OriginalLevel = 0.001 * ( this->OriginalLevel < 0.0 ? -1 : 1 );
    }

    this->SetWindowLevel(this->OriginalWindow,this->OriginalLevel);
  }
}

//----------------------------------------------------------------------------
void vtkImagePlaneWidget::SetSlicePosition(double position)
{
  double amount = 0.0;
  double 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->UpdatePlane();
  this->BuildRepresentation();
  this->Modified();
}

//----------------------------------------------------------------------------
double vtkImagePlaneWidget::GetSlicePosition()
{
  double 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 0.0;
}

//----------------------------------------------------------------------------
void vtkImagePlaneWidget::SetSliceIndex(int index)
{
  if ( !this->Reslice )
  {
      return;
  }
  if ( !this->ImageData )
  {
    return;
  }
  vtkAlgorithm* inpAlg = this->Reslice->GetInputAlgorithm();
  inpAlg->UpdateInformation();
  vtkInformation* outInfo = inpAlg->GetOutputInformation(0);
  double origin[3];
  outInfo->Get(vtkDataObject::ORIGIN(), origin);
  double spacing[3];
  outInfo->Get(vtkDataObject::SPACING(), spacing);
  double planeOrigin[3];
  this->PlaneSource->GetOrigin(planeOrigin);
  double pt1[3];
  this->PlaneSource->GetPoint1(pt1);
  double 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->UpdatePlane();
  this->BuildRepresentation();
  this->Modified();
}

//----------------------------------------------------------------------------
int vtkImagePlaneWidget::GetSliceIndex()
{
  if ( ! this->Reslice )
  {
    return 0;
  }
  if ( ! this->ImageData )
  {
    return 0;
  }
  vtkAlgorithm* inpAlg = this->Reslice->GetInputAlgorithm();
  inpAlg->UpdateInformation();
  vtkInformation* outInfo = inpAlg->GetOutputInformation(0);
  double origin[3];
  outInfo->Get(vtkDataObject::ORIGIN(), origin);
  double spacing[3];
  outInfo->Get(vtkDataObject::SPACING(), spacing);
  double 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 )
{
  if ( !this->ImageData )
  {
    return;
  }
  // We're going to be extracting values with GetScalarComponentAsDouble(),
  // we might as well make sure that the data is there.  If the data is
  // up to date already, this call doesn't cost very much.  If we don't make
  // this call and the data is not up to date, the GetScalar... call will
  // cause a segfault.
  this->Reslice->GetInputAlgorithm()->Update();

  vtkAssemblyPath* path = this->GetAssemblyPath(X, Y, 0., this->PlanePicker);

  this->CurrentImageValue = VTK_DOUBLE_MAX;

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

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

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

  if(this->UseContinuousCursor)
  {
    found = this->UpdateContinuousCursor(q);
  }
  else
  {
    found = this->UpdateDiscreteCursor(q);
  }

  if(!found)
  {
    this->CursorActor->VisibilityOff();
    return;
  }

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

  // q relative to the plane origin
  //
  double qro[3];
  qro[0]= q[0] - o[0];
  qro[1]= q[1] - o[1];
  qro[2]= q[2] - o[2];

  double p1o[3];
  double p2o[3];

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

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

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

  double a[3];
  double b[3];
  double c[3];
  double 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->CursorPolyData->Modified();
}

//----------------------------------------------------------------------------
int vtkImagePlaneWidget::UpdateContinuousCursor(double *q)
{
  double tol2;
  vtkCell *cell;
  vtkPointData *pd;
  int subId;
  double pcoords[3], weights[8];

  this->CurrentCursorPosition[0] = q[0];
  this->CurrentCursorPosition[1] = q[1];
  this->CurrentCursorPosition[2] = q[2];

  pd = this->ImageData->GetPointData();

  vtkPointData* outPD = vtkPointData::New();
  outPD->InterpolateAllocate(pd, 1, 1);

  // Use tolerance as a function of size of source data
  //
  tol2 = this->ImageData->GetLength();
  tol2 = tol2 ? tol2*tol2 / 1000.0 : 0.001;

  // Find the cell that contains q and get it
  //
  cell = this->ImageData->FindAndGetCell(q,NULL,-1,tol2,subId,pcoords,weights);
  int found = 0;
  if (cell)
  {
    // Interpolate the point data
    //
    outPD->InterpolatePoint(pd,0,cell->PointIds,weights);
    this->CurrentImageValue = outPD->GetScalars()->GetTuple1(0);
    found = 1;
  }

  outPD->Delete();
  return found;
}

//----------------------------------------------------------------------------
int vtkImagePlaneWidget::UpdateDiscreteCursor(double *q)
{
  // vtkImageData will find the nearest implicit point to q
  //
  vtkIdType ptId = this->ImageData->FindPoint(q);

  if ( ptId == -1 )
  {
    return 0;
  }

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

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

  int iq[3];
  int iqtemp;
  for (int 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];

    this->CurrentCursorPosition[i] = iq[i];
  }

  this->CurrentImageValue = this->ImageData->GetScalarComponentAsDouble( \
                   static_cast<int>(this->CurrentCursorPosition[0]),
                   static_cast<int>(this->CurrentCursorPosition[1]),
                   static_cast<int>(this->CurrentCursorPosition[2]),0);
  return 1;
}

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

//----------------------------------------------------------------------------
vtkPolyDataAlgorithm *vtkImagePlaneWidget::GetPolyDataAlgorithm()
{
  return this->PlaneSource;
}

//----------------------------------------------------------------------------
void vtkImagePlaneWidget::UpdatePlacement(void)
{
  this->UpdatePlane();
  this->UpdateMargins();
  this->BuildRepresentation();
}

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

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

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

//----------------------------------------------------------------------------
void vtkImagePlaneWidget::GetVector1(double v1[3])
{
  double* p1 = this->PlaneSource->GetPoint1();
  double* 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(double v2[3])
{
  double* p2 = this->PlaneSource->GetPoint2();
  double* 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()
{
  int *auto_modifier = NULL;
  switch (this->LastButtonPressed)
  {
    case vtkImagePlaneWidget::VTK_LEFT_BUTTON:
      auto_modifier = &this->LeftButtonAutoModifier;
      break;
    case vtkImagePlaneWidget::VTK_MIDDLE_BUTTON:
      auto_modifier = &this->MiddleButtonAutoModifier;
      break;
    case vtkImagePlaneWidget::VTK_RIGHT_BUTTON:
      auto_modifier = &this->RightButtonAutoModifier;
      break;
  }

  if (this->Interactor->GetShiftKey() ||
      (auto_modifier &&
       (*auto_modifier & vtkImagePlaneWidget::VTK_SHIFT_MODIFIER)))
  {
    this->State = vtkImagePlaneWidget::Scaling;
    return;
  }

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

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

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

  if ( x2D > planeSize1 ) { x2D = planeSize1; }
  else if ( x2D < 0.0 ) { x2D = 0.0; }
  if ( y2D > planeSize2 ) { y2D = planeSize2; }
  else if ( y2D < 0.0 ) { y2D = 0.0; }

  // 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
  //
  double marginX = planeSize1 * this->MarginSizeX;
  double marginY = planeSize2 * this->MarginSizeY;

  double x0 = marginX;
  double y0 = marginY;
  double x1 = planeSize1 - marginX;
  double 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 or on the very edge
  {
    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() ||
      (auto_modifier &&
       (*auto_modifier & vtkImagePlaneWidget::VTK_CONTROL_MODIFIER)))
  {
    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;
    }
  }

  double *raPtr = 0;
  double *rvPtr = 0;
  double rvfac = 1.0;
  double 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
  //
  double 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
  //
  double* wc = this->PlaneSource->GetCenter();
  double* wn = this->PlaneSource->GetNormal();

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

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

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

  // Spin angle
  //
  double dw = vtkMath::DegreesFromRadians( 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]);

  double 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);
}

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

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

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

  // Radius of the rotating circle of the picked point
  //
  double 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
  //
  double rd[3];
  vtkMath::Cross(this->RotateAxis,this->RadiusVector,rd);

  // Direction cosin between rotating direction and view normal
  //
  double 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
  //
  double dw = vtkMath::DegreesFromRadians( 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]);

  double 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);
}

//----------------------------------------------------------------------------
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();

  vtkPolyDataMapper* planeOutlineMapper = vtkPolyDataMapper::New();
  planeOutlineMapper->SetInputData( this->PlaneOutlinePolyData );
  planeOutlineMapper->SetResolveCoincidentTopologyToPolygonOffset();
  this->PlaneOutlineActor->SetMapper(planeOutlineMapper);
  this->PlaneOutlineActor->PickableOff();
  planeOutlineMapper->Delete();
}

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

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

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

  vtkPolyDataMapper* texturePlaneMapper = vtkPolyDataMapper::New();
  texturePlaneMapper->SetInputConnection(
    this->PlaneSource->GetOutputPort());

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

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

//----------------------------------------------------------------------------
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();

  vtkPolyDataMapper* marginMapper = vtkPolyDataMapper::New();
  marginMapper->SetInputData(this->MarginPolyData);
  marginMapper->SetResolveCoincidentTopologyToPolygonOffset();
  this->MarginActor->SetMapper(marginMapper);
  this->MarginActor->PickableOff();
  this->MarginActor->VisibilityOff();
  marginMapper->Delete();
}

//----------------------------------------------------------------------------
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();

  vtkPolyDataMapper* cursorMapper = vtkPolyDataMapper::New();
  cursorMapper->SetInputData(this->CursorPolyData);
  cursorMapper->SetResolveCoincidentTopologyToPolygonOffset();
  this->CursorActor->SetMapper(cursorMapper);
  this->CursorActor->PickableOff();
  this->CursorActor->VisibilityOff();
  cursorMapper->Delete();
}

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

  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()
{
  double v1[3];
  this->GetVector1(v1);
  double v2[3];
  this->GetVector2(v2);
  double o[3];
  this->PlaneSource->GetOrigin(o);
  double p1[3];
  this->PlaneSource->GetPoint1(p1);
  double p2[3];
  this->PlaneSource->GetPoint2(p2);

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

  double s = this->MarginSizeX;
  double t = this->MarginSizeY;

  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->MarginPolyData->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];

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

  double vdrv = this->RadiusVector[0]*v[0] + \
               this->RadiusVector[1]*v[1] + \
               this->RadiusVector[2]*v[2];
  double 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);
  }
}

//----------------------------------------------------------------------------
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];

  double *o = this->PlaneSource->GetOrigin();
  double *pt1 = this->PlaneSource->GetPoint1();
  double *pt2 = this->PlaneSource->GetPoint2();
  double* center = this->PlaneSource->GetCenter();

  // Compute the scale factor
  //
  double 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
  //
  double 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);
}