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

  Program:   Visualization Toolkit
  Module:    vtkLODProp3D.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 "vtkLODProp3D.h"

#include "vtkActor.h"
#include "vtkCommand.h"
#include "vtkMapper.h"
#include "vtkMatrix4x4.h"
#include "vtkObjectFactory.h"
#include "vtkPropCollection.h"
#include "vtkVolume.h"
#include "vtkAbstractVolumeMapper.h"
#include "vtkLinearTransform.h"

#include <math.h>

vtkCxxRevisionMacro(vtkLODProp3D, "1.44");
vtkStandardNewMacro(vtkLODProp3D);

#define VTK_INDEX_NOT_IN_USE    -1

#define VTK_INVALID_LOD_INDEX   -2

#define VTK_LOD_ACTOR_TYPE       1
#define VTK_LOD_VOLUME_TYPE      2

class vtkLODProp3DCallback : public vtkCommand
{
public:
  // generic new method
  static vtkLODProp3DCallback *New()
    { return new vtkLODProp3DCallback; }
  
  // the execute
  virtual void Execute(vtkObject *caller, 
                       unsigned long event, void* vtkNotUsed(v))
    {
      vtkProp *po = vtkProp::SafeDownCast(caller);
      if (event == vtkCommand::PickEvent && po)
        {
        this->Self->InvokeEvent(vtkCommand::PickEvent,NULL);
        }
    }
  
  // some ivars that should be set
  vtkLODProp3D *Self;
};


// Construct a new vtkLODProp3D. Automatic LOD selection is on, there are
// no LODs.
vtkLODProp3D::vtkLODProp3D()
{
  this->NumberOfEntries               = 0;
  this->NumberOfLODs                  = 0;
  this->LODs                          = NULL;
  this->CurrentIndex                  = 1000;
  this->AutomaticLODSelection         = 1;
  this->SelectedLODID                 = 1000;
  this->SelectedLODIndex              = -1;
  this->SelectedPickLODID             = 1000;
  this->AutomaticPickLODSelection     = 1;
  this->PickCallback = vtkLODProp3DCallback::New();
  this->PickCallback->Self = this;
}

// Destruct the vtkLODProp3D. Delete the vtkProp3Ds that were created
// for the LODs. Delete the array of LODs.
vtkLODProp3D::~vtkLODProp3D()
{
  int i;

  // Delete the vtkProp3D objects that were created
  for ( i = 0; i < this->NumberOfEntries; i++ )
    {
    if ( this->LODs[i].ID != VTK_INDEX_NOT_IN_USE )
      {
      this->LODs[i].Prop3D->RemoveObserver(this->PickCallback);
      this->LODs[i].Prop3D->Delete();
      }
    }

  // Delete the array of LODs
  if ( this->NumberOfEntries > 0 )
    {
    delete [] this->LODs;
    }
  
  this->PickCallback->Delete();
}

int vtkLODProp3D::ConvertIDToIndex( int id )
{
  int    index=0;

  while ( index < this->NumberOfEntries && this->LODs[index].ID != id )
    {
    index++;
    }
  if ( index == this->NumberOfEntries )
    {
    vtkErrorMacro( << "Could not locate ID: " << id );
    index = VTK_INVALID_LOD_INDEX;
    }

  return index;
}


// Get the next available entry index
int vtkLODProp3D::GetNextEntryIndex()
{
  int                 index;
  int                 i;
  int                 amount;
  vtkLODProp3DEntry   *newLODs;

  // Search for an available index
  index = 0;
  while ( index < this->NumberOfEntries && this->LODs[index].ID != 
          VTK_INDEX_NOT_IN_USE )
    {
    index++;
    }

  // If an available index was not found, we need more entries
  if ( index >= this->NumberOfEntries )
    {
    // If we have no entries, create 10. If we already have some, create
    // twice as many as we already have.
    amount = (this->NumberOfEntries)?(this->NumberOfEntries*2):(10);
    
    // Make the new array
    newLODs = new vtkLODProp3DEntry[amount];

    // Copy the old entries into the new array
    for ( i = 0; i < this->NumberOfEntries; i++ )
      {
      newLODs[i].Prop3D        = this->LODs[i].Prop3D;
      newLODs[i].Prop3DType    = this->LODs[i].Prop3DType;
      newLODs[i].ID            = this->LODs[i].ID;
      newLODs[i].EstimatedTime = this->LODs[i].EstimatedTime;
      newLODs[i].Level         = this->LODs[i].Level;
      newLODs[i].State         = this->LODs[i].State;
      }

    // This is the index that we will return - one past the old entries
    index = i;

    // Initialize the new entries to default values
    for ( ; i < amount; i++ )
      {
      newLODs[i].Prop3D = NULL;
      newLODs[i].ID     = VTK_INDEX_NOT_IN_USE;
      }

    // Delete the old array and set the pointer to the new one
    delete [] this->LODs;
    this->LODs = newLODs;

    // Set the new number of entries that we have
    this->NumberOfEntries = amount;
    }
  return index;
}

// Get the bounds of this prop. This is just the max bounds of all LODs
double *vtkLODProp3D::GetBounds()
{
  double newBounds[6];
  int   i;
  int   first = 1;

  // Loop through all valid entries
  for ( i = 0; i < this->NumberOfEntries; i++ )
    {
    if ( this->LODs[i].ID != VTK_INDEX_NOT_IN_USE )
      {
      vtkProp3D *p = this->LODs[i].Prop3D;
      if ( p->GetMTime() < this->GetMTime() )
        {
        p->SetUserMatrix( this->GetMatrix() );
        }

      // Get the bounds of this entry
      p->GetBounds(newBounds);

      // If this is the first entry, this is the current bounds
      if ( first )
        {
        memcpy( this->Bounds, newBounds, 6*sizeof(double) );
        first = 0;
        }
      // If this is not the first entry, compare these bounds with the
      // current bounds expanding the current ones as necessary
      else
        {
        this->Bounds[0] = 
          (newBounds[0] < this->Bounds[0])?(newBounds[0]):(this->Bounds[0]);
        this->Bounds[1] = 
          (newBounds[1] > this->Bounds[1])?(newBounds[1]):(this->Bounds[1]);
        this->Bounds[2] = 
          (newBounds[2] < this->Bounds[2])?(newBounds[2]):(this->Bounds[2]);
        this->Bounds[3] = 
          (newBounds[3] > this->Bounds[3])?(newBounds[3]):(this->Bounds[3]);
        this->Bounds[4] = 
          (newBounds[4] < this->Bounds[4])?(newBounds[4]):(this->Bounds[4]);
        this->Bounds[5] = 
          (newBounds[5] > this->Bounds[5])?(newBounds[5]):(this->Bounds[5]);
        }
      }
    }

  return this->Bounds;
}

// Method to remove a LOD based on an ID
void vtkLODProp3D::RemoveLOD( int id )
{
  int index = this->ConvertIDToIndex( id );

  if ( index == VTK_INVALID_LOD_INDEX )
    {
    return;
    }
  
  this->LODs[index].Prop3D->RemoveObserver(this->PickCallback);
  this->LODs[index].Prop3D->Delete();
  this->LODs[index].ID = VTK_INDEX_NOT_IN_USE;
  this->NumberOfLODs--;
}


// Convenience method to get the ID of the LOD that was used
// during the last render
int vtkLODProp3D::GetLastRenderedLODID( )
{
  // Check if the selected index is in range
  if ( this->SelectedLODIndex < 0 ||
       this->SelectedLODIndex >= this->NumberOfEntries )
    {
    return -1;
    }

  // Check if the selected index is valid
  if ( this->LODs[this->SelectedLODIndex].ID == VTK_INDEX_NOT_IN_USE )
    {
    return -1;
    }

  return this->LODs[this->SelectedLODIndex].ID;
}

// Convenience method to get the estimated render time for a given LOD
// based on an ID (the number returned when the LOD was added)
double vtkLODProp3D::GetLODEstimatedRenderTime( int id )
{
  int index = this->ConvertIDToIndex( id );

  if ( index != VTK_INVALID_LOD_INDEX )
    {
    return this->GetLODIndexEstimatedRenderTime( index );
    }
  else
    {
    return 0.0;
    }
}

double vtkLODProp3D::GetLODIndexEstimatedRenderTime( int index )
{
  if ( this->SelectedLODIndex < 0 ||
       this->SelectedLODIndex >= this->NumberOfEntries )
    {
    return 0;
    }  

  return this->LODs[index].EstimatedTime;
}

// Convenience method to set an actor LOD without a texture, or a 
// backface property.  Needed from tcl (for example) where null pointers 
// are not possible
int vtkLODProp3D::AddLOD( vtkMapper *m, vtkProperty *p, double time )
{
  return this->AddLOD( m, p, (vtkProperty *) NULL, (vtkTexture *)NULL, time );
}

// Convenience method to set an actor LOD without a texture.
// Needed from tcl (for example) where null pointers are not possible
int vtkLODProp3D::AddLOD( vtkMapper *m, vtkProperty *p, 
                         vtkProperty *back, double time )
{
  return this->AddLOD( m, p, back, (vtkTexture *)NULL, time );
}

// Convenience method to set an actor LOD without a backface property.
// Needed from tcl (for example) where null pointers are not possible
int vtkLODProp3D::AddLOD( vtkMapper *m, vtkProperty *p, 
                         vtkTexture *t, double time )
{
  return this->AddLOD( m, p, (vtkProperty *)NULL, t, time );
}

// Convenience method to set an actor LOD without a property.
// Needed from tcl (for example) where null pointers are not possible
int vtkLODProp3D::AddLOD( vtkMapper *m, vtkTexture *t, double time )
{
  return this->AddLOD( m, (vtkProperty *)NULL, (vtkProperty *)NULL, t, time );
}

// Convenience method to set an actor LOD without a texture or a property.
// Needed from tcl (for example) where null pointers are not possible
int vtkLODProp3D::AddLOD( vtkMapper *m, double time )
{
  return this->AddLOD( m, (vtkProperty *)NULL, (vtkProperty *)NULL, 
      (vtkTexture *)NULL, time );
} 

// The real method for adding an actor LOD.
int vtkLODProp3D::AddLOD( vtkMapper *m, vtkProperty *p, 
                          vtkProperty *back, vtkTexture *t, double time )
{
  int          index;
  vtkActor     *actor;
  vtkMatrix4x4 *matrix;

  index = this->GetNextEntryIndex();

  actor = vtkActor::New();
  matrix = vtkMatrix4x4::New();
  this->GetMatrix( matrix );
  actor->SetUserMatrix( matrix );
  matrix->Delete();
  actor->SetMapper( m );
  if ( p ) 
    {
    actor->SetProperty( p );
    }

  if ( back )
    {
    actor->SetBackfaceProperty(back);
    }

  if ( t )
    {
    actor->SetTexture( t );
    }

  this->LODs[index].Prop3D        = (vtkProp3D *)actor;
  this->LODs[index].Prop3DType    = VTK_LOD_ACTOR_TYPE;
  this->LODs[index].ID            = this->CurrentIndex++;
  this->LODs[index].EstimatedTime = time;
  this->LODs[index].Level         = 0.0;
  this->LODs[index].State         = 1;
  this->LODs[index].Prop3D->AddObserver(vtkCommand::PickEvent,
                                        this->PickCallback);
  this->NumberOfLODs++;

  actor->SetEstimatedRenderTime(time);
  
  return this->LODs[index].ID;
}

// Convenience method to set a volume LOD without a property.
// Needed from tcl (for example) where null pointers are not possible
int vtkLODProp3D::AddLOD( vtkAbstractVolumeMapper *m, double time )
{
  return this->AddLOD( m, (vtkVolumeProperty *)NULL, time );
}

// The real method for adding a volume LOD.
int vtkLODProp3D::AddLOD( vtkAbstractVolumeMapper *m, vtkVolumeProperty *p, 
                          double time )
{
  int           index;
  vtkVolume     *volume;
  vtkMatrix4x4  *matrix;

  index = this->GetNextEntryIndex();

  volume = vtkVolume::New();
  matrix = vtkMatrix4x4::New();
  this->GetMatrix(matrix);
  volume->SetUserMatrix( matrix );
  matrix->Delete();
  volume->SetMapper( m );
  if ( p ) 
    {
    volume->SetProperty( p );
    }

  this->LODs[index].Prop3D        = (vtkProp3D *)volume;
  this->LODs[index].Prop3DType    = VTK_LOD_VOLUME_TYPE;
  this->LODs[index].ID            = this->CurrentIndex++;
  this->LODs[index].EstimatedTime = time;
  this->LODs[index].Level         = 0.0;
  this->LODs[index].State         = 1;
  this->LODs[index].Prop3D->AddObserver(vtkCommand::PickEvent,
                                        this->PickCallback);
  this->NumberOfLODs++;

  volume->SetEstimatedRenderTime(time);
  
  return this->LODs[index].ID;
}

// Set the mapper for an LOD that is an actor
void vtkLODProp3D::SetLODMapper( int id, vtkMapper *m )
{
  int index = this->ConvertIDToIndex( id );

  if ( index == VTK_INVALID_LOD_INDEX )
    {
    return;
    }

  if ( this->LODs[index].Prop3DType != VTK_LOD_ACTOR_TYPE )
    {
    vtkErrorMacro( << "Error: Cannot set an actor mapper on a non-actor!");
    return;
    }

  ((vtkActor *)this->LODs[index].Prop3D)->SetMapper( m );
}

// Get the mapper for an LOD that is an actor
void vtkLODProp3D::GetLODMapper( int id, vtkMapper **m )
{
  *m = NULL;
        
  int index = this->ConvertIDToIndex( id );

  if ( index == VTK_INVALID_LOD_INDEX )
    {
    return;
    }

  if ( this->LODs[index].Prop3DType != VTK_LOD_ACTOR_TYPE )
    {
    vtkErrorMacro( << "Error: Cannot get an actor mapper on a non-actor!");

    return;
    }

  *m = ((vtkActor *)this->LODs[index].Prop3D)->GetMapper();
}

// Set the mapper for an LOD that is a volume
void vtkLODProp3D::SetLODMapper( int id, vtkAbstractVolumeMapper *m )
{
  int index = this->ConvertIDToIndex( id );

  if ( index == VTK_INVALID_LOD_INDEX )
    {
    return;
    }

  if ( this->LODs[index].Prop3DType != VTK_LOD_VOLUME_TYPE )
    {
    vtkErrorMacro( << "Error: Cannot set a volume mapper on a non-volume!");
    return;
    }

  ((vtkVolume *)this->LODs[index].Prop3D)->SetMapper( m );
}

// Get the mapper for an LOD that is an actor
void vtkLODProp3D::GetLODMapper( int id, vtkAbstractVolumeMapper **m )
{
  *m = NULL;
  
  int index = this->ConvertIDToIndex( id );

  if ( index == VTK_INVALID_LOD_INDEX )
    {
    return;
    }

  if ( this->LODs[index].Prop3DType != VTK_LOD_VOLUME_TYPE )
    {
    vtkErrorMacro( << "Error: Cannot get a volume mapper on a non-volume!");
    return;
    }

  *m = ((vtkVolume *)this->LODs[index].Prop3D)->GetMapper();
}

// Get the mapper for an LOD that is an AbstractMapper3D
vtkAbstractMapper3D *vtkLODProp3D::GetLODMapper( int id )
{
  vtkAbstractMapper3D *m = NULL;
  
  int index = this->ConvertIDToIndex( id );

  if ( index == VTK_INVALID_LOD_INDEX )
    {
    return m;
    }

  if ( this->LODs[index].Prop3DType == VTK_LOD_ACTOR_TYPE )
    {
        m = ((vtkActor *)this->LODs[index].Prop3D)->GetMapper();
    }
  else if ( this->LODs[index].Prop3DType == VTK_LOD_VOLUME_TYPE )
    {
        m = ((vtkVolume *)this->LODs[index].Prop3D)->GetMapper();
    }

  return m;
}


// Set the property for an LOD that is an actor
void vtkLODProp3D::SetLODProperty( int id, vtkProperty *p )
{
  int index = this->ConvertIDToIndex( id );

  if ( index == VTK_INVALID_LOD_INDEX )
    {
    return;
    }

  if ( this->LODs[index].Prop3DType != VTK_LOD_ACTOR_TYPE )
    {
    vtkErrorMacro( << "Error: Cannot set an actor property on a non-actor!");
    return;
    }

  ((vtkActor *)this->LODs[index].Prop3D)->SetProperty( p );
}

// Get the property for an LOD that is an actor
void vtkLODProp3D::GetLODProperty( int id, vtkProperty **p )
{
  int index = this->ConvertIDToIndex( id );

  if ( index == VTK_INVALID_LOD_INDEX )
    {
    return;
    }

  if ( this->LODs[index].Prop3DType != VTK_LOD_ACTOR_TYPE )
    {
    vtkErrorMacro( << "Error: Cannot get an actor property on a non-actor!");
    return;
    }

  *p = ((vtkActor *)this->LODs[index].Prop3D)->GetProperty();
}

// Set the property for an LOD that is a volume
void vtkLODProp3D::SetLODProperty( int id, vtkVolumeProperty *p )
{
  int index = this->ConvertIDToIndex( id );

  if ( index == VTK_INVALID_LOD_INDEX )
    {
    return;
    }

  if ( this->LODs[index].Prop3DType != VTK_LOD_VOLUME_TYPE )
    {
    vtkErrorMacro( << "Error: Cannot set a volume property on a non-volume!");
    return;
    }

  ((vtkVolume *)this->LODs[index].Prop3D)->SetProperty( p );
}

// Get the property for an LOD that is an actor
void vtkLODProp3D::GetLODProperty( int id, vtkVolumeProperty **p )
{
  int index = this->ConvertIDToIndex( id );

  if ( index == VTK_INVALID_LOD_INDEX )
    {
    return;
    }

  if ( this->LODs[index].Prop3DType != VTK_LOD_VOLUME_TYPE )
    {
    vtkErrorMacro( << "Error: Cannot get a volume property on a non-volume!");
    return;
    }

  *p = ((vtkVolume *)this->LODs[index].Prop3D)->GetProperty();
}

// Set the texture for an LOD that is an actor
void vtkLODProp3D::SetLODTexture( int id, vtkTexture *t )
{
  int index = this->ConvertIDToIndex( id );

  if ( index == VTK_INVALID_LOD_INDEX )
    {
    return;
    }

  if ( this->LODs[index].Prop3DType != VTK_LOD_ACTOR_TYPE )
    {
    vtkErrorMacro( << "Error: Cannot set an actor texture on a non-actor!");
    return;
    }

  ((vtkActor *)this->LODs[index].Prop3D)->SetTexture( t );
}

// Get the texture for an LOD that is an actor
void vtkLODProp3D::GetLODTexture( int id, vtkTexture **t )
{
  int index = this->ConvertIDToIndex( id );

  if ( index == VTK_INVALID_LOD_INDEX )
    {
    return;
    }

  if ( this->LODs[index].Prop3DType != VTK_LOD_ACTOR_TYPE )
    {
    vtkErrorMacro( << "Error: Cannot get an actor texture on a non-actor!");
    return;
    }

  *t = ((vtkActor *)this->LODs[index].Prop3D)->GetTexture();
}

// Set the backface property for an LOD that is an actor
void vtkLODProp3D::SetLODBackfaceProperty( int id, vtkProperty *t )
{
  int index = this->ConvertIDToIndex( id );

  if ( index == VTK_INVALID_LOD_INDEX )
    {
    return;
    }

  if ( this->LODs[index].Prop3DType != VTK_LOD_ACTOR_TYPE )
    {
    vtkErrorMacro( << "Error: Cannot set an actor backface property on a non-actor!");
    return;
    }

  ((vtkActor *)this->LODs[index].Prop3D)->SetBackfaceProperty( t );
}

// Get the backface property for an LOD that is an actor
void vtkLODProp3D::GetLODBackfaceProperty( int id, vtkProperty **t )
{
  int index = this->ConvertIDToIndex( id );

  if ( index == VTK_INVALID_LOD_INDEX )
    {
    return;
    }

  if ( this->LODs[index].Prop3DType != VTK_LOD_ACTOR_TYPE )
    {
    vtkErrorMacro( << "Error: Cannot get an actor backface property on a non-actor!");
    return;
    }

  *t = ((vtkActor *)this->LODs[index].Prop3D)->GetBackfaceProperty();
}

void vtkLODProp3D::EnableLOD( int id )
{
  int index = this->ConvertIDToIndex( id );

  if ( index == VTK_INVALID_LOD_INDEX || index == VTK_INDEX_NOT_IN_USE )
    {
    return;
    }
  
  this->LODs[index].State = 1;
}

void vtkLODProp3D::DisableLOD( int id )
{
  int index = this->ConvertIDToIndex( id );

  if ( index == VTK_INVALID_LOD_INDEX || index == VTK_INDEX_NOT_IN_USE )
    {
    return;
    }
  
  this->LODs[index].State = 0;
}

int vtkLODProp3D::IsLODEnabled( int id )
{
  int index = this->ConvertIDToIndex( id );

  if ( index == VTK_INVALID_LOD_INDEX || index == VTK_INDEX_NOT_IN_USE )
    {
    return 0;
    }
  
  return this->LODs[index].State;
}

void vtkLODProp3D::SetLODLevel( int id, double level )
{
  int index = this->ConvertIDToIndex( id );

  if ( index == VTK_INVALID_LOD_INDEX || index == VTK_INDEX_NOT_IN_USE )
    {
    return;
    }
  
  this->LODs[index].Level = level;
}

double vtkLODProp3D::GetLODLevel( int id )
{
  int index = this->ConvertIDToIndex( id );

  if ( index == VTK_INVALID_LOD_INDEX || index == VTK_INDEX_NOT_IN_USE )
    {
    return -1;
    }
  
  return this->LODs[index].Level;
}

double vtkLODProp3D::GetLODIndexLevel( int index )
{

  if ( index == VTK_INVALID_LOD_INDEX || index == VTK_INDEX_NOT_IN_USE )
    {
    return -1;
    }
  
  return this->LODs[index].Level;
}

// Release any graphics resources that any of the LODs might be using
// for a particular window (such as display lists). 
void vtkLODProp3D::ReleaseGraphicsResources(vtkWindow *w)
{
  int i;

  // Loop through all LODs and pass this message along
  for ( i = 0; i < this->NumberOfEntries; i++ )
    {
    if ( this->LODs[i].ID != VTK_INDEX_NOT_IN_USE )
      {
      this->LODs[i].Prop3D->ReleaseGraphicsResources( w );
      }
    }
}

// Standard render method - render any opaque geometry in the selected LOD
int vtkLODProp3D::RenderOpaqueGeometry(vtkViewport *viewport)
{
  int retval;

  // Check if the selected index is in range
  if ( this->SelectedLODIndex < 0 ||
       this->SelectedLODIndex >= this->NumberOfEntries )
    {
    vtkErrorMacro( << "Index out of range!" );
    return 0;
    }

  // Check if the selected index is valid
  if ( this->LODs[this->SelectedLODIndex].ID == VTK_INDEX_NOT_IN_USE )
    {
    vtkErrorMacro( << "Index not valid!" );
    return 0;
    }

  // Actually do the rendering
  retval = 
    this->LODs[this->SelectedLODIndex].Prop3D->RenderOpaqueGeometry(viewport);

  this->EstimatedRenderTime += 
    this->LODs[this->SelectedLODIndex].Prop3D->GetEstimatedRenderTime();

  return retval;
}

// Standard render method - render any translucent geometry in the selected LOD
int vtkLODProp3D::RenderTranslucentPolygonalGeometry(vtkViewport *viewport)
{
  int retval;

  // Check if the selected index is in range
  if ( this->SelectedLODIndex < 0 ||
       this->SelectedLODIndex >= this->NumberOfEntries )
    {
    vtkErrorMacro( << "Index out of range!" );
    return 0;
    }

  // Check if the selected index is valid
  if ( this->LODs[this->SelectedLODIndex].ID == VTK_INDEX_NOT_IN_USE )
    {
    vtkErrorMacro( << "Index not valid!" );
    return 0;
    }

  // Actually do the rendering
  retval = this->LODs[this->SelectedLODIndex].Prop3D->
    RenderTranslucentPolygonalGeometry(viewport);

  this->EstimatedRenderTime += 
    this->LODs[this->SelectedLODIndex].Prop3D->GetEstimatedRenderTime();
  
  return retval;
}

// Description:
// Does this prop have some translucent polygonal geometry?
int vtkLODProp3D::HasTranslucentPolygonalGeometry()
{
  int result;

  // Check if the selected index is in range
  if ( this->SelectedLODIndex < 0 ||
       this->SelectedLODIndex >= this->NumberOfEntries )
    {
    vtkErrorMacro( << "Index out of range!" );
    return 0;
    }

  // Check if the selected index is valid
  if ( this->LODs[this->SelectedLODIndex].ID == VTK_INDEX_NOT_IN_USE )
    {
    vtkErrorMacro( << "Index not valid!" );
    return 0;
    }
  
  result = this->LODs[this->SelectedLODIndex].Prop3D->HasTranslucentPolygonalGeometry();
  
  return result;
}

// Standard render method - render any translucent geometry in the selected LOD
int vtkLODProp3D::RenderVolumetricGeometry(vtkViewport *viewport)
{
  int retval;

  // Check if the selected index is in range
  if ( this->SelectedLODIndex < 0 ||
       this->SelectedLODIndex >= this->NumberOfEntries )
    {
    vtkErrorMacro( << "Index out of range!" );
    return 0;
    }

  // Check if the selected index is valid
  if ( this->LODs[this->SelectedLODIndex].ID == VTK_INDEX_NOT_IN_USE )
    {
    vtkErrorMacro( << "Index not valid!" );
    return 0;
    }

  // Actually do the rendering
  retval = this->LODs[this->SelectedLODIndex].Prop3D->
    RenderVolumetricGeometry(viewport);

  this->EstimatedRenderTime += 
    this->LODs[this->SelectedLODIndex].Prop3D->GetEstimatedRenderTime();
  
  return retval;
} 

// Override the method from vtkProp - add to both this prop and the prop of
// the selected LOD
void vtkLODProp3D::AddEstimatedRenderTime( double t, vtkViewport *vp )
{
  // Add to this prop's estimated render time
  this->EstimatedRenderTime += t;

  // Check if the selected index is in range
  if ( this->SelectedLODIndex < 0 ||
       this->SelectedLODIndex >= this->NumberOfEntries )
    {
    vtkErrorMacro( << "Index out of range!" );
    return;
    }

  // Check if the selected index is valid
  if ( this->LODs[this->SelectedLODIndex].ID == VTK_INDEX_NOT_IN_USE )
    {
    vtkErrorMacro( << "Index not valid!" );
    return;
    }
  
  // Now that error checking is done, add to the estimated render time
  // of the selected LOD
  this->LODs[this->SelectedLODIndex].Prop3D->AddEstimatedRenderTime(t, vp);
}

void vtkLODProp3D::RestoreEstimatedRenderTime()
{
  // restore the EstimatedTime of the last LOD to be rendered
  if ( this->SelectedLODIndex >= 0 &&
       this->SelectedLODIndex < this->NumberOfEntries )
    {
    this->LODs[this->SelectedLODIndex].Prop3D->RestoreEstimatedRenderTime();
    }
}

// Set the allocated render time - this is where the decision is made
// as to which LOD to select
void vtkLODProp3D::SetAllocatedRenderTime( double t, vtkViewport *vp )
{
  int    i;
  int    index = -1;
  double  bestTime;
  double  bestLevel = 0;
  double  targetTime;
  double  estimatedTime;
  double  newTime;

  // update the EstimatedTime of the last LOD to be rendered
  if ( this->SelectedLODIndex >= 0 &&
       this->SelectedLODIndex < this->NumberOfEntries &&
       this->LODs[this->SelectedLODIndex].ID != VTK_INDEX_NOT_IN_USE )
    {
    // For stability, blend in the new time - 25% old + 75% new
    newTime = 
      this->LODs[this->SelectedLODIndex].Prop3D->GetEstimatedRenderTime(vp);
    this->LODs[this->SelectedLODIndex].EstimatedTime = 
      0.25 * this->LODs[this->SelectedLODIndex].EstimatedTime +
      0.75 * newTime;
    }
  
  this->SavedEstimatedRenderTime = this->EstimatedRenderTime;
  
  if ( this->AutomaticLODSelection )
    {
    bestTime = -1.0;

    targetTime = t;

    for ( i = 0; i < this->NumberOfEntries; i++ )
      {
      if ( this->LODs[i].ID != VTK_INDEX_NOT_IN_USE &&
           this->LODs[i].State == 1 )
        {
        // Gather some information
        estimatedTime = this->GetLODIndexEstimatedRenderTime(i);
        
        // If we've never rendered this LOD and we have no info on it,
        // then try it out
        if ( estimatedTime == 0.0 )
          {
          index = i;
          bestTime = 0.0;
          bestLevel = this->GetLODIndexLevel(i);
          break;
          }
        
        // If we do have at least a guess as to the render time, and
        // this seems like the best we have so far, pick it.
        // It is the best we have if 
        //
        // 1) our estimated time is less than what we are looking for, 
        //    but greater than any we have selected so far. 
        //
        // 2) we have not selected anything else yet 
        //    (regardless of what the estimated time is)
        //
        // 3) it is less than the time of the currently selected LOD 
        //    if that LOD's time is greater than the time we are targeting.
        //
        if ( estimatedTime > 0.0 && 
             ( ( estimatedTime > bestTime && estimatedTime < targetTime ) ||
               ( bestTime == -1.0 ) ||
               ( estimatedTime < bestTime && bestTime > targetTime ) ) )
          {
          index = i;
          bestTime = estimatedTime;
          bestLevel = this->GetLODIndexLevel(i);
          }
        }
      }

    // If we aren't trying some level for the first time with 0.0 bestTime,
    // make sure there isn't a LOD that can be rendered faster and has a 
    // higher level 
    double level;
    if ( bestTime != 0.0 )
      {
      for ( i = 0; i < this->NumberOfEntries; i++ )
        {
        if ( this->LODs[i].ID != VTK_INDEX_NOT_IN_USE &&
             this->LODs[i].State == 1 )
          {
          // Gather some information
          estimatedTime = this->GetLODIndexEstimatedRenderTime(i);
          level = this->GetLODIndexLevel(i);

          // Update the index and the level, but not the time. This is
          // so that we find the best level that can be rendered
          // faster than the LOD selected above.
          if ( estimatedTime <= bestTime && level < bestLevel )
            {
            index = i;
            bestLevel = level;
            }
          }
        }
      }
    }
  else
    {
    index = 0;
    while ( index < this->NumberOfEntries && this->LODs[index].ID != 
            this->SelectedLODID )
      {
      index++;
      }
    if ( index == this->NumberOfEntries )
      {
      vtkErrorMacro( << "Could not render selected LOD ID: " << 
                     this->SelectedLODID );
      index = 0;
      while ( index < this->NumberOfEntries && this->LODs[index].ID != 
              VTK_INDEX_NOT_IN_USE )
        {
        index++;
        }
      }
    
    }

  this->SelectedLODIndex = index;
  this->LODs[this->SelectedLODIndex].Prop3D->SetAllocatedRenderTime( t, vp );
  this->EstimatedRenderTime = 0.0;
  this->AllocatedRenderTime = t;

  // Push the matrix down into the selected LOD
  vtkProp3D *p = this->LODs[this->SelectedLODIndex].Prop3D;
  // Getting our matrix here triggers a ComputeMatrix, if necessary,
  // which updates our MatrixMTime
  vtkMatrix4x4 *mat = this->GetMatrix();
  if ( p->GetUserTransformMatrixMTime() < this->MatrixMTime )
    {
    p->SetUserMatrix(mat) ;
    }

}


void vtkLODProp3D::PrintSelf(ostream& os, vtkIndent indent)
{
  this->Superclass::PrintSelf(os,indent);

  os << indent << "Number Of LODs: " << this->NumberOfLODs << endl;

  os << indent << "Selected LOD ID: " << this->SelectedLODID << endl;

  os << indent << "AutomaticLODSelection: " 
     << (this->AutomaticLODSelection ? "On\n" : "Off\n");

  os << indent << "AutomaticPickLODSelection: " 
     << (this->AutomaticPickLODSelection ? "On\n" : "Off\n");

  os << indent << "SelectedPickLODID: " << this->SelectedPickLODID << endl;
  
  os << indent << "CurrentIndex: " << this->CurrentIndex << endl;
}

void vtkLODProp3D::GetActors(vtkPropCollection *ac)
{
  vtkDebugMacro(<< "vtkLODProp3D::GetActors");
  int index;
  int lodID;

  lodID = this->GetPickLODID();
  index = this->ConvertIDToIndex(lodID);

  if (index == VTK_INVALID_LOD_INDEX) 
    {
    return;
    }

  if (! this->LODs[index].Prop3D->IsA("vtkVolume"))
    {
    ac->AddItem(this->LODs[index].Prop3D);
    }
}

int vtkLODProp3D::GetAutomaticPickPropIndex()
{
  double bestTime = -1.0;
  int index = 0;
  double targetTime = 0;
  double estimatedTime;

    for (int i = 0; i < this->NumberOfEntries; i++ )
      {
      if ( this->LODs[i].ID != VTK_INDEX_NOT_IN_USE )
        {
        // Gather some information
        estimatedTime = this->GetLODIndexEstimatedRenderTime(i);
        
        // If we've never rendered this LOD and we have no info on it,
        // then try it out
        if ( estimatedTime == 0.0 )
          {
          index = i;
          break;
          }
        
        // If we do have at least a guess as to the render time, and
        // this seems like the best we have so far, pick it.
        // It is the best we have if 
        //
        // 1) our estimated time is less than what we are looking for, 
        //    but greater than any we have selected so far. 
        //
        // 2) we have not selected anything else yet 
        //    (regardless of what the estimated time is)
        //
        // 3) it is less than the time of the currently selected LOD 
        //    if that LOD's time is greater than the time we are targeting.
        //
        if ( estimatedTime > 0.0 && 
             ( ( estimatedTime > bestTime && estimatedTime < targetTime ) ||
               ( bestTime == -1.0 ) ||
               ( estimatedTime < bestTime && bestTime > targetTime ) ) )
          {
          index = i;
          bestTime = estimatedTime;
          }
        }
      }
    return index;
}


int vtkLODProp3D::GetPickLODID(void)
{
  int lodID;

  vtkDebugMacro(<< "vtkLODProp3D::GetPickLODID");
  int index;
  if (this->AutomaticPickLODSelection)
    {
    if ( this->SelectedLODIndex < 0 ||
         this->SelectedLODIndex >= this->NumberOfEntries )
      {
      index = this->GetAutomaticPickPropIndex();
      }
    else
      {
      index = this->SelectedLODIndex;
      }
    lodID = this->LODs[index].ID;
    }
  else
    {
    lodID = this->SelectedPickLODID;
    }
  
    return lodID;
}


void vtkLODProp3D::SetSelectedPickLODID(int id)
{
  this->SelectedPickLODID = id;
  this->Modified();
}

void vtkLODProp3D::ShallowCopy(vtkProp *prop)
{
  vtkLODProp3D *a = vtkLODProp3D::SafeDownCast(prop);

  if ( a != NULL )
    {
    this->SetAutomaticLODSelection(a->GetAutomaticLODSelection());
    this->SetAutomaticPickLODSelection(a->GetAutomaticPickLODSelection());
    this->SetSelectedLODID(a->GetSelectedLODID());
    this->NumberOfLODs = a->NumberOfLODs;
    for(int i=0; i<this->NumberOfLODs; i++)
      {
      }
    }

  // Now do superclass
  this->vtkProp3D::ShallowCopy(prop);
}


