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

  Program:   Visualization Toolkit
  Module:    vtkImageStack.h

  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.

=========================================================================*/
// .NAME vtkImageStack - manages a stack of composited images
// .SECTION Description
// vtkImageStack manages the compositing of a set of images. Each image
// is assigned a layer number through its property object, and it is
// this layer number that determines the compositing order: images with
// a higher layer number are drawn over top of images with a lower layer
// number.  The image stack has a SetActiveLayer method for controlling
// which layer to use for interaction and picking.
// .SECTION Thanks
// Thanks to David Gobbi at the Seaman Family MR Centre and Dept. of Clinical
// Neurosciences, Foothills Medical Centre, Calgary, for providing this class.
// .SECTION See also
// vtkImageMapper3D vtkImageProperty vtkProp3D

#ifndef __vtkImageStack_h
#define __vtkImageStack_h

#include "vtkImageSlice.h"

class vtkImageSliceCollection;
class vtkImageProperty;
class vtkImageMapper3D;
class vtkCollection;

class VTK_RENDERING_EXPORT vtkImageStack : public vtkImageSlice
{
public:
  vtkTypeMacro(vtkImageStack,vtkImageSlice);
  void PrintSelf(ostream& os, vtkIndent indent);
  static vtkImageStack *New();

  // Description:
  // Add an image to the stack.  If the image is already present, then
  // this method will do nothing.
  void AddImage(vtkImageSlice *prop);

  // Description:
  // Remove an image from the stack.  If the image is not present, then
  // this method will do nothing.
  void RemoveImage(vtkImageSlice *prop);

  // Description:
  // Check if an image is present.  The returned value is one or zero.
  int HasImage(vtkImageSlice *prop);

  // Description:
  // Get the list of images as a vtkImageSliceCollection.
  vtkImageSliceCollection *GetImages() { return this->Images; }

  // Description:
  // Set the active layer number.  This is the layer that will be
  // used for picking and interaction.
  vtkSetMacro(ActiveLayer, int);
  int GetActiveLayer() { return this->ActiveLayer; }

  // Description:
  // Get the active image.  This will be the topmost image whose
  // LayerNumber is the ActiveLayer.  If no image matches, then NULL
  // will be returned.
  vtkImageSlice *GetActiveImage();

  // Description:
  // Get the mapper for the currently active image.
  vtkImageMapper3D *GetMapper();

  // Description:
  // Get the property for the currently active image.
  vtkImageProperty *GetProperty();

  // Description:
  // Get the combined bounds of all of the images.
  double *GetBounds();
  void GetBounds(double bounds[6]) { this->vtkProp3D::GetBounds( bounds ); };

  // Description:
  // Return the max MTime of all the images. 
  unsigned long int GetMTime();

  // Description:
  // Return the mtime of anything that would cause the rendered image to
  // appear differently. Usually this involves checking the mtime of the
  // prop plus anything else it depends on such as properties, mappers,
  // etc.
  unsigned long GetRedrawMTime();

  // Description:
  // Shallow copy of this prop. Overloads the virtual vtkProp method.
  void ShallowCopy(vtkProp *prop);

  // Description:
  // For some exporters and other other operations we must be
  // able to collect all the actors, volumes, and images. These
  // methods are used in that process.
  void GetImages(vtkPropCollection *);

  // Description:
  // Support the standard render methods.
  virtual int RenderOverlay(vtkViewport *viewport);
  virtual int RenderOpaqueGeometry(vtkViewport *viewport);
  virtual int RenderTranslucentPolygonalGeometry(vtkViewport *viewport);

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

  // Description:
  // Release any resources held by this prop.
  void ReleaseGraphicsResources(vtkWindow *win);

  // Description:
  // Methods for traversing the stack as if it was an assembly.
  // The traversal only gives the view prop for the active layer.
  void InitPathTraversal();
  vtkAssemblyPath *GetNextPath();
  int GetNumberOfPaths();

  // Description:
  // WARNING: INTERNAL METHOD - NOT INTENDED FOR GENERAL USE
  // DO NOT USE THIS METHOD OUTSIDE OF THE RENDERING PROCESS
  // Used to construct assembly paths and perform part traversal.
  void BuildPaths(vtkAssemblyPaths *paths, vtkAssemblyPath *path);

protected:
  vtkImageStack();
  ~vtkImageStack();

  void SetMapper(vtkImageMapper3D *mapper);
  void SetProperty(vtkImageProperty *property);

  void PokeMatrices(vtkMatrix4x4 *matrix);
  void UpdatePaths();

  vtkTimeStamp PathTime;
  vtkCollection *ImageMatrices;
  vtkImageSliceCollection *Images;
  int ActiveLayer;

private:
  vtkImageStack(const vtkImageStack&);  // Not implemented.
  void operator=(const vtkImageStack&);  // Not implemented.
};

#endif