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

  Program:   Visualization Toolkit
  Module:    vtkRayBounder.h
  Language:  C++
  Date:      $Date$
  Version:   $Revision$


Copyright (c) 1993-2000 Ken Martin, Will Schroeder, Bill Lorensen 
All rights reserved.

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   of any contributors may be used to endorse or promote products derived
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=========================================================================*/
// .NAME vtkRayBounder - An abstract class for bounding rays
// .SECTION Description
// vtkRayBounder is an abstract class for bounding view rays during
// ray casting. Each concrete subclass must have a GetRayBounds 
// method which, given a renderer, produces a floating point array
// that is w*h*2 (w = width of viewport, h = height of viewport).
// For each pixel, this array contains the near and far clipping
// values for the corresponding ray. A value of -1 means no clipping
// should be performed on that ray.

// .SECTION see also
// 

#ifndef __vtkRayBounder_h
#define __vtkRayBounder_h

#include "vtkObject.h"
#include "vtkRenderer.h"

class vtkWindow;

class VTK_EXPORT vtkRayBounder : public vtkObject
{
public:
  vtkTypeMacro(vtkRayBounder,vtkObject);

  // Description:
  // Get the ray bounds - a floating point array with two
  // values for every pixel in the viewport. These values
  // indicate near and far clipping distances, or -1 for
  // no clipping.
  virtual float *GetRayBounds( vtkRenderer *ren )=0;


  // Description:
  // Release any graphics resources that are being consumed by this ray bounder.
  // The parameter window could be used to determine which graphic
  // resources to release.
  virtual void ReleaseGraphicsResources(vtkWindow *) {};

  
protected:
  vtkRayBounder() {};
  ~vtkRayBounder() {};
  vtkRayBounder(const vtkRayBounder &) {};
  void operator=(const vtkRayBounder &) {};
};

#endif

