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

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


Copyright (c) 1993-2001 Ken Martin, Will Schroeder, Bill Lorensen 
All rights reserved.

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 * Redistributions of source code must retain the above copyright notice,
   this list of conditions and the following disclaimer.

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 * Neither name of Ken Martin, Will Schroeder, or Bill Lorensen nor the names
   of any contributors may be used to endorse or promote products derived
   from this software without specific prior written permission.

 * Modified source versions must be plainly marked as such, and must not be
   misrepresented as being the original software.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS''
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE FOR
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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

