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

  Program:   Visualization Toolkit
  Module:    $RCSfile: vtkRenderedAreaPicker.h,v $

  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 vtkRenderedAreaPicker - Uses graphics hardware to picks props behind
// a selection rectangle on a viewport.
//
// .SECTION Description
// Like vtkAreaPicker, this class picks all props within a selection area 
// on the screen. The difference is in implementation. This class uses
// graphics hardware to perform the test where the other uses software 
// bounding box/frustum intersection testing. 
//
// This picker is more conservative than vtkAreaPicker. It will reject 
// some objects that pass the bounding box test of vtkAreaPicker. This 
// will happen, for instance, when picking through a corner of the bounding
// box when the data set does not have any visible geometry in that corner.
#ifndef __vtkRenderedAreaPicker_h
#define __vtkRenderedAreaPicker_h

#include "vtkAreaPicker.h"

class vtkRenderer;

class VTK_RENDERING_EXPORT vtkRenderedAreaPicker : public vtkAreaPicker
{
public:
  static vtkRenderedAreaPicker *New();
  vtkTypeRevisionMacro(vtkRenderedAreaPicker,vtkAreaPicker);
  void PrintSelf(ostream& os, vtkIndent indent);

  // Description:
  // Perform pick operation in volume behind the given screen coordinates.
  // Props intersecting the selection frustum will be accesible via GetProp3D.
  // GetPlanes returns a vtkImplicitFunciton suitable for vtkExtractGeometry.
  virtual int AreaPick(double x0, double y0, double x1, double y1, vtkRenderer *renderer);

protected:
  vtkRenderedAreaPicker();
  ~vtkRenderedAreaPicker();

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

#endif


