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

  Program:   Visualization Toolkit
  Module:    vtkLightActor.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 vtkLightActor - a cone and a frustum to represent a spotlight.
// .SECTION Description
// vtkLightActor is a composite actor used to represent a spotlight. The cone
// angle is equal to the spotlight angle, the cone apex is at the position of
// the light, the direction of the light goes from the cone apex to the center
// of the base of the cone. The square frustum position is the light position,
// the frustum focal point is in the direction of the light direction. The
// frustum vertical view angle (aperture) (this is also the horizontal view
// angle as the frustum is square) is equal to twice the cone angle. The
// clipping range of the frustum is arbitrary set by the user
// (initially at 0.5,11.0).

// .SECTION Caveats
// Right now only spotlight are supported but directional light might be
// supported in the future.

// .SECTION See Also
// vtkLight vtkConeSource vtkFrustumSource vtkCameraActor

#ifndef __vtkLightActor_h
#define __vtkLightActor_h

#include "vtkProp3D.h"

class vtkLight;
class vtkConeSource;
class vtkPolyDataMapper;
class vtkActor;
class vtkCamera;
class vtkCameraActor;
class vtkBoundingBox;

class VTK_RENDERING_EXPORT vtkLightActor : public vtkProp3D
{
public:
  static vtkLightActor *New();
  vtkTypeRevisionMacro(vtkLightActor,vtkProp3D);
  void PrintSelf(ostream& os, vtkIndent indent);

  // Description:
  // The spotlight to represent. Initial value is NULL.
  void SetLight(vtkLight *light);
  vtkGetObjectMacro(Light,vtkLight);
  
  // Description:
  // Set/Get the location of the near and far clipping planes along the
  // direction of projection.  Both of these values must be positive.
  // Initial values are  (0.5,11.0)
  void SetClippingRange(double dNear,
                        double dFar);
  void SetClippingRange(const double a[2]);
  vtkGetVector2Macro(ClippingRange,double);
  
  // Description:
  // Support the standard render methods.
  virtual int RenderOpaqueGeometry(vtkViewport *viewport);

  // Description:
  // Does this prop have some translucent polygonal geometry? No.
  virtual int HasTranslucentPolygonalGeometry();

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

  // Description:
  // Get the bounds for this Actor as (Xmin,Xmax,Ymin,Ymax,Zmin,Zmax).
  double *GetBounds();

  // Description:
  // Get the actors mtime plus consider its properties and texture if set.
  unsigned long int GetMTime();
  
protected:
  vtkLightActor();
  ~vtkLightActor();
  
  void UpdateViewProps();
  
  vtkLight *Light;
  double ClippingRange[2];
  
  vtkConeSource *ConeSource;
  vtkPolyDataMapper *ConeMapper;
  vtkActor *ConeActor;
  
  vtkCamera *CameraLight;
  vtkCameraActor *FrustumActor;

  vtkBoundingBox *BoundingBox;
  
private:
  vtkLightActor(const vtkLightActor&);  // Not implemented.
  void operator=(const vtkLightActor&);  // Not implemented.
};

#endif
