vtkExternalLight.h

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

  Program:   Visualization Toolkit
  Module:    vtkExternalLight.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 vtkExternalLight - a virtual light object for tweaking existing lights
// in an external 3D rendering context
//
// .SECTION Description
// vtkExternalLight is a virtual light object for tweaking existing lights in
// an external 3D rendering context. It provides a mechanism to adjust and
// control parameters of existing lights in an external OpenGL context.
//
// It provides methods to locate and point the light,
// and set its brightness and color. In addition to the
// basic infinite distance point light source attributes, you can also specify
// the light attenuation values and cone angle. These attributes are only used
// if the light is a positional light.
//
// By default, vtkExternalLight overrides specific light parameters as set by
// the user. Setting the \em ReplaceMode to ALL_PARAMS, will set all
// the light parameter values to the ones set in vtkExternalLight.
//
// .SECTION Caveats
// Use the vtkExternalLight object to tweak parameters of lights created in the
// external context. This class does not create new lights in the scene.
// One must explicitly set the \em LightIndex to control the light of choice.
//
// .SECTION Example
// \code{.cpp}
//    vtkNew<vtkExternalLight> exLight;
//    exLight->SetLightIndex(GL_LIGHT0); // GL_LIGHT0 identifies the external light
//    exLight->SetDiffuseColor(1.0, 0.0, 0.0); // Changing diffuse color
//    vtkNew<ExternalVTKWidget> exWidget;
//    vtkExternalOpenGLRenderer* ren = vtkExternalOpenGLRenderer::SafeDownCast(exWidget->AddRenderer());
//    ren->AddExternalLight(exLight.GetPointer());
// \endcode
//
// .SECTION see also
// vtkExternalOpenGLRenderer ExternalVTKWidget

#ifndef vtkExternalLight_h
#define vtkExternalLight_h

#include "vtkRenderingExternalModule.h" // For export macro
#include "vtkLight.h"

class VTKRENDERINGEXTERNAL_EXPORT vtkExternalLight : public vtkLight
{
public:
  vtkTypeMacro(vtkExternalLight, vtkLight);
  void PrintSelf(ostream& os, vtkIndent indent);

  // Description:
  // Create an external light object
  static vtkExternalLight *New();

  enum ReplaceModes
    {
    INDIVIDUAL_PARAMS   = 0, // default
    ALL_PARAMS          = 1
    };

  // Set/Get OpenGL light index
  // This should be the OpenGL light identifier. (e.g.: GL_LIGHT0)
  vtkSetMacro(LightIndex, int);
  vtkGetMacro(LightIndex, int);

  // Set/Get replace mode
  vtkSetMacro(ReplaceMode, int);
  vtkGetMacro(ReplaceMode, int);

  // Override Set method to keep a record of changed value
  void SetPosition(double, double, double);

  // Override Set method to keep a record of changed value
  void SetFocalPoint(double, double, double);

  // Override Set method to keep a record of changed value
  void SetAmbientColor(double, double, double);

  // Override Set method to keep a record of changed value
  void SetDiffuseColor(double, double, double);

  // Override Set method to keep a record of changed value
  void SetSpecularColor(double, double, double);

  // Override Set method to keep a record of changed value
  void SetIntensity(double);

  // Override Set method to keep a record of changed value
  void SetConeAngle(double);

  // Override Set method to keep a record of changed value
  void SetAttenuationValues(double, double, double);

  // Override Set method to keep a record of changed value
  void SetExponent(double);

  // Override Set method to keep a record of changed value
  void SetPositional(int);

  // Check whether value set by user
  vtkGetMacro(PositionSet, bool);

  // Check whether value set by user
  vtkGetMacro(FocalPointSet, bool);

  // Check whether value set by user
  vtkGetMacro(AmbientColorSet, bool);

  // Check whether value set by user
  vtkGetMacro(DiffuseColorSet, bool);

  // Check whether value set by user
  vtkGetMacro(SpecularColorSet, bool);

  // Check whether value set by user
  vtkGetMacro(IntensitySet, bool);

  // Check whether value set by user
  vtkGetMacro(ConeAngleSet, bool);

  // Check whether value set by user
  vtkGetMacro(AttenuationValuesSet, bool);

  // Check whether value set by user
  vtkGetMacro(ExponentSet, bool);

  // Check whether value set by user
  vtkGetMacro(PositionalSet, bool);

protected:
  vtkExternalLight();
  ~vtkExternalLight();

  int LightIndex;
  int ReplaceMode;

  bool PositionSet;
  bool FocalPointSet;
  bool AmbientColorSet;
  bool DiffuseColorSet;
  bool SpecularColorSet;
  bool IntensitySet;
  bool ConeAngleSet;
  bool AttenuationValuesSet;
  bool ExponentSet;
  bool PositionalSet;

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

#endif // vtkExternalLight_h