// This code implementation is the intellectual property of
// the GEANT4 collaboration.
//
// By copying, distributing or modifying the Program (or any work
// based on the Program) you indicate your acceptance of this statement,
// and all its terms.
//
// $Id: G4RayTracer.hh,v 1.5 2000/03/09 17:38:33 asaim Exp $
// GEANT4 tag $Name: geant4-02-00 $
//
//


#ifndef G4RayTracer_H
#define G4RayTracer_H 1

// class description:
//
// G4RayTracer
//   This is a graphics driver of Geant4 which generates a figure file by
// ray tracing technique. The format of output figure file can be selected
// by assigning a pointer of G4VFigureFileMaker concrete class object.
//   The main entry of ray tracing is Trace() method, which is available
// only at Idle state. G4RayTracer shoots rays and controls its own event
// loop. It generates G4Event objects used for its own purpose. When ray
// tracing is working, all sensitive detectors are inactivated and all
// user action classes are swapped out. Still, verbosities set to Geant4
// manager classes are concerned. Thus, it is recommended to set verbosities
// to minimum (usually zero).
//   G4RayTracer can visualise absolutely all kinds of geometrical shapes
// which G4Navigator can deal with. Instead, it can NOT visualise hits
// nor trajectories generated by usual simulation.
//   To make G4RayTracer library, G4VIS_BUILD_RAYTRACER_DRIVER environment
// variable must be set before compiling visualization category. To use
// G4RayTracer with your program, G4VIS_USE_RAYTRACER environment variable
// must be set before compiling your program and your VisManager concrete
// implementation must contain 
//           RegisterGraphicsSystem (new G4RayTracer);
//

#if defined (G4VIS_BUILD_RAYTRACER_DRIVER) || defined (G4VIS_USE_RAYTRACER)

#include "globals.hh"
#include "G4ThreeVector.hh"
#include "G4VGraphicsSystem.hh"

class G4Event;
class G4EventManager;
class G4UserEventAction;
class G4UserStackingAction;
class G4UserTrackingAction;
class G4UserSteppingAction;
class G4RTTrackingAction;
class G4RTSteppingAction;
class G4Colour;
class G4RTMessenger;
class G4RayShooter;
class G4VFigureFileMaker;
class G4RayTrajectoryPoint;
class G4VisAttributes;


class G4RayTracer : public G4VGraphicsSystem
{
  public: // with description
    G4RayTracer(G4VFigureFileMaker* figMaker = 0);
    // Constructor. The argument is the pointer to G4VFigureFileMaker concrete
    // class object. If it is not set and SetFigureFileMaker() method is not
    // invoked before Trace() command is invoked, then G4RTJpegMaker will be
    // used and JPEG file will be generated.

  public:
    ~G4RayTracer();

  public: // with description
    void Trace(G4String fileName);
    // The main entry point which triggers ray tracing. "fileName" is output
    // file name, and it must contain extention (e.g. myFigure.jpg). This
    // method is available only if Geant4 is at Idle state.

  public:
    virtual G4VSceneHandler* CreateSceneHandler (const G4String& );
    virtual G4VViewer* CreateViewer (G4VSceneHandler&, const G4String& );

  private:
    G4bool CreateBitMap();
    // Event loop
    void CreateFigureFile(G4String fileName);
    // Create figure file after an event loop
    G4bool GenerateColour(G4Event* anEvent);
    // Calcurate RGB for one trajectory
    void StoreUserActions();
    void RestoreUserActions();
    // Store and restore user action classes if defined

    G4Colour GetSurfaceColour(G4RayTrajectoryPoint* point);
    G4Colour GetMixedColour(G4Colour surfCol,G4Colour transCol,G4double weight=0.5);
    G4Colour Attenuate(G4RayTrajectoryPoint* point, G4Colour sourceCol);
    G4bool ValidColour(const G4VisAttributes* visAtt);

  public: // with description
    inline void SetFigureFileMaker(G4VFigureFileMaker* figMaker)
    // Set a concrete class of G4VFigureFileMaker for assigning the format of
    // output figure file.
    { theFigMaker = figMaker; }

  private:
    G4RayShooter * theRayShooter;
    G4VFigureFileMaker * theFigMaker;
    G4RTMessenger * theMessenger;

    G4EventManager * theEventManager;

    G4UserEventAction * theUserEventAction;
    G4UserStackingAction * theUserStackingAction;
    G4UserTrackingAction * theUserTrackingAction;
    G4UserSteppingAction * theUserSteppingAction;

    G4UserEventAction * theRayTracerEventAction;
    G4UserStackingAction * theRayTracerStackingAction;
    G4RTTrackingAction * theRayTracerTrackingAction;
    G4RTSteppingAction * theRayTracerSteppingAction;

    unsigned char* colorR;
    unsigned char* colorG;
    unsigned char* colorB;

    G4int nColumn;
    G4int nRow;

    G4ThreeVector eyePosition;
    G4ThreeVector targetPosition;
    G4ThreeVector eyeDirection;
    G4ThreeVector lightDirection;
    G4double headAngle;
    G4double viewSpan; // Angle per 100 pixels
    G4double attenuationLength;

    G4bool distortionOn;

  public:
    inline void SetNColumn(G4int val) { nColumn = val; }
    inline G4int GetNColumn() const { return nColumn; }
    inline void SetNRow(G4int val) { nRow = val; }
    inline G4int GetNRow() const { return nRow; }
    inline void SetEyePosition(G4ThreeVector val) { eyePosition = val; }
    inline G4ThreeVector GetEyePosition() const { return eyePosition; }
    inline void SetTargetPosition(G4ThreeVector val) { targetPosition = val; }
    inline G4ThreeVector GetTargetPosition() const { return targetPosition; }
    inline void SetLightDirection(G4ThreeVector val) { lightDirection = val.unit(); }
    inline G4ThreeVector GetLightDirection() const { return lightDirection; }
    inline void SetHeadAngle(G4double val) { headAngle = val; }
    inline G4double GetHeadAngle() const { return headAngle; }
    inline void SetViewSpan(G4double val) { viewSpan = val; }
    inline G4double GetViewSpan() const { return viewSpan; }
    inline void SetAttenuationLength(G4double val) { attenuationLength = val; }
    inline G4double GetAttenuationLength() const { return attenuationLength; }
    inline void SetDistortion(G4bool val) { distortionOn = val; }
    inline G4bool GetDistortion() const { return distortionOn; }
};

#endif
#endif


