#ifndef __RENDERER_H
#define __RENDERER_H

#include <QtOpenGL>
#include <QWaitCondition>
//#include <QGLPixelBuffer>

#include "Vector3.h"
#include "Containers.h"
#include "Halton.h"
#include "Renderer.h"

class SceneGraph;
class ViewCellsManager;
class Mesh;
class MeshInstance;
class Intersectable;
class Material;
class Beam;

struct PvsRenderStatistics {
  
  float maxError;
  float sumError;
  int frames;
  int errorFreeFrames;

  PvsRenderStatistics() { Reset(); }
  
  void Reset() {
	maxError = 0.0f;
	sumError = 0.0f;
	frames = 0;
	errorFreeFrames = 0;
  }

  float GetMaxError() { return maxError; }
  float GetAvgError() { return sumError/frames; }
  float GetErrorFreeFrames() { return errorFreeFrames/(float)frames; }
  
};


/** Class encapsulating gl rendering for the scene.
	There is no gl context binding so the binding is performed in the
	derived classes
*/

class GlRenderer: public Renderer
{

public:
  ObjectContainer mObjects;
   
  Vector3 mViewPoint;
  Vector3 mViewDirection;

  int timerId;
  bool mUseFalseColors;

  HaltonSequence halton;
  
  int mFrame;
  bool mWireFrame;

  QWaitCondition mRenderingFinished;
  
  
  GlRenderer(SceneGraph *sceneGraph,
			 ViewCellsManager *viewcells);
  
  ~GlRenderer();


  void SetupFalseColor(const int id);
  void RenderIntersectable(Intersectable *);
  void RenderMeshInstance(MeshInstance *mi);
  void RenderMesh(Mesh *m);
  void SetupMaterial(Material *m);
  virtual void SetupCamera();
  void RandomViewPoint();
  
  bool
  RenderScene();

  void
  SetupProjection(const int w, const int h);

  
  
  float
  GetPixelError();

  void InitGL();

  virtual int GetWidth() const = 0;
  virtual int GetHeight() const = 0;
};


class GlRendererBuffer : public QGLPixelBuffer, public GlRenderer
{

public:
  int mPvsStatFrames;
  vector<float> mPvsErrorBuffer;
  
  PvsRenderStatistics mPvsStat;


  GlRendererBuffer(const int w,
				   const int h,
				   SceneGraph *sceneGraph,
				   ViewCellsManager *viewcells):
	QGLPixelBuffer(QSize(w, h)), GlRenderer(sceneGraph, viewcells) {

	mPvsStatFrames = 10000;
	mPvsErrorBuffer.resize(mPvsStatFrames);
	ClearErrorBuffer();

	makeCurrent();
	InitGL();
	doneCurrent();

  }
  
  void
  EvalPvsStat();

  void
  ClearErrorBuffer();
  

  virtual int GetWidth() const { return width(); }
  virtual int GetHeight() const { return height(); }



  // the values need for rss tree update computed already inside the glrendererbuffer
  // not all of them need to be computed
  struct BeamSampleStatistics {

	enum {COMPUTE_PVS_SIZE, COMPUTE_RAY_CONTRIBUTIONS, COMPUTE_PVS_ENTROPY};
	int flags;

	BeamSampleStatistics():flags(COMPUTE_RAY_CONTRIBUTIONS) {}
	
	float pvsSize;
	float rays;
	float rayContributions;
	float pvsEntropy;
	float rayLengthEntropy;
	float importance;
	
	float weightedRayContribution;
  };
  

  void SampleBeamContributions(
							   Intersectable *sourceObject,
							   Beam &beam,
							   const int samples,
							   BeamSampleStatistics &stat
							   );

  void
  SampleViewpointContributions(
							   Intersectable *sourceObject,
							   const Vector3 viewPoint,
							   Beam &beam,
							   const int desiredSamples,
							   BeamSampleStatistics &stat
							   );

private:
	static void GenQueries(const int numQueries);
	void SetupProjectionForViewPoint(const Vector3 &viewPoint, 
									 const Beam &beam, 
									 Intersectable *sourceObject);
};



class GlRendererWidget : public QGLWidget, public GlRenderer
{
  Q_OBJECT
public:

  // point of the last mouse click used for movement in the scene
  Vector3 mousePoint;

  bool mTopView;
  
  GlRendererWidget(SceneGraph *sceneGraph,
				   ViewCellsManager *viewcells,
				   QWidget * parent = 0, const QGLWidget * shareWidget = 0, Qt::WFlags f = 0
				   ):
	GlRenderer(sceneGraph, viewcells), QGLWidget(parent, shareWidget, f)
  {
	mTopView = false;
  }

  virtual void SetupCamera();

  void initializeGL() {
	InitGL();
  }
  void resizeGL(int w, int h);
  void paintGL();
  void timerEvent(QTimerEvent *) {
	  update();
  }

  void mousePressEvent(QMouseEvent *);
  void mouseReleaseEvent(QMouseEvent *);
  void mouseMoveEvent(QMouseEvent *);

  void keyPressEvent ( QKeyEvent * e ) ;
  
  float
  RenderErrors();

  virtual int GetWidth() const { return width(); }
  virtual int GetHeight() const { return height(); }

};


extern GlRendererWidget *rendererWidget;

#endif