#ifndef _SamplingStategy_H__
#define _SamplingStategy_H__


namespace GtpVisibilityPreprocessor {


class Preprocessor;
struct SimpleRay;
class SimpleRayContainer;

/** This class generates a specific sampling strategy.
*/
class SamplingStrategy
{
public:

	/** Sample rays of particular type
	*/
	enum 
	{
		OBJECT_BASED_DISTRIBUTION,
		DIRECTION_BASED_DISTRIBUTION,
		DIRECTION_BOX_BASED_DISTRIBUTION,
		SPATIAL_BOX_BASED_DISTRIBUTION,
		RSS_BASED_DISTRIBUTION,
		RSS_SILHOUETTE_BASED_DISTRIBUTION,
		VSS_BASED_DISTRIBUTION,
		OBJECT_DIRECTION_BASED_DISTRIBUTION,
		OBJECTS_INTERIOR_DISTRIBUTION,
		REVERSE_OBJECT_BASED_DISTRIBUTION,
		VIEWCELL_BORDER_BASED_DISTRIBUTION,
		VIEWSPACE_BORDER_BASED_DISTRIBUTION,
		REVERSE_VIEWSPACE_BORDER_BASED_DISTRIBUTION
	};

	/** Default constructor
	*/
	SamplingStrategy(const Preprocessor &preprocessor);

	virtual ~SamplingStrategy();

	/** Each strategy has to implement this function.
	@returns true if generated valid sample.
	*/

	virtual int GenerateSamples(const int number, SimpleRayContainer &rays) const;

private:

	virtual bool GenerateSample(SimpleRay &ray) const = 0;

public:
	/// variables usefull for mixed distribution sampling
	int mType;
	int mRays;
	float mContribution;
	float mTime;
	float mRatio;

protected:

	const Preprocessor &mPreprocessor;

};


class ObjectBasedDistribution: public SamplingStrategy
{
 public:
	
  ObjectBasedDistribution(const Preprocessor &preprocessor):
	SamplingStrategy(preprocessor) {
	mType = OBJECT_BASED_DISTRIBUTION;
  }

private:
  virtual bool GenerateSample(SimpleRay &ray) const;
};


class ReverseObjectBasedDistribution: public SamplingStrategy
{
 public:
	
	 ReverseObjectBasedDistribution(const Preprocessor &preprocessor):
	   SamplingStrategy(preprocessor) {
	   mType = REVERSE_OBJECT_BASED_DISTRIBUTION;
	 }

private:
  virtual bool GenerateSample(SimpleRay &ray) const;
};


class ObjectDirectionBasedDistribution: public SamplingStrategy
{
 public:
	 ObjectDirectionBasedDistribution(const Preprocessor &preprocessor):
	 SamplingStrategy(preprocessor) {
	   mType = OBJECT_DIRECTION_BASED_DISTRIBUTION;
	 }
private:
	virtual bool GenerateSample(SimpleRay &ray) const;
};


class DirectionBasedDistribution: public SamplingStrategy
{
 public:
  DirectionBasedDistribution(const Preprocessor &preprocessor):
	SamplingStrategy(preprocessor){
	mType = DIRECTION_BASED_DISTRIBUTION;
  }
private:
  virtual bool GenerateSample(SimpleRay &ray) const;
};


class DirectionBoxBasedDistribution: public SamplingStrategy
{
 public:
	 DirectionBoxBasedDistribution(const Preprocessor &preprocessor):
	   SamplingStrategy(preprocessor){
	   mType = DIRECTION_BOX_BASED_DISTRIBUTION;
	 }
	   
private:
	   virtual bool GenerateSample(SimpleRay &ray) const;
};


class SpatialBoxBasedDistribution: public SamplingStrategy
{
 public:
	 SpatialBoxBasedDistribution(const Preprocessor &preprocessor):
	   SamplingStrategy(preprocessor){
	   mType = DIRECTION_BOX_BASED_DISTRIBUTION;
	 }
	   
private:
	   virtual bool GenerateSample(SimpleRay &ray) const;
};


class ViewSpaceBorderBasedDistribution: public SamplingStrategy
{
 public:
	 ViewSpaceBorderBasedDistribution(const Preprocessor &preprocessor):
	   SamplingStrategy(preprocessor){
	   mType = SPATIAL_BOX_BASED_DISTRIBUTION;
	 }
	 
private:
	 virtual bool GenerateSample(SimpleRay &ray) const;
};


class ReverseViewSpaceBorderBasedDistribution: public SamplingStrategy
{
 public:
	 ReverseViewSpaceBorderBasedDistribution(const Preprocessor &preprocessor):
	   SamplingStrategy(preprocessor){
	   mType = SPATIAL_BOX_BASED_DISTRIBUTION;
	 }
	 
private:
	 virtual bool GenerateSample(SimpleRay &ray) const;
};


class RssBasedDistribution: public SamplingStrategy
{
 public:
  RssBasedDistribution(const Preprocessor &preprocessor):
	SamplingStrategy(preprocessor){
	mType = RSS_BASED_DISTRIBUTION;
  }


  virtual int GenerateSamples(const int number, SimpleRayContainer &ray) const {
	// TBD!!!
	return 0;
  }

private:
  virtual bool GenerateSample(SimpleRay &ray) const;
  
};


class ViewCellBorderBasedDistribution: public SamplingStrategy
{
 public:
  ViewCellBorderBasedDistribution(const Preprocessor &preprocessor):
	SamplingStrategy(preprocessor) {}
  
  virtual bool GenerateSample(SimpleRay &ray) const;
};


/** This strategy generates samples inside of the objects, e.g.,
	for sampling the inside of a colon.
*/
/*class ObjectsInteriorDistribution: public SamplingStrategy
{
 public:
	 ObjectsInteriorDistribution(const Preprocessor &preprocessor):
	 SamplingStrategy(preprocessor) {}
	 
	 virtual bool GenerateSample(SimpleRay &ray) const;
};
*/
};

#endif