#ifndef _SamplingStategy_H__
#define _SamplingStategy_H__


namespace GtpVisibilityPreprocessor {


class Preprocessor;
struct SimpleRay;

/** 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
	 };

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

	 virtual ~SamplingStrategy();

	 /** Each strategy has to implement this function.
		 @returns true if generated valid sample.
	 */
	 virtual bool GenerateSample(SimpleRay &ray) const = 0;

protected:

	const Preprocessor &mPreprocessor;

};


class ObjectBasedDistribution: public SamplingStrategy
{
 public:
	
	 ObjectBasedDistribution(const Preprocessor &preprocessor):
	 SamplingStrategy(preprocessor) {}

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


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


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


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


class SpatialBoxBasedDistribution: public SamplingStrategy
{
 public:
	 SpatialBoxBasedDistribution(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