source: GTP/trunk/Lib/Vis/Preprocessing/src/DifferenceSampling.h @ 2560

#ifndef _DifferenceSampling_H__
#define _DifferenceSampling_H__

#include "common.h"
//#include "ObjectPvs.h"

class SimpleRay;

namespace GtpVisibilityPreprocessor {


/** This sampling strategy utilizes the spatial filter to find 
        areas that are likely to be visible.

        First the filter is applied. The difference set of objects 
        (filtered pvs - unfiltered pvs) gives you the objects which 
        are not found visible yet but have a good probability that they 
        are in fact visible, based on the current 
        state of the sampling and the size of the filter. In fact the 
        difference set is a probably visible set.

        Algorithm overview:
        We apply the filter for n times, each time with a higher filter radius. 
        The difference set gives you the probable visible set. 
        Then we use a certain #random samples for sampling the view cell border + 
        the object border. We can use different filter sizes to estimate the probability 
        distribution. The objects shouldreceived samples 
        roughly according to their probability of becoming invisible.
*/      
class DifferenceSampling: public SamplingStrategy
{
public:
        DifferenceSampling(Preprocessor &preprocessor);
        /** Compute the difference set between filtered and unfiltered pvs.
        */
        void ComputeDifferenceSet(ViewCell *vc, ObjectContainer &differenceSet);

private:

        virtual bool GenerateSample(SimpleRay &ray);

        //ObjectPvs mDifferencePvs;
        ObjectContainer mPvsDifference;

        ViewCell *mCurrentViewCell;
        int mNumSamples;
};


}

#endif