source: trunk/VUT/GtpVisibilityPreprocessor/src/Halton.h @ 355

#ifndef __HALTON_H
#define __HALTON_H

class Halton2 {
        
        float _invBases[2];
        float _prev[2];

        float halton(float baseRec, float prev) const {
                float r = 1 - prev - 1e-10;
                if (baseRec < r) return prev + baseRec;
                float h = baseRec;
                float hh;
                do {
                        hh = h;
                        h *= baseRec;
                } while (h >= r);
                return prev + hh + h - 1;
        }
        
public:

        void Reset() {
                _prev[0] =_prev[1] = 0;
        }

        Halton2() {
                _invBases[0] = 1./2;
                _invBases[1] = 1./3;
                Reset();
        }
        
        void
        GetNext(float &a, float &b) {
                a = halton(_invBases[0], _prev[0]);
                b = halton(_invBases[1], _prev[1]);
                _prev[0] = a;
                _prev[1] = b;
        }
};

extern Halton2 halton2;

#endif