#ifndef GL_SCENE_STAT_H
#define GL_SCENE_STAT_H
 
#include <time.h>
#include <unistd.h>
 
 
 
class GlSceneStat {
private:
    double meanFrameComputationTime;
    double frameComputationTime;
    int nbFrameComputationTime;
 
 
    timespec starting_time;
    timespec endding_time;
public:
 
    GlSceneStat()
    {
        this->nbFrameComputationTime=0;
        this->frameComputationTime=0;
        this->meanFrameComputationTime=0;
    }
 
 
    double getDeltaTime(timespec &starting_time,timespec &endding_time)
    {
        int64_t t1 = ((int64_t) starting_time.tv_sec)*1000000000 + starting_time.tv_nsec;
        int64_t t2 = ((int64_t) endding_time.tv_sec)*1000000000 + endding_time.tv_nsec;
        int64_t diff_time = t2 - t1;
        return diff_time/1.0e9;
    }
 
    void setTime(float delta)
    {
        if (nbFrameComputationTime <100)
        {
            this->frameComputationTime += delta;
            this->nbFrameComputationTime++;
        } else
            this->frameComputationTime=100*(100.0*frameComputationTime/nbFrameComputationTime +delta)/101.0;
 
        this->meanFrameComputationTime=frameComputationTime/nbFrameComputationTime;
    }
 
    void startScene()
    {
        clock_gettime(CLOCK_REALTIME, &starting_time);
    }
 
    void endScene()
    {
        clock_gettime(CLOCK_REALTIME, &endding_time);
        float delta=getDeltaTime(starting_time,endding_time);
        setTime(delta);
    }
 
 
    float getMeanTime()
    {
        return this->meanFrameComputationTime;
    }
 
 
};
 
 
 
#endif