FrameRateController.h

#pragma once

namespace ParaEngine
{
class CFrameRateController
{
public:
    enum ControllerType{
        FRC_NONE = 0,   // output delta time without interpolation
        FRC_CONSTANT,   // output a constant delta time disregarding the input time
        FRC_CONSTANT_OR_ABOVE,  // output a constant delta time or a smaller one
        FRC_FIRSTORDER, // interpolating using a linear function
        FRC_SECONDORDER,    // interpolating using a second order function
        FRC_BELOW,  // ensure that frame rate is smaller than a given value. 
        FRC_CONSTANT_OR_BELOW,  // output a constant delta time or a smaller one
    };

    ControllerType  m_nType;        
    float   m_fConstDeltaTime;      
    float   m_fMaxDeltaTime;        
    float   m_fMinDeltaTime;        
    
    float   m_fLinearSlope;         
    float   m_fMaxLinearDeltaTime;  
    double  m_fNextTime;            
public:

    double  m_fTime;                
    double  m_fLastTime;            

    double  m_fElapsedTime;         
    double  m_fLastElapsedTime;     

public:
    CFrameRateController(ControllerType type);
    CFrameRateController(void);
    ~CFrameRateController(void);
public:
    double  GetTime(){return m_fTime;}
    //double    GetElapsedTime(){return m_fElapsedTime;}
public:
    void SetType(ControllerType nType);

    void SetConstDeltaTime(double fConstDeltaTime);

    double FrameMove(double time);

    double FrameMoveDelta(double deltatime);

public:
    static void LoadFRCNormal(float fIdealInterval = -1.f);
    static void LoadFRCRealtime(float fIdealInterval = -1.f);
    static void LoadFRCCapture(int nFPS);
    static void LoadFRCServerMode();
};

}