/**
 * @file clock.h
 *
 * @brief Engine clock.
 */
#ifndef CLOCK_H
#define CLOCK_H

#include "common.h"

typedef unsigned long long TICK;

/**
 * @brief Engine clock.
 */
struct CLOCK
{
    int fEnabled; // clock enabled flag
    float t;
    float dt;	  // time since last frame
    float dtPrev; // dt from previous frame
    float tReal;  // t factoring in EE clock cyclerate
    float dtReal; // dt factoring in EE clock cyclerate
    TICK tickFrame;
};

/**
 * @brief Sets the rate of the global clock.
 *
 * @param rt The new tick rate.
*/
void SetClockRate(float rt);

/**
 * @brief Updates clock values based to time elapsed.
 *
 * @param pclock Pointer to the clock.
*/
void MarkClockTick(CLOCK *pclock);

/**
 * @brief Updates clock values based to time elapsed.
 *
 * Only updates the real clock values (those determined by the EE clock cyclerate).
 *
 * @param pclock Pointer to the clock.
*/
void MarkClockTickRealOnly(CLOCK *pClock);

/**
 * @brief Resets the clock to the given time t.
 *
 * @param pclock Pointer to the clock.
 * @param t Time to set.
*/
void ResetClock(CLOCK *pclock, float t);

/**
 * @brief Sets the fEnabled flag on the clock to the given value.
 *
 * @param pclock Pointer to the clock.
 * @param fEnabled 1 to enable, 0 to disable.
*/
void SetClockEnabled(CLOCK *pclock, int fEnabled);

/**
 * @brief Initializes and enables the global clock.
*/
void StartupClock();

/**
 * @brief Gets the current tick.
 *
 * @return The current tick.
*/
const TICK TickNow();

extern float g_rtClock;
extern float g_rtClockPowerUp;
extern struct CLOCK g_clock;
extern TICK s_tickLastRaw;

#endif // CLOCK_H