// File: timer.h
#pragma once

typedef unsigned long long timer_ticks;

class timer {
public:
    timer();
    timer(timer_ticks start_ticks);

    void start();
    void start(timer_ticks start_ticks);

    void stop();

    double get_elapsed_secs() const;
    inline double get_elapsed_ms() const {
        return get_elapsed_secs() * 1000.0f;
    }
    timer_ticks get_elapsed_us() const;

    static void init();
    static inline timer_ticks get_ticks_per_sec() {
        return g_freq;
    }
    static timer_ticks get_init_ticks();
    static timer_ticks get_ticks();
    static double ticks_to_secs(timer_ticks ticks);
    static inline double ticks_to_ms(timer_ticks ticks) {
        return ticks_to_secs(ticks) * 1000.0f;
    }
    static inline double get_secs() {
        return ticks_to_secs(get_ticks());
    }
    static inline double get_ms() {
        return ticks_to_ms(get_ticks());
    }

private:
    static timer_ticks g_init_ticks;
    static timer_ticks g_freq;
    static double g_inv_freq;

    timer_ticks m_start_time;
    timer_ticks m_stop_time;

    bool m_started : 1;
    bool m_stopped : 1;
};
