4 files changed, 347 insertions, 0 deletions
diff --git a/src/models/counter.cpp b/src/models/counter.cpp
new file mode 100644
index 0000000..4855c24
--- /dev/null
+++ b/src/models/counter.cpp
@@ -0,0 +1,35 @@
+#include "models/counter.hpp"
+
+double FreqCounter::rate() const {
+	uint64_t ms = _timer->total_duration_ms();
+
+	if(_timer->overtime()) {
+		ms = _timer->preset_ms();
+	}
+
+	return static_cast<double>(_cnt) / (ms / 60.0e3);
+}
+
+
+double FreqCounter::overtime_rate() const {
+	return static_cast<double>(_overtime_cnt) / (_timer->total_duration_ms() / 60.0e3);
+}
+
+std::string FreqCounter::display_value() const {
+	if(_cnt == UINT32_MAX) {
+		return "ERR";
+	}
+
+	return std::to_string(_cnt);
+}
+
+void FreqCounter::inc() {
+
+	if(_overtime_cnt != UINT32_MAX)
+		_overtime_cnt++;
+
+	if(!_timer->overtime()) {
+		_cnt = _overtime_cnt;
+	}
+
+}
diff --git a/src/models/counter.hpp b/src/models/counter.hpp
new file mode 100644
index 0000000..d1b68fc
--- /dev/null
+++ b/src/models/counter.hpp
@@ -0,0 +1,33 @@
+#pragma once
+
+#include <inttypes.h>
+#include <string>
+#include "models/timer.hpp"
+
+class FreqCounter {
+
+	public:
+
+	FreqCounter(FreqTimer const & timer)
+		: _timer(&timer)
+	{}
+
+	void reset() { _cnt = _overtime_cnt = 0; }
+
+	void inc();
+
+	uint32_t cnt() const { return _cnt; }
+
+	[[nodiscard]] double rate() const;
+
+	[[nodiscard]] double overtime_rate() const;
+
+	[[nodiscard]] std::string display_value() const;
+
+
+	private:
+
+	uint32_t _cnt;
+	uint32_t _overtime_cnt;
+	FreqTimer const * _timer;
+};
diff --git a/src/models/timer.cpp b/src/models/timer.cpp
new file mode 100644
index 0000000..a05e8c1
--- /dev/null
+++ b/src/models/timer.cpp
@@ -0,0 +1,153 @@
+#include "timer.hpp"
+#include <cinttypes>
+
+#ifdef EMSCRIPTEN
+#include <emscripten/html5.h>
+#endif
+
+#ifdef TEST
+#define OVERRIDABLE_DURING_TESTING __attribute__((weak))
+#else
+#define OVERRIDABLE_DURING_TESTING static inline
+#endif
+
+
+OVERRIDABLE_DURING_TESTING uint64_t monotonic_timestamp_ms() {
+#ifdef EMSCRIPTEN
+	return emscripten_get_now();
+#else
+	return 0.0; // TODO: unimplemented
+#endif
+}
+
+namespace time_const {
+	static const int64_t MSEC = 1;
+	static const int64_t SEC = 1000 * MSEC;
+	static const int64_t MIN = 60 * SEC;
+	static const int64_t HOUR = 60 * MIN;
+};
+
+FreqTimer::FreqTimer() {
+	clear();
+}
+
+static void _append_ratio(std::string & display_val, int64_t & ms, int64_t ratio, bool two_digit = true) {
+	int64_t amount = ms / ratio;
+	ms -= amount * ratio;
+
+	char buf[3];
+
+	if(two_digit) {
+		snprintf(buf, sizeof(buf), "%02" PRIi64, amount);
+	} else {
+		snprintf(buf, sizeof(buf), "%1" PRIi64, amount);
+	}
+
+	display_val.append(buf);
+}
+
+std::string FreqTimer::counter_display_value() const {
+	using namespace time_const;
+
+	int64_t ms = time_ms();
+
+	std::string display_val;
+
+	if(ms < 0) {
+		display_val.append("+ ");
+		ms = -ms;
+	}
+
+	if(ms > 99 * HOUR) {
+		return "MAX TIME EXCEEDED";
+	}
+
+	_append_ratio(display_val, ms, HOUR);
+	display_val.append(" : ");
+	_append_ratio(display_val, ms, MIN);
+	display_val.append(" : ");
+	_append_ratio(display_val, ms, SEC);
+	display_val.append(".");
+	_append_ratio(display_val, ms, 100 * MSEC, false);
+
+	return display_val;
+}
+
+void FreqTimer::increment_preset_ms(uint64_t amount_ms) {
+	if(_state != State::SETTING) {
+		clear();
+	}
+
+	_preset_ms += amount_ms;
+}
+
+void FreqTimer::toggleStart() {
+	if(_state == State::RUNNING) {
+		_stop();
+	} else {
+		_start();
+	}
+}
+
+bool FreqTimer::has_preset() const {
+	return _preset_ms != 0;
+}
+
+void FreqTimer::reset() {
+	_time_offset_ms = 0;
+	_time_start_ms = monotonic_timestamp_ms();
+	_state = State::RESET;
+}
+
+void FreqTimer::clear() {
+	_time_offset_ms = 0;
+	_time_start_ms = monotonic_timestamp_ms();
+	_preset_ms = 0;
+	_state = State::SETTING;
+}
+
+double FreqTimer::record_floor() const {
+
+	int64_t ms;
+	if(has_preset()) {
+		ms = _preset_ms;
+	} else {
+		ms = total_duration_ms();
+	}
+
+	return 60.0e3 / ms;
+}
+
+double FreqTimer::overtime_record_floor() const {
+	return 60.0e3 / total_duration_ms();
+}
+
+uint64_t FreqTimer::_duration_since_last_stop_ms() const {
+	if(_state != State::RUNNING) {
+		return 0;
+	}
+
+	return monotonic_timestamp_ms() - _time_start_ms;
+}
+
+int64_t FreqTimer::time_ms() const {
+	if (_preset_ms == 0) {
+		return total_duration_ms();
+	}
+
+	return static_cast<int64_t>(_preset_ms) - total_duration_ms();
+}
+
+uint64_t FreqTimer::total_duration_ms() const {
+	return _time_offset_ms + _duration_since_last_stop_ms();
+}
+
+void FreqTimer::_stop() {
+	_time_offset_ms += _duration_since_last_stop_ms();
+	_state = State::STOPPED;
+}
+
+void FreqTimer::_start() {
+	_time_start_ms = monotonic_timestamp_ms();
+	_state = State::RUNNING;
+}
diff --git a/src/models/timer.hpp b/src/models/timer.hpp
new file mode 100644
index 0000000..0b0a978
--- /dev/null
+++ b/src/models/timer.hpp
@@ -0,0 +1,126 @@
+#pragma once
+
+#include <stdint.h>
+#include <string>
+
+class FreqTimer {
+	public:
+
+	FreqTimer();
+
+	/*
+	 * Starts the timer if stopped
+	 */
+	void toggleStart();
+
+	/*
+	 * Timer is running
+	 */
+	[[nodiscard]] bool running() const { return _state == State::RUNNING; }
+
+	/*
+	 * Timer has been started
+	 */
+	[[nodiscard]] bool started() const {
+		return _state == State::RUNNING or _state == State::STOPPED;
+	}
+
+	/*
+	 * Current preset in ms
+	 */
+	[[nodiscard]] int64_t preset_ms() const noexcept { return _preset_ms; }
+
+	/*
+	 * Whether the preset time has been exceeded
+	 */
+	[[nodiscard]] bool overtime() const { return time_ms() < 0; }
+
+	/*
+	 * Reset the time
+	 */
+	void reset();
+
+	/*
+	 * Reset the time and preset
+	 */
+	void clear();
+
+	[[nodiscard]] std::string counter_display_value() const;
+
+	/*
+	 * Lowest frequency which can be measured
+	 * in the interval (as measured in events/min
+	 * or multiples of 60 Hz)
+	 */
+	[[nodiscard]] double record_floor() const;
+
+
+	[[nodiscard]] double overtime_record_floor() const;
+
+	/*
+	 * Without a preset, the timer acts like a
+	 * stopwatch and counts freely from zero.
+	 * With a preset, the timer acts like a timer
+	 * counting down to zero, then counts up to
+	 * measure the number of seconds since the
+	 * timing has ended.
+	 */
+	[[nodiscard]] bool has_preset() const;
+
+	/*
+	 * The current duration in milliseconds.
+	 *
+	 * If the timer has exceeded the preset,
+	 * this time will be negative.
+	 */
+	[[nodiscard]] int64_t time_ms() const;
+
+	[[nodiscard]] uint64_t total_duration_ms() const;
+
+
+	/*
+	 * Increment the timer's preset by the specified
+	 * amount (in milisec.) Subsequent calls between
+	 * timings increment the time. Incrementing a
+	 * timing after a timing has been restarted will
+	 * reset the timing and start from zero.
+	 */
+	void increment_preset_ms(uint64_t amount_ms);
+
+	private:
+
+	enum class State {
+		// The timer initially starts in
+		// "setting" mode and the preset
+		// can be modified by incrementing
+		// it by values (measured in seconds)
+		//
+		// Once it is started, this preset
+		// is "sticky" and a reset returns
+		// the timer to the preset value.
+		// Incrementing the preset or clearing
+		// the timer moves the timer back
+		// into setting mode.
+		SETTING,
+		// Timer is active
+		RUNNING,
+		// Timer is temporarily stopped
+		STOPPED,
+		// Reset
+		RESET,
+	};
+
+	State _state;
+
+	uint64_t _time_offset_ms;
+	uint64_t _time_start_ms;
+
+	int64_t _preset_ms;
+
+	[[nodiscard]] uint64_t _duration_since_last_stop_ms() const;
+
+
+	void _stop();
+	void _start();
+
+};