1 files changed, 90 insertions, 0 deletions
diff --git a/src/crepe/manager/LoopTimerManager.cpp b/src/crepe/manager/LoopTimerManager.cpp
new file mode 100644
index 0000000..9c77785
--- /dev/null
+++ b/src/crepe/manager/LoopTimerManager.cpp
@@ -0,0 +1,90 @@
+#include <chrono>
+#include <thread>
+
+#include "../facade/SDLContext.h"
+#include "../util/Log.h"
+
+#include "LoopTimerManager.h"
+
+using namespace crepe;
+
+LoopTimerManager::LoopTimerManager(Mediator & mediator) : Manager(mediator) {
+	this->mediator.loop_timer = *this;
+	dbg_trace();
+}
+
+void LoopTimerManager::start() {
+	this->last_frame_time = std::chrono::steady_clock::now();
+
+	this->elapsed_time = std::chrono::milliseconds(0);
+	// by starting the elapsed_fixed_time at (0 - fixed_delta_time) in milliseconds it calls a fixed update at the start of the loop.
+	this->elapsed_fixed_time
+		= -std::chrono::duration_cast<std::chrono::milliseconds>(fixed_delta_time);
+	this->delta_time = std::chrono::milliseconds(0);
+}
+
+void LoopTimerManager::update() {
+	auto current_frame_time = std::chrono::steady_clock::now();
+	// Convert to duration in seconds for delta time
+	this->delta_time = std::chrono::duration_cast<std::chrono::duration<double>>(
+		current_frame_time - last_frame_time);
+
+	if (this->delta_time > this->maximum_delta_time) {
+		this->delta_time = this->maximum_delta_time;
+	}
+	this->actual_fps = 1.0 / this->delta_time.count();
+
+	this->elapsed_time += this->delta_time;
+	this->last_frame_time = current_frame_time;
+}
+
+double LoopTimerManager::get_delta_time() const {
+	return this->delta_time.count() * this->time_scale;
+}
+
+double LoopTimerManager::get_current_time() const { return this->elapsed_time.count(); }
+
+void LoopTimerManager::advance_fixed_update() {
+	this->elapsed_fixed_time += this->fixed_delta_time;
+}
+
+void LoopTimerManager::set_target_fps(int fps) {
+	this->target_fps = fps;
+	// target time per frame in seconds
+	this->frame_target_time = std::chrono::duration<double>(1.0) / this->target_fps;
+}
+
+int LoopTimerManager::get_fps() const { return this->actual_fps; }
+
+void LoopTimerManager::set_time_scale(double value) { this->time_scale = value; }
+
+double LoopTimerManager::get_time_scale() const { return this->time_scale; }
+
+void LoopTimerManager::enforce_frame_rate() {
+	auto current_frame_time = std::chrono::steady_clock::now();
+	auto frame_duration = current_frame_time - this->last_frame_time;
+
+	// Check if frame duration is less than the target frame time
+	if (frame_duration < this->frame_target_time) {
+		auto delay_time = std::chrono::duration_cast<std::chrono::microseconds>(
+			this->frame_target_time - frame_duration);
+
+		if (delay_time.count() > 0) {
+			std::this_thread::sleep_for(delay_time);
+		}
+	}
+}
+
+double LoopTimerManager::get_lag() const {
+	return (this->elapsed_time - this->elapsed_fixed_time).count();
+}
+double LoopTimerManager::get_fixed_delta_time() const {
+	return this->fixed_delta_time.count() * this->time_scale;
+}
+void LoopTimerManager::set_fixed_delta_time(int seconds) {
+	this->fixed_delta_time = std::chrono::duration<double>(seconds);
+}
+
+double LoopTimerManager::get_fixed_loop_interval() const {
+	return this->fixed_delta_time.count();
+}