adding timer to engine instead of separate thread

CMakeLists.txt

@@ -7,7 +7,6 @@ project(pong)
 set(SOURCES
 	src/main.cpp
 	src/engine.cpp
-	src/timer.cpp
 )
 add_executable(pong ${SOURCES})
 

include/engine.hpp

@@ -2,6 +2,7 @@
 #define ENGINE_HPP
 
 #include <array>
+#include <chrono>
 #include <ncurses.h>
 
 constexpr int ROW = 15;
@@ -43,12 +44,13 @@ public:
 
 private:
 	Window win;
-	int time_seconds { 30 };
+	int clock { 30 };
 	vec2 score { 0, 0 };
 	vec2 ball { (COL / 2), (ROW / 2) };
 	vec2 ball_direction { 1, 1 };
 	Paddle p1 { { 1, (ROW / 2) - (SIZE / 2) } };
 	Paddle p2 { { COL - 2, (ROW / 2) - (SIZE / 2) } };
+	std::chrono::steady_clock::time_point last_clock_update;
 
 	bool exit_process();
 	bool process_input();

include/timer.hpp

@@ -1,8 +0,0 @@
-#ifndef TIMER_HPP
-#define TIMER_HPP
-
-struct Timer {
-	void decrement_time(int &time, bool &running);
-};
-
-#endif

src/engine.cpp

@@ -52,6 +52,7 @@ Engine::Engine() {
 	noecho();
 	curs_set(0);
 	nodelay(stdscr, true);
+	last_clock_update = std::chrono::steady_clock::now();
 }
 
 void Engine::on_collision_with_ball() {
@@ -82,7 +83,13 @@ void Engine::run() {
 		win.clear_display();
 		win.update_display(ball, p1, p2);
 		win.draw_display();
-		std::cout << "Time left: " << time_seconds << ", Score ( " << score.a << " : " << score.b << " )\n";
+		auto current_time = std::chrono::steady_clock::now();
+		auto elapsed_time = std::chrono::duration_cast<std::chrono::seconds>(current_time - last_clock_update).count();
+		if(elapsed_time >= 1) {
+			clock -= elapsed_time;
+			last_clock_update = current_time;
+		}
+		std::cout << "Time left: " << clock << ", Score ( " << score.a << " : " << score.b << " )\n";
 		std::this_thread::sleep_for(std::chrono::milliseconds(150)); // 1000 / fps; 200ms = 5fps
 	}
 }

src/timer.cpp

@@ -1,10 +0,0 @@
-#include <thread>
-#include <chrono>
-#include "timer.hpp"
-
-void Timer::decrement_time(int &time, bool &running) {
-	while (running) {
-		std::this_thread::sleep_for(std::chrono::seconds(1));
-		time--;
-	}
-}