From af8476c4ba71b3cb55844b3a10698a294253fe0e Mon Sep 17 00:00:00 2001
From: Thomas <thomas.rubini@pm.me>
Date: Thu, 6 Jan 2022 13:41:51 +0100
Subject: [PATCH] New FPS system, editable in config

---
 config.yml               |  4 ++++
 headers/configData.h     |  3 +++
 src/configManagement.cpp |  2 ++
 src/game/gameBasics.cpp  | 26 ++++++++++++++------------
 4 files changed, 23 insertions(+), 12 deletions(-)

diff --git a/config.yml b/config.yml
index 24b0bbb..c11844d 100644
--- a/config.yml
+++ b/config.yml
@@ -1,3 +1,7 @@
+# General configuration
+general:
+ maxFPS: 50
+
 # Players config
 players:
  width: 250
diff --git a/headers/configData.h b/headers/configData.h
index 02dd67c..38dae41 100644
--- a/headers/configData.h
+++ b/headers/configData.h
@@ -10,6 +10,9 @@ typedef string configKey;
 
 struct ConfigData {
 
+	unsigned maxFPS;
+
+
 	InvadersGrid grid;
 
 	unsigned startXPosition;
diff --git a/src/configManagement.cpp b/src/configManagement.cpp
index 7656bdd..e621bc7 100644
--- a/src/configManagement.cpp
+++ b/src/configManagement.cpp
@@ -160,6 +160,8 @@ void ConfigBuilder::readInvaderType(const configKey& baseKey, InvaderTypeDef& in
 
 void ConfigBuilder::readConfig() {
 
+	collectedData.maxFPS = getInt("general.maxFPS");
+
 	readGrid("grid");
 
 	// players
diff --git a/src/game/gameBasics.cpp b/src/game/gameBasics.cpp
index c8a2d86..3fba575 100644
--- a/src/game/gameBasics.cpp
+++ b/src/game/gameBasics.cpp
@@ -84,14 +84,19 @@ WinValue Game::playGame(){ // returns when game is finished
 	basePos = Position(200, 0);
 	// GAMELOOP
 
-	const int MAX_FPS = 60;
+	// computed in advance for performance reasons
+	chrono::milliseconds maxFrameTime = chrono::milliseconds(1000/confData.maxFPS);
 
-	chrono::milliseconds fpsTime;
 	unsigned tmpFps = 0;
 	unsigned fps = 0;
+	typedef chrono::high_resolution_clock::time_point MyTimePoint;
+	MyTimePoint fpsStartTime = {};
 	while(window.isOpen()){
 
-		chrono::time_point startTime = chrono::high_resolution_clock::now();
+		MyTimePoint startTime = chrono::high_resolution_clock::now();
+		if(fpsStartTime.time_since_epoch()==chrono::seconds(0)){
+			fpsStartTime = startTime;
+		}
 
 		pm.startFrame();
 
@@ -118,19 +123,16 @@ WinValue Game::playGame(){ // returns when game is finished
 
 		pm.endFrame();
 
-		chrono::time_point endTime = chrono::high_resolution_clock::now();
-		chrono::milliseconds frameTime = chrono::duration_cast<chrono::milliseconds>(endTime-startTime);
-		fpsTime = fpsTime + frameTime;
-		if(fpsTime>chrono::seconds(1)){
+		MyTimePoint endTime = chrono::high_resolution_clock::now();
+
+		// This code is counted as part of frames, but that's not really something we can control
+		if(fpsStartTime+chrono::seconds(1) < endTime){
 			fps = tmpFps;
 			tmpFps = 0;
-			fpsTime = chrono::milliseconds(0);
+			fpsStartTime = {};
 		}else ++tmpFps;
 
-		// old implementation, too volatile
-//		cout << "FPS : " << chrono::milliseconds(1000)/frameTime << endl;
-
-		this_thread::sleep_until(startTime+chrono::duration<double, ratio<1, MAX_FPS>>(1));
+		this_thread::sleep_until(startTime+maxFrameTime);
 	}
 	return WinValue::NOBODY;
 }