From b8969cde39c1866a621eba9f9d97bc3af7d7408c Mon Sep 17 00:00:00 2001
From: CuriouslyCurious <thecuriouslycurious@protonmail.com>
Date: Mon, 15 Dec 2025 17:54:36 +0100
Subject: [PATCH] Add sleep to game loop

This should ensure that the program does not hog up an entire CPU core just to get the current time.
---
 client/src/main/java/rt4/GameShell.java   | 11 ++++++++++-
 client/src/main/java/rt4/ThreadUtils.java |  5 +++++
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/client/src/main/java/rt4/GameShell.java b/client/src/main/java/rt4/GameShell.java
index 80a799d..a28f006 100644
--- a/client/src/main/java/rt4/GameShell.java
+++ b/client/src/main/java/rt4/GameShell.java
@@ -613,6 +613,7 @@ public abstract class GameShell extends Applet implements Runnable, FocusListene
 
 			long lastUpdateTime = 0;
 			long lastDrawTime = 0;
+			long nextUpdate = 0;
 			while (killTime == 0L) {
 				if (GameShell.killTime > MonotonicClock.currentTimeMillis()) {
 					break;
@@ -621,6 +622,14 @@ public abstract class GameShell extends Applet implements Runnable, FocusListene
 				long currentTime = System.nanoTime();
 
 				updateDelta = currentTime - lastUpdateTime;
+				renderDelta = currentTime - lastDrawTime;
+
+				nextUpdate = Math.min(FIXED_UPDATE_RATE_NS - updateDelta, VARIABLE_RENDER_RATE_NS - renderDelta);
+				// Convert from ns to ms
+				nextUpdate /= 1_000_000;
+				ThreadUtils.sleep(nextUpdate);
+
+				// Game update
 				if (updateDelta >= FIXED_UPDATE_RATE_NS) {
 					logicCycles = timer.count(minimumDelay, (int) FIXED_UPDATE_RATE);
 					for (int cycle = 0; cycle < logicCycles; ++cycle) {
@@ -630,7 +639,7 @@ public abstract class GameShell extends Applet implements Runnable, FocusListene
 					flush(signLink, canvas);
 				}
 
-				renderDelta = currentTime - lastDrawTime;
+				// Render update
 				if (renderDelta >= VARIABLE_RENDER_RATE_NS) {
 					this.mainInputLoop();
 					this.mainRedrawWrapper();
diff --git a/client/src/main/java/rt4/ThreadUtils.java b/client/src/main/java/rt4/ThreadUtils.java
index ae4c3cf..3fe9905 100644
--- a/client/src/main/java/rt4/ThreadUtils.java
+++ b/client/src/main/java/rt4/ThreadUtils.java
@@ -5,6 +5,11 @@ import org.openrs2.deob.annotation.OriginalMember;
 import org.openrs2.deob.annotation.Pc;
 
 public class ThreadUtils {
+	/**
+	 * Sleeps the current thread for a set amount of milliseconds.
+	 *
+	 * @param arg0. Time in milliseconds to sleep for.
+	*/
 	@OriginalMember(owner = "client!sk", name = "a", descriptor = "(JI)V")
 	public static void sleep(@OriginalArg(0) long arg0) {
 		if (arg0 <= 0L) {