From bda602f4b0a214d860653754df8c616c081df347 Mon Sep 17 00:00:00 2001
From: Bouke Haarsma <bouke@haarsma.eu>
Date: Tue, 27 Sep 2022 17:34:55 +0200
Subject: [PATCH] Fix: reduce framerate overhead on train ticks

Tick() is a noop for all but front-engine / crashed vehicles. Starting a framerate is rather cheap, but not free, and introduces a lot of overhead for such close loops.
---
 src/train_cmd.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/train_cmd.cpp b/src/train_cmd.cpp
index 983b5ccd1c..e84ac6b8ea 100644
--- a/src/train_cmd.cpp
+++ b/src/train_cmd.cpp
@@ -3910,11 +3910,11 @@ Money Train::GetRunningCost() const
  */
 bool Train::Tick()
 {
-	PerformanceAccumulator framerate(PFE_GL_TRAINS);
-
 	this->tick_counter++;
 
 	if (this->IsFrontEngine()) {
+		PerformanceAccumulator framerate(PFE_GL_TRAINS);
+
 		if (!(this->vehstatus & VS_STOPPED) || this->cur_speed > 0) this->running_ticks++;
 
 		this->current_order_time++;