From 69a70cb7fb2aea028b52e086eb854d32d3598762 Mon Sep 17 00:00:00 2001
From: peternewell <peter_new123@yahoo.com.au>
Date: Sun, 3 Oct 2021 17:01:05 +1100
Subject: [PATCH] Adjust Train Driver Window to line up with HuD operation of
 derailment window.

---
 .../Viewer3D/Popups/TrainDrivingWindow.cs     | 53 +++++++++++--------
 1 file changed, 32 insertions(+), 21 deletions(-)

diff --git a/Source/RunActivity/Viewer3D/Popups/TrainDrivingWindow.cs b/Source/RunActivity/Viewer3D/Popups/TrainDrivingWindow.cs
index 09e0214174..f8b529d1ef 100644
--- a/Source/RunActivity/Viewer3D/Popups/TrainDrivingWindow.cs
+++ b/Source/RunActivity/Viewer3D/Popups/TrainDrivingWindow.cs
@@ -1178,47 +1178,58 @@ void AddSeparator() => AddLabel(new ListLabel
             }
 
             //Derailment Coefficient. Changed the float value output by a text label.
-            var maxDerailCoeff = 0.0f;
             var carIDerailCoeff = "";
+            var carDerailPossible = false;
+            var carDerailExpected = false;
+
             for (var i = 0; i < train.Cars.Count; i++)
             {
                 var carDerailCoeff = train.Cars[i].DerailmentCoefficient;
                 carDerailCoeff = float.IsInfinity(carDerailCoeff) || float.IsNaN(carDerailCoeff) ? 0 : carDerailCoeff;
-                if (carDerailCoeff > maxDerailCoeff)
+
+                carIDerailCoeff = train.Cars[i].CarID;
+
+                // Only record the first car that has derailed, stop looking for other derailed cars
+                carDerailExpected = train.Cars[i].DerailExpected;
+                if (carDerailExpected)
+                {
+                    break;
+                }
+
+                // Only record first instance of a possible car derailment (warning)
+                if (train.Cars[i].DerailPossible && !carDerailPossible)
                 {
-                    maxDerailCoeff = carDerailCoeff;
-                    carIDerailCoeff = train.Cars[i].CarID;
+                    carDerailPossible = train.Cars[i].DerailPossible;
                 }
             }
 
-            if (maxDerailCoeff > 0.66)
+            if (carDerailPossible || carDerailExpected)
             {
                 derailLabelVisible = true;
                 clockDerailTime = Owner.Viewer.Simulator.ClockTime;
             }
 
-            if (maxDerailCoeff > 0.66)
+            // The most extreme instance of the derail coefficient will only be displayed in the TDW
+            if (carDerailExpected)
             {
-                if (maxDerailCoeff > 1)
+                AddLabel(new ListLabel
                 {
-                    AddLabel(new ListLabel
-                    {
-                        FirstCol = Viewer.Catalog.GetString("DerailCoeff"),
-                        LastCol = $"{Viewer.Catalog.GetString("Derailed")} {carIDerailCoeff}" + ColorCode[Color.OrangeRed],
-                    });
-                }
-                else if (maxDerailCoeff < 1 && maxDerailCoeff > 0.66)
+                    FirstCol = Viewer.Catalog.GetString("DerailCoeff"),
+                    LastCol = $"{Viewer.Catalog.GetString("Derailed")} {carIDerailCoeff}" + ColorCode[Color.OrangeRed],
+                });
+            }
+            else if (carDerailPossible)
+            {
+                AddLabel(new ListLabel
                 {
-                    AddLabel(new ListLabel
-                    {
-                        FirstCol = Viewer.Catalog.GetString("DerailCoeff"),
-                        LastCol = $"{Viewer.Catalog.GetString("Warning")} {carIDerailCoeff}" + ColorCode[Color.Yellow],
-                    });
-                }
+                    FirstCol = Viewer.Catalog.GetString("DerailCoeff"),
+                    LastCol = $"{Viewer.Catalog.GetString("Warning")} {carIDerailCoeff}" + ColorCode[Color.Yellow],
+                });
             }
+
             else
             {
-                // delay to hide the derailcoeff label
+                // delay to hide the derailcoeff label if normal
                 if (derailLabelVisible && clockDerailTime + 3 < Owner.Viewer.Simulator.ClockTime)
                     derailLabelVisible = false;