considerate bus stop behaviour

TLM/TLM/Patch/_NetLane/CalculateStopPositionAndDirection.cs

@@ -0,0 +1,42 @@
+namespace TrafficManager.Patch._NetLane; 
+using ColossalFramework.Math;
+using HarmonyLib;
+using System;
+using TrafficManager.Util;
+using UnityEngine;
+
+[HarmonyPatch(typeof(NetLane), nameof(NetLane.CalculateStopPositionAndDirection))]
+internal static class CalculateStopPositionAndDirection {
+    internal static bool Prefix(ref NetLane __instance, float laneOffset, float stopOffset, out Vector3 position, out Vector3 direction) {
+        try {
+            ref Bezier3 bezier = ref __instance.m_bezier;
+            position = bezier.Position(laneOffset);
+            direction = bezier.Tangent(laneOffset);
+            if (stopOffset != 0) {
+                Vector3 sideDir = Vector3.Cross(Vector3.up, direction).normalized;
+
+                const float t1 = 0.12f; // bus starts turning from this offset to avoid going over the pavement.
+                const float t2_0 = 0.20f; // bus does not finish turning until this offset to avoid going over the pavement
+                float t2 = t1 + 0.7f / (__instance.m_length + 1); // bus finishes turning at this offset for a smooth turn (if segment has space).
+                t2 = Mathf.Clamp(t2, t2_0, 0.5f);
+
+                float t = laneOffset <= 0.5f ? laneOffset : 1 - laneOffset;
+                float d;
+                if (t < t1) {
+                    d = 0;
+                } else if (t > t2) {
+                    d = 1;
+                } else {
+                    // t=[t1:t2] => d=[0:1]
+                    d = (t - t1) / (t2 - t1);
+                }
+
+                position += sideDir * stopOffset * d;
+            }
+            return false;
+        } catch (Exception ex) {
+            ex.LogException(true);
+            throw;
+        }
+    }
+}

TLM/TLM/TLM.csproj

@@ -158,6 +158,7 @@
     <Compile Include="Manager\Impl\LaneConnection\LaneEnd.cs" />
     <Compile Include="Patch\_CitizenAI\GetPathTargetPositionPatch.cs" />
     <Compile Include="Patch\_External\RTramAIModPatch.cs" />
+    <Compile Include="Patch\_NetLane\CalculateStopPositionAndDirection.cs" />
     <Compile Include="Patch\_PedestrianZoneRoadAI\BollardSimulationStepPatch.cs" />
     <Compile Include="Patch\_VehicleAI\InvalidPathPatch.cs" />
     <Compile Include="Patch\_VehicleAI\_BusAI\CalculateSegmentPositionPatch.cs" />