Refresh Vector Lines Cache on each draw

CHANGELOG.md

@@ -8,6 +8,7 @@
 - Improved the **FastLoader** second config pass by refreshing GameData directories in parallel and using faster filesystem functions.
 
 **Bug Fixes**
+- **OptimisedVectorLines** : Fixed orbit and CommNet lines lagging the camera by a frame, seen as the lines sliding against the bodies whenever the camera moved. The cached camera projection matrix was scoped to a frame and filled lazily by whichever `LateUpdate` drew first. Every Vectrosity consumer draws from its own `LateUpdate` and the cameras move during `LateUpdate` too, with no defined order between them, so a draw issued before the camera moved would pin the previous frame's pose for every line drawn after it. The cache is now refreshed per draw call.
 - **BlockMapViewPartClick** : Fixed a `NullReferenceException` thrown from `Part.UpdateMouseOver` on every frame of a scene load into flight. The scene reports itself as flight well before `CameraManager.Instance` exists, and both the patch and stock dereferenced it unconditionally. `Part.UpdateMouseOver` is now skipped until there is a camera manager.
 - **EditorAnimatedPartsShipModified** : Fixed a memory leak ([issue #396](https://github.com/KSPModdingLibs/KSPCommunityFixes/issues/396)) where listeners were not properly cleaned up.
 - **EditorAnimatedPartsShipModified** : This patch is now disabled if DMagic Orbital Science is installed because DMagic Orbital Science has a bug that causes a stack overflow crash if you ever call `DMSoilMoisture.OnStop`, which this patch does.

KSPCommunityFixes/Performance/OptimisedVectorLines.cs

@@ -29,6 +29,9 @@ protected override void ApplyPatches()
             AddPatch(PatchType.Transpiler, typeof(VectorLine), nameof(VectorLine.IntersectAndDoSkip));
 
             AddPatch(PatchType.Transpiler, typeof(VectorLine), nameof(VectorLine.Draw3D));
+
+            AddPatch(PatchType.Prefix, typeof(VectorLine), nameof(VectorLine.Draw3D));
+            AddPatch(PatchType.Prefix, typeof(VectorLine), nameof(VectorLine.Draw));
         }
 
         #region VectorLine Patches
@@ -42,6 +45,17 @@ static IEnumerable<CodeInstruction> VectorLine_BehindCamera_Transpiler(IEnumerab
         static IEnumerable<CodeInstruction> VectorLine_IntersectAndDoSkip_Transpiler(IEnumerable<CodeInstruction> instructions) =>
             ReplaceWorldToScreenPoint(instructions, 2);
 
+        // Because draw calls originate from multiple LateUpdate methods with unpredictable
+        // execution orders, the camera pose might change mid-frame. To ensure consistency,
+        // we scope the cache strictly to a single draw call.
+        static void VectorLine_Draw3D_Prefix() => VectorLineCameraProjection.UpdateCache();
+
+        static void VectorLine_Draw_Prefix(VectorLine __instance)
+        {
+            if (!__instance.is2D)
+                VectorLineCameraProjection.UpdateCache();
+        }
+
         static IEnumerable<CodeInstruction> VectorLine_Draw3D_Transpiler(IEnumerable<CodeInstruction> instructions)
         {
             instructions = ReplaceWorldToScreenPoint(instructions, 2);
@@ -145,7 +159,7 @@ public ViewportInfo(Rect viewport)
 
         private static ViewportInfo viewport;
 
-        private static void UpdateCache()
+        internal static void UpdateCache()
         {
             lastCachedFrame = KSPCommunityFixes.UpdateCount;
             Camera camera = VectorLine.cam3D;