Fix hitscan visuals

Content.Client/Weapons/Ranged/Systems/GunSystem.cs

@@ -37,6 +37,7 @@ public sealed partial class GunSystem : SharedGunSystem
     [Dependency] private readonly InputSystem _inputSystem = default!;
     [Dependency] private readonly SharedCameraRecoilSystem _recoil = default!;
     [Dependency] private readonly SharedMapSystem _maps = default!;
+    [Dependency] private readonly SharedTransformSystem _xform = default!;
 
     [ValidatePrototypeId<EntityPrototype>]
     public const string HitscanProto = "HitscanEffect";
@@ -102,20 +103,32 @@ private void OnMuzzleFlash(MuzzleFlashEvent args)
     private void OnHitscan(HitscanEvent ev)
     {
         // ALL I WANT IS AN ANIMATED EFFECT
+
+        // This is very jank
+        // because the effect consists of three unrelatd entities, the hitscan beam can be split appart.
+        // E.g., if a grid rotates while part of the beam is parented to the grid, and part of it is parented to the map.
+        // Ideally, there should only be one entity, with one sprite that has multiple layers
+        // Or at the very least, have the other entities parented to the same entity to make sure they stick together.
+        // TODO EFFECTS
+        // Fix this jank
         foreach (var a in ev.Sprites)
         {
             if (a.Sprite is not SpriteSpecifier.Rsi rsi)
                 continue;
 
             var coords = GetCoordinates(a.coordinates);
 
-            if (Deleted(coords.EntityId))
+            if (!TryComp(coords.EntityId, out TransformComponent? relativeXform))
                 continue;
 
             var ent = Spawn(HitscanProto, coords);
             var sprite = Comp<SpriteComponent>(ent);
+
             var xform = Transform(ent);
-            xform.LocalRotation = a.angle;
+            var targetWorldRot = a.angle + _xform.GetWorldRotation(relativeXform);
+            var delta = targetWorldRot - _xform.GetWorldRotation(xform);
+            _xform.SetLocalRotationNoLerp(ent, xform.LocalRotation + delta, xform);
+
             sprite[EffectLayers.Unshaded].AutoAnimated = false;
             sprite.LayerSetSprite(EffectLayers.Unshaded, rsi);
             sprite.LayerSetState(EffectLayers.Unshaded, rsi.RsiState);

Content.Server/Weapons/Ranged/Systems/GunSystem.cs

@@ -396,48 +396,45 @@ private void FireEffects(EntityCoordinates fromCoordinates, float distance, Angl
         // Forgive me for the shitcode I am about to do
         // Effects tempt me not
         var sprites = new List<(NetCoordinates coordinates, Angle angle, SpriteSpecifier sprite, float scale)>();
-        var gridUid = fromCoordinates.GetGridUid(EntityManager);
+        var fromXform = Transform(fromCoordinates.EntityId);
         var angle = mapDirection;
 
         // We'll get the effects relative to the grid / map of the firer
         // Look you could probably optimise this a bit with redundant transforms at this point.
-        var xformQuery = GetEntityQuery<TransformComponent>();
 
-        if (xformQuery.TryGetComponent(gridUid, out var gridXform))
+        var gridUid = fromXform.GridUid;
+        if (gridUid != fromCoordinates.EntityId && TryComp(gridUid, out TransformComponent? gridXform))
         {
-            var (_, gridRot, gridInvMatrix) = TransformSystem.GetWorldPositionRotationInvMatrix(gridXform, xformQuery);
-
-            fromCoordinates = new EntityCoordinates(gridUid.Value,
-                Vector2.Transform(fromCoordinates.ToMapPos(EntityManager, TransformSystem), gridInvMatrix));
-
-            // Use the fallback angle I guess?
+            var (_, gridRot, gridInvMatrix) = TransformSystem.GetWorldPositionRotationInvMatrix(gridXform);
+            var map = _transform.ToMapCoordinates(fromCoordinates);
+            fromCoordinates = new EntityCoordinates(gridUid.Value, Vector2.Transform(map.Position, gridInvMatrix));
             angle -= gridRot;
         }
+        else
+        {
+            angle -= _transform.GetWorldRotation(fromXform);
+        }
 
+        var fromNetCoords = GetNetCoordinates(fromCoordinates);
+        var dir = angle.ToVec();
         if (distance >= 1f)
         {
             if (hitscan.MuzzleFlash != null)
             {
-                var coords = fromCoordinates.Offset(angle.ToVec().Normalized() / 2);
-                var netCoords = GetNetCoordinates(coords);
-
+                var netCoords = new NetCoordinates(fromNetCoords.NetEntity, fromNetCoords.Position + dir / 2);
                 sprites.Add((netCoords, angle, hitscan.MuzzleFlash, 1f));
             }
 
             if (hitscan.TravelFlash != null)
             {
-                var coords = fromCoordinates.Offset(angle.ToVec() * (distance + 0.5f) / 2);
-                var netCoords = GetNetCoordinates(coords);
-
+                var netCoords = new NetCoordinates(fromNetCoords.NetEntity, fromNetCoords.Position + dir * (distance + 0.5f) / 2);
                 sprites.Add((netCoords, angle, hitscan.TravelFlash, distance - 1.5f));
             }
         }
 
         if (hitscan.ImpactFlash != null)
         {
-            var coords = fromCoordinates.Offset(angle.ToVec() * distance);
-            var netCoords = GetNetCoordinates(coords);
-
+            var netCoords = new NetCoordinates(fromNetCoords.NetEntity,fromNetCoords.Position + dir * distance);
             sprites.Add((netCoords, angle.FlipPositive(), hitscan.ImpactFlash, 1f));
         }