Add SpawnIfUnobstructed IEntityManager extension method (#3165)

* Add SpawnIfUnobstructed IEntityManager extension method * Clarify test comments * Use GetCollidingEntities * Enable nullable in test
2021-02-13 17:52:06 +01:00
parent 18584d77fd
commit a296a5b9b9
2 changed files with 167 additions and 0 deletions
--- a/Content.Shared/Utility/EntitySystemExtensions.cs
+++ b/Content.Shared/Utility/EntitySystemExtensions.cs
@@ -0,0 +1,85 @@
+#nullable enable
+using System.Diagnostics.CodeAnalysis;
+using Content.Shared.Physics;
+using Robust.Shared.GameObjects;
+using Robust.Shared.IoC;
+using Robust.Shared.Map;
+using Robust.Shared.Maths;
+using Robust.Shared.Physics;
+
+namespace Content.Shared.Utility
+{
+    public static class EntitySystemExtensions
+    {
+        public static IEntity? SpawnIfUnobstructed(
+            this IEntityManager entityManager,
+            string? prototypeName,
+            EntityCoordinates coordinates,
+            CollisionGroup collisionLayer,
+            in Box2? box = null,
+            IPhysicsManager? physicsManager = null)
+        {
+            physicsManager ??= IoCManager.Resolve<IPhysicsManager>();
+            var mapCoordinates = coordinates.ToMap(entityManager);
+
+            return entityManager.SpawnIfUnobstructed(prototypeName, mapCoordinates, collisionLayer, box, physicsManager);
+        }
+
+        public static IEntity? SpawnIfUnobstructed(
+            this IEntityManager entityManager,
+            string? prototypeName,
+            MapCoordinates coordinates,
+            CollisionGroup collisionLayer,
+            in Box2? box = null,
+            IPhysicsManager? physicsManager = null)
+        {
+            var boxOrDefault = box.GetValueOrDefault(Box2.UnitCentered);
+            physicsManager ??= IoCManager.Resolve<IPhysicsManager>();
+
+            foreach (var body in physicsManager.GetCollidingEntities(coordinates.MapId, in boxOrDefault))
+            {
+                if (!body.Hard)
+                {
+                    continue;
+                }
+
+                if (collisionLayer == 0 || (body.CollisionMask & (int) collisionLayer) == 0)
+                {
+                    continue;
+                }
+
+                return null;
+            }
+
+            return entityManager.SpawnEntity(prototypeName, coordinates);
+        }
+
+        public static bool TrySpawnIfUnobstructed(
+            this IEntityManager entityManager,
+            string? prototypeName,
+            EntityCoordinates coordinates,
+            CollisionGroup collisionLayer,
+            [NotNullWhen(true)] out IEntity? entity,
+            Box2? box = null,
+            IPhysicsManager? physicsManager = null)
+        {
+            entity = entityManager.SpawnIfUnobstructed(prototypeName, coordinates, collisionLayer, box, physicsManager);
+
+            return entity != null;
+        }
+
+        public static bool TrySpawnIfUnobstructed(
+            this IEntityManager entityManager,
+            string? prototypeName,
+            MapCoordinates coordinates,
+            CollisionGroup collisionLayer,
+            [NotNullWhen(true)] out IEntity? entity,
+            in Box2? box = null,
+            IPhysicsManager? physicsManager = null)
+        {
+            entity = entityManager.SpawnIfUnobstructed(prototypeName, coordinates, collisionLayer, box, physicsManager);
+
+            return entity != null;
+        }
+    }
+}