Merge branch 'master' into expl_int_analyzer

Content.Shared/Construction/ConstructionConditions/WallmountCondition.cs

@@ -0,0 +1,56 @@
+#nullable enable
+using Content.Shared.GameObjects.Components.Tag;
+using Content.Shared.Physics;
+using JetBrains.Annotations;
+using Robust.Shared.Interfaces.GameObjects;
+using Robust.Shared.Interfaces.Physics;
+using Robust.Shared.IoC;
+using Robust.Shared.Map;
+using Robust.Shared.Maths;
+using Robust.Shared.Serialization;
+using System.Linq;
+using Robust.Shared.Interfaces.Serialization;
+
+namespace Content.Shared.Construction.ConstructionConditions
+{
+    [UsedImplicitly]
+    public class WallmountCondition : IConstructionCondition
+    {
+        void IExposeData.ExposeData(ObjectSerializer serializer) { }
+
+        public bool Condition(IEntity user, EntityCoordinates location, Direction direction)
+        {
+            var entManager = IoCManager.Resolve<IEntityManager>();
+
+            // get blueprint and user position
+            var userWorldPosition = user.Transform.WorldPosition;
+            var objWorldPosition = location.ToMap(entManager).Position;
+
+            // find direction from user to blueprint
+            var userToObject = (objWorldPosition - userWorldPosition);
+
+            // dot product will be positive if user direction and blueprint are co-directed
+            var dotProd = Vector2.Dot(direction.ToVec(), userToObject);
+            if (dotProd > 0)
+                return false;
+
+            // now we need to check that user actually tries to build wallmount on a wall
+            var physics = IoCManager.Resolve<IPhysicsManager>();
+            var rUserToObj = new CollisionRay(userWorldPosition, userToObject.Normalized, (int) CollisionGroup.Impassable);
+            var length = userToObject.Length;
+            var userToObjRaycastResults = physics.IntersectRayWithPredicate(user.Transform.MapID, rUserToObj, maxLength: length,
+                predicate: (e) => !e.HasTag("Wall"));
+            if (!userToObjRaycastResults.Any())
+                return false;
+
+            // get this wall entity
+            var targetWall = userToObjRaycastResults.First().HitEntity;
+
+            // check that we didn't try to build wallmount that facing another adjacent wall
+            var rAdjWall = new CollisionRay(objWorldPosition, direction.ToVec(), (int) CollisionGroup.Impassable);
+            var adjWallRaycastResults = physics.IntersectRayWithPredicate(user.Transform.MapID, rAdjWall, maxLength: 0.5f,
+               predicate: (e) => e == targetWall || !e.HasTag("Wall"));
+            return !adjWallRaycastResults.Any();
+        }
+    }
+}