Fix interaction and add comments to CollisionGroup (#8149)

Content.Shared/Interaction/SharedInteractionSystem.cs

@@ -48,6 +48,9 @@ namespace Content.Shared.Interaction
         [Dependency] private readonly SharedPhysicsSystem _physicsSystem = default!;
         [Dependency] protected readonly SharedContainerSystem ContainerSystem = default!;
 
+        private const CollisionGroup InRangeUnobstructedMask
+            = CollisionGroup.Impassable | CollisionGroup.InteractImpassable;
+
         public const float InteractionRange = 2;
         public const float InteractionRangeSquared = InteractionRange * InteractionRange;
 
@@ -329,7 +332,7 @@ namespace Content.Shared.Interaction
         public float UnobstructedDistance(
             MapCoordinates origin,
             MapCoordinates other,
-            int collisionMask = (int) CollisionGroup.Impassable,
+            int collisionMask = (int) InRangeUnobstructedMask,
             Ignored? predicate = null)
         {
             var dir = other.Position - origin.Position;
@@ -368,7 +371,7 @@ namespace Content.Shared.Interaction
             MapCoordinates origin,
             MapCoordinates other,
             float range = InteractionRange,
-            CollisionGroup collisionMask = CollisionGroup.Impassable,
+            CollisionGroup collisionMask = InRangeUnobstructedMask,
             Ignored? predicate = null)
         {
             // Have to be on same map regardless.
@@ -425,7 +428,7 @@ namespace Content.Shared.Interaction
             EntityUid origin,
             EntityUid other,
             float range = InteractionRange,
-            CollisionGroup collisionMask = CollisionGroup.Impassable,
+            CollisionGroup collisionMask = InRangeUnobstructedMask,
             Ignored? predicate = null,
             bool popup = false)
         {;
@@ -446,7 +449,7 @@ namespace Content.Shared.Interaction
             MapCoordinates origin,
             EntityUid target,
             float range = InteractionRange,
-            CollisionGroup collisionMask = CollisionGroup.Impassable,
+            CollisionGroup collisionMask = InRangeUnobstructedMask,
             Ignored? predicate = null)
         {
             var transform = Transform(target);
@@ -518,7 +521,7 @@ namespace Content.Shared.Interaction
             EntityUid origin,
             EntityCoordinates other,
             float range = InteractionRange,
-            CollisionGroup collisionMask = CollisionGroup.Impassable,
+            CollisionGroup collisionMask = InRangeUnobstructedMask,
             Ignored? predicate = null,
             bool popup = false)
         {
@@ -553,7 +556,7 @@ namespace Content.Shared.Interaction
             EntityUid origin,
             MapCoordinates other,
             float range = InteractionRange,
-            CollisionGroup collisionMask = CollisionGroup.Impassable,
+            CollisionGroup collisionMask = InRangeUnobstructedMask,
             Ignored? predicate = null,
             bool popup = false)
         {

Content.Shared/Physics/CollisionGroup.cs

@@ -7,6 +7,7 @@ namespace Content.Shared.Physics;
 
 /// <summary>
 ///     Defined collision groups for the physics system.
+///     Mask is what it collides with when moving. Layer is what CollisionGroup it is part of.
 /// </summary>
 [Flags, PublicAPI]
 [FlagsFor(typeof(CollisionLayer)), FlagsFor(typeof(CollisionMask))]
@@ -20,44 +21,59 @@ public enum CollisionGroup
     LowImpassable      = 1 << 4, // 16 For things that can fit under a table or squeeze under an airlock
     GhostImpassable    = 1 << 5, // 32 Things impassible by ghosts/observers, ie blessed tiles or forcefields
     BulletImpassable   = 1 << 6, // 64 Can be hit by bullets
+    InteractImpassable = 1 << 7, // 128 Blocks interaction/InRangeUnobstructed
 
     MapGrid = MapGridHelpers.CollisionGroup, // Map grids, like shuttles. This is the actual grid itself, not the walls or other entities connected to the grid.
 
     // 32 possible groups
     AllMask = -1,
 
+    // Humanoids, etc.
     MobMask = Impassable | HighImpassable | MidImpassable | LowImpassable,
     MobLayer = Opaque | BulletImpassable,
+    // Mice, drones
     SmallMobMask = Impassable | LowImpassable,
     SmallMobLayer = Opaque | BulletImpassable,
+    // Birds/other small flyers
     FlyingMobMask = Impassable,
     FlyingMobLayer = Opaque | BulletImpassable,
 
+    // Mechs
     LargeMobMask = Impassable | HighImpassable | MidImpassable | LowImpassable,
     LargeMobLayer = Opaque | HighImpassable | MidImpassable | LowImpassable | BulletImpassable,
 
+    // Machines, computers
     MachineMask = Impassable | MidImpassable | LowImpassable,
     MachineLayer = Opaque | MidImpassable | LowImpassable | BulletImpassable,
 
+    // Tables that SmallMobs can go under
     TableMask = Impassable | MidImpassable,
     TableLayer = MidImpassable,
 
+    // Tabletop machines, windoors, firelocks
     TabletopMachineMask = Impassable | HighImpassable,
+    // Tabletop machines
     TabletopMachineLayer = Opaque | HighImpassable | BulletImpassable,
 
-    GlassAirlockLayer = HighImpassable | MidImpassable | BulletImpassable,
+    // Airlocks, windoors, firelocks
+    GlassAirlockLayer = HighImpassable | MidImpassable | BulletImpassable | InteractImpassable,
     AirlockLayer = Opaque | GlassAirlockLayer,
 
+    // Airlock assembly
     HumanoidBlockLayer = HighImpassable | MidImpassable,
 
+    // Soap, spills
     SlipLayer = MidImpassable | LowImpassable,
     ItemMask = Impassable | HighImpassable,
     ThrownItem = Impassable | HighImpassable,
-    WallLayer = Opaque | Impassable | HighImpassable | MidImpassable | LowImpassable | BulletImpassable,
+    WallLayer = Opaque | Impassable | HighImpassable | MidImpassable | LowImpassable | BulletImpassable | InteractImpassable,
-    GlassLayer = Impassable | HighImpassable | MidImpassable | LowImpassable | BulletImpassable,
+    GlassLayer = Impassable | HighImpassable | MidImpassable | LowImpassable | BulletImpassable | InteractImpassable,
     HalfWallLayer = MidImpassable | LowImpassable,
-    FullTileMask = Impassable | HighImpassable | MidImpassable | LowImpassable,
+
-    FullTileLayer = Opaque | HighImpassable | MidImpassable | LowImpassable | BulletImpassable,
+    // Statue, monument, airlock, window
+    FullTileMask = Impassable | HighImpassable | MidImpassable | LowImpassable | InteractImpassable,
+    // FlyingMob can go past
+    FullTileLayer = Opaque | HighImpassable | MidImpassable | LowImpassable | BulletImpassable | InteractImpassable,
 
     SubfloorMask = Impassable | LowImpassable
 }