Allow Smellers to smell Scent bearers directly (#5544)

## Short description
<!-- What do you propose to change with your PR? -->
Allow a Smeller to smell someone directly if they have a Scent.

## Why we need to add this
<!-- What is the reason for adding these changes? Please post links to
Discussions as well as Bug Reports here. Please describe how this will
change the game balance. -->
It made the most sense to do this. The current way you smell someone
directly is by hugging them and then smelling yourself. Very weird and
unintuitive action.
This turned out to be more effort than I had anticipated, and I was
gonna bundle this in with a few extra things like an olfactory implant.
Turns out these are all a bit chunky so I'm gonna part these out for
easier review and handling.

## Media (Video/Screenshots)
<!--
If your PR contains in-game changes you must provide screenshots/videos
of the changes.
-->
<img width="635" height="324" alt="image"
src="https://github.com/user-attachments/assets/40fb71b2-77cc-43b0-87d0-8127ebdaffa6"
/>


## Checks
<!-- check boxes for faster reviewing of your PR -->

- [X] I do not require assistance to complete the PR.
- [X] Before posting/requesting review of a PR, I have verified that the
changes work.
- [X] I have added screenshots/videos of the changes, or this PR does
not change in-game mechanics.
- [X] I affirm that my changes are licensed under the [MIT
License](https://github.com/ss14Starlight/space-station-14/blob/Starlight/LICENSE.TXT)
and grant permission for use in this repository under its conditions.

**Changelog**

:cl: Sparlight
- add: Individuals that can smell can now smell anything with a scent
directly now, in addition to the scent traces left behind on them.
<!--
If you want the players to know about changes made in this PR, specify
them using the template outside the comment. Short and informative.

:cl: STARLIGHT TEAM
- add: Added Starlight.
- remove: Removed SS13.
- tweak: Changed SS14.
- fix: Fixed Rinary.
-->

Author: Sparlight

Content.Client/_Starlight/Scent/ScentSniffBoundUserInterface.cs

@@ -31,6 +31,6 @@ protected override void UpdateState(BoundUserInterfaceState state)
         if (_window == null || state is not ScentSniffBoundUserInterfaceState cast)
             return;
 
-        _window.UpdateEntries(cast.Entries);
+        _window.UpdateEntries(cast.Entries, cast.OwnScentId);
     }
 }

Content.Client/_Starlight/Scent/ScentSniffMenu.xaml.cs

@@ -1,6 +1,9 @@
+using System.Numerics;
+using Content.Client.Administration.UI.CustomControls;
 using Content.Client.Message;
 using Content.Shared._Starlight.Scent;
 using Robust.Client.AutoGenerated;
+using Robust.Client.UserInterface;
 using Robust.Client.UserInterface.Controls;
 using Robust.Client.UserInterface.CustomControls;
 using Robust.Client.UserInterface.XAML;
@@ -19,13 +22,30 @@ public ScentSniffMenu()
         RobustXamlLoader.Load(this);
     }
 
-    public void UpdateEntries(List<ScentTraceEntry> entries)
+    public void UpdateEntries(List<ScentTraceEntry> entries, string? ownScentId)
     {
         Rows.RemoveAllChildren();
 
+        if (ownScentId is { } ownId)
+        {
+            var ownRow = new ContainerButton
+            {
+                ToolTip = Loc.GetString("scent-sniff-window-track-own-tooltip"),
+                HorizontalExpand = true,
+            };
+            ownRow.AddStyleClass(ContainerButton.StyleClassButton);
+            ownRow.AddChild(new Label { Text = Loc.GetString("scent-sniff-window-track-own") });
+            ownRow.OnPressed += _ => OnTrackPressed?.Invoke(ownId);
+            Rows.AddChild(ownRow);
+
+            Rows.AddChild(new HSeparator());
+            Rows.AddChild(new Control { MinSize = new Vector2(0, 10) });
+        }
+
         if (entries.Count == 0)
         {
-            Rows.AddChild(new Label { Text = Loc.GetString("scent-sniff-window-empty") });
+            var emptyKey = ownScentId != null ? "scent-sniff-window-empty-traces" : "scent-sniff-window-empty";
+            Rows.AddChild(new Label { Text = Loc.GetString(emptyKey) });
             return;
         }
 

Content.Server/_Starlight/Scent/Systems/ScentSystem.cs

@@ -101,7 +101,9 @@ private void OnSniffObjectAction(Entity<SmellerComponent> ent, ref SniffObjectAc
         if (trace != null)
             PruneExpiredTraces(trace);
 
-        if (trace == null || trace.Scents.Count == 0)
+        var hasOwnScent = TryComp<ScentComponent>(args.Target, out var targetScent) && targetScent.ScentId != null;
+
+        if ((trace == null || trace.Scents.Count == 0) && !hasOwnScent)
         {
             _popup.PopupEntity(Loc.GetString("scent-sniff-no-scents", ("target", Name(args.Target))), args.Target, ent.Owner);
             args.Handled = true;
@@ -126,23 +128,27 @@ private void OnSniffObjectDoAfter(EntityUid uid, SmellerComponent component, Sni
         if (args.Handled || args.Cancelled || args.Args.Target is not { } target)
             return;
 
-        if (!TryComp<ScentTraceComponent>(target, out var trace))
-            return;
-
-        PruneExpiredTraces(trace);
+        TryComp<ScentTraceComponent>(target, out var trace);
+        if (trace != null)
+            PruneExpiredTraces(trace);
 
         var now = _timing.CurTime;
-        var entries = new List<ScentTraceEntry>(trace.Scents.Count);
-        foreach (var (scentId, info) in trace.Scents)
+        var entries = new List<ScentTraceEntry>(trace?.Scents.Count ?? 0);
+        if (trace != null)
         {
-            var speciesName = Loc.GetString("scent-species-non-humanoid");
-            if (info.Species != null && _prototype.TryIndex<SpeciesPrototype>(info.Species, out var species))
-                speciesName = Loc.GetString(species.Name);
+            foreach (var (scentId, info) in trace.Scents)
+            {
+                var speciesName = Loc.GetString("scent-species-non-humanoid");
+                if (info.Species != null && _prototype.TryIndex<SpeciesPrototype>(info.Species, out var species))
+                    speciesName = Loc.GetString(species.Name);
 
-            var age = (float)(now - info.LastTouched).TotalSeconds;
-            entries.Add(new ScentTraceEntry(scentId, GetFreshness(age, trace.TraceLifetime), speciesName));
+                var age = (float)(now - info.LastTouched).TotalSeconds;
+                entries.Add(new ScentTraceEntry(scentId, GetFreshness(age, trace.TraceLifetime), speciesName));
+            }
         }
 
+        var ownScentId = TryComp<ScentComponent>(target, out var targetScent) ? targetScent.ScentId : null;
+
         if (!_ui.TryOpenUi(uid, ScentSniffUiKey.Key, uid))
         {
             Log.Warning($"{ToPrettyString(uid)} has SmellerComponent but couldn't open ScentSniffUiKey - " +
@@ -151,7 +157,7 @@ private void OnSniffObjectDoAfter(EntityUid uid, SmellerComponent component, Sni
         }
 
         component.SniffTarget = target;
-        _ui.SetUiState(uid, ScentSniffUiKey.Key, new ScentSniffBoundUserInterfaceState(entries));
+        _ui.SetUiState(uid, ScentSniffUiKey.Key, new ScentSniffBoundUserInterfaceState(entries, ownScentId));
 
         args.Handled = true;
     }
@@ -191,7 +197,10 @@ private void OnTrackMessage(EntityUid uid, SmellerComponent component, ScentSnif
         if (!_transform.InRange(xform.Coordinates, targetXform.Coordinates, component.SniffRange))
             return;
 
-        if (!TryComp<ScentTraceComponent>(target, out var trace) || !trace.Scents.ContainsKey(args.ScentId))
+        var isOwnScent = TryComp<ScentComponent>(target, out var targetScent) && targetScent.ScentId == args.ScentId;
+        var isTracedScent = TryComp<ScentTraceComponent>(target, out var trace) && trace.Scents.ContainsKey(args.ScentId);
+
+        if (!isOwnScent && !isTracedScent)
             return;
 
         SetTrackedScent((uid, component), args.ScentId, target);

Content.Shared/_Starlight/Scent/ScentSniffUi.cs

@@ -45,9 +45,14 @@ public sealed class ScentSniffBoundUserInterfaceState : BoundUserInterfaceState
 {
     public readonly List<ScentTraceEntry> Entries;
 
-    public ScentSniffBoundUserInterfaceState(List<ScentTraceEntry> entries)
+    // The target's own current scent, if it has ScentComponent. Always offered as a pinned
+    // option above the trace list, separately from whatever traces were found on it.
+    public readonly string? OwnScentId;
+
+    public ScentSniffBoundUserInterfaceState(List<ScentTraceEntry> entries, string? ownScentId)
     {
         Entries = entries;
+        OwnScentId = ownScentId;
     }
 }
 

Resources/Locale/en-US/_Starlight/scent/scent.ftl

@@ -1,9 +1,12 @@
 scent-sniff-window-title = Scent Trace
 scent-sniff-window-empty = No scents detected.
+scent-sniff-window-empty-traces = No other scent traces detected.
 scent-sniff-window-entry-id = [color={$color}]Scent ({$id}...)[/color]
 scent-sniff-window-entry-detail = [color={$color}]{$species} - {$freshness}[/color]
 scent-sniff-window-track-tooltip = Click to track this scent
 scent-sniff-window-tracking-popup = You start tracking this scent.
+scent-sniff-window-track-own = Track this creature's scent directly
+scent-sniff-window-track-own-tooltip = Track this individual's scent directly.
 
 scent-species-non-humanoid = Non-Humanoid