Mirror: Added winddown to space drugs effect (#131)

## Mirror of PR #25652: [Added winddown to space drugs
effect](space-wizards/space-station-14#25652)
from <img src="https://avatars.githubusercontent.com/u/10567778?v=4"
alt="space-wizards" width="22"/>
[space-wizards](https://github.com/space-wizards)/[space-station-14](https://github.com/space-wizards/space-station-14)

###### `865765d4eca5483d22c5d1e496b7f7c8787833a8`

PR opened by <img
src="https://avatars.githubusercontent.com/u/62557990?v=4"
width="16"/><a href="https://github.com/PolterTzi"> PolterTzi</a> at
2024-02-27 18:09:49 UTC
PR merged by <img
src="https://avatars.githubusercontent.com/u/19864447?v=4"
width="16"/><a href="https://github.com/web-flow"> web-flow</a> at
2024-03-09 19:33:40 UTC

---

PR changed 2 files with 14 additions and 1 deletions.

The PR had the following labels:


---

<details open="true"><summary><h1>Original Body</h1></summary>

> <!-- Please read these guidelines before opening your PR:
https://docs.spacestation14.io/en/getting-started/pr-guideline -->
> <!-- The text between the arrows are comments - they will not be
visible on your PR. -->
> 
> ## About the PR
> <!-- What did you change in this PR? -->
> 
> The space drugs shader effect now gradually loses intensity as it's
nearing its end.
> 
> ## Why / Balance
> <!-- Why was it changed? Link any discussions or issues here. Please
discuss how this would affect game balance. -->
> Makes for a smoother transition than going from 100% to 0% instantly.
> 
> ## Media
> <!-- 
> PRs which make ingame changes (adding clothing, items, new features,
etc) are required to have media attached that showcase the changes.
> Small fixes/refactors are exempt.
> Any media may be used in SS14 progress reports, with clear credit
given.
> 
> If you're unsure whether your PR will require media, ask a maintainer.
> 
> Check the box below to confirm that you have in fact seen this (put an
X in the brackets, like [X]):
> -->
> 
>
https://github.com/space-wizards/space-station-14/assets/62557990/1dd19974-1066-4f76-a270-6844f35af042
> 
> 
> - [X] I have added screenshots/videos to this PR showcasing its
changes ingame, **or** this PR does not require an ingame showcase


</details>

Co-authored-by: Flesh <[email protected]>

Content.Client/Drugs/DrugOverlaySystem.cs

@@ -38,6 +38,7 @@ private void OnPlayerAttached(EntityUid uid, SeeingRainbowsComponent component,
     private void OnPlayerDetached(EntityUid uid, SeeingRainbowsComponent component, LocalPlayerDetachedEvent args)
     {
         _overlay.Intoxication = 0;
+        _overlay.TimeTicker = 0;
         _overlayMan.RemoveOverlay(_overlay);
     }
 
@@ -52,6 +53,7 @@ private void OnShutdown(EntityUid uid, SeeingRainbowsComponent component, Compon
         if (_player.LocalEntity == uid)
         {
             _overlay.Intoxication = 0;
+            _overlay.TimeTicker = 0;
             _overlayMan.RemoveOverlay(_overlay);
         }
     }

Content.Client/Drugs/RainbowOverlay.cs

@@ -20,6 +20,7 @@ public sealed class RainbowOverlay : Overlay
     private readonly ShaderInstance _rainbowShader;
 
     public float Intoxication = 0.0f;
+    public float TimeTicker = 0.0f;
 
     private const float VisualThreshold = 10.0f;
     private const float PowerDivisor = 250.0f;
@@ -48,7 +49,17 @@ protected override void FrameUpdate(FrameEventArgs args)
             return;
 
         var timeLeft = (float) (time.Value.Item2 - time.Value.Item1).TotalSeconds;
-        Intoxication += (timeLeft - Intoxication) * args.DeltaSeconds / 16f;
+
+        TimeTicker += args.DeltaSeconds;
+
+        if (timeLeft - TimeTicker > timeLeft / 16f)
+        {
+            Intoxication += (timeLeft - Intoxication) * args.DeltaSeconds / 16f;
+        }
+        else
+        {
+            Intoxication -= Intoxication/(timeLeft - TimeTicker) * args.DeltaSeconds;
+        }
     }
 
     protected override bool BeforeDraw(in OverlayDrawArgs args)