Jetpacks (#9023)

* Movement acceleration

* tweaks

* Weightless refactor coz fuck it

* CCVars

* weightless movement tweaks

* Some cleanup while I'm here

* dorkpacks

* thanks fork

* fixes

* zoomies

* toggles

* hmm

* yamls

* b

* so true

* Effects refactor

* namespace

* review

Content.Client/Movement/Systems/JetpackSystem.cs

@@ -0,0 +1,80 @@
+using Content.Client.Clothing;
+using Content.Shared.Movement.Components;
+using Content.Shared.Movement.Systems;
+using Content.Shared.Weapons.Ranged.Systems;
+using Robust.Client.Animations;
+using Robust.Client.GameObjects;
+using Robust.Shared.GameStates;
+using Robust.Shared.Map;
+using Robust.Shared.Timing;
+
+namespace Content.Client.Movement.Systems;
+
+public sealed class JetpackSystem : SharedJetpackSystem
+{
+    [Dependency] private readonly IGameTiming _timing = default!;
+    [Dependency] private readonly IMapManager _mapManager = default!;
+
+    public override void Initialize()
+    {
+        base.Initialize();
+        SubscribeLocalEvent<JetpackComponent, AppearanceChangeEvent>(OnJetpackAppearance);
+    }
+
+    protected override bool CanEnable(JetpackComponent component)
+    {
+        // No predicted atmos so you'd have to do a lot of funny to get this working.
+        return false;
+    }
+
+    private void OnJetpackAppearance(EntityUid uid, JetpackComponent component, ref AppearanceChangeEvent args)
+    {
+        args.Component.TryGetData(JetpackVisuals.Enabled, out bool enabled);
+
+        var state = "icon" + (enabled ? "-on" : "");
+        args.Sprite?.LayerSetState(0, state);
+
+        if (TryComp<ClothingComponent>(uid, out var clothing))
+            clothing.EquippedPrefix = enabled ? "on" : null;
+    }
+
+    public override void Update(float frameTime)
+    {
+        base.Update(frameTime);
+
+        if (!_timing.IsFirstTimePredicted) return;
+
+        foreach (var comp in EntityQuery<ActiveJetpackComponent>())
+        {
+            comp.Accumulator += frameTime;
+
+            if (comp.Accumulator < comp.EffectCooldown) continue;
+            comp.Accumulator -= comp.EffectCooldown;
+            CreateParticles(comp.Owner);
+        }
+    }
+
+    private void CreateParticles(EntityUid uid)
+    {
+        var uidXform = Transform(uid);
+        var coordinates = uidXform.Coordinates;
+        var gridUid = coordinates.GetGridUid(EntityManager);
+
+        if (_mapManager.TryGetGrid(gridUid, out var grid))
+        {
+            coordinates = new EntityCoordinates(grid.GridEntityId, grid.WorldToLocal(coordinates.ToMapPos(EntityManager)));
+        }
+        else if (uidXform.MapUid != null)
+        {
+            coordinates = new EntityCoordinates(uidXform.MapUid.Value, uidXform.WorldPosition);
+        }
+        else
+        {
+            return;
+        }
+
+        var ent = Spawn("JetpackEffect", coordinates);
+        var xform = Transform(ent);
+        xform.Coordinates = coordinates;
+    }
+}