Rework emergency lights (#1830)

* Implement emergency lights reacting to lost power

* Add emergency light sprites
Remove shared emergency light component

* Remove unused import

* Remove EmergencyLight NetID

* Add rich description
Change comments
Add license
Implement ExposeData

Co-authored-by: Julian Giebel <j.giebel@netrocks.info>

Content.Client/GameObjects/Components/EmergencyLightComponent.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using Robust.Client.Animations;
 using Robust.Client.GameObjects;
 using Robust.Client.GameObjects.Components.Animations;
@@ -13,6 +13,7 @@ namespace Content.Client.GameObjects.Components
     {
         public override string Name => "EmergencyLight";
 
+        /// <inheritdoc/>
         protected override void Startup()
         {
             base.Startup();

Content.Server/GameObjects/Components/Power/ApcNetComponents/PowerReceiverUsers/EmergencyLightComponent.cs

@@ -0,0 +1,143 @@
+using System;
+using System.Collections.Generic;
+using Content.Shared.GameObjects.EntitySystems;
+using Robust.Server.GameObjects;
+using Robust.Shared.GameObjects;
+using Robust.Shared.IoC;
+using Robust.Shared.Localization;
+using Robust.Shared.Serialization;
+using Robust.Shared.Utility;
+using Robust.Shared.ViewVariables;
+
+namespace Content.Server.GameObjects.Components.Power.ApcNetComponents.PowerReceiverUsers
+{
+    /// <summary>
+    ///     Component that represents an emergency light, it has an internal battery that charges when the power is on.
+    /// </summary>
+    [RegisterComponent]
+    public class EmergencyLightComponent : Component, IExamine
+    {
+        public override string Name => "EmergencyLight";
+
+        [ViewVariables]
+        private EmergencyLightState _lightState = EmergencyLightState.Charging;
+
+        [ViewVariables]
+        private BatteryComponent Battery => Owner.GetComponent<BatteryComponent>();
+        [ViewVariables]
+        private PointLightComponent Light => Owner.GetComponent<PointLightComponent>();
+        [ViewVariables]
+        private PowerReceiverComponent PowerReceiver => Owner.GetComponent<PowerReceiverComponent>();
+        private SpriteComponent Sprite => Owner.GetComponent<SpriteComponent>();
+
+        [ViewVariables(VVAccess.ReadWrite)]
+        private float _wattage;
+        [ViewVariables(VVAccess.ReadWrite)]
+        private float _chargingWattage;
+        [ViewVariables(VVAccess.ReadWrite)]
+        private float _chargingEfficiency;
+
+        public override void ExposeData(ObjectSerializer serializer)
+        {
+            base.ExposeData(serializer);
+            serializer.DataField(ref _wattage, "wattage", 5);
+            serializer.DataField(ref _chargingWattage, "chargingWattage", 60);
+            serializer.DataField(ref _chargingEfficiency, "chargingEfficiency", 0.85f);
+        }
+
+        /// <summary>
+        ///     For attaching UpdateState() to events.
+        /// </summary>
+        public void UpdateState(object sender, EventArgs e)
+        {
+            UpdateState();
+        }
+
+        /// <summary>
+        ///     Updates the light's power drain, battery drain, sprite and actual light state.
+        /// </summary>
+        public void UpdateState()
+        {
+            if (PowerReceiver.Powered)
+            {
+                PowerReceiver.Load = (int) Math.Abs(_wattage);
+                TurnOff();
+                _lightState = EmergencyLightState.Charging;
+            }
+            else
+            {
+                TurnOn();
+                _lightState = EmergencyLightState.On;
+            }
+        }
+
+        public void OnUpdate(float frameTime)
+        {
+            if (_lightState == EmergencyLightState.Empty
+                || _lightState == EmergencyLightState.Full) return;
+
+            if(_lightState == EmergencyLightState.On)
+            {
+                if (!Battery.TryUseCharge(_wattage * frameTime))
+                {
+                    _lightState = EmergencyLightState.Empty;
+                    TurnOff();
+                }
+            }
+            else
+            {
+                Battery.CurrentCharge += _chargingWattage * frameTime * _chargingEfficiency;
+                if (Battery.BatteryState == BatteryState.Full)
+                {
+                    PowerReceiver.Load = 1;
+                    _lightState = EmergencyLightState.Full;
+                }
+            }
+        }
+
+        private void TurnOff()
+        {
+            Sprite.LayerSetState(0, "emergency_light_off");
+            Light.Enabled = false;
+        }
+
+        private void TurnOn()
+        {
+            Sprite.LayerSetState(0, "emergency_light_on");
+            Light.Enabled = true;
+        }
+
+        public override void Initialize()
+        {
+            base.Initialize();
+            Owner.GetComponent<PowerReceiverComponent>().OnPowerStateChanged += UpdateState;
+        }
+
+        public override void OnRemove()
+        {
+            Owner.GetComponent<PowerReceiverComponent>().OnPowerStateChanged -= UpdateState;
+            base.OnRemove();
+        }
+
+        void IExamine.Examine(FormattedMessage message, bool inDetailsRange)
+        {
+            message.AddMarkup(Loc.GetString($"The battery indicator displays: {BatteryStateText[_lightState]}."));
+        }
+
+        public enum EmergencyLightState
+        {
+            Charging,
+            Full,
+            Empty,
+            On
+        }
+
+        public Dictionary<EmergencyLightState, string> BatteryStateText = new Dictionary<EmergencyLightState, String>
+        {
+            { EmergencyLightState.Full, "[color=darkgreen]Full[/color]"},
+            { EmergencyLightState.Empty, "[color=darkred]Empty[/color]"},
+            { EmergencyLightState.Charging, "[color=darkorange]Charging[/color]"},
+            { EmergencyLightState.On, "[color=darkorange]Discharging[/color]"}
+        };
+    }
+}

Content.Server/GameObjects/EntitySystems/EmergencyLightSystem.cs

@@ -0,0 +1,18 @@
+using Content.Server.GameObjects.Components.Power.ApcNetComponents.PowerReceiverUsers;
+using JetBrains.Annotations;
+using Robust.Shared.GameObjects.Systems;
+
+namespace Content.Server.GameObjects.EntitySystems
+{
+    [UsedImplicitly]
+    internal sealed class EmergencyLightSystem : EntitySystem
+    {
+        public override void Update(float frameTime)
+        {
+            foreach (var comp in ComponentManager.EntityQuery<EmergencyLightComponent>())
+            {
+                comp.OnUpdate(frameTime);
+            }
+        }
+    }
+}

Content.Server/IgnoredComponents.cs

@@ -17,7 +17,6 @@
             "AnimationsTest",
             "ItemStatus",
             "Marker",
-            "EmergencyLight",
             "Clickable",
             "RadiatingLight",
         };

Resources/Prototypes/Entities/Constructible/Walls/emergency_light.yml

@@ -1,17 +1,27 @@
-- type: entity
+- type: entity
   id: EmergencyLight
   name: "emergency light"
+  description: A small red light with an internal battery that turns on as soon as it stops receiving any power.
   parent: WallLight
   components:
   - type: PointLight
+    enabled: false
     radius: 10
     energy: 2.5
     offset: "0.5, 0"
     color: "#FF4020"
     mask: /Textures/emergency_mask.png
-
   - type: EmergencyLight
-
+  - type: PowerReceiver
+  - type: Battery
+    maxCharge: 30000
+    startingCharge: 0
+  - type: Sprite
+    sprite: Constructible/Lighting/emergency_light.rsi
+    state: emergency_light_off
+  - type: Icon
+    sprite: Constructible/Lighting/emergency_light.rsi
+    state: emergency_light_off
   placement:
     snap:
     - Wallmount

Resources/Textures/Constructible/Lighting/emergency_light.rsi/meta.json

@@ -0,0 +1,66 @@
+{
+    "version": 1,
+    "size": {
+        "x": 32,
+        "y": 32
+    },
+    "license": "CC-BY-SA-3.0",
+    "states": [
+        {
+            "name": "emergency_light_off",
+            "directions": 4,
+            "delays": [
+                [
+                    1.0
+                ],
+                [
+                    1.0
+                ],
+                [
+                    1.0
+                ],
+                [
+                    1.0
+                ]
+            ]
+        },
+        {
+            "name": "emergency_light_on",
+            "directions": 4,
+            "delays": [
+                [
+                    0.3,
+                    0.3,
+                    0.3,
+                    0.3,
+                    0.3,
+                    0.3
+                ],
+                [
+                    0.3,
+                    0.3,
+                    0.3,
+                    0.3,
+                    0.3,
+                    0.3
+                ],
+                [
+                    0.3,
+                    0.3,
+                    0.3,
+                    0.3,
+                    0.3,
+                    0.3
+                ],
+                [
+                    0.3,
+                    0.3,
+                    0.3,
+                    0.3,
+                    0.3,
+                    0.3
+                ]
+            ]
+        }
+    ]
+}