Add flash reaction effect (#32377)

add flash reaction effect

Content.Server/EntityEffects/Effects/FlashReactionEffect.cs

@@ -0,0 +1,82 @@
+using Content.Shared.EntityEffects;
+using Content.Server.Flash;
+using Robust.Server.GameObjects;
+using Robust.Shared.Audio;
+using Robust.Shared.Prototypes;
+
+namespace Content.Server.EntityEffects.Effects;
+
+[DataDefinition]
+public sealed partial class FlashReactionEffect : EntityEffect
+{
+    /// <summary>
+    ///     Flash range per unit of reagent.
+    /// </summary>
+    [DataField]
+    public float RangePerUnit = 0.2f;
+
+    /// <summary>
+    ///     Maximum flash range.
+    /// </summary>
+    [DataField]
+    public float MaxRange = 10f;
+
+    /// <summary>
+    ///     How much to entities are slowed down.
+    /// </summary>
+    [DataField]
+    public float SlowTo = 0.5f;
+
+    /// <summary>
+    ///     The time entities will be flashed in seconds.
+    ///     The default is chosen to be better than the hand flash so it is worth using it for grenades etc.
+    /// </summary>
+    [DataField]
+    public float Duration = 4f;
+
+    /// <summary>
+    ///     The prototype ID used for the visual effect.
+    /// </summary>
+    [DataField]
+    public EntProtoId? FlashEffectPrototype = "ReactionFlash";
+
+    /// <summary>
+    ///     The sound the flash creates.
+    /// </summary>
+    [DataField]
+    public SoundSpecifier? Sound = new SoundPathSpecifier("/Audio/Weapons/flash.ogg");
+
+    protected override string? ReagentEffectGuidebookText(IPrototypeManager prototype, IEntitySystemManager entSys)
+        => Loc.GetString("reagent-effect-guidebook-flash-reaction-effect", ("chance", Probability));
+
+    public override void Effect(EntityEffectBaseArgs args)
+    {
+        var transform = args.EntityManager.GetComponent<TransformComponent>(args.TargetEntity);
+        var transformSystem = args.EntityManager.System<SharedTransformSystem>();
+
+        var range = 1f;
+
+        if (args is EntityEffectReagentArgs reagentArgs)
+            range = MathF.Min((float)(reagentArgs.Quantity * RangePerUnit), MaxRange);
+
+        args.EntityManager.System<FlashSystem>().FlashArea(
+            args.TargetEntity,
+            null,
+            range,
+            Duration * 1000,
+            slowTo: SlowTo,
+            sound: Sound);
+
+        if (FlashEffectPrototype == null)
+            return;
+
+        var uid = args.EntityManager.SpawnEntity(FlashEffectPrototype, transformSystem.GetMapCoordinates(transform));
+        transformSystem.AttachToGridOrMap(uid);
+
+        if (!args.EntityManager.TryGetComponent<PointLightComponent>(uid, out var pointLightComp))
+            return;
+        var pointLightSystem = args.EntityManager.System<SharedPointLightSystem>();
+        // PointLights with a radius lower than 1.1 are too small to be visible, so this is hardcoded
+        pointLightSystem.SetRadius(uid, MathF.Max(1.1f, range), pointLightComp);
+    }
+}