Gunify pneumatic cannon (#13296)

Content.Shared/PneumaticCannon/PneumaticCannonComponent.cs

@@ -0,0 +1,53 @@
+using Content.Shared.Tools;
+using Robust.Shared.GameStates;
+using Robust.Shared.Serialization.TypeSerializers.Implementations.Custom.Prototype;
+
+namespace Content.Shared.PneumaticCannon;
+
+/// <summary>
+///     Handles gas powered guns--cancels shooting if no gas is available, and takes gas from the given container slot.
+/// </summary>
+[RegisterComponent, NetworkedComponent]
+public sealed class PneumaticCannonComponent : Component
+{
+    public const string TankSlotId = "gas_tank";
+
+    [ViewVariables(VVAccess.ReadWrite)]
+    public PneumaticCannonPower Power = PneumaticCannonPower.Medium;
+
+    [DataField("toolModifyPower", customTypeSerializer:typeof(PrototypeIdSerializer<ToolQualityPrototype>))]
+    public string ToolModifyPower = "Anchoring";
+
+    /// <summary>
+    ///     How long to stun for if they shoot the pneumatic cannon at high power.
+    /// </summary>
+    [DataField("highPowerStunTime")]
+    [ViewVariables(VVAccess.ReadWrite)]
+    public float HighPowerStunTime = 3.0f;
+
+    /// <summary>
+    ///     Amount of moles to consume for each shot at any power.
+    /// </summary>
+    [DataField("gasUsage")]
+    [ViewVariables(VVAccess.ReadWrite)]
+    public float GasUsage = 2f;
+
+    /// <summary>
+    ///     Base projectile speed at default power.
+    /// </summary>
+    [DataField("baseProjectileSpeed")]
+    public float BaseProjectileSpeed = 20f;
+}
+
+/// <summary>
+///     How strong the pneumatic cannon should be.
+///     Each tier throws items farther and with more speed, but has drawbacks.
+///     The highest power knocks the player down for a considerable amount of time.
+/// </summary>
+public enum PneumaticCannonPower : byte
+{
+    Low = 0,
+    Medium = 1,
+    High = 2,
+    Len = 3 // used for length calc
+}

Content.Shared/PneumaticCannon/SharedPneumaticCannon.cs

@@ -1,17 +0,0 @@
-using Robust.Shared.Serialization;
-
-namespace Content.Shared.PneumaticCannon
-{
-    [Serializable, NetSerializable]
-    public enum PneumaticCannonVisualLayers : byte
-    {
-        Base,
-        Tank
-    }
-
-    [Serializable, NetSerializable]
-    public enum PneumaticCannonVisuals
-    {
-        Tank
-    }
-}

Content.Shared/PneumaticCannon/SharedPneumaticCannonSystem.cs

@@ -0,0 +1,32 @@
+using Content.Shared.Popups;
+using Content.Shared.Weapons.Ranged.Systems;
+using Robust.Shared.Containers;
+using Robust.Shared.Serialization;
+
+namespace Content.Shared.PneumaticCannon;
+
+public abstract class SharedPneumaticCannonSystem : EntitySystem
+{
+    [Dependency] protected readonly SharedContainerSystem Container = default!;
+    [Dependency] protected readonly SharedPopupSystem Popup = default!;
+
+
+    public override void Initialize()
+    {
+        base.Initialize();
+
+        SubscribeLocalEvent<PneumaticCannonComponent, AttemptShootEvent>(OnAttemptShoot);
+    }
+
+    private void OnAttemptShoot(EntityUid uid, PneumaticCannonComponent component, ref AttemptShootEvent args)
+    {
+        // we don't have atmos on shared, so just predict by the existence of a slot item
+        // server will handle auto ejecting/not adding the slot item if it doesnt have enough gas,
+        // so this won't mispredict
+        if (!Container.TryGetContainer(uid, PneumaticCannonComponent.TankSlotId, out var container) ||
+            container is not ContainerSlot slot || slot.ContainedEntity is null)
+        {
+            args.Cancelled = true;
+        }
+    }
+}