NPC refactor (#10122)

Co-authored-by: metalgearsloth <metalgearsloth@gmail.com>

Content.Server/NPC/Systems/NPCCombatSystem.Ranged.cs

@@ -0,0 +1,159 @@
+using Content.Server.NPC.Components;
+using Content.Shared.CombatMode;
+using Content.Shared.Interaction;
+using Robust.Shared.Map;
+
+namespace Content.Server.NPC.Systems;
+
+public sealed partial class NPCCombatSystem
+{
+    [Dependency] private readonly RotateToFaceSystem _rotate = default!;
+
+    // TODO: Don't predict for hitscan
+    private const float ShootSpeed = 20f;
+
+    /// <summary>
+    /// Cooldown on raycasting to check LOS.
+    /// </summary>
+    public const float UnoccludedCooldown = 0.2f;
+
+    private void InitializeRanged()
+    {
+        SubscribeLocalEvent<NPCRangedCombatComponent, ComponentStartup>(OnRangedStartup);
+        SubscribeLocalEvent<NPCRangedCombatComponent, ComponentShutdown>(OnRangedShutdown);
+    }
+
+    private void OnRangedStartup(EntityUid uid, NPCRangedCombatComponent component, ComponentStartup args)
+    {
+        if (TryComp<SharedCombatModeComponent>(uid, out var combat))
+        {
+            combat.IsInCombatMode = true;
+        }
+        else
+        {
+            component.Status = CombatStatus.Unspecified;
+        }
+    }
+
+    private void OnRangedShutdown(EntityUid uid, NPCRangedCombatComponent component, ComponentShutdown args)
+    {
+        if (TryComp<SharedCombatModeComponent>(uid, out var combat))
+        {
+            combat.IsInCombatMode = false;
+        }
+    }
+
+    private void UpdateRanged(float frameTime)
+    {
+        var bodyQuery = GetEntityQuery<PhysicsComponent>();
+        var xformQuery = GetEntityQuery<TransformComponent>();
+        var combatQuery = GetEntityQuery<SharedCombatModeComponent>();
+
+        foreach (var (comp, xform) in EntityQuery<NPCRangedCombatComponent, TransformComponent>())
+        {
+            if (comp.Status == CombatStatus.Unspecified)
+                continue;
+
+            if (!xformQuery.TryGetComponent(comp.Target, out var targetXform) ||
+                !bodyQuery.TryGetComponent(comp.Target, out var targetBody))
+            {
+                comp.Status = CombatStatus.TargetUnreachable;
+                comp.ShootAccumulator = 0f;
+                continue;
+            }
+
+            if (targetXform.MapID != xform.MapID)
+            {
+                comp.Status = CombatStatus.TargetUnreachable;
+                comp.ShootAccumulator = 0f;
+                continue;
+            }
+
+            if (combatQuery.TryGetComponent(comp.Owner, out var combatMode))
+            {
+                combatMode.IsInCombatMode = true;
+            }
+
+            var gun = _gun.GetGun(comp.Owner);
+
+            if (gun == null)
+            {
+                comp.Status = CombatStatus.NoWeapon;
+                comp.ShootAccumulator = 0f;
+                continue;
+            }
+
+            comp.LOSAccumulator -= frameTime;
+
+            var (worldPos, worldRot) = _transform.GetWorldPositionRotation(xform, xformQuery);
+            var (targetPos, targetRot) = _transform.GetWorldPositionRotation(targetXform, xformQuery);
+
+            // We'll work out the projected spot of the target and shoot there instead of where they are.
+            var distance = (targetPos - worldPos).Length;
+            var oldInLos = comp.TargetInLOS;
+
+            // TODO: Should be doing these raycasts in parallel
+            // Ideally we'd have 2 steps, 1. to go over the normal details for shooting and then 2. to handle beep / rotate / shoot
+            if (comp.LOSAccumulator < 0f)
+            {
+                comp.LOSAccumulator += UnoccludedCooldown;
+                comp.TargetInLOS = _interaction.InRangeUnobstructed(comp.Owner, comp.Target, distance + 0.1f);
+            }
+
+            if (!comp.TargetInLOS)
+            {
+                comp.ShootAccumulator = 0f;
+                comp.Status = CombatStatus.TargetUnreachable;
+                continue;
+            }
+
+            if (!oldInLos && comp.SoundTargetInLOS != null)
+            {
+                _audio.PlayPvs(comp.SoundTargetInLOS, comp.Owner);
+            }
+
+            comp.ShootAccumulator += frameTime;
+
+            if (comp.ShootAccumulator < comp.ShootDelay)
+            {
+                continue;
+            }
+
+            var mapVelocity = targetBody.LinearVelocity;
+            var targetSpot = targetPos + mapVelocity * distance / ShootSpeed;
+
+            // If we have a max rotation speed then do that.
+            var goalRotation = (targetSpot - worldPos).ToWorldAngle();
+            var rotationSpeed = comp.RotationSpeed;
+
+            if (!_rotate.TryRotateTo(comp.Owner, goalRotation, frameTime, comp.AccuracyThreshold, rotationSpeed?.Theta ?? double.MaxValue, xform))
+            {
+                continue;
+            }
+
+            // TODO: LOS
+            // TODO: Ammo checks
+            // TODO: Burst fire
+            // TODO: Cycling
+            // Max rotation speed
+
+            // TODO: Check if we can face
+
+            if (!_gun.CanShoot(gun))
+                continue;
+
+            EntityCoordinates targetCordinates;
+
+            if (_mapManager.TryFindGridAt(xform.MapID, targetPos, out var mapGrid))
+            {
+                targetCordinates = new EntityCoordinates(mapGrid.GridEntityId, mapGrid.WorldToLocal(targetSpot));
+            }
+            else
+            {
+                targetCordinates = new EntityCoordinates(xform.MapUid!.Value, targetSpot);
+            }
+
+            _gun.AttemptShoot(comp.Owner, gun, targetCordinates);
+        }
+    }
+}