Files
tbd-station-14/Content.Server/AI/Steering/NPCSteeringSystem.cs
metalgearsloth 098b536fb8 NPC Steering refactor (#10190)
Co-authored-by: metalgearsloth <metalgearsloth@gmail.com>
2022-08-03 16:02:50 +10:00

399 lines
15 KiB
C#

using System.Linq;
using System.Threading;
using Content.Server.AI.Components;
using Content.Server.AI.Pathfinding;
using Content.Server.AI.Pathfinding.Pathfinders;
using Content.Server.CPUJob.JobQueues;
using Content.Shared.Access.Systems;
using Content.Shared.CCVar;
using Content.Shared.Movement.Components;
using Robust.Shared.Configuration;
using Robust.Shared.Map;
using Robust.Shared.Physics;
using Robust.Shared.Timing;
using Robust.Shared.Utility;
namespace Content.Server.AI.Steering
{
public sealed class NPCSteeringSystem : EntitySystem
{
// http://www.red3d.com/cwr/papers/1999/gdc99steer.html for a steering overview
[Dependency] private readonly IConfigurationManager _configManager = default!;
[Dependency] private readonly IGameTiming _timing = default!;
[Dependency] private readonly IMapManager _mapManager = default!;
[Dependency] private readonly PathfindingSystem _pathfindingSystem = default!;
[Dependency] private readonly AccessReaderSystem _accessReader = default!;
// This will likely get moved onto an abstract pathfinding node that specifies the max distance allowed from the coordinate.
private const float TileTolerance = 0.1f;
private bool _enabled;
public override void Initialize()
{
base.Initialize();
_configManager.OnValueChanged(CCVars.NPCEnabled, SetNPCEnabled, true);
SubscribeLocalEvent<NPCSteeringComponent, ComponentShutdown>(OnSteeringShutdown);
}
private void OnSteeringShutdown(EntityUid uid, NPCSteeringComponent component, ComponentShutdown args)
{
component.PathfindToken?.Cancel();
}
private void SetNPCEnabled(bool obj)
{
if (!obj)
{
foreach (var (_, mover) in EntityQuery<NPCSteeringComponent, InputMoverComponent>())
{
mover.CurTickSprintMovement = Vector2.Zero;
}
}
_enabled = obj;
}
public override void Shutdown()
{
base.Shutdown();
_configManager.UnsubValueChanged(CCVars.NPCEnabled, SetNPCEnabled);
}
/// <summary>
/// Adds the AI to the steering system to move towards a specific target
/// </summary>
public NPCSteeringComponent Register(EntityUid entity, EntityCoordinates coordinates)
{
if (TryComp<NPCSteeringComponent>(entity, out var comp))
{
comp.PathfindToken?.Cancel();
comp.PathfindToken = null;
comp.CurrentPath.Clear();
}
else
{
comp = AddComp<NPCSteeringComponent>(entity);
}
comp.Coordinates = coordinates;
return comp;
}
/// <summary>
/// Stops the steering behavior for the AI and cleans up.
/// </summary>
public void Unregister(EntityUid uid, NPCSteeringComponent? component = null)
{
if (!Resolve(uid, ref component, false))
return;
if (EntityManager.TryGetComponent(component.Owner, out InputMoverComponent? controller))
{
controller.CurTickSprintMovement = Vector2.Zero;
}
component.PathfindToken?.Cancel();
component.PathfindToken = null;
component.Pathfind = null;
RemComp<NPCSteeringComponent>(uid);
}
public override void Update(float frameTime)
{
base.Update(frameTime);
if (!_enabled)
return;
// Not every mob has the modifier component so do it as a separate query.
var bodyQuery = GetEntityQuery<PhysicsComponent>();
var modifierQuery = GetEntityQuery<MovementSpeedModifierComponent>();
foreach (var (steering, _, mover, xform) in EntityQuery<NPCSteeringComponent, ActiveNPCComponent, InputMoverComponent, TransformComponent>())
{
Steer(steering, mover, xform, modifierQuery, bodyQuery, frameTime);
}
}
private void SetDirection(InputMoverComponent component, Vector2 value)
{
component.CurTickSprintMovement = value;
component.LastInputTick = _timing.CurTick;
component.LastInputSubTick = ushort.MaxValue;
}
/// <summary>
/// Go through each steerer and combine their vectors
/// </summary>
private void Steer(
NPCSteeringComponent steering,
InputMoverComponent mover,
TransformComponent xform,
EntityQuery<MovementSpeedModifierComponent> modifierQuery,
EntityQuery<PhysicsComponent> bodyQuery,
float frameTime)
{
var ourCoordinates = xform.Coordinates;
var destinationCoordinates = steering.Coordinates;
// We've arrived, nothing else matters.
if (xform.Coordinates.TryDistance(EntityManager, destinationCoordinates, out var distance) &&
distance <= steering.Range)
{
SetDirection(mover, Vector2.Zero);
steering.Status = SteeringStatus.InRange;
return;
}
// Can't move at all, just noop input.
if (!mover.CanMove)
{
SetDirection(mover, Vector2.Zero);
steering.Status = SteeringStatus.Moving;
return;
}
// If we were pathfinding then try to update our path.
if (steering.Pathfind != null)
{
switch (steering.Pathfind.Status)
{
case JobStatus.Waiting:
case JobStatus.Running:
case JobStatus.Pending:
case JobStatus.Paused:
break;
case JobStatus.Finished:
steering.CurrentPath.Clear();
if (steering.Pathfind.Result != null)
{
PrunePath(ourCoordinates, steering.Pathfind.Result);
foreach (var node in steering.Pathfind.Result)
{
steering.CurrentPath.Enqueue(node);
}
}
steering.Pathfind = null;
steering.PathfindToken = null;
break;
default:
throw new ArgumentOutOfRangeException();
}
}
// Grab the target position, either the path or our end goal.
// TODO: Some situations we may not want to move at our target without a path.
var targetCoordinates = GetTargetCoordinates(steering);
var arrivalDistance = TileTolerance;
if (targetCoordinates.Equals(steering.Coordinates))
{
// What's our tolerance for arrival.
// If it's a pathfinding node it might be different to the destination.
arrivalDistance = steering.Range;
}
// Check if mapids match.
var targetMap = targetCoordinates.ToMap(EntityManager);
var ourMap = ourCoordinates.ToMap(EntityManager);
if (targetMap.MapId != ourMap.MapId)
{
SetDirection(mover, Vector2.Zero);
steering.Status = SteeringStatus.NoPath;
return;
}
var direction = targetMap.Position - ourMap.Position;
// Are we in range
if (direction.Length <= arrivalDistance)
{
// It was just a node, not the target, so grab the next destination (either the target or next node).
if (steering.CurrentPath.Count > 0)
{
steering.CurrentPath.Dequeue();
// Alright just adjust slightly and grab the next node so we don't stop moving for a tick.
// TODO: If it's the last node just grab the target instead.
targetCoordinates = GetTargetCoordinates(steering);
targetMap = targetCoordinates.ToMap(EntityManager);
// Can't make it again.
if (ourMap.MapId != targetMap.MapId)
{
SetDirection(mover, Vector2.Zero);
steering.Status = SteeringStatus.NoPath;
return;
}
// Gonna resume now business as usual
direction = targetMap.Position - ourMap.Position;
}
else
{
// This probably shouldn't happen as we check above but eh.
SetDirection(mover, Vector2.Zero);
steering.Status = SteeringStatus.InRange;
return;
}
}
// Do we have no more nodes to follow OR has the target moved sufficiently? If so then re-path.
var needsPath = steering.CurrentPath.Count == 0;
// TODO: Probably need partial planning support i.e. patch from the last node to where the target moved to.
if (!needsPath)
{
var lastNode = steering.CurrentPath.Last();
// I know this is bad and doesn't account for tile size
// However with the path I'm going to change it to return pathfinding nodes which include coordinates instead.
var lastCoordinate = new EntityCoordinates(lastNode.GridUid, (Vector2) lastNode.GridIndices + 0.5f);
if (lastCoordinate.TryDistance(EntityManager, steering.Coordinates, out var lastDistance) &&
lastDistance > steering.RepathRange)
{
needsPath = true;
}
}
// Request the new path.
if (needsPath && bodyQuery.TryGetComponent(steering.Owner, out var body))
{
RequestPath(steering, xform, body);
}
modifierQuery.TryGetComponent(steering.Owner, out var modifier);
var moveSpeed = GetSprintSpeed(modifier);
var input = direction.Normalized;
// If we're going to overshoot then... don't.
// TODO: For tile / movement we don't need to get bang on, just need to make sure we don't overshoot the far end.
var tickMovement = moveSpeed * frameTime;
if (tickMovement.Equals(0f))
{
SetDirection(mover, Vector2.Zero);
steering.Status = SteeringStatus.NoPath;
return;
}
// We may overshoot slightly but still be in the arrival distance which is okay.
var maxDistance = direction.Length + arrivalDistance;
if (tickMovement > maxDistance)
{
input *= maxDistance / tickMovement;
}
// TODO: This isn't going to work for space.
if (_mapManager.TryGetGrid(xform.GridUid, out var grid))
{
input = (-grid.WorldRotation).RotateVec(input);
}
SetDirection(mover, input);
// todo: Need a console command to make an NPC steer to a specific spot.
// TODO: Actual steering behaviours and collision avoidance.
// TODO: Need to handle path invalidation if nodes change.
}
/// <summary>
/// We may be pathfinding and moving at the same time in which case early nodes may be out of date.
/// </summary>
private void PrunePath(EntityCoordinates coordinates, Queue<TileRef> nodes)
{
// Right now the pathfinder gives EVERY TILE back but ideally it won't someday, it'll just give straightline ones.
// For now, we just prune up until the closest node + 1 extra.
var closest = ((Vector2) nodes.Peek().GridIndices + 0.5f - coordinates.Position).Length;
// TODO: Need to handle multi-grid and stuff.
while (nodes.TryPeek(out var node))
{
// TODO: Tile size
var nodePosition = (Vector2) node.GridIndices + 0.5f;
var length = (coordinates.Position - nodePosition).Length;
if (length < closest)
{
closest = length;
nodes.Dequeue();
continue;
}
nodes.Dequeue();
break;
}
}
/// <summary>
/// Get the coordinates we should be heading towards.
/// </summary>
private EntityCoordinates GetTargetCoordinates(NPCSteeringComponent steering)
{
// Depending on what's going on we may return the target or a pathfind node.
// If it's the last node then just head to the target.
if (steering.CurrentPath.Count > 1 && steering.CurrentPath.TryPeek(out var nextTarget))
{
return new EntityCoordinates(nextTarget.GridUid, (Vector2) nextTarget.GridIndices + 0.5f);
}
return steering.Coordinates;
}
/// <summary>
/// Get a new job from the pathfindingsystem
/// </summary>
private void RequestPath(NPCSteeringComponent steering, TransformComponent xform, PhysicsComponent? body)
{
// If we already have a pathfinding request then don't grab another.
if (steering.Pathfind != null)
return;
if (!_mapManager.TryGetGrid(xform.GridUid, out var grid))
return;
steering.PathfindToken = new CancellationTokenSource();
var startTile = grid.GetTileRef(xform.Coordinates);
var endTile = grid.GetTileRef(steering.Coordinates);
var collisionMask = 0;
if (body != null)
{
collisionMask = body.CollisionMask;
}
var access = _accessReader.FindAccessTags(steering.Owner);
steering.Pathfind = _pathfindingSystem.RequestPath(new PathfindingArgs(
steering.Owner,
access,
collisionMask,
startTile,
endTile,
steering.Range
), steering.PathfindToken.Token);
}
private float GetSprintSpeed(MovementSpeedModifierComponent? modifier)
{
return modifier?.CurrentSprintSpeed ?? MovementSpeedModifierComponent.DefaultBaseSprintSpeed;
}
private float GetWalkSpeed(MovementSpeedModifierComponent? modifier)
{
return modifier?.CurrentWalkSpeed ?? MovementSpeedModifierComponent.DefaultBaseWalkSpeed;
}
}
}