using Barotrauma.Networking; using FarseerPhysics; using FarseerPhysics.Dynamics; using FarseerPhysics.Dynamics.Contacts; using FarseerPhysics.Dynamics.Joints; using Microsoft.Xna.Framework; using System; using System.Collections.Generic; using System.Linq; using System.Xml.Linq; namespace Barotrauma.Items.Components { class Projectile : ItemComponent { struct HitscanResult { public Fixture Fixture; public Vector2 Point; public Vector2 Normal; public float Fraction; public HitscanResult(Fixture fixture, Vector2 point, Vector2 normal, float fraction) { Fixture = fixture; Point = point; Normal = normal; Fraction = fraction; } } //continuous collision detection is used while the projectile is moving faster than this const float ContinuousCollisionThreshold = 5.0f; //a duration during which the projectile won't drop from the body it's stuck to private const float PersistentStickJointDuration = 1.0f; private float launchImpulse; private PrismaticJoint stickJoint; private Body stickTarget; private Attack attack; public List IgnoredBodies; private Character user; public Character User { get { return user; } set { user = value; attack?.SetUser(user); } } private float persistentStickJointTimer; [Serialize(10.0f, false)] public float LaunchImpulse { get { return launchImpulse; } set { launchImpulse = value; } } [Serialize(0.0f, false)] public float LaunchRotation { get { return MathHelper.ToDegrees(LaunchRotationRadians); } set { LaunchRotationRadians = MathHelper.ToRadians(value); } } public float LaunchRotationRadians { get; private set; } [Serialize(false, false)] //backwards compatibility, can stick to anything public bool DoesStick { get; set; } [Serialize(false, false)] public bool StickToCharacters { get; set; } [Serialize(false, false)] public bool StickToStructures { get; set; } [Serialize(false, false)] public bool StickToItems { get; set; } [Serialize(false, false)] public bool Hitscan { get; set; } [Serialize(false, false)] public bool RemoveOnHit { get; set; } public Projectile(Item item, XElement element) : base (item, element) { IgnoredBodies = new List(); foreach (XElement subElement in element.Elements()) { if (subElement.Name.ToString().ToLowerInvariant() != "attack") continue; attack = new Attack(subElement, item.Name + ", Projectile"); } } public override void OnItemLoaded() { if (attack != null && attack.DamageRange <= 0.0f && item.body != null) { switch (item.body.BodyShape) { case PhysicsBody.Shape.Circle: attack.DamageRange = item.body.radius; break; case PhysicsBody.Shape.Capsule: attack.DamageRange = item.body.height / 2 + item.body.radius; break; case PhysicsBody.Shape.Rectangle: attack.DamageRange = new Vector2(item.body.width / 2.0f, item.body.height / 2.0f).Length(); break; } attack.DamageRange = ConvertUnits.ToDisplayUnits(attack.DamageRange); } } public override bool Use(float deltaTime, Character character = null) { if (character != null && !characterUsable) return false; Vector2 launchDir = new Vector2((float)Math.Cos(item.body.Rotation), (float)Math.Sin(item.body.Rotation)); if (Hitscan) { DoHitscan(launchDir); } else { Launch(launchDir * launchImpulse * item.body.Mass); } User = character; return true; } private void Launch(Vector2 impulse) { item.Drop(null); item.body.Enabled = true; item.body.ApplyLinearImpulse(impulse, maxVelocity: NetConfig.MaxPhysicsBodyVelocity); item.body.FarseerBody.OnCollision += OnProjectileCollision; item.body.FarseerBody.IsBullet = true; item.body.CollisionCategories = Physics.CollisionProjectile; item.body.CollidesWith = Physics.CollisionCharacter | Physics.CollisionWall | Physics.CollisionLevel; IsActive = true; if (stickJoint == null) return; if (stickTarget != null) { #if DEBUG try { #endif item.body.FarseerBody.RestoreCollisionWith(stickTarget); #if DEBUG } catch (Exception e) { DebugConsole.ThrowError("Failed to restore collision with stickTarget", e); } #endif stickTarget = null; } GameMain.World.RemoveJoint(stickJoint); stickJoint = null; } private void DoHitscan(Vector2 dir) { float rotation = item.body.Rotation; Vector2 simPositon = item.SimPosition; item.Drop(null); item.body.Enabled = true; //set the velocity of the body because the OnProjectileCollision method //uses it to determine the direction from which the projectile hit item.body.LinearVelocity = dir; IsActive = true; Vector2 rayStart = simPositon; Vector2 rayEnd = simPositon + dir * 1000.0f; List hits = new List(); hits.AddRange(DoRayCast(rayStart, rayEnd)); if (item.Submarine != null) { //shooting indoors, do a hitscan outside as well hits.AddRange(DoRayCast(rayStart + item.Submarine.SimPosition, rayEnd + item.Submarine.SimPosition)); } else { //shooting outdoors, see if we can hit anything inside a sub foreach (Submarine submarine in Submarine.Loaded) { var inSubHits = DoRayCast(rayStart - submarine.SimPosition, rayEnd - submarine.SimPosition); //transform back to world coordinates for (int i = 0; i < inSubHits.Count; i++) { inSubHits[i] = new HitscanResult( inSubHits[i].Fixture, inSubHits[i].Point + submarine.SimPosition, inSubHits[i].Normal, inSubHits[i].Fraction); } hits.AddRange(inSubHits); } } bool hitSomething = false; hits = hits.OrderBy(h => h.Fraction).ToList(); foreach (HitscanResult h in hits) { item.body.SetTransform(h.Point, rotation); if (OnProjectileCollision(h.Fixture, h.Normal)) { hitSomething = true; break; } } //the raycast didn't hit anything -> the projectile flew somewhere outside the level and is permanently lost if (!hitSomething) { Entity.Spawner.AddToRemoveQueue(item); } } private List DoRayCast(Vector2 rayStart, Vector2 rayEnd) { List hits = new List(); GameMain.World.RayCast((fixture, point, normal, fraction) => { if (fixture == null || fixture.IsSensor) return -1; if (fixture.UserData is Item) return -1; if (!fixture.CollisionCategories.HasFlag(Physics.CollisionCharacter) && !fixture.CollisionCategories.HasFlag(Physics.CollisionWall) && !fixture.CollisionCategories.HasFlag(Physics.CollisionLevel)) return -1; hits.Add(new HitscanResult(fixture, point, normal, fraction)); return hits.Count < 25 ? 1 : 0; }, rayStart, rayEnd); return hits; } public override void Update(float deltaTime, Camera cam) { ApplyStatusEffects(ActionType.OnActive, deltaTime, null); if (item.body != null && item.body.FarseerBody.IsBullet) { if (item.body.LinearVelocity.LengthSquared() < ContinuousCollisionThreshold * ContinuousCollisionThreshold) { item.body.FarseerBody.IsBullet = false; //projectiles with a stickjoint don't become inactive until the stickjoint is detached if (stickJoint == null) IsActive = false; } } if (stickJoint == null) return; if (persistentStickJointTimer > 0.0f) { persistentStickJointTimer -= deltaTime; return; } if (stickJoint.JointTranslation < stickJoint.LowerLimit * 0.9f || stickJoint.JointTranslation > stickJoint.UpperLimit * 0.9f) { if (stickTarget != null) { if (GameMain.World.BodyList.Contains(stickTarget)) { item.body.FarseerBody.RestoreCollisionWith(stickTarget); } stickTarget = null; } if (stickJoint != null) { if (GameMain.World.JointList.Contains(stickJoint)) { GameMain.World.RemoveJoint(stickJoint); } stickJoint = null; } if (!item.body.FarseerBody.IsBullet) IsActive = false; } } private bool OnProjectileCollision(Fixture f1, Fixture f2, Contact contact) { return OnProjectileCollision(f2, contact.Manifold.LocalNormal); } private bool OnProjectileCollision(Fixture target, Vector2 collisionNormal) { if (User != null && User.Removed) User = null; if (IgnoredBodies.Contains(target.Body)) return false; if (target.UserData is Item) return false; if (target.CollisionCategories == Physics.CollisionCharacter && !(target.Body.UserData is Limb)) { return false; } AttackResult attackResult = new AttackResult(); Character character = null; if (target.Body.UserData is Submarine submarine) { item.Move(-submarine.Position); item.Submarine = submarine; item.body.Submarine = submarine; return !Hitscan; } else if (target.Body.UserData is Limb limb) { //severed limbs don't deactivate the projectile (but may still slow it down enough to make it inactive) if (limb.IsSevered) { target.Body.ApplyLinearImpulse(item.body.LinearVelocity * item.body.Mass); return true; } limb.character.LastDamageSource = item; if (attack != null) { attackResult = attack.DoDamageToLimb(User, limb, item.WorldPosition, 1.0f); } if (limb.character != null) { character = limb.character; } } else if (target.Body.UserData is Structure structure) { if (attack != null) { attackResult = attack.DoDamage(User, structure, item.WorldPosition, 1.0f); } } if (character != null) character.LastDamageSource = item; ApplyStatusEffects(ActionType.OnUse, 1.0f, character, target.Body.UserData as Limb, user: user); ApplyStatusEffects(ActionType.OnImpact, 1.0f, character, target.Body.UserData as Limb, user: user); item.body.FarseerBody.OnCollision -= OnProjectileCollision; item.body.CollisionCategories = Physics.CollisionItem; item.body.CollidesWith = Physics.CollisionWall | Physics.CollisionLevel; IgnoredBodies.Clear(); target.Body.ApplyLinearImpulse(item.body.LinearVelocity * item.body.Mass); if (attackResult.AppliedDamageModifiers != null && attackResult.AppliedDamageModifiers.Any(dm => dm.DeflectProjectiles)) { item.body.LinearVelocity *= 0.1f; } else if (Vector2.Dot(item.body.LinearVelocity, collisionNormal) < 0.0f && (DoesStick || (StickToCharacters && target.Body.UserData is Limb) || (StickToStructures && target.Body.UserData is Structure) || (StickToItems && target.Body.UserData is Item))) { Vector2 dir = new Vector2( (float)Math.Cos(item.body.Rotation), (float)Math.Sin(item.body.Rotation)); StickToTarget(target.Body, dir); item.body.LinearVelocity *= 0.5f; return Hitscan; } else { item.body.LinearVelocity *= 0.5f; } var containedItems = item.ContainedItems; if (containedItems != null) { foreach (Item contained in containedItems) { if (contained.body != null) { contained.SetTransform(item.SimPosition, contained.body.Rotation); } } } if (RemoveOnHit) { Entity.Spawner.AddToRemoveQueue(item); } return true; } private void StickToTarget(Body targetBody, Vector2 axis) { if (stickJoint != null) return; stickJoint = new PrismaticJoint(targetBody, item.body.FarseerBody, item.body.SimPosition, axis, true) { MotorEnabled = true, MaxMotorForce = 30.0f, LimitEnabled = true }; if (item.Sprite != null) { stickJoint.LowerLimit = ConvertUnits.ToSimUnits(item.Sprite.size.X * -0.3f); stickJoint.UpperLimit = ConvertUnits.ToSimUnits(item.Sprite.size.X * 0.3f); } persistentStickJointTimer = PersistentStickJointDuration; item.body.FarseerBody.IgnoreCollisionWith(targetBody); stickTarget = targetBody; GameMain.World.AddJoint(stickJoint); IsActive = true; } protected override void RemoveComponentSpecific() { if (stickJoint != null) { try { GameMain.World.RemoveJoint(stickJoint); } catch { //the body that the projectile was stuck to has been removed } stickJoint = null; } } } }