BarotraumaShared/SharedSource/Map/Explosion.cs

using Barotrauma.Extensions;
using Barotrauma.Items.Components;
using Barotrauma.MapCreatures.Behavior;
using Barotrauma.Networking;
using FarseerPhysics;
using Microsoft.Xna.Framework;
using System;
using System.Collections.Generic;
using System.Linq;
 
namespace Barotrauma
{
    partial class Explosion
    {
        public readonly Attack Attack;
 
        private readonly float force;
 
        public float CameraShake { get; set; }
 
        public float CameraShakeRange { get; set; }
 
        private readonly Color screenColor;
 
        private readonly float screenColorRange;
 
        private readonly float screenColorDuration;
 
        private bool sparks;
 
        private bool shockwave;
 
        private bool flames;
 
        private bool smoke;
 
        private bool flash;
 
        private bool debris;
 
        private bool underwaterBubble;
 
        private readonly Color flashColor;
 
        private readonly bool playTinnitus;
 
        private readonly bool applyFireEffects;
 
        private readonly Identifier[] ignoreFireEffectsForTags;
 
        public bool IgnoreCover { get; set; }
 
        public bool DistanceFalloff { get; set; } = true;
 
        public IEnumerable<Structure> IgnoredCover;
 
        private readonly float flashDuration;
 
        private readonly float? flashRange;
 
        private readonly string decal;
 
        private readonly float decalSize;
 
        public bool OnlyInside;
 
        public bool OnlyOutside;
 
        public bool PlayDamageSounds;
 
        private readonly float itemRepairStrength;
 
        public readonly HashSet<Submarine> IgnoredSubmarines = new HashSet<Submarine>();
 
        public readonly HashSet<Character> IgnoredCharacters = new HashSet<Character>();
 
        public float EmpStrength { get; set; }
 
        public float BallastFloraDamage { get; set; }
 
        public Explosion(float range, float force, float damage, float structureDamage, float itemDamage, float empStrength = 0.0f, float ballastFloraStrength = 0.0f)
        {
            Attack = new Attack(damage, 0.0f, 0.0f, structureDamage, itemDamage, Math.Min(range, 1000000))
            {
                SeverLimbsProbability = 1.0f
            };
            this.force = force;
            this.EmpStrength = empStrength;
            BallastFloraDamage = ballastFloraStrength;
            sparks = true;
            debris = true;
            shockwave = true;
            smoke = true;
            flames = true;
            underwaterBubble = true;
            ignoreFireEffectsForTags = Array.Empty<Identifier>();
        }
        
        public Explosion(ContentXElement element, string parentDebugName)
        {
            Attack = new Attack(element, parentDebugName + ", Explosion");
 
            force = element.GetAttributeFloat("force", 0.0f);
 
            //the "abilityexplosion" field is kept for backwards compatibility (basically the opposite of "showeffects")
            bool showEffects = !element.GetAttributeBool("abilityexplosion", false) && element.GetAttributeBool("showeffects", true);
            sparks = element.GetAttributeBool("sparks", showEffects);
            shockwave = element.GetAttributeBool("shockwave", showEffects);
            flames = element.GetAttributeBool("flames", showEffects);
            underwaterBubble = element.GetAttributeBool("underwaterbubble", showEffects);
            smoke = element.GetAttributeBool("smoke", showEffects);
            debris = element.GetAttributeBool("debris", false);
 
            playTinnitus = element.GetAttributeBool("playtinnitus", showEffects);
 
            applyFireEffects = element.GetAttributeBool("applyfireeffects", flames && showEffects);
            ignoreFireEffectsForTags = element.GetAttributeIdentifierArray("ignorefireeffectsfortags", Array.Empty<Identifier>());
 
            IgnoreCover = element.GetAttributeBool("ignorecover", false);
            OnlyInside = element.GetAttributeBool("onlyinside", false);
            OnlyOutside = element.GetAttributeBool("onlyoutside", false);
 
            flash           = element.GetAttributeBool("flash", showEffects);
            flashDuration   = element.GetAttributeFloat("flashduration", 0.05f);
            if (element.GetAttribute("flashrange") != null) { flashRange = element.GetAttributeFloat("flashrange", 100.0f); }
            flashColor = element.GetAttributeColor("flashcolor", Color.LightYellow);
 
            PlayDamageSounds = element.GetAttributeBool(nameof(PlayDamageSounds), false);
 
            EmpStrength = element.GetAttributeFloat("empstrength", 0.0f);
            BallastFloraDamage = element.GetAttributeFloat("ballastfloradamage", 0.0f);
 
            itemRepairStrength = element.GetAttributeFloat("itemrepairstrength", 0.0f);
 
            decal = element.GetAttributeString("decal", "");
            decalSize   = element.GetAttributeFloat(1.0f, "decalSize", "decalsize");
 
            CameraShake = element.GetAttributeFloat("camerashake", showEffects ? Attack.Range * 0.1f : 0f);
            CameraShakeRange = element.GetAttributeFloat("camerashakerange", showEffects ? Attack.Range : 0f);
 
            screenColorRange = element.GetAttributeFloat("screencolorrange", showEffects ? Attack.Range * 0.1f : 0f);
            screenColor = element.GetAttributeColor("screencolor", Color.Transparent);
            screenColorDuration = element.GetAttributeFloat("screencolorduration", 0.1f);
 
        }
 
        public void DisableParticles()
        {
            sparks = false;
            shockwave = false;
            smoke = false;
            flash = false;
            debris = false;
            flames = false;
            underwaterBubble = false;
        }
 
        public void Explode(Vector2 worldPosition, Entity damageSource, Character attacker = null)
        {
            Hull hull = Hull.FindHull(worldPosition);
            ExplodeProjSpecific(worldPosition, hull);
 
            if (hull != null && !string.IsNullOrWhiteSpace(decal) && decalSize > 0.0f)
            {
                hull.AddDecal(decal, worldPosition, decalSize, isNetworkEvent: false);
            }
 
            Attack.DamageMultiplier = 1.0f;
            float displayRange = Attack.Range;
            if (damageSource is Item sourceItem)
            {
                var launcher = sourceItem.GetComponent<Projectile>()?.Launcher;
                displayRange *=
                    1.0f
                    + sourceItem.GetQualityModifier(Quality.StatType.ExplosionRadius)
                    + (launcher?.GetQualityModifier(Quality.StatType.ExplosionRadius) ?? 0);
                Attack.DamageMultiplier *=
                    1.0f
                    + sourceItem.GetQualityModifier(Quality.StatType.ExplosionDamage)
                    + (launcher?.GetQualityModifier(Quality.StatType.ExplosionDamage) ?? 0);
                Attack.SourceItem ??= sourceItem;
            }
 
            if (attacker is not null)
            {
                displayRange *= 1f + attacker.GetStatValue(StatTypes.ExplosionRadiusMultiplier);
                Attack.DamageMultiplier *= 1f + attacker.GetStatValue(StatTypes.ExplosionDamageMultiplier);
            }
 
            Vector2 cameraPos = GameMain.GameScreen.Cam.Position;
            float cameraDist = Vector2.Distance(cameraPos, worldPosition) / 2.0f;
            GameMain.GameScreen.Cam.Shake = CameraShake * Math.Max((CameraShakeRange - cameraDist) / CameraShakeRange, 0.0f);
#if CLIENT
            if (screenColor != Color.Transparent)
            {
                Color flashColor = Color.Lerp(Color.Transparent, screenColor, Math.Max((screenColorRange - cameraDist) / screenColorRange, 0.0f));
                Screen.Selected.ColorFade(flashColor, Color.Transparent, screenColorDuration);
            }
            foreach (Item item in Item.ItemList)
            {
                item.GetComponent<Sonar>()?.RegisterExplosion(this, worldPosition);
            }
#endif
 
            if (displayRange < 0.1f) { return; }
 
            if (!MathUtils.NearlyEqual(Attack.GetStructureDamage(1.0f), 0.0f) || !MathUtils.NearlyEqual(Attack.GetLevelWallDamage(1.0f), 0.0f))
            {
                RangedStructureDamage(worldPosition, displayRange, 
                    Attack.GetStructureDamage(1.0f),
                    Attack.GetLevelWallDamage(1.0f), 
                    attacker, IgnoredSubmarines, 
                    Attack.EmitStructureDamageParticles,
                    Attack.CreateWallDamageProjectiles,
                    DistanceFalloff);
            }
 
            if (BallastFloraDamage > 0.0f)
            {
                RangedBallastFloraDamage(worldPosition, displayRange, BallastFloraDamage, attacker, DistanceFalloff);
            }
 
            if (EmpStrength > 0.0f)
            {
                float displayRangeSqr = displayRange * displayRange;
                foreach (Item item in Item.ItemList)
                {
                    float distSqr = Vector2.DistanceSquared(item.WorldPosition, worldPosition);
                    if (distSqr > displayRangeSqr) { continue; }
                    float distFactor = DistanceFalloff ? CalculateDistanceFactor(distSqr, displayRange) : 1.0f;
 
                    //damage repairable power-consuming items
                    var powered = item.GetComponent<Powered>();
                    if (powered == null || !powered.VulnerableToEMP) { continue; }
                    if (item.Repairables.Any())
                    {
                        item.Condition -= item.MaxCondition * EmpStrength * distFactor;
                    }
 
                    var lightComponent = item.GetComponent<LightComponent>();
                    if (lightComponent != null)
                    {
                        //multiply by 10 to make the effect more noticeable
                        //(a strength of 1 is already enough to kill power and shut down the lights, but we want weaker EMPs to make the lights flicker noticeably)
                        lightComponent.TemporaryFlickerTimer = Math.Min(EmpStrength * distFactor * 10.0f, 10.0f);
                    }
 
                    //discharge batteries
                    var powerContainer = item.GetComponent<PowerContainer>();
                    if (powerContainer != null)
                    {
                        powerContainer.Charge -= powerContainer.GetCapacity() * EmpStrength * distFactor;
                    }
                }
                static float CalculateDistanceFactor(float distSqr, float displayRange) => 1.0f - MathF.Sqrt(distSqr) / displayRange;
            }
 
            if (itemRepairStrength > 0.0f)
            {
                float displayRangeSqr = displayRange * displayRange;
                foreach (Item item in Item.ItemList)
                {
                    float distSqr = Vector2.DistanceSquared(item.WorldPosition, worldPosition);
                    if (distSqr > displayRangeSqr) { continue; }
 
                    float distFactor = 
                        DistanceFalloff ? 
                        1.0f - (float)Math.Sqrt(distSqr) / displayRange :
                        1.0f;
                    //repair repairable items
                    if (item.Repairables.Any())
                    {
                        item.Condition += itemRepairStrength * distFactor;
                    }
                }
            }
 
            if (MathUtils.NearlyEqual(force, 0.0f) && MathUtils.NearlyEqual(Attack.Stun, 0.0f) && Attack.Afflictions.None())
            {
                return;
            }
 
            DamageCharacters(worldPosition, Attack, force, damageSource, attacker);
 
            if (GameMain.NetworkMember == null || !GameMain.NetworkMember.IsClient)
            {
                foreach (Item item in Item.ItemList)
                {
                    if (item.Condition <= 0.0f) { continue; }
                    float dist = Vector2.Distance(item.WorldPosition, worldPosition);
                    float itemRadius = item.body == null ? 0.0f : item.body.GetMaxExtent();
                    dist = Math.Max(0.0f, dist - ConvertUnits.ToDisplayUnits(itemRadius));
                    if (dist > displayRange) { continue; }
 
                    if (dist < displayRange * 0.5f && applyFireEffects && !item.FireProof && ignoreFireEffectsForTags.None(t => item.HasTag(t)))
                    {
                        //don't apply OnFire effects if the item is inside a fireproof container
                        //(or if it's inside a container that's inside a fireproof container, etc)
                        Item container = item.Container;
                        bool fireProof = false;
                        while (container != null)
                        {
                            if (container.FireProof)
                            {
                                fireProof = true;
                                break;
                            }
                            container = container.Container;
                        }
                        if (!fireProof)
                        {
                            item.ApplyStatusEffects(ActionType.OnFire, 1.0f);
                            if (item.Condition <= 0.0f && GameMain.NetworkMember is { IsServer: true })
                            {
                                GameMain.NetworkMember.CreateEntityEvent(item, new Item.ApplyStatusEffectEventData(ActionType.OnFire));
                            }
                        }                        
                    }
 
                    if (item.Prefab.DamagedByExplosions && !item.Indestructible)
                    {
                        float distFactor = 
                            DistanceFalloff ? 
                            1.0f - dist / displayRange : 
                            1.0f;
                        float damageAmount = Attack.GetItemDamage(1.0f, item.Prefab.ExplosionDamageMultiplier);
 
                        Vector2 explosionPos = worldPosition;
                        if (item.Submarine != null) { explosionPos -= item.Submarine.Position; }
 
                        damageAmount *= GetObstacleDamageMultiplier(ConvertUnits.ToSimUnits(explosionPos), worldPosition, item.SimPosition, IgnoredCover);
                        item.Condition -= damageAmount * distFactor;
                    }
                }
            }
        }
 
        partial void ExplodeProjSpecific(Vector2 worldPosition, Hull hull);
 
        private void DamageCharacters(Vector2 worldPosition, Attack attack, float force, Entity damageSource, Character attacker)
        {
            if (attack.Range <= 0.0f) { return; }
 
            //long range for the broad distance check, because large characters may still be in range even if their collider isn't
            float broadRange = Math.Max(attack.Range * 10.0f, 10000.0f);
 
            foreach (Character c in Character.CharacterList)
            {
                if (attack.OnlyHumans && !c.IsHuman) { continue; }
                if (IgnoredCharacters.Contains(c)) { continue; }
 
                if (!c.Enabled || 
                    Math.Abs(c.WorldPosition.X - worldPosition.X) > broadRange ||
                    Math.Abs(c.WorldPosition.Y - worldPosition.Y) > broadRange)
                {
                    continue;
                }
 
                if (OnlyInside && c.Submarine == null) 
                { 
                    continue; 
                }
                else if (OnlyOutside && c.Submarine != null) 
                { 
                    continue; 
                }
 
                Vector2 explosionPos = worldPosition;
                if (c.Submarine != null) { explosionPos -= c.Submarine.Position; }
 
                Hull hull = Hull.FindHull(explosionPos, null, false);
                bool underWater = hull == null || explosionPos.Y < hull.Surface;
 
                explosionPos = ConvertUnits.ToSimUnits(explosionPos);
 
                Dictionary<Limb, float> distFactors = new Dictionary<Limb, float>();
                Dictionary<Limb, float> damages = new Dictionary<Limb, float>();
                List<Affliction> modifiedAfflictions = new List<Affliction>();
 
                Limb closestLimb = null;
                float closestDistFactor = 0;
                foreach (Limb limb in c.AnimController.Limbs)
                {
                    if (limb.IsSevered || limb.IgnoreCollisions || !limb.body.Enabled) { continue; }
 
                    float dist = Vector2.Distance(limb.WorldPosition, worldPosition);
 
                    //calculate distance from the "outer surface" of the physics body
                    //doesn't take the rotation of the limb into account, but should be accurate enough for this purpose
                    float limbRadius = limb.body.GetMaxExtent();
                    dist = Math.Max(0.0f, dist - ConvertUnits.ToDisplayUnits(limbRadius));
 
                    if (dist > attack.Range) { continue; }
 
                    float distFactor = 
                        DistanceFalloff ? 
                        1.0f - dist / attack.Range : 
                        1.0f;
 
                    //solid obstacles between the explosion and the limb reduce the effect of the explosion
                    if (!IgnoreCover)
                    {
                        distFactor *= GetObstacleDamageMultiplier(explosionPos, worldPosition, limb.SimPosition, IgnoredCover);
                    }
                    if (distFactor > 0)
                    {
                        distFactors.Add(limb, distFactor);
                        if (distFactor > closestDistFactor)
                        {
                            closestLimb = limb;
                            closestDistFactor = distFactor;
                        }
                    }
                }
 
                foreach (Limb limb in distFactors.Keys)
                {
                    if (!distFactors.TryGetValue(limb, out float distFactor)) { continue; }
                    modifiedAfflictions.Clear();
                    foreach (Affliction affliction in attack.Afflictions.Keys)
                    {
                        float dmgMultiplier = distFactor;
                        if (affliction.DivideByLimbCount)
                        {
                            float limbCountFactor = distFactors.Count;
                            if (affliction.Prefab.LimbSpecific && affliction.Prefab.AfflictionType == AfflictionPrefab.DamageType)
                            {
                                // Shouldn't go above 15, or the damage can be unexpectedly low -> doesn't break armor
                                // Effectively this makes large explosions more effective against large creatures (because more limbs are affected), but I don't think that's necessarily a bad thing.
                                limbCountFactor = Math.Min(distFactors.Count, 15);
                            }
                            dmgMultiplier /= limbCountFactor;
                        }
                        modifiedAfflictions.Add(affliction.CreateMultiplied(dmgMultiplier, affliction));
                    }
                    c.LastDamageSource = damageSource;
                    if (attacker == null)
                    {
                        if (damageSource is Item item)
                        {
                            attacker = item.GetComponent<Projectile>()?.User;
                            attacker ??= item.GetComponent<MeleeWeapon>()?.User;
                        }
                    }
 
                    if (attack.Afflictions.Any() || attack.Stun > 0.0f)
                    {
                        if (!attack.OnlyHumans || c.IsHuman)
                        {
                            AbilityAttackData attackData = new AbilityAttackData(Attack, c, attacker);
                            if (attackData.Afflictions != null)
                            {
                                modifiedAfflictions.AddRange(attackData.Afflictions);
                            }
 
                            //use a position slightly from the limb's position towards the explosion
                            //ensures that the attack hits the correct limb and that the direction of the hit can be determined correctly in the AddDamage methods
                            Vector2 dir = worldPosition - limb.WorldPosition;
                            Vector2 hitPos = limb.WorldPosition + (dir.LengthSquared() <= 0.001f ? Rand.Vector(1.0f) : Vector2.Normalize(dir)) * 0.01f;
 
                            //only play the damage sound on the closest limb (playing it on all just sounds like a mess)
                            bool playSound = PlayDamageSounds && limb == closestLimb;
 
                            AttackResult attackResult = c.AddDamage(hitPos, modifiedAfflictions, attack.Stun * distFactor, playSound: playSound, attacker: attacker, damageMultiplier: attack.DamageMultiplier * attackData.DamageMultiplier);
                            damages.Add(limb, attackResult.Damage);
                        }
                    }
 
                    if (attack.StatusEffects != null && attack.StatusEffects.Any())
                    {
                        attack.SetUser(attacker);
                        var statusEffectTargets = new List<ISerializableEntity>();
                        foreach (StatusEffect statusEffect in attack.StatusEffects)
                        {
                            statusEffectTargets.Clear();
                            if (statusEffect.HasTargetType(StatusEffect.TargetType.Character)) { statusEffectTargets.Add(c); }
                            if (statusEffect.HasTargetType(StatusEffect.TargetType.Limb)) { statusEffectTargets.Add(limb); }
                            statusEffect.Apply(ActionType.OnUse, 1.0f, damageSource, statusEffectTargets);
                            statusEffect.Apply(ActionType.Always, 1.0f, damageSource, statusEffectTargets);
                            statusEffect.Apply(underWater ? ActionType.InWater : ActionType.NotInWater, 1.0f, damageSource, statusEffectTargets);
                        }
                    }
                    
                    if (limb.WorldPosition != worldPosition && !MathUtils.NearlyEqual(force, 0.0f))
                    {
                        Vector2 limbDiff = Vector2.Normalize(limb.WorldPosition - worldPosition);
                        if (!MathUtils.IsValid(limbDiff)) { limbDiff = Rand.Vector(1.0f); }
                        Vector2 impulse = limbDiff * distFactor * force;
                        Vector2 impulsePoint = limb.SimPosition - limbDiff * limb.body.GetMaxExtent();
                        limb.body.ApplyLinearImpulse(impulse, impulsePoint, maxVelocity: NetConfig.MaxPhysicsBodyVelocity * 0.2f);
                    }
                }
 
                if (c == Character.Controlled && !c.IsDead && playTinnitus)
                {
                    Limb head = c.AnimController.GetLimb(LimbType.Head);
                    if (head != null && damages.TryGetValue(head, out float headDamage) && headDamage > 0.0f && distFactors.TryGetValue(head, out float headFactor))
                    {
                        PlayTinnitusProjSpecific(headFactor);
                    }
                }
 
                //sever joints 
                if (attack.SeverLimbsProbability > 0.0f)
                {
                    foreach (Limb limb in c.AnimController.Limbs)
                    {
                        if (limb.character.Removed || limb.Removed) { continue; }
                        if (limb.IsSevered) { continue; }
                        if (!c.IsDead && !limb.CanBeSeveredAlive) { continue; }
                        if (distFactors.TryGetValue(limb, out float distFactor))
                        {
                            if (damages.TryGetValue(limb, out float damage))
                            {
                                c.TrySeverLimbJoints(limb, attack.SeverLimbsProbability * distFactor, damage, allowBeheading: true, attacker: attacker);
                            }
                        }
                    }
                }
            }
        }
 
        private static readonly Dictionary<Structure, float> damagedStructures = new Dictionary<Structure, float>();
        public static Dictionary<Structure, float> RangedStructureDamage(Vector2 worldPosition, float worldRange, float damage, float levelWallDamage, Character attacker = null, IEnumerable<Submarine> ignoredSubmarines = null, 
            bool emitWallDamageParticles = true,
            bool createWallDamageProjectiles = false, 
            bool distanceFalloff = true)
        {
            float dist = 600.0f;
            damagedStructures.Clear();
            foreach (Structure structure in Structure.WallList)
            {
                if (ignoredSubmarines != null && structure.Submarine != null && ignoredSubmarines.Contains(structure.Submarine)) { continue; }
 
                if (structure.HasBody &&
                    !structure.IsPlatform &&
                    Vector2.Distance(structure.WorldPosition, worldPosition) < dist * 3.0f)
                {
                    for (int i = 0; i < structure.SectionCount; i++)
                    {
                        float distFactor = 
                            distanceFalloff ? 
                            1.0f - (Vector2.Distance(structure.SectionPosition(i, true), worldPosition) / worldRange) :
                            1.0f;
                        if (distFactor <= 0.0f) { continue; }
 
                        structure.AddDamage(i, damage * distFactor, attacker, emitParticles: emitWallDamageParticles, createWallDamageProjectiles);
 
                        if (damagedStructures.ContainsKey(structure))
                        {
                            damagedStructures[structure] += damage * distFactor;
                        }
                        else
                        {
                            damagedStructures.Add(structure, damage * distFactor);
                        }
                    }
                }
            }
 
            if (Level.Loaded != null && !MathUtils.NearlyEqual(levelWallDamage, 0.0f))
            {
                if (Level.Loaded?.LevelObjectManager != null)
                {
                    foreach (var levelObject in Level.Loaded.LevelObjectManager.GetAllObjects(worldPosition, worldRange))
                    {
                        if (levelObject.Prefab.TakeLevelWallDamage)
                        {
                            float distFactor = 1.0f - (Vector2.Distance(levelObject.WorldPosition, worldPosition) / worldRange);
                            if (distFactor <= 0.0f) { continue; }
                            levelObject.AddDamage(levelWallDamage * distFactor, 1.0f, null);
                        }
                    }
                }
 
                for (int i = Level.Loaded.ExtraWalls.Count - 1; i >= 0; i--)
                {
                    if (Level.Loaded.ExtraWalls[i] is not DestructibleLevelWall destructibleWall) { continue; }
 
                    bool inRange = false;
                    foreach (var cell in destructibleWall.Cells)
                    {
                        if (cell.IsPointInside(worldPosition))
                        {
                            inRange = true;
                            break;
                        }
                        foreach (var edge in cell.Edges)
                        {
                            if (MathUtils.LineSegmentToPointDistanceSquared((edge.Point1 + cell.Translation).ToPoint(), (edge.Point2 + cell.Translation).ToPoint(), worldPosition.ToPoint()) < worldRange * worldRange)
                            {
                                inRange = true;
                                break;
                            }
                        }
                        if (inRange) { break; }
                    }
                    if (inRange)
                    {
                        destructibleWall.AddDamage(levelWallDamage, worldPosition);
                    }
                }
            }
 
            return damagedStructures;
        }
 
        public static void RangedBallastFloraDamage(Vector2 worldPosition, float worldRange, float damage, Character attacker = null, bool distanceFalloff = true)
        {
            List<BallastFloraBehavior> ballastFlorae = new List<BallastFloraBehavior>();
 
            foreach (Hull hull in Hull.HullList)
            {
                if (hull.BallastFlora != null) { ballastFlorae.Add(hull.BallastFlora); }
            }
 
            foreach (BallastFloraBehavior ballastFlora in ballastFlorae)
            {
                float resistanceMuliplier = ballastFlora.HasBrokenThrough ? 1f : 1f - ballastFlora.ExplosionResistance; 
                ballastFlora.Branches.ForEachMod(branch =>
                {
                    Vector2 branchWorldPos = ballastFlora.GetWorldPosition() + branch.Position;
                    float branchDist = Vector2.Distance(branchWorldPos, worldPosition);
                    if (branchDist < worldRange)
                    {
                        float distFactor = 
                            distanceFalloff ? 
                            1.0f - (branchDist / worldRange) : 
                            1.0f;
                        if (distFactor <= 0.0f) { return; }
 
                        Vector2 explosionPos = worldPosition;
                        Vector2 branchPos = branchWorldPos;
                        if (ballastFlora.Parent?.Submarine != null) 
                        { 
                            explosionPos -= ballastFlora.Parent.Submarine.Position;
                            branchPos -= ballastFlora.Parent.Submarine.Position; 
                        }
                        distFactor *= GetObstacleDamageMultiplier(ConvertUnits.ToSimUnits(explosionPos), worldPosition, ConvertUnits.ToSimUnits(branchPos));
                        ballastFlora.DamageBranch(branch, damage * distFactor * resistanceMuliplier, BallastFloraBehavior.AttackType.Explosives, attacker);
                    }
                });
            }
        }
 
        private static float GetObstacleDamageMultiplier(Vector2 explosionSimPos, Vector2 explosionWorldPos, Vector2 targetSimPos, IEnumerable<Structure> ignoredCover = null)
        {
            float damageMultiplier = 1.0f;
            var obstacles = Submarine.PickBodies(targetSimPos, explosionSimPos, collisionCategory: Physics.CollisionItem | Physics.CollisionItemBlocking | Physics.CollisionWall);
            foreach (var body in obstacles)
            {
                if (body.UserData is Item item)
                {
                    var door = item.GetComponent<Door>();
                    if (door != null && !door.IsOpen && !door.IsBroken) { damageMultiplier *= 0.01f; }
                }
                else if (body.UserData is Structure structure)
                {
                    if (ignoredCover != null)
                    {
                        if (ignoredCover.Contains(structure)) { continue; }
                    }
                    int sectionIndex = structure.FindSectionIndex(explosionWorldPos, world: true, clamp: true);
                    if (structure.SectionBodyDisabled(sectionIndex))
                    {
                        continue;
                    }
                    else if (structure.SectionIsLeaking(sectionIndex))
                    {
                        damageMultiplier *= 0.1f;
                    }
                    else
                    {
                        damageMultiplier *= 0.01f;
                    }
                }
                else
                {
                    damageMultiplier *= 0.1f;
                }
            }
            return damageMultiplier;
        }
 
        static partial void PlayTinnitusProjSpecific(float volume);
    }
}