Initial Combat Implementation

2026-05-31 21:35:12 -07:00
parent 7fa77ce821
commit 1f647dd5e1
166 changed files with 93337 additions and 91 deletions
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+using Unity.Entities;
+using Unity.NetCode;
+
+namespace ProjectM.Simulation
+{
+    /// <summary>
+    /// Predicted per-player ability cooldown gate. Holds the earliest server tick at which the
+    /// owning player may fire again, so <see cref="AbilityFireSystem"/> can throttle shots
+    /// deterministically across client prediction and server simulation.
+    /// <para>
+    /// Replicated as a <see cref="GhostField"/> so the cooldown survives the frame→tick→rollback
+    /// boundary: when the client re-predicts ticks after a snapshot, it sees the same authoritative
+    /// gate the server applied and converges without double-firing. Stored as a raw <c>uint</c>
+    /// rather than a <see cref="NetworkTick"/> for simple, quantization-free serialization; compare
+    /// by wrapping it back into a <see cref="NetworkTick"/> and using
+    /// <see cref="NetworkTick.IsNewerThan"/> (raw subtraction is unsafe across tick wraparound).
+    /// </para>
+    /// </summary>
+    public struct AbilityCooldown : IComponentData
+    {
+        /// <summary>
+        /// Raw tick value of the earliest tick the player may fire again. <c>0</c> = ready (no
+        /// cooldown pending). Set by <see cref="AbilityFireSystem"/> to
+        /// <c>serverTick + max(1, CooldownTicks)</c> on fire; treat as "still cooling down" only
+        /// while a valid <see cref="NetworkTick"/> built from it is newer than the current
+        /// <c>ServerTick</c>.
+        /// </summary>
+        [GhostField] public uint NextFireTick;
+    }
+}
@@ -0,0 +1,2 @@
+fileFormatVersion: 2
+guid: b7a2b67b22b2a4abaa8efd84759445c0
@@ -0,0 +1,14 @@
+using Unity.Entities;
+
+namespace ProjectM.Simulation
+{
+    /// <summary>
+    /// Singleton handle to the baked ability/character definition database (config, not replicated -
+    /// baked identically into both worlds from the gameplay subscene). The companion AbilityPrefabElement
+    /// buffer on the same entity carries the per-ability projectile prefab entity refs.
+    /// </summary>
+    public struct AbilityDatabase : IComponentData
+    {
+        public BlobAssetReference<AbilityDatabaseBlob> Value;
+    }
+}
@@ -0,0 +1,2 @@
+fileFormatVersion: 2
+guid: 6b297f7d451084342af25012ccb3a3e8
@@ -0,0 +1,74 @@
+using Unity.Collections;
+using Unity.Entities;
+
+namespace ProjectM.Simulation
+{
+    /// <summary>One authored ability definition, baked immutable into the AbilityDatabase blob.</summary>
+    public struct AbilityDefBlob
+    {
+        public byte Id; // AbilityId
+        public float Damage;
+        public float ProjectileSpeed;
+        public float Range;
+        public float AutoTargetRange;
+        public float AutoTargetConeRadians;
+        public int CooldownTicks;
+        public FixedString64Bytes Name;
+    }
+
+    /// <summary>One authored character-stats definition, baked immutable into the AbilityDatabase blob.</summary>
+    public struct CharacterStatsBlob
+    {
+        public byte Id; // CharacterId
+        public float MoveSpeed;
+        public float TurnRateRadiansPerSec;
+        public float MaxHealth;
+        public FixedString64Bytes Name;
+    }
+
+    /// <summary>
+    /// Immutable designer-authored definition database, baked from ScriptableObjects to a blob asset and
+    /// shared by every entity (Burst-fast, zero per-instance cost). Looked up by stable id. Entity/prefab
+    /// references are NOT stored here (blobs don't remap entity refs) - see AbilityPrefabElement.
+    ///
+    /// NOTE: the lookups are intentionally NOT 'readonly' methods. A readonly struct method forces a
+    /// defensive copy of a field when calling a non-readonly member on it; copying a BlobArray breaks its
+    /// relative-offset pointer, so the array would read as empty. Plain (non-readonly) methods access the
+    /// BlobArray in place. Always reach these through 'ref blob.Value'.
+    /// </summary>
+    public struct AbilityDatabaseBlob
+    {
+        public BlobArray<AbilityDefBlob> Abilities;
+        public BlobArray<CharacterStatsBlob> Characters;
+
+        /// <summary>Linear lookup by ability id (the array is tiny). Returns false if not present.</summary>
+        public bool TryGetAbility(byte id, out AbilityDefBlob def)
+        {
+            for (int i = 0; i < Abilities.Length; i++)
+            {
+                if (Abilities[i].Id == id)
+                {
+                    def = Abilities[i];
+                    return true;
+                }
+            }
+            def = default;
+            return false;
+        }
+
+        /// <summary>Linear lookup by character id (the array is tiny). Returns false if not present.</summary>
+        public bool TryGetCharacter(byte id, out CharacterStatsBlob def)
+        {
+            for (int i = 0; i < Characters.Length; i++)
+            {
+                if (Characters[i].Id == id)
+                {
+                    def = Characters[i];
+                    return true;
+                }
+            }
+            def = default;
+            return false;
+        }
+    }
+}
@@ -0,0 +1,2 @@
+fileFormatVersion: 2
+guid: 974be1ee95bef486ea49a4d42ecc9796
@@ -0,0 +1,173 @@
+using Unity.Burst;
+using Unity.Collections;
+using Unity.Entities;
+using Unity.Mathematics;
+using Unity.NetCode;
+using Unity.Transforms;
+
+namespace ProjectM.Simulation
+{
+    /// <summary>
+    /// Predicted "fire" ability: on the single fully-predicting pass of each tick, spawns a
+    /// Projectile ghost for every player whose PlayerInput.Fire event is set this tick and whose
+    /// AbilityCooldown has elapsed. Runs in both worlds: the owning client predict-spawns the
+    /// projectile (classified into the authoritative ghost by ProjectileClassificationSystem via the
+    /// Projectile.SpawnId key), and the server spawns the replicated truth.
+    ///
+    /// M3 data-driven: ability stats are read from the per-entity EffectiveAbilityStats (authored base
+    /// from the AbilityDatabase blob keyed by AbilityRef, folded with the replicated StatModifier buffer
+    /// by StatRecomputeSystem earlier this tick). The projectile ghost prefab is resolved per ability via
+    /// the AbilityPrefabElement buffer on the AbilityDatabase singleton. Effective Speed/Damage/Range are
+    /// snapshotted into the spawned Projectile, so the downstream move/damage systems are unchanged and
+    /// predicted + server projectiles match (both folded the same replicated modifiers).
+    ///
+    /// Determinism / idempotency: the prediction loop re-runs this system on rollback, so all
+    /// non-idempotent effects (spawning, cooldown advance) are gated behind
+    /// NetworkTime.IsFirstTimeFullyPredictingTick so they happen exactly once per tick. The absolute
+    /// fire count comes from the replicated input command buffer at NetworkTime.ServerTick (not a
+    /// local counter) so the SpawnId matches on client and server. No wall-clock, no System.Random,
+    /// no UnityEngine.Time.
+    ///
+    /// Auto-target is intentionally server-only: the client fires along raw aim, and the server's
+    /// authoritative Projectile.Direction GhostField reconciles the predicted projectile to the
+    /// assisted heading.
+    /// </summary>
+    [UpdateInGroup(typeof(PredictedSimulationSystemGroup))]
+    [UpdateAfter(typeof(PlayerAimSystem))]
+    [BurstCompile]
+    public partial struct AbilityFireSystem : ISystem
+    {
+        [BurstCompile]
+        public void OnCreate(ref SystemState state)
+        {
+            state.RequireForUpdate<AbilityDatabase>();
+            state.RequireForUpdate<NetworkTime>();
+        }
+
+        [BurstCompile]
+        public void OnUpdate(ref SystemState state)
+        {
+            // Spawning is a one-off effect: only run on the unique fully-predicting pass of this tick
+            // so a rollback re-simulation does not double-spawn.
+            var networkTime = SystemAPI.GetSingleton<NetworkTime>();
+            if (!networkTime.IsFirstTimeFullyPredictingTick)
+                return;
+
+            var serverTick = networkTime.ServerTick;
+            if (!serverTick.IsValid)
+                return;
+
+            // Per-ability projectile ghost prefabs live on the AbilityDatabase singleton's companion buffer.
+            var dbEntity = SystemAPI.GetSingletonEntity<AbilityDatabase>();
+            var abilityPrefabs = SystemAPI.GetBuffer<AbilityPrefabElement>(dbEntity);
+
+            bool isServer = state.WorldUnmanaged.IsServer();
+
+            // Server-only auto-target candidate set: training-dummy world XZ positions, collected once.
+            var candidatePositions = new NativeList<float3>(Allocator.Temp);
+            if (isServer)
+            {
+                foreach (var dummyTransform in
+                         SystemAPI.Query<RefRO<LocalTransform>>().WithAll<TrainingDummyTag>())
+                {
+                    candidatePositions.Add(dummyTransform.ValueRO.Position);
+                }
+            }
+            var candidates = candidatePositions.AsArray();
+
+            var ecb = new EntityCommandBuffer(state.WorldUpdateAllocator);
+
+            foreach (var (input, facing, xform, eff, abilityRef, cd, owner, entity) in
+                     SystemAPI.Query<RefRO<PlayerInput>, RefRO<PlayerFacing>, RefRO<LocalTransform>,
+                             RefRO<EffectiveAbilityStats>, RefRO<AbilityRef>, RefRW<AbilityCooldown>,
+                             RefRO<GhostOwner>>()
+                         .WithAll<Simulate>()
+                         .WithEntityAccess())
+            {
+                // The InputEvent on the component carries the per-tick delta: set => fired this tick.
+                if (!input.ValueRO.Fire.IsSet)
+                    continue;
+
+                // Cooldown gate. NextFireTick == 0 means "ready". Otherwise the player may fire only
+                // once serverTick is at-or-newer than the stored tick (i.e. the stored tick is not
+                // strictly newer than now).
+                uint nextFireRaw = cd.ValueRO.NextFireTick;
+                if (nextFireRaw != 0)
+                {
+                    var nextTick = new NetworkTick(nextFireRaw);
+                    if (nextTick.IsValid && nextTick.IsNewerThan(serverTick))
+                        continue; // still cooling down
+                }
+
+                // Resolve the projectile ghost prefab for this player's selected ability id.
+                Entity prefab = Entity.Null;
+                for (int i = 0; i < abilityPrefabs.Length; i++)
+                {
+                    if (abilityPrefabs[i].Id == abilityRef.ValueRO.Id)
+                    {
+                        prefab = abilityPrefabs[i].Prefab;
+                        break;
+                    }
+                }
+                if (prefab == Entity.Null)
+                    continue; // ability has no projectile prefab wired
+
+                // Absolute (monotonic) fire count from the replicated command buffer at this tick.
+                // This is the classification key shared by client prediction and server truth.
+                var inputBuffer = SystemAPI.GetBuffer<InputBufferData<PlayerInput>>(entity);
+                if (!inputBuffer.GetDataAtTick(serverTick, out var applied))
+                    continue;
+                uint absoluteFireCount = applied.InternalInput.Fire.Count;
+
+                float2 rawAim = facing.ValueRO.Direction;
+                if (math.lengthsq(rawAim) < 1e-6f)
+                    rawAim = new float2(0f, 1f);
+                else
+                    rawAim = math.normalize(rawAim);
+
+                // Client fires along raw aim; only the server applies the auto-target assist cone.
+                float2 dir = rawAim;
+                if (isServer && eff.ValueRO.AutoTargetRange > 0f)
+                {
+                    dir = AutoTarget.Resolve(
+                        xform.ValueRO.Position,
+                        rawAim,
+                        eff.ValueRO.AutoTargetRange,
+                        eff.ValueRO.AutoTargetConeRadians,
+                        candidates);
+                }
+
+                uint spawnId = (uint)owner.ValueRO.NetworkId << 16 | absoluteFireCount;
+
+                var projectile = ecb.Instantiate(prefab);
+
+                float3 planarDir = new float3(dir.x, 0f, dir.y);
+                float3 spawnPos = xform.ValueRO.Position + planarDir * 0.6f;
+                spawnPos.y = xform.ValueRO.Position.y;
+                quaternion rot = quaternion.LookRotationSafe(planarDir, math.up());
+
+                ecb.SetComponent(projectile, LocalTransform.FromPositionRotation(spawnPos, rot));
+                ecb.SetComponent(projectile, new GhostOwner { NetworkId = owner.ValueRO.NetworkId });
+                // Snapshot the effective ability stats into the projectile (base + modifiers, computed
+                // identically on both worlds), so the move/damage systems need no modifier lookup.
+                ecb.SetComponent(projectile, new Projectile
+                {
+                    Direction = math.normalize(dir),
+                    SpawnId = spawnId,
+                    Speed = eff.ValueRO.ProjectileSpeed,
+                    Damage = eff.ValueRO.Damage,
+                    Range = eff.ValueRO.Range,
+                    DistanceTravelled = 0f,
+                });
+
+                // Earliest raw tick the player may fire again. Clamp cooldown to >= 1 tick.
+                uint cooldownTicks = (uint)math.max(1, eff.ValueRO.CooldownTicks);
+                cd.ValueRW.NextFireTick = serverTick.TickIndexForValidTick + cooldownTicks;
+            }
+
+            ecb.Playback(state.EntityManager);
+            ecb.Dispose();
+            candidatePositions.Dispose();
+        }
+    }
+}
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+fileFormatVersion: 2
+guid: 473b7521bce4d4d1abc794bcd4e8e6fe
@@ -0,0 +1,15 @@
+using Unity.Entities;
+
+namespace ProjectM.Simulation
+{
+    /// <summary>
+    /// Companion buffer on the AbilityDatabase singleton mapping an ability id to its projectile ghost
+    /// prefab entity. Prefab/entity references are kept OUT of the blob (blob assets don't remap entity
+    /// references); they are baked here via GetEntity, which the entity serializer patches correctly.
+    /// </summary>
+    public struct AbilityPrefabElement : IBufferElementData
+    {
+        public byte Id; // AbilityId
+        public Entity Prefab;
+    }
+}
@@ -0,0 +1,2 @@
+fileFormatVersion: 2
+guid: 91844bb3b4d7843318fc0cdbfe68d43e
@@ -0,0 +1,15 @@
+using Unity.Entities;
+using Unity.NetCode;
+
+namespace ProjectM.Simulation
+{
+    /// <summary>
+    /// Which authored ability definition occupies this entity's primary slot - a light replicated key
+    /// into the AbilityDatabase blob, replacing M2's inlined AbilityStats values. Replicated so an
+    /// ability swap is server-authoritative and prediction-correct. <c>Id</c> stores an <see cref="AbilityId"/>.
+    /// </summary>
+    public struct AbilityRef : IComponentData
+    {
+        [GhostField] public byte Id;
+    }
+}
@@ -0,0 +1,2 @@
+fileFormatVersion: 2
+guid: d6ea08a11ef3d4afdb722b735ca3ed03
@@ -0,0 +1,92 @@
+using Unity.Collections;
+using Unity.Mathematics;
+
+namespace ProjectM.Simulation
+{
+    /// <summary>
+    /// Pure, deterministic auto-target assist helper for player abilities (M2 combat). Given a shooter
+    /// position, a raw aim direction, and a set of candidate target positions, picks the best target
+    /// inside an assist cone and snaps the shot toward it; otherwise returns the raw aim unchanged.
+    /// <para>
+    /// Authored as a <see langword="static"/> class (no state) so it is Burst-safe and allocation-free,
+    /// callable from inside predicted/jobified systems. It is intended to run server-side only (see
+    /// <c>AbilityFireSystem</c>) — the server's authoritative <c>Projectile.Direction</c> GhostField then
+    /// reconciles the client's raw-aim predicted projectile. Determinism: no wall-clock, no randomness,
+    /// pure math; ties are broken by smallest candidate index so identical inputs always yield identical
+    /// output across the prediction loop and across machines.
+    /// </para>
+    /// </summary>
+    public static class AutoTarget
+    {
+        /// <summary>
+        /// Resolves the planar (XZ) direction a shot should take. Returns the normalized direction toward
+        /// the nearest candidate within <paramref name="autoTargetRange"/> whose bearing from
+        /// <paramref name="from"/> lies within <paramref name="coneHalfAngleRadians"/> of
+        /// <paramref name="rawAimDir"/>; if no candidate qualifies, returns <paramref name="rawAimDir"/>
+        /// unchanged.
+        /// </summary>
+        /// <param name="from">Shooter world position; only the XZ plane is considered.</param>
+        /// <param name="rawAimDir">
+        /// Caller-normalized planar aim direction (world XZ mapped to <c>float2(x, y)</c>). If it is
+        /// effectively zero-length, it is returned unchanged (no valid heading to assist).
+        /// </param>
+        /// <param name="autoTargetRange">Max planar distance to consider a candidate; <c>0</c> (or less) disables assist.</param>
+        /// <param name="coneHalfAngleRadians">Half-angle of the assist cone, measured from <paramref name="rawAimDir"/>.</param>
+        /// <param name="candidatePositions">Candidate target world positions (XZ used). Read-only; not modified.</param>
+        /// <returns>
+        /// The normalized direction toward the chosen candidate, or <paramref name="rawAimDir"/> when no
+        /// candidate qualifies. Ties on distance are broken by the smallest candidate index for determinism.
+        /// </returns>
+        public static float2 Resolve(float3 from, float2 rawAimDir, float autoTargetRange, float coneHalfAngleRadians,
+                                     in NativeArray<float3> candidatePositions)
+        {
+            // No valid heading to assist along — caller guarantees normalization, but guard zero-length.
+            if (math.lengthsq(rawAimDir) < 1e-6f)
+                return rawAimDir;
+
+            // Disabled / nothing to consider.
+            if (autoTargetRange <= 0f || candidatePositions.Length == 0)
+                return rawAimDir;
+
+            float rangeSq = autoTargetRange * autoTargetRange;
+            float cosCone = math.cos(coneHalfAngleRadians);
+
+            int bestIndex = -1;
+            float bestDistSq = float.MaxValue;
+            float2 bestDir = rawAimDir;
+
+            for (int i = 0; i < candidatePositions.Length; i++)
+            {
+                // Planar (XZ) offset from shooter to candidate.
+                float3 offset = candidatePositions[i] - from;
+                float2 planar = new float2(offset.x, offset.z);
+
+                float distSq = math.lengthsq(planar);
+
+                // Skip self / coincident candidates (effectively zero distance → undefined bearing).
+                if (distSq < 1e-6f)
+                    continue;
+
+                // Out of range.
+                if (distSq > rangeSq)
+                    continue;
+
+                // Bearing test: dot of unit bearing with the (unit) raw aim vs cos(half-angle).
+                float2 dir = planar * math.rsqrt(distSq); // normalized planar bearing
+                float dot = math.dot(dir, rawAimDir);
+                if (dot < cosCone)
+                    continue; // outside the assist cone
+
+                // Nearest wins; strict less-than keeps the first (smallest-index) candidate on ties.
+                if (distSq < bestDistSq)
+                {
+                    bestDistSq = distSq;
+                    bestIndex = i;
+                    bestDir = dir;
+                }
+            }
+
+            return bestIndex >= 0 ? bestDir : rawAimDir;
+        }
+    }
+}
@@ -0,0 +1,2 @@
+fileFormatVersion: 2
+guid: ac02264d177dd426e8f6972c7c3ceaae
@@ -0,0 +1,20 @@
+using Unity.Entities;
+
+namespace ProjectM.Simulation
+{
+    /// <summary>
+    /// One pending hit against a damageable entity, queued as a per-entity buffer element. The server
+    /// appends a DamageEvent when a projectile hits (ProjectileDamageSystem), then HealthApplyDamageSystem
+    /// drains the buffer once per tick to subtract from Health. Buffering decouples hit detection from
+    /// health resolution and lets multiple simultaneous hits accumulate before being applied. Not
+    /// replicated — only Health.Current is a GhostField; the buffer is server-side and cleared each tick.
+    /// </summary>
+    public struct DamageEvent : IBufferElementData
+    {
+        /// <summary>Damage to subtract from the target's Health.Current (world health units).</summary>
+        public float Amount;
+
+        /// <summary>NetworkId of the firing player that caused this hit (attribution / self-hit filtering upstream).</summary>
+        public int SourceNetworkId;
+    }
+}
@@ -0,0 +1,2 @@
+fileFormatVersion: 2
+guid: 498738282d585418893b23454a4b88a0
@@ -0,0 +1,20 @@
+using Unity.Entities;
+
+namespace ProjectM.Simulation
+{
+    /// <summary>
+    /// Per-entity effective ability stats: the authored base (from the AbilityDatabase blob keyed by
+    /// AbilityRef) folded with the entity's StatModifier buffer by StatRecomputeSystem each predicted
+    /// tick. Derived/local, NOT replicated - both worlds recompute it deterministically from the
+    /// replicated modifier buffer, so it matches under prediction without being in the snapshot.
+    /// </summary>
+    public struct EffectiveAbilityStats : IComponentData
+    {
+        public float Damage;
+        public float ProjectileSpeed;
+        public float Range;
+        public float AutoTargetRange;
+        public float AutoTargetConeRadians;
+        public int CooldownTicks;
+    }
+}
@@ -0,0 +1,2 @@
+fileFormatVersion: 2
+guid: a8bb3a5c343e74e7fb249e96c0c55fdc
@@ -0,0 +1,16 @@
+using Unity.Entities;
+
+namespace ProjectM.Simulation
+{
+    /// <summary>
+    /// Per-entity effective character stats (movement + survivability): authored base (from the
+    /// CharacterStats blob keyed by CharacterStatsRef) folded with the StatModifier buffer by
+    /// StatRecomputeSystem each predicted tick. Derived/local, NOT replicated (see EffectiveAbilityStats).
+    /// </summary>
+    public struct EffectiveCharacterStats : IComponentData
+    {
+        public float MoveSpeed;
+        public float TurnRateRadiansPerSec;
+        public float MaxHealth;
+    }
+}
@@ -0,0 +1,2 @@
+fileFormatVersion: 2
+guid: 1d8413eebbeda4761b33430128e7a437
@@ -0,0 +1,20 @@
+using Unity.Entities;
+using Unity.NetCode;
+
+namespace ProjectM.Simulation
+{
+    /// <summary>
+    /// Hit points for any damageable ghost (players, training dummies). Server-authoritative:
+    /// only server systems write <see cref="Current"/>; clients receive it via the [GhostField]
+    /// for display and prediction reconciliation. <see cref="Max"/> is baked identically on both
+    /// worlds and is not replicated. Added by PlayerBaker / TrainingDummyBaker.
+    /// </summary>
+    public struct Health : IComponentData
+    {
+        /// <summary>Current hit points. Replicated for display and reconciles the predicted value against the server's authoritative state.</summary>
+        [GhostField] public float Current;
+
+        /// <summary>Maximum hit points. Baked identically on client and server; not replicated.</summary>
+        public float Max;
+    }
+}
@@ -0,0 +1,2 @@
+fileFormatVersion: 2
+guid: dbe438fe95346418f9ae1908c9288a75
@@ -0,0 +1,15 @@
+using Unity.Entities;
+
+namespace ProjectM.Simulation
+{
+    /// <summary>
+    /// Hit-test radius (world units) for a damageable entity. Baked identically on client and server
+    /// from authoring so projectile collision is deterministic; consumed server-side by
+    /// ProjectileDamageSystem to decide whether a projectile struck this entity. Not replicated.
+    /// </summary>
+    public struct HitRadius : IComponentData
+    {
+        /// <summary>Collision radius in world units; the projectile hit test compares planar (XZ) distance against this.</summary>
+        public float Value;
+    }
+}
@@ -0,0 +1,2 @@
+fileFormatVersion: 2
+guid: df72a4dfa71044e5683932cb89ec912a
@@ -0,0 +1,39 @@
+using Unity.Entities;
+using Unity.Mathematics;
+using Unity.NetCode;
+
+namespace ProjectM.Simulation
+{
+    /// <summary>
+    /// Ghost component on the projectile prefab. Drives predicted+server movement and carries the
+    /// classification key used to reconcile a client's predicted-spawned projectile with the server's
+    /// authoritative ghost. <see cref="Direction"/> is replicated so the server's auto-targeted aim
+    /// reconciles the client's raw-aim prediction; <see cref="SpawnId"/> is replicated so it lives in
+    /// snapshot history for the predicted-spawn classifier. Speed/Damage/Range are baked on the prefab
+    /// (identical both worlds → deterministic) and not replicated; DistanceTravelled is integrated
+    /// locally each tick and not replicated.
+    /// </summary>
+    public struct Projectile : IComponentData
+    {
+        /// <summary>Planar XZ travel direction (world XZ mapped to float2 x,y), normalized.</summary>
+        [GhostField(Quantization = 1000)] public float2 Direction;
+
+        /// <summary>
+        /// Classification key: (ownerNetId << 16) | absoluteFireCount. Replicated so it is present
+        /// in snapshot history; the client classifier matches this against its predicted spawn.
+        /// </summary>
+        [GhostField] public uint SpawnId;
+
+        /// <summary>Travel speed in units/second. Baked on the prefab; not replicated.</summary>
+        public float Speed;
+
+        /// <summary>Damage applied on hit. Baked on the prefab; not replicated.</summary>
+        public float Damage;
+
+        /// <summary>Max travel distance before the server expires the projectile. Baked on the prefab; not replicated.</summary>
+        public float Range;
+
+        /// <summary>Integrated distance travelled (predicted on client + authoritative on server). Not replicated.</summary>
+        public float DistanceTravelled;
+    }
+}
@@ -0,0 +1,2 @@
+fileFormatVersion: 2
+guid: 33b95996c22674decbe6d858e8e37a73
@@ -0,0 +1,42 @@
+using Unity.Burst;
+using Unity.Entities;
+using Unity.Mathematics;
+using Unity.NetCode;
+using Unity.Transforms;
+
+namespace ProjectM.Simulation
+{
+    /// <summary>
+    /// Predicted projectile integrator: advances every live <see cref="Projectile"/> along its
+    /// replicated planar (XZ) <see cref="Projectile.Direction"/> at its baked <see cref="Projectile.Speed"/>,
+    /// accumulating <see cref="Projectile.DistanceTravelled"/>. Runs inside the prediction loop on the
+    /// owning client (re-simulated on rollback) and once per tick on the server, after
+    /// <see cref="AbilityFireSystem"/> has spawned this tick's shots; filtered to <see cref="Simulate"/>
+    /// so only predicted ghosts move. Deterministic by construction: uses <c>SystemAPI.Time.DeltaTime</c>
+    /// (the fixed tick step) only — no wall-clock, no <c>System.Random</c>. Pure motion: range expiry and
+    /// destruction are server-authoritative in <c>ProjectileDamageSystem</c>, so this system never
+    /// performs structural changes and is fully idempotent across rollback re-simulation.
+    /// </summary>
+    [UpdateInGroup(typeof(PredictedSimulationSystemGroup))]
+    [UpdateAfter(typeof(AbilityFireSystem))]
+    [BurstCompile]
+    public partial struct ProjectileMoveSystem : ISystem
+    {
+        [BurstCompile]
+        public void OnUpdate(ref SystemState state)
+        {
+            float dt = SystemAPI.Time.DeltaTime;
+
+            foreach (var (transform, projectile) in
+                     SystemAPI.Query<RefRW<LocalTransform>, RefRW<Projectile>>()
+                         .WithAll<Simulate>())
+            {
+                float step = projectile.ValueRO.Speed * dt;
+                float3 dir = new float3(projectile.ValueRO.Direction.x, 0f, projectile.ValueRO.Direction.y);
+
+                transform.ValueRW.Position += dir * step;
+                projectile.ValueRW.DistanceTravelled += step;
+            }
+        }
+    }
+}
@@ -0,0 +1,2 @@
+fileFormatVersion: 2
+guid: b7e91cb40d3af4ff2b260589a3b19b31
@@ -0,0 +1,16 @@
+using Unity.Entities;
+
+namespace ProjectM.Simulation
+{
+    /// <summary>
+    /// Baked singleton holding the entity reference to the projectile ghost prefab. Present in both
+    /// client and server worlds (the prefab is a predicted ghost), so AbilityFireSystem can instantiate
+    /// it deterministically during prediction on either side. Authored once via ProjectileSpawnerAuthoring;
+    /// AbilityFireSystem reads the prefab's baked Projectile component for Speed/Damage/Range. Not replicated.
+    /// </summary>
+    public struct ProjectileSpawner : IComponentData
+    {
+        /// <summary>The projectile ghost prefab to instantiate when a player fires.</summary>
+        public Entity Prefab;
+    }
+}
@@ -0,0 +1,2 @@
+fileFormatVersion: 2
+guid: 49212356bd330423ca66ed65e44f90f4
@@ -0,0 +1,43 @@
+namespace ProjectM.Simulation
+{
+    /// <summary>Stable, index-independent key for an authored ability definition in the AbilityDatabase blob.</summary>
+    public enum AbilityId : byte
+    {
+        None = 0,
+        Primary = 1,
+        FastLight = 2,
+        SlowHeavy = 3,
+    }
+
+    /// <summary>Stable key for an authored character-stats definition in the AbilityDatabase blob.</summary>
+    public enum CharacterId : byte
+    {
+        None = 0,
+        Default = 1,
+    }
+
+    /// <summary>
+    /// Which base stat a <see cref="StatModifier"/> targets. Replicated as a raw byte on the modifier
+    /// buffer to keep the generated ghost serializer trivial; mapped back to this enum only in StatMath.
+    /// </summary>
+    public enum StatTarget : byte
+    {
+        Damage = 0,
+        CooldownTicks = 1,
+        Range = 2,
+        ProjectileSpeed = 3,
+        AutoTargetRange = 4,
+        AutoTargetConeRadians = 5,
+        MoveSpeed = 6,
+        TurnRate = 7,
+        MaxHealth = 8,
+    }
+
+    /// <summary>How a <see cref="StatModifier"/> combines into the effective stat.</summary>
+    public enum ModOp : byte
+    {
+        Flat = 0,        // additive: + Value
+        PercentAdd = 1,  // additive percent, pooled into (1 + sum Value)
+        PercentMult = 2, // multiplicative percent, product of (1 + Value)
+    }
+}
@@ -0,0 +1,2 @@
+fileFormatVersion: 2
+guid: 5b103cd0b266a4776bcd47c2f12b1d7d
@@ -0,0 +1,42 @@
+using Unity.Collections;
+using Unity.Entities;
+
+namespace ProjectM.Simulation
+{
+    /// <summary>
+    /// Pure, deterministic folding of a StatModifier set into an effective value for one StatTarget:
+    /// effective = (base + sum flat) * (1 + sum percentAdd) * product(1 + percentMult).
+    /// Order-independent within each op class, Burst-friendly, and unit-tested like AutoTarget.Resolve.
+    /// Returns the raw fold; consumers clamp domain bounds (e.g. cooldown >= 1 tick).
+    /// </summary>
+    public static class StatMath
+    {
+        public static float Apply(float baseValue, StatTarget target, in DynamicBuffer<StatModifier> mods)
+        {
+            return Apply(baseValue, target, mods.AsNativeArray());
+        }
+
+        public static float Apply(float baseValue, StatTarget target, in NativeArray<StatModifier> mods)
+        {
+            float flat = 0f;
+            float percentAdd = 0f;
+            float percentMult = 1f;
+            byte t = (byte)target;
+
+            for (int i = 0; i < mods.Length; i++)
+            {
+                var m = mods[i];
+                if (m.Target != t)
+                    continue;
+                switch ((ModOp)m.Op)
+                {
+                    case ModOp.Flat: flat += m.Value; break;
+                    case ModOp.PercentAdd: percentAdd += m.Value; break;
+                    case ModOp.PercentMult: percentMult *= 1f + m.Value; break;
+                }
+            }
+
+            return (baseValue + flat) * (1f + percentAdd) * percentMult;
+        }
+    }
+}
@@ -0,0 +1,2 @@
+fileFormatVersion: 2
+guid: 49228160eb5a44dfda64b623389055d5
@@ -0,0 +1,34 @@
+using Unity.Entities;
+using Unity.NetCode;
+
+namespace ProjectM.Simulation
+{
+    /// <summary>
+    /// One runtime stat modifier (from an upgrade, pickup, or buff) on a modifiable entity. The
+    /// per-entity DynamicBuffer of these is the server-authoritative source StatRecomputeSystem folds
+    /// into the effective-stat components, on both the server and the predicting client.
+    ///
+    /// Replication: this is a GhostField buffer, so it is part of the ghost snapshot and is restored on
+    /// rollback - that is what lets the predicting owner recompute identical effective stats.
+    /// OwnerSendType.All is explicit so the owning (predicting) client receives it; without it the
+    /// owner would recompute from an empty list and mispredict every tick. Target/Op replicate as raw
+    /// bytes (not the enums) to keep the generated serializer trivial and avoid the cross-assembly
+    /// enum-codegen hazard that already de-Bursted ProjectileClassificationSystem.
+    /// </summary>
+    [GhostComponent(OwnerSendType = SendToOwnerType.All)]
+    [InternalBufferCapacity(8)]
+    public struct StatModifier : IBufferElementData
+    {
+        /// <summary>The <see cref="StatTarget"/> this modifier applies to (stored as a byte).</summary>
+        [GhostField] public byte Target;
+
+        /// <summary>The <see cref="ModOp"/> combine operation (stored as a byte).</summary>
+        [GhostField] public byte Op;
+
+        /// <summary>Magnitude: a flat amount, or a fractional percent (0.1 = +10%).</summary>
+        [GhostField(Quantization = 1000)] public float Value;
+
+        /// <summary>Provenance tag (e.g. pickup SpawnId / debug sentinel). Reserved for future ClearByType / timed buffs.</summary>
+        [GhostField] public uint SourceId;
+    }
+}
@@ -0,0 +1,2 @@
+fileFormatVersion: 2
+guid: f44086f6603c74fe6909b731cf99ff82
@@ -0,0 +1,68 @@
+using Unity.Burst;
+using Unity.Entities;
+using Unity.Mathematics;
+using Unity.NetCode;
+
+namespace ProjectM.Simulation
+{
+    /// <summary>
+    /// Folds each modifiable entity's authored base stats (from the AbilityDatabase blob, keyed by
+    /// AbilityRef / CharacterStatsRef) with its replicated StatModifier buffer into the
+    /// EffectiveAbilityStats / EffectiveCharacterStats components - every predicted tick, on both worlds.
+    ///
+    /// Runs at the head of the predicted group (UpdateBefore PlayerAimSystem and PlayerMoveSystem;
+    /// AbilityFireSystem runs after PlayerAimSystem, so it sees fresh values too). Recompute is
+    /// unconditional every tick: it is a pure function of (blob base + replicated buffer), both of which
+    /// are restored on rollback, so predicted and server results always agree. A dirty-flag / change
+    /// filter would be WRONG here - the Effective* components are NOT in the ghost snapshot and would go
+    /// stale across reprediction.
+    /// </summary>
+    [UpdateInGroup(typeof(PredictedSimulationSystemGroup))]
+    [UpdateBefore(typeof(PlayerAimSystem))]
+    [UpdateBefore(typeof(PlayerMoveSystem))]
+    [BurstCompile]
+    public partial struct StatRecomputeSystem : ISystem
+    {
+        [BurstCompile]
+        public void OnCreate(ref SystemState state)
+        {
+            state.RequireForUpdate<AbilityDatabase>();
+        }
+
+        [BurstCompile]
+        public void OnUpdate(ref SystemState state)
+        {
+            var database = SystemAPI.GetSingleton<AbilityDatabase>();
+            ref var db = ref database.Value.Value;
+
+            foreach (var (abilityRef, charRef, mods, effAbility, effChar) in
+                     SystemAPI.Query<RefRO<AbilityRef>, RefRO<CharacterStatsRef>, DynamicBuffer<StatModifier>,
+                             RefRW<EffectiveAbilityStats>, RefRW<EffectiveCharacterStats>>()
+                         .WithAll<Simulate>())
+            {
+                if (db.TryGetAbility(abilityRef.ValueRO.Id, out var a))
+                {
+                    effAbility.ValueRW = new EffectiveAbilityStats
+                    {
+                        Damage = StatMath.Apply(a.Damage, StatTarget.Damage, mods),
+                        ProjectileSpeed = StatMath.Apply(a.ProjectileSpeed, StatTarget.ProjectileSpeed, mods),
+                        Range = StatMath.Apply(a.Range, StatTarget.Range, mods),
+                        AutoTargetRange = StatMath.Apply(a.AutoTargetRange, StatTarget.AutoTargetRange, mods),
+                        AutoTargetConeRadians = StatMath.Apply(a.AutoTargetConeRadians, StatTarget.AutoTargetConeRadians, mods),
+                        CooldownTicks = (int)math.round(StatMath.Apply(a.CooldownTicks, StatTarget.CooldownTicks, mods)),
+                    };
+                }
+
+                if (db.TryGetCharacter(charRef.ValueRO.Id, out var c))
+                {
+                    effChar.ValueRW = new EffectiveCharacterStats
+                    {
+                        MoveSpeed = StatMath.Apply(c.MoveSpeed, StatTarget.MoveSpeed, mods),
+                        TurnRateRadiansPerSec = StatMath.Apply(c.TurnRateRadiansPerSec, StatTarget.TurnRate, mods),
+                        MaxHealth = StatMath.Apply(c.MaxHealth, StatTarget.MaxHealth, mods),
+                    };
+                }
+            }
+        }
+    }
+}
@@ -0,0 +1,2 @@
+fileFormatVersion: 2
+guid: 4aa8d74c3871e4fdf9b9fc45a0193130
@@ -0,0 +1,26 @@
+using Unity.Entities;
+using Unity.Mathematics;
+
+namespace ProjectM.Simulation
+{
+    /// <summary>
+    /// Baked singleton describing the training-dummy field to spawn at world start. Consumed once by
+    /// the server-only TrainingDummySpawnSystem, which instantiates <see cref="Count"/> dummies from
+    /// <see cref="Prefab"/> and then destroys this singleton so the spawn runs exactly once. Not
+    /// replicated — dummies are spawned authoritatively on the server and reach clients as ghosts.
+    /// </summary>
+    public struct TrainingDummySpawner : IComponentData
+    {
+        /// <summary>Baked entity prefab to instantiate for each dummy.</summary>
+        public Entity Prefab;
+
+        /// <summary>Number of dummies to spawn.</summary>
+        public int Count;
+
+        /// <summary>World-unit gap between consecutive dummies along the spawn line (X axis).</summary>
+        public float Spacing;
+
+        /// <summary>World-space position of the first dummy; subsequent dummies offset by <see cref="Spacing"/>.</summary>
+        public float3 Origin;
+    }
+}
@@ -0,0 +1,2 @@
+fileFormatVersion: 2
+guid: a8f27601fb20640718aaed2c48d1d016
@@ -0,0 +1,11 @@
+using Unity.Entities;
+
+namespace ProjectM.Simulation
+{
+    /// <summary>
+    /// Zero-size marker identifying a training-dummy enemy. Server auto-target collects
+    /// <see cref="TrainingDummyTag"/> entities as candidates, and the damage/death path destroys
+    /// a dummy when its <c>Health.Current</c> reaches zero. Added by TrainingDummyBaker.
+    /// </summary>
+    public struct TrainingDummyTag : IComponentData { }
+}
@@ -0,0 +1,2 @@
+fileFormatVersion: 2
+guid: ebe9114e40db748669d89ef861415bac
@@ -0,0 +1,17 @@
+using Unity.Entities;
+
+namespace ProjectM.Simulation
+{
+    /// <summary>
+    /// A world pickup that, on player overlap, grants one StatModifier (server-authoritative) and is then
+    /// destroyed. Mirrors a single StatModifier payload (Target/Op as bytes). The pickup is an
+    /// interpolated ghost so clients see and despawn it; the grant is applied by UpgradePickupSystem.
+    /// </summary>
+    public struct UpgradePickup : IComponentData
+    {
+        public byte Target;  // StatTarget
+        public byte Op;      // ModOp
+        public float Value;
+        public uint SourceId;
+    }
+}
@@ -0,0 +1,2 @@
+fileFormatVersion: 2
+guid: a0d34f4d0b12241c7b0f0b1d002142f3
@@ -0,0 +1,17 @@
+using Unity.Entities;
+using Unity.Mathematics;
+
+namespace ProjectM.Simulation
+{
+    /// <summary>
+    /// Singleton describing how many upgrade pickups to spawn and where (mirrors TrainingDummySpawner).
+    /// Consumed once by the server's UpgradePickupSpawnSystem.
+    /// </summary>
+    public struct UpgradePickupSpawner : IComponentData
+    {
+        public Entity Prefab;
+        public float3 Origin;
+        public int Count;
+        public float Spacing;
+    }
+}
@@ -0,0 +1,2 @@
+fileFormatVersion: 2
+guid: 059368b62be834614ae3a110a51d42da