fix: normalize Bedrock entity network offsets

anticheat/entity/entity.go

@@ -2,6 +2,7 @@ package entity
 
 import (
 	"log/slog"
+	"maps"
 
 	"github.com/ethaniccc/float32-cube/cube"
 	"github.com/go-gl/mathgl/mgl32"
@@ -15,6 +16,7 @@ const (
 
 type Entity struct {
 	RuntimeId uint64
+	UniqueId  int64
 
 	Metadata map[uint32]any
 	Type     string
@@ -39,43 +41,64 @@ type Entity struct {
 	Height float32
 	Scale  float32
 
+	NetworkOffset float32
+
 	IsPlayer bool
 
 	historySize int
 	log         **slog.Logger
 }
 
+// Config ...
+type Config struct {
+	RuntimeID uint64
+	UniqueID  int64
+
+	Type     string
+	Metadata map[uint32]any
+
+	NetworkPosition mgl32.Vec3
+	HistorySize     int
+	IsPlayer        bool
+
+	Width, Height, Scale float32
+
+	Log **slog.Logger
+}
+
 // New creates and returns a new Entity instance.
-func New(
-	runtimeId uint64,
-	entType string,
-	metadata map[uint32]any,
-	pos mgl32.Vec3,
-	historySize int,
-	isPlayer bool,
-	width, height, scale float32,
-	log **slog.Logger,
-) *Entity {
+func New(c Config) *Entity {
+	metadata := maps.Clone(c.Metadata)
+	if metadata == nil {
+		metadata = make(map[uint32]any)
+	}
+	offset := networkOffset(c.Type, metadata)
+	pos := c.NetworkPosition
+	pos[1] -= offset
+
 	e := &Entity{
-		RuntimeId: runtimeId,
+		RuntimeId: c.RuntimeID,
+		UniqueId:  c.UniqueID,
 
-		Type:     entType,
+		Type:     c.Type,
 		Metadata: metadata,
 
 		Position:     pos,
 		PrevPosition: pos,
 		RecvPosition: pos,
 
-		Width:  width,
-		Height: height,
-		Scale:  scale,
+		Width:  c.Width,
+		Height: c.Height,
+		Scale:  c.Scale,
+
+		NetworkOffset: offset,
 
-		PositionHistory: utils.NewCircularQueue(historySize, func() (hp HistoricalPosition) { return }),
+		PositionHistory: utils.NewCircularQueue(c.HistorySize, func() (hp HistoricalPosition) { return }),
 
-		IsPlayer: isPlayer,
+		IsPlayer: c.IsPlayer,
 
-		log:         log,
-		historySize: historySize,
+		log:         c.Log,
+		historySize: c.HistorySize,
 	}
 	/* e.InterpolationTicks = EntityMobInterpolationTicks
 	if isPlayer {
@@ -86,16 +109,16 @@ func New(
 }
 
 // ReceivePosition updates the position of the entity, and adds the previous position to its position history.
-func (e *Entity) ReceivePosition(hp HistoricalPosition) {
+func (e *Entity) ReceivePosition(pos mgl32.Vec3, teleport bool) {
 	e.PrevRecvPosition = e.RecvPosition
-	e.RecvPosition = hp.Position
+	e.RecvPosition = pos
 
 	e.InterpolationTicks = EntityMobInterpolationTicks
 	if e.IsPlayer {
 		e.InterpolationTicks = EntityPlayerInterpolationTicks
 	}
 
-	if hp.Teleport {
+	if teleport {
 		e.TicksSinceTeleport = 0
 		e.InterpolationTicks = 1
 	}
@@ -120,6 +143,15 @@ func (e *Entity) UpdateVelocity(vel mgl32.Vec3) {
 	e.RecvVelocity = vel
 }
 
+// UpdateMetadata ...
+func (e *Entity) UpdateMetadata(metadata map[uint32]any) {
+	if e.Metadata == nil {
+		e.Metadata = make(map[uint32]any, len(metadata))
+	}
+	maps.Copy(e.Metadata, metadata)
+	e.NetworkOffset = networkOffset(e.Type, e.Metadata)
+}
+
 // Box returns the entity's bounding box.
 func (e *Entity) Box(pos mgl32.Vec3) cube.BBox {
 	w := (e.Width * e.Scale) / 2

anticheat/entity/metadata.go

@@ -5,9 +5,17 @@ const (
 	DataKeyOwnerID           = 5
 	DataKeyTargetID          = 6
 	DataKeyFireworkMetadata  = 16
+	DataKeyPlayerFlags       = 26
 	DataKeyScale             = 38
 	DataKeyBoundingBoxWidth  = 53
 	DataKeyBoundingBoxHeight = 54
+	DataKeyFlagsTwo          = 92
+)
+
+// DataPlayerFlag ...
+const (
+	DataPlayerFlagSleep = 1
+	DataPlayerFlagDead  = 2
 )
 
 const (

anticheat/entity/network_offset.go

@@ -0,0 +1,25 @@
+package entity
+
+import (
+	"github.com/oomph-ac/oomph/anticheat/game"
+	"github.com/oomph-ac/oomph/anticheat/utils"
+)
+
+// networkOffset ...
+func networkOffset(entityType string, metadata map[uint32]any) float32 {
+	switch entityType {
+	case TypePlayer:
+		if utils.HasMetadataFlag[byte](metadata, DataKeyPlayerFlags, DataPlayerFlagSleep) || utils.HasMetadataFlag[int64](metadata, DataKeyFlagsTwo, DataFlagSleeping) {
+			return game.SleepingPlayerHeightOffset
+		}
+		return game.DefaultPlayerHeightOffset
+	case TypeItem, TypeFallingBlock, TypeMinecart, TypeChestMinecart, TypeCommandBlockMinecart, TypeHopperMinecart, TypeTNTMinecart:
+		return game.ItemAndMinecartNetworkOffset
+	case TypeBoat, TypeChestBoat:
+		return game.BoatNetworkOffset
+	case TypeTNT:
+		return game.PrimedTNTNetworkOffset
+	default:
+		return 0
+	}
+}

anticheat/entity/type.go

@@ -2,4 +2,16 @@ package entity
 
 const (
 	TypeFireworksRocket = "minecraft:fireworks_rocket"
+
+	TypeBoat                 = "minecraft:boat"
+	TypeChestBoat            = "minecraft:chest_boat"
+	TypeChestMinecart        = "minecraft:chest_minecart"
+	TypeCommandBlockMinecart = "minecraft:command_block_minecart"
+	TypeFallingBlock         = "minecraft:falling_block"
+	TypeHopperMinecart       = "minecraft:hopper_minecart"
+	TypeItem                 = "minecraft:item"
+	TypeMinecart             = "minecraft:minecart"
+	TypePlayer               = "minecraft:player"
+	TypeTNT                  = "minecraft:tnt"
+	TypeTNTMinecart          = "minecraft:tnt_minecart"
 )

anticheat/game/movement.go

@@ -18,8 +18,13 @@ const (
 	MaxSneakImpulse      = float32(0.3)
 	MaxNormalizedImpulse = float32(0.70710678118) // 1/sqrt(2)
 
-	DefaultPlayerHeightOffset  = float32(1.62)
+	DefaultPlayerHeightOffset  = float32(1.62001)
 	SneakingPlayerHeightOffset = float32(1.27)
+	SleepingPlayerHeightOffset = float32(0.2)
+
+	ItemAndMinecartNetworkOffset = float32(0.5)
+	BoatNetworkOffset            = float32(0.375)
+	PrimedTNTNetworkOffset       = float32(0.49)
 
 	JumpDelayTicks  = 10
 	GlideBoostTicks = 20

anticheat/player/component/acknowledgement/entities.go

@@ -4,26 +4,30 @@ import (
 	"github.com/go-gl/mathgl/mgl32"
 	"github.com/oomph-ac/oomph/anticheat/entity"
 	"github.com/oomph-ac/oomph/anticheat/player"
+	"github.com/sandertv/gophertunnel/minecraft/protocol"
 )
 
-type EntitySize struct {
-	mEntity *entity.Entity
-	width   float32
-	height  float32
-	scale   float32
+type EntityData struct {
+	mEntity  *entity.Entity
+	metadata map[uint32]any
+	width    float32
+	height   float32
+	scale    float32
 }
 
-func NewEntitySizeACK(e *entity.Entity, width, height, scale float32) *EntitySize {
-	return &EntitySize{
-		mEntity: e,
+func NewEntityDataACK(e *entity.Entity, metadata map[uint32]any, width, height, scale float32) *EntityData {
+	return &EntityData{
+		mEntity:  e,
+		metadata: metadata,
 
 		width:  width,
 		height: height,
 		scale:  scale,
 	}
 }
 
-func (ack *EntitySize) Run() {
+func (ack *EntityData) Run() {
+	ack.mEntity.UpdateMetadata(ack.metadata)
 	ack.mEntity.Width = ack.width
 	ack.mEntity.Height = ack.height
 	ack.mEntity.Scale = ack.scale
@@ -56,3 +60,36 @@ func (ack *EntityPosition) Run() {
 	)
 	ack.mPlayer = nil
 }
+
+type EntityDeltaPosition struct {
+	mPlayer *player.Player
+
+	positionX protocol.Optional[float32]
+	positionY protocol.Optional[float32]
+	positionZ protocol.Optional[float32]
+	runtimeID uint64
+	teleport  bool
+}
+
+func NewEntityDeltaPositionACK(p *player.Player, posX, posY, posZ protocol.Optional[float32], rid uint64, teleport bool) *EntityDeltaPosition {
+	return &EntityDeltaPosition{
+		mPlayer:   p,
+		positionX: posX,
+		positionY: posY,
+		positionZ: posZ,
+		runtimeID: rid,
+		teleport:  teleport,
+	}
+}
+
+func (ack *EntityDeltaPosition) Run() {
+	ack.mPlayer.ClientEntityTracker().MoveEntityDelta(
+		ack.runtimeID,
+		0,
+		ack.positionX,
+		ack.positionY,
+		ack.positionZ,
+		ack.teleport,
+	)
+	ack.mPlayer = nil
+}

anticheat/player/component/combat.go

@@ -489,6 +489,9 @@ func (c *AuthoritativeCombatComponent) checkForMispredictedEntity() bool {
 	rewTick := c.mPlayer.ClientTick - 1
 	attackPos := c.endAttackPos
 	for rid, e := range c.entityTracker().All() {
+		if e.Type == entity.TypeItem {
+			continue
+		}
 		rewind, ok := e.Rewind(rewTick)
 		if !ok {
 			continue