first commit

internal/world/aoi.go

@@ -0,0 +1,70 @@
+package world
+
+import (
+	"a301_game_server/internal/entity"
+	"a301_game_server/pkg/mathutil"
+)
+
+// AOIEvent represents an entity entering or leaving another entity's area of interest.
+type AOIEvent struct {
+	Observer entity.Entity
+	Target   entity.Entity
+	Type     AOIEventType
+}
+
+type AOIEventType int
+
+const (
+	AOIEnter AOIEventType = iota
+	AOILeave
+)
+
+// AOIManager determines which entities can see each other.
+type AOIManager interface {
+	Add(ent entity.Entity)
+	Remove(ent entity.Entity) []AOIEvent
+	UpdatePosition(ent entity.Entity, oldPos, newPos mathutil.Vec3) []AOIEvent
+	GetNearby(ent entity.Entity) []entity.Entity
+}
+
+// BroadcastAllAOI is a trivial AOI that treats all entities as visible to each other.
+// Used when AOI is disabled for debugging/comparison.
+type BroadcastAllAOI struct {
+	entities map[uint64]entity.Entity
+}
+
+func NewBroadcastAllAOI() *BroadcastAllAOI {
+	return &BroadcastAllAOI{
+		entities: make(map[uint64]entity.Entity),
+	}
+}
+
+func (b *BroadcastAllAOI) Add(ent entity.Entity) {
+	b.entities[ent.EntityID()] = ent
+}
+
+func (b *BroadcastAllAOI) Remove(ent entity.Entity) []AOIEvent {
+	delete(b.entities, ent.EntityID())
+	var events []AOIEvent
+	for _, other := range b.entities {
+		if other.EntityID() == ent.EntityID() {
+			continue
+		}
+		events = append(events, AOIEvent{Observer: other, Target: ent, Type: AOILeave})
+	}
+	return events
+}
+
+func (b *BroadcastAllAOI) UpdatePosition(_ entity.Entity, _, _ mathutil.Vec3) []AOIEvent {
+	return nil
+}
+
+func (b *BroadcastAllAOI) GetNearby(ent entity.Entity) []entity.Entity {
+	result := make([]entity.Entity, 0, len(b.entities)-1)
+	for _, e := range b.entities {
+		if e.EntityID() != ent.EntityID() {
+			result = append(result, e)
+		}
+	}
+	return result
+}