feat(world-streaming): 添加世界流式加载系统 (#288)

实现基于区块的世界流式加载系统，支持开放世界游戏：

运行时包 (@esengine/world-streaming):
- ChunkComponent: 区块实体组件，包含坐标、边界、状态
- StreamingAnchorComponent: 流式锚点组件（玩家/摄像机）
- ChunkLoaderComponent: 流式加载配置组件
- ChunkStreamingSystem: 区块加载/卸载调度系统
- ChunkCullingSystem: 区块可见性剔除系统
- ChunkManager: 区块生命周期管理服务
- SpatialHashGrid: 空间哈希网格
- ChunkSerializer: 区块序列化

编辑器包 (@esengine/world-streaming-editor):
- ChunkVisualizer: 区块可视化覆盖层
- ChunkLoaderInspectorProvider: 区块加载器检视器
- StreamingAnchorInspectorProvider: 流式锚点检视器
- WorldStreamingPlugin: 完整插件导出

packages/world-streaming/src/components/ChunkComponent.ts

@@ -0,0 +1,103 @@
+import { Component, ECSComponent, Serializable, Serialize, Property } from '@esengine/ecs-framework';
+import type { IChunkCoord, IChunkBounds } from '../types';
+import { EChunkState } from '../types';
+
+/**
+ * 区块组件
+ *
+ * Attached to chunk root entities. Tracks chunk state and bounds.
+ *
+ * 区块组件挂载在区块根实体上，用于管理区块状态和边界信息。
+ */
+@ECSComponent('Chunk')
+@Serializable({ version: 1, typeId: 'Chunk' })
+export class ChunkComponent extends Component {
+    @Serialize()
+    @Property({ type: 'integer', label: 'Coord X', readOnly: true })
+    private _coordX: number = 0;
+
+    @Serialize()
+    @Property({ type: 'integer', label: 'Coord Y', readOnly: true })
+    private _coordY: number = 0;
+
+    @Serialize()
+    @Property({ type: 'string', label: 'State', readOnly: true })
+    private _state: EChunkState = EChunkState.Unloaded;
+
+    @Serialize()
+    private _minX: number = 0;
+
+    @Serialize()
+    private _minY: number = 0;
+
+    @Serialize()
+    private _maxX: number = 0;
+
+    @Serialize()
+    private _maxY: number = 0;
+
+    private _lastAccessTime: number = 0;
+
+    get coord(): IChunkCoord {
+        return { x: this._coordX, y: this._coordY };
+    }
+
+    get bounds(): IChunkBounds {
+        return {
+            minX: this._minX,
+            minY: this._minY,
+            maxX: this._maxX,
+            maxY: this._maxY
+        };
+    }
+
+    get state(): EChunkState {
+        return this._state;
+    }
+
+    get lastAccessTime(): number {
+        return this._lastAccessTime;
+    }
+
+    /**
+     * 初始化区块
+     *
+     * Initialize chunk with coordinates and bounds.
+     */
+    initialize(coord: IChunkCoord, bounds: IChunkBounds): void {
+        this._coordX = coord.x;
+        this._coordY = coord.y;
+        this._minX = bounds.minX;
+        this._minY = bounds.minY;
+        this._maxX = bounds.maxX;
+        this._maxY = bounds.maxY;
+        this._lastAccessTime = Date.now();
+    }
+
+    /**
+     * 设置区块状态
+     *
+     * Set chunk state.
+     */
+    setState(state: EChunkState): void {
+        this._state = state;
+    }
+
+    /**
+     * 更新访问时间
+     *
+     * Update last access time for LRU tracking.
+     */
+    touch(): void {
+        this._lastAccessTime = Date.now();
+    }
+
+    /**
+     * 检查点是否在区块内
+     *
+     * Check if a point is within chunk bounds.
+     */
+    containsPoint(x: number, y: number): boolean {
+        return x >= this._minX && x < this._maxX && y >= this._minY && y < this._maxY;
+    }
+}

packages/world-streaming/src/components/ChunkLoaderComponent.ts

@@ -0,0 +1,133 @@
+import { Component, ECSComponent, Serializable, Serialize, Property } from '@esengine/ecs-framework';
+import type { IChunkCoord, IStreamingConfig } from '../types';
+import { DEFAULT_STREAMING_CONFIG } from '../types';
+
+/**
+ * 区块加载器组件
+ *
+ * Singleton component that manages streaming configuration.
+ * Attach to a manager entity in the scene.
+ *
+ * 单例组件，管理流式加载配置。挂载在场景管理实体上。
+ */
+@ECSComponent('ChunkLoader')
+@Serializable({ version: 1, typeId: 'ChunkLoader' })
+export class ChunkLoaderComponent extends Component {
+    @Serialize()
+    @Property({ type: 'integer', label: 'Chunk Size', min: 64, max: 4096 })
+    private _chunkSize: number = DEFAULT_STREAMING_CONFIG.chunkSize;
+
+    @Serialize()
+    @Property({ type: 'integer', label: 'Load Radius', min: 1, max: 10 })
+    private _loadRadius: number = DEFAULT_STREAMING_CONFIG.loadRadius;
+
+    @Serialize()
+    @Property({ type: 'integer', label: 'Unload Radius', min: 2, max: 20 })
+    private _unloadRadius: number = DEFAULT_STREAMING_CONFIG.unloadRadius;
+
+    @Serialize()
+    @Property({ type: 'integer', label: 'Max Loads Per Frame', min: 1, max: 10 })
+    private _maxLoadsPerFrame: number = DEFAULT_STREAMING_CONFIG.maxLoadsPerFrame;
+
+    @Serialize()
+    @Property({ type: 'integer', label: 'Max Unloads Per Frame', min: 1, max: 10 })
+    private _maxUnloadsPerFrame: number = DEFAULT_STREAMING_CONFIG.maxUnloadsPerFrame;
+
+    @Serialize()
+    @Property({ type: 'integer', label: 'Unload Delay (ms)', min: 0, max: 30000 })
+    private _unloadDelay: number = DEFAULT_STREAMING_CONFIG.unloadDelay;
+
+    @Serialize()
+    @Property({ type: 'boolean', label: 'Enable Prefetch' })
+    private _bEnablePrefetch: boolean = DEFAULT_STREAMING_CONFIG.bEnablePrefetch;
+
+    @Serialize()
+    @Property({ type: 'integer', label: 'Prefetch Radius', min: 0, max: 5 })
+    private _prefetchRadius: number = DEFAULT_STREAMING_CONFIG.prefetchRadius;
+
+    get chunkSize(): number {
+        return this._chunkSize;
+    }
+
+    get loadRadius(): number {
+        return this._loadRadius;
+    }
+
+    get unloadRadius(): number {
+        return this._unloadRadius;
+    }
+
+    get maxLoadsPerFrame(): number {
+        return this._maxLoadsPerFrame;
+    }
+
+    get maxUnloadsPerFrame(): number {
+        return this._maxUnloadsPerFrame;
+    }
+
+    get unloadDelay(): number {
+        return this._unloadDelay;
+    }
+
+    get bEnablePrefetch(): boolean {
+        return this._bEnablePrefetch;
+    }
+
+    get prefetchRadius(): number {
+        return this._prefetchRadius;
+    }
+
+    /**
+     * 应用配置
+     *
+     * Apply streaming configuration.
+     */
+    applyConfig(config: Partial<IStreamingConfig>): void {
+        if (config.chunkSize !== undefined) this._chunkSize = config.chunkSize;
+        if (config.loadRadius !== undefined) this._loadRadius = config.loadRadius;
+        if (config.unloadRadius !== undefined) this._unloadRadius = config.unloadRadius;
+        if (config.maxLoadsPerFrame !== undefined) this._maxLoadsPerFrame = config.maxLoadsPerFrame;
+        if (config.maxUnloadsPerFrame !== undefined) this._maxUnloadsPerFrame = config.maxUnloadsPerFrame;
+        if (config.unloadDelay !== undefined) this._unloadDelay = config.unloadDelay;
+        if (config.bEnablePrefetch !== undefined) this._bEnablePrefetch = config.bEnablePrefetch;
+        if (config.prefetchRadius !== undefined) this._prefetchRadius = config.prefetchRadius;
+    }
+
+    /**
+     * 世界坐标转区块坐标
+     *
+     * Convert world position to chunk coordinates.
+     */
+    worldToChunk(worldX: number, worldY: number): IChunkCoord {
+        return {
+            x: Math.floor(worldX / this._chunkSize),
+            y: Math.floor(worldY / this._chunkSize)
+        };
+    }
+
+    /**
+     * 区块坐标转世界坐标（返回区块中心）
+     *
+     * Convert chunk coordinates to world position (chunk center).
+     */
+    chunkToWorld(coord: IChunkCoord): { x: number; y: number } {
+        return {
+            x: coord.x * this._chunkSize + this._chunkSize * 0.5,
+            y: coord.y * this._chunkSize + this._chunkSize * 0.5
+        };
+    }
+
+    /**
+     * 获取区块边界
+     *
+     * Get chunk world-space bounds.
+     */
+    getChunkBounds(coord: IChunkCoord): { minX: number; minY: number; maxX: number; maxY: number } {
+        return {
+            minX: coord.x * this._chunkSize,
+            minY: coord.y * this._chunkSize,
+            maxX: (coord.x + 1) * this._chunkSize,
+            maxY: (coord.y + 1) * this._chunkSize
+        };
+    }
+}

packages/world-streaming/src/components/StreamingAnchorComponent.ts

@@ -0,0 +1,61 @@
+import { Component, ECSComponent, Serializable, Serialize, Property } from '@esengine/ecs-framework';
+
+/**
+ * 流式锚点组件
+ *
+ * Marks an entity as a streaming anchor point.
+ * Chunks are loaded/unloaded based on distance to anchors.
+ *
+ * 标记实体作为流式加载锚点。通常挂载在玩家或摄像机实体上，
+ * 系统会根据锚点位置加载/卸载周围区块。
+ */
+@ECSComponent('StreamingAnchor')
+@Serializable({ version: 1, typeId: 'StreamingAnchor' })
+export class StreamingAnchorComponent extends Component {
+    /**
+     * 锚点权重
+     *
+     * Weight multiplier for this anchor's load radius.
+     * Higher values mean larger load radius around this anchor.
+     */
+    @Serialize()
+    @Property({ type: 'number', label: 'Weight', min: 0.1, max: 10 })
+    weight: number = 1.0;
+
+    /**
+     * 是否启用预加载
+     *
+     * Enable directional prefetching based on movement.
+     */
+    @Serialize()
+    @Property({ type: 'boolean', label: 'Enable Prefetch' })
+    bEnablePrefetch: boolean = true;
+
+    /**
+     * 上一帧位置 X
+     *
+     * Previous frame X position for velocity calculation.
+     */
+    previousX: number = 0;
+
+    /**
+     * 上一帧位置 Y
+     *
+     * Previous frame Y position for velocity calculation.
+     */
+    previousY: number = 0;
+
+    /**
+     * 速度 X 分量
+     *
+     * X component of velocity (units per second).
+     */
+    velocityX: number = 0;
+
+    /**
+     * 速度 Y 分量
+     *
+     * Y component of velocity (units per second).
+     */
+    velocityY: number = 0;
+}

packages/world-streaming/src/components/index.ts

@@ -0,0 +1,3 @@
+export { ChunkComponent } from './ChunkComponent';
+export { StreamingAnchorComponent } from './StreamingAnchorComponent';
+export { ChunkLoaderComponent } from './ChunkLoaderComponent';