8c7d5b9d38
用户定向：在 python 层写 switch，调用不同 java 后端（而非一个文件里 switch）。
新增：
mcfold/backends/{__init__,base,gen_1_20,gen_1_21}.py 后端体系与分派
scaffold/java/gen_1_20/ 对 1.20.x client jar 编译
scaffold/java/gen_1_21/ 对 1.21.1 client jar 编译（✅ 实测编译通过）
scaffold/java/VERSION-DIFFS.md 实测差异全表
判据：DeltaTracker 类是否存在（1.21 引入，正是 render 签名变化的根源）
⇒ 比硬编码版本号稳
实测差异共 11 处（21 个检查点里 13 个跨世代完全一致）：
setLevel / GameRenderer.render / countRendered* / createPackRepository /
ResourceLocation 构造 / enableDataFixerOptimizations(移除) / User 构造 /
ChunkStatus 包路径 / ClientPacketListener 构造(参数个数语义都变) /
loadEffect(变 private)
为什么必须分后端：DeltaTracker 在 1.20.x jar 中不存在，
两代调用无法共存于一份源码（实测编译报 cannot find symbol）。
1.21.1 反混淆已验证（29MB named jar，DeltaTracker 3 处）
351 lines
12 KiB
Python
351 lines
12 KiB
Python
"""渲染后端基类 —— 世代无关的协议与生命周期。
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设计（用户 2026-09-25 定向）：
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Python 层做 switch 选择后端；每个世代一个**独立编译**的 Java 服务端。
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原因：Java 是编译期绑定的，世代间的签名差异（DeltaTracker 等）无法写在同一份源码里。
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本基类承载所有世代共用的部分：
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- NDJSON 通道（子进程 + 行分隔 JSON）
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- 命令集（chunk / camera / resolve / render / registry / debug / view）
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- base64 载荷编解码
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子类只需声明世代特征（Java 目录、判据类、API 差异说明）。
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"""
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from __future__ import annotations
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import base64
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import json
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import os
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import subprocess
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import threading
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import time
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from dataclasses import dataclass, field
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from pathlib import Path
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from typing import Any
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class BackendError(RuntimeError):
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"""后端不可用或渲染失败。"""
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@dataclass
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class RenderResult:
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"""一次渲染的结果。
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distinct_colors 是本项目实测最锐利的判据：
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空屏/纯色 1-2 色 / 加载屏 ~199 / 简单地形 ~1450 / 真实存档 >10000
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（non-black 会被红底加载屏骗过 —— 实测踩过）
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"""
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image: bytes | None = None
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path: str | None = None
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width: int = 0
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height: int = 0
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chunks_rendered: int = 0
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distinct_colors: int = 0
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camera: tuple[float, float, float] = (0.0, 0.0, 0.0)
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warnings: list[str] = field(default_factory=list)
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raw: dict[str, Any] = field(default_factory=dict)
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@property
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def has_world_content(self) -> bool:
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return self.distinct_colors > 400 and self.chunks_rendered > 0
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class RenderBackend:
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"""所有世代后端共用的实现。子类覆写类属性即可。"""
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generation: str = "base"
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min_mc_version: str = ""
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max_mc_version: str = ""
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java_dir: str = ""
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markers: tuple[str, ...] = ()
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main_class: str = "McfoldRenderServer"
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def __init__(
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self,
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java: str = "java",
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classpath: str | list[str] | None = None,
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game_dir: str | None = None,
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assets: str | None = None,
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asset_index: str | None = None,
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java_args: list[str] | None = None,
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startup_timeout: float = 240.0,
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cwd: str | None = None,
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):
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self.java = java
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if classpath is None:
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classpath = os.environ.get("MCFOLD_RENDER_CLASSPATH")
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if isinstance(classpath, (list, tuple)):
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classpath = os.pathsep.join(classpath)
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self.classpath = classpath
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self.game_dir = game_dir
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self.assets = assets
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self.asset_index = asset_index
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self.startup_timeout = startup_timeout
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self.cwd = cwd
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self.java_args = java_args or [
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"-Xmx1200M", "-Xms512M", "-Djava.awt.headless=true",
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]
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self._proc: subprocess.Popen | None = None
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self._next_id = 1
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self._pending: dict[int, tuple[threading.Event, dict]] = {}
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self._lock = threading.Lock()
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self._stderr_tail: list[str] = []
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# ---------------- 生命周期 ----------------
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@property
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def running(self) -> bool:
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return self._proc is not None and self._proc.poll() is None
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def start(self) -> "RenderBackend":
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if self.running:
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return self
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if not self.classpath:
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raise BackendError(
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f"未提供 classpath。设置 MCFOLD_RENDER_CLASSPATH，"
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f"或先跑 scaffold/build.sh 编译 {self.generation} 后端。"
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)
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cmd = [self.java, *self.java_args, "-cp", self.classpath, self.main_class]
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if self.game_dir:
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cmd += ["--gameDir", self.game_dir]
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if self.assets:
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cmd += ["--assets", self.assets]
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if self.asset_index:
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cmd += ["--assetIndex", self.asset_index]
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env = dict(os.environ)
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nat = env.get("MCFOLD_NATIVES_DIR")
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if nat:
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env["LD_LIBRARY_PATH"] = nat + os.pathsep + env.get("LD_LIBRARY_PATH", "")
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try:
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self._proc = subprocess.Popen(
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cmd, cwd=self.cwd, env=env,
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stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE,
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text=False, bufsize=0,
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)
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except FileNotFoundError as e:
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raise BackendError(f"无法启动 java: {e}") from e
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threading.Thread(target=self._read_loop, daemon=True).start()
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threading.Thread(target=self._stderr_loop, daemon=True).start()
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ready = self._await_event("ready", self.startup_timeout)
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if not ready.get("_ok"):
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self.stop()
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tail = "".join(self._stderr_tail[-6:])
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raise BackendError(
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f"{self.generation} 后端启动失败：{ready.get('error') or '超时'}"
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+ (f"\n{tail}" if tail else "")
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)
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return self
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def stop(self, timeout: float = 10.0) -> None:
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p = self._proc
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if p is None:
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return
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try:
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if p.poll() is None:
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try:
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self._send_raw({"cmd": "shutdown"})
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p.wait(timeout=timeout)
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except subprocess.TimeoutExpired:
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p.terminate()
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try:
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p.wait(timeout=5)
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except subprocess.TimeoutExpired:
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p.kill()
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except Exception:
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try:
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p.kill()
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except Exception:
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pass
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finally:
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self._proc = None
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def __enter__(self):
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return self.start()
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def __exit__(self, *exc):
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self.stop()
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# ---------------- 数据注入 ----------------
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def feed_chunk(self, cx: int, cz: int, chunk_data: bytes) -> dict:
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return self._request({"cmd": "chunk", "cx": cx, "cz": cz,
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"data": self._b64(chunk_data)})
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def feed_chunks(self, chunks: list[tuple[int, int, bytes]]) -> dict:
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return self._request({
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"cmd": "chunks",
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"items": [{"cx": cx, "cz": cz, "data": self._b64(d)} for cx, cz, d in chunks],
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}, timeout=300.0)
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def set_viewport(self, cx: int, cz: int, radius: int | None = None) -> dict:
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"""视野中心 —— 必须在注入前设好，否则区块被 ClientChunkCache 丢弃（实测）。"""
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req: dict[str, Any] = {"cmd": "viewport", "cx": cx, "cz": cz}
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if radius is not None:
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req["radius"] = radius
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return self._request(req)
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# ---------------- 视角与视觉 ----------------
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def set_camera(self, x: float, y: float, z: float,
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yaw: float = 0.0, pitch: float = 0.0) -> dict:
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return self._request({"cmd": "camera", "x": x, "y": y, "z": z,
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"yaw": yaw, "pitch": pitch})
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def set_view(self, **kw) -> dict:
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"""视觉设置。各世代支持的项见子类 api_notes()。
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世代无关的项：camera_type / render_distance / fov
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原版画质（所有世代都有）：graphics_mode / ambient_occlusion /
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mipmap_levels / gamma / entity_shadows / clouds / particles
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后处理链：post_effect（原版 PostChain，非第三方光影包）
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"""
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req: dict[str, Any] = {"cmd": "view"}
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mapping = {
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"camera_type": "cameraType", "render_distance": "renderDistance",
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"fov": "fov", "graphics_mode": "graphicsMode",
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"ambient_occlusion": "ambientOcclusion", "mipmap_levels": "mipmapLevels",
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"gamma": "gamma", "entity_shadows": "entityShadows",
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"clouds": "clouds", "particles": "particles",
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"post_effect": "postEffect",
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}
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for py, js in mapping.items():
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if py in kw and kw[py] is not None:
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req[js] = kw[py]
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return self._request(req)
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# ---------------- 查询 ----------------
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def registry_info(self) -> dict:
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return self._request({"cmd": "registry"})
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def lookup_state(self, state_id: int) -> dict:
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return self._request({"cmd": "lookup", "stateId": state_id})
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def resolve_blocks(self, specs: list[str]) -> list[int]:
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"""方块名(+属性) → state id。名字→id 的权威映射在客户端注册表。"""
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if not specs:
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return []
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return self._request({"cmd": "resolve", "blocks": specs})["ids"]
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def debug(self) -> dict:
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return self._request({"cmd": "debug"})
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# ---------------- 渲染 ----------------
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def render(self, out: str | None = None, frames: int = 60,
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width: int | None = None, height: int | None = None) -> RenderResult:
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req: dict[str, Any] = {"cmd": "render", "frames": frames}
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if out:
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req["out"] = out
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if width:
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req["width"] = width
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if height:
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req["height"] = height
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resp = self._request(req, timeout=600.0)
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img = resp.pop("image", None)
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cam = resp.get("camera") or (0.0, 0.0, 0.0)
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if not isinstance(cam, (list, tuple)):
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cam = (0.0, 0.0, 0.0)
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return RenderResult(
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image=base64.b64decode(img) if img else None,
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path=resp.get("path"),
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width=resp.get("width", 0),
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height=resp.get("height", 0),
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chunks_rendered=resp.get("chunksRendered", 0),
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distinct_colors=resp.get("distinctColors", 0),
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camera=tuple(float(c) for c in cam[:3]),
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warnings=resp.get("warnings", []),
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raw=resp,
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)
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# ---------------- 内部 ----------------
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@staticmethod
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def _b64(b: bytes) -> str:
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return base64.b64encode(b).decode("ascii")
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def _request(self, req: dict, timeout: float = 180.0) -> dict:
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if not self.running:
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raise BackendError("后端未运行（先 start()）")
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with self._lock:
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rid = self._next_id
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self._next_id += 1
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req["id"] = rid
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ev = threading.Event()
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self._pending[rid] = (ev, {})
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self._send_raw(req)
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if not ev.wait(timeout):
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self._pending.pop(rid, None)
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raise BackendError(f"后端无响应（{timeout}s）：cmd={req.get('cmd')}")
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_, resp = self._pending.pop(rid)
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if not resp.get("_ok", True):
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raise BackendError(resp.get("error", "未知错误"))
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return resp
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def _await_event(self, kind: str, timeout: float) -> dict:
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deadline = time.time() + timeout
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while time.time() < deadline:
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if not self.running:
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code = self._proc.poll() if self._proc else "?"
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return {"_ok": False, "error": f"进程退出（code={code}）"}
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box = self._pending.pop(-1, None)
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if box is not None:
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ev, payload = box
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if payload.get("_event") == kind:
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return {"_ok": True, **payload}
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self._pending[-1] = (ev, payload) # 不是目标事件，放回
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time.sleep(0.05)
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return {"_ok": False, "error": f"等待 {kind} 超时"}
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def _send_raw(self, obj: dict) -> None:
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if not self._proc or self._proc.stdin is None:
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raise BackendError("stdin 不可用")
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self._proc.stdin.write((json.dumps(obj) + "\n").encode("utf-8"))
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self._proc.stdin.flush()
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def _read_loop(self) -> None:
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assert self._proc and self._proc.stdout
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for raw in self._proc.stdout:
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line = raw.decode("utf-8", "replace").strip()
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if not line.startswith("{"):
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continue
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try:
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msg = json.loads(line)
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except json.JSONDecodeError:
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continue
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if msg.get("event") == "ready":
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ev = threading.Event()
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box = dict(msg); box["_event"] = "ready"
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self._pending[-1] = (ev, box)
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ev.set()
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continue
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rid = msg.get("id")
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if rid in self._pending:
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ev, box = self._pending[rid]
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box.update(msg)
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ev.set()
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def _stderr_loop(self) -> None:
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assert self._proc and self._proc.stderr
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for raw in self._proc.stderr:
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line = raw.decode("utf-8", "replace").rstrip()
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self._stderr_tail.append(line)
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if len(self._stderr_tail) > 300:
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del self._stderr_tail[:150]
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# ---------------- 元信息 ----------------
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def api_notes(self) -> dict:
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"""本世代的 API 特征（子类覆写）。"""
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return {}
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def describe(self) -> str:
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return (f"{self.generation} [{self.min_mc_version}..{self.max_mc_version}] "
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f"java_dir={self.java_dir}")
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