fix(level): find a scene file's chunks and sections as the client does

SceneLoader::ReadLvlFile (1.10.64):
- chunked files: the file info chunk starts the file and gives where
  the environment, object and particle chunks start, 0 for none
  (DoLvlChunk, ReadLvlChunk1000); the reader walked the chunks one after
  another by their sizes instead;
- older files: the editor settings are a u32 size and that many bytes
  (SceneLoader::ReadEditorSettings, skipped by size); the reader took
  them for a u32 and then a count of 12 byte points;
- older files before version 3 have no objects for the client ("Level
  file is unsupported").

LevelFile now does the same. Every scene file on disk reads the same
objects as before.

Check in game: every world spawns its objects as before.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

dCommon/LevelFile.cpp

@@ -9,109 +9,114 @@
 void LevelFile::Read(std::istream& file) {
 	const uint32_t CHNK_HEADER = ('C' + ('H' << 8) + ('N' << 16) + ('K' << 24));
 
-	while (!file.eof()) {
+	uint32_t magic = 0;
-		uint32_t initPos = uint32_t(file.tellg());
+	BinaryIO::BinaryRead(file, magic);
-		uint32_t header = 0;
+	if (magic == CHNK_HEADER) {
-		BinaryIO::BinaryRead(file, header);
+		// SceneLoader::ReadLvlFile / DoLvlChunk: the file info chunk starts the file and gives where the environment,
-		if (header == CHNK_HEADER) { //Make sure we're reading a valid CHNK
+		// object and particle chunks start (0 for none); only the objects are read here
-			ChunkHeader header;
+		ChunkHeader fileInfo = ReadChunkHeader(file, 0);
-			BinaryIO::BinaryRead(file, header.id);
+		file.seekg(fileInfo.startPosition);
-			BinaryIO::BinaryRead(file, header.chunkVersion);
+		ReadFileInfoChunk(file, fileInfo);
-			BinaryIO::BinaryRead(file, header.chunkType);
+		chunkHeaders.insert({ fileInfo.id, fileInfo });
-			BinaryIO::BinaryRead(file, header.size);
+		for (const auto start : { fileInfo.fileInfo.enviromentChunkStart, fileInfo.fileInfo.objectChunkStart, fileInfo.fileInfo.particleChunkStart }) {
-			BinaryIO::BinaryRead(file, header.startPosition);
+			if (start == 0) continue;
-
+			const auto header = ReadChunkHeader(file, start);
-			uint32_t target = initPos + header.size;
+			chunkHeaders.insert({ header.id, header });
+			if (start != fileInfo.fileInfo.objectChunkStart) continue;
+			// The objects are laid out by the file's version, from its file info chunk
 			file.seekg(header.startPosition);
+			ReadSceneObjectDataChunk(file, fileInfo.fileInfo.version);
+		}
+		return;
+	}
 
-			//We're currently not loading env or particle data
+	// Scenes from before chunks (SceneLoader::ReadLvlSections): a header, then lighting, skydome and editor settings
-			if (header.id == ChunkTypeID::FileInfo) {
+	// the world skips, then the objects
-				ReadFileInfoChunk(file, header);
+	file.seekg(0);
-			} else if (header.id == ChunkTypeID::SceneObjectData) {
+	ChunkHeader header;
-				// The objects are laid out by the file's version, from its file info chunk
+	header.id = ChunkTypeID::FileInfo;
-				const auto fileInfo = chunkHeaders.find(ChunkTypeID::FileInfo);
+	BinaryIO::BinaryRead(file, header.chunkVersion);
-				ReadSceneObjectDataChunk(file, fileInfo == chunkHeaders.end() ? 0 : fileInfo->second.fileInfo.version);
+	BinaryIO::BinaryRead(file, header.chunkType);
+	// Only from version 32 (SceneLoader::ReadLvlHeader)
+	uint8_t important = 0;
+	if (header.chunkVersion >= 32) BinaryIO::BinaryRead(file, important);
+	if (header.chunkVersion > 36) {
+		BinaryIO::BinaryRead(file, header.fileInfo.revision);
+	}
+	// Lighting (SceneLoader::ReadLightingInfo)
+	if (header.chunkVersion >= 45) file.ignore(4);
+	file.ignore(4 * (4 * 3));
+
+	if (header.chunkVersion >= 31) {
+		if (header.chunkVersion >= 39) {
+			file.ignore(12 * 4);
+
+			if (header.chunkVersion >= 40) {
+				uint32_t s = 0;
+				BinaryIO::BinaryRead(file, s);
+				for (uint32_t i = 0; i < s; ++i) {
+					file.ignore(4 * 3); //a uint and two floats
+				}
 			}
-
-			chunkHeaders.insert(std::make_pair(header.id, header));
-			file.seekg(target);
 		} else {
-			if (initPos == std::streamoff(0)) { //Really old chunk version
+			file.ignore(8);
-				file.seekg(0);
+		}
-				ChunkHeader header;
-				header.id = ChunkTypeID::FileInfo;
-				BinaryIO::BinaryRead(file, header.chunkVersion);
-				BinaryIO::BinaryRead(file, header.chunkType);
-				// Only from version 32 (SceneLoader::ReadLvlHeader)
-				uint8_t important = 0;
-				if (header.chunkVersion >= 32) BinaryIO::BinaryRead(file, important);
-				if (header.chunkVersion > 36) {
-					BinaryIO::BinaryRead(file, header.fileInfo.revision);
-				}
-				// HARDCODED 3
-				if (header.chunkVersion >= 45) file.ignore(4);
-				file.ignore(4 * (4 * 3));
 
-				if (header.chunkVersion >= 31) {
+		file.ignore(3 * 4);
-					if (header.chunkVersion >= 39) {
+	}
-						file.ignore(12 * 4);
 
-						if (header.chunkVersion >= 40) {
+	if (header.chunkVersion >= 36) {
-							uint32_t s = 0;
+		file.ignore(3 * 4);
-							BinaryIO::BinaryRead(file, s);
+	}
-							for (uint32_t i = 0; i < s; ++i) {
-								file.ignore(4 * 3); //a uint and two floats
-							}
-						}
-					} else {
-						file.ignore(8);
-					}
 
-					file.ignore(3 * 4);
+	if (header.chunkVersion < 42) {
-				}
+		file.ignore(3 * 4);
 
-				if (header.chunkVersion >= 36) {
+		if (header.chunkVersion >= 33) {
-					file.ignore(3 * 4);
+			file.ignore(4 * 4);
-				}
-
-				if (header.chunkVersion < 42) {
-					file.ignore(3 * 4);
-
-					if (header.chunkVersion >= 33) {
-						file.ignore(4 * 4);
-					}
-				}
-
-				// skydome info
-				uint32_t count = 0;
-				BinaryIO::BinaryRead(file, count);
-				file.ignore(count);
-
-				// Five more strings from version 34 (SceneLoader::ReadSkydomeInfo)
-				if (header.chunkVersion >= 34) {
-					for (uint32_t i = 0; i < 5; ++i) {
-						uint32_t count = 0;
-						BinaryIO::BinaryRead(file, count);
-						file.ignore(count);
-					}
-				}
-				// editor settings
-				if (!important && header.chunkVersion >= 37){
-					file.ignore(4);
-
-					uint32_t count = 0;
-					BinaryIO::BinaryRead(file, count);
-					file.ignore(count * 12);
-
-				}
-
-				header.id = ChunkTypeID::SceneObjectData;
-				header.fileInfo.version = header.chunkVersion;
-				ReadSceneObjectDataChunk(file, header.fileInfo.version);
-				chunkHeaders.insert(std::make_pair(header.id, header));
-			} break;
 		}
 	}
+
+	// skydome info; five more strings from version 34 (SceneLoader::ReadSkydomeInfo)
+	uint32_t count = 0;
+	BinaryIO::BinaryRead(file, count);
+	file.ignore(count);
+
+	if (header.chunkVersion >= 34) {
+		for (uint32_t i = 0; i < 5; ++i) {
+			uint32_t count = 0;
+			BinaryIO::BinaryRead(file, count);
+			file.ignore(count);
+		}
+	}
+	// editor settings: their size and then that many bytes (SceneLoader::ReadEditorSettings)
+	if (!important && header.chunkVersion >= 37) {
+		uint32_t size = 0;
+		BinaryIO::BinaryRead(file, size);
+		file.ignore(size);
+	}
+
+	// The client has no objects for a file older than version 3 ("Level file is unsupported")
+	header.fileInfo.version = header.chunkVersion;
+	if (header.chunkVersion >= 3) {
+		header.id = ChunkTypeID::SceneObjectData;
+		ReadSceneObjectDataChunk(file, header.fileInfo.version);
+	}
+	chunkHeaders.insert(std::make_pair(header.id, header));
+}
+
+LevelFile::ChunkHeader LevelFile::ReadChunkHeader(std::istream& file, uint32_t start) {
+	// No check of the magic, as in the client (0x01063a00)
+	file.seekg(start);
+	uint32_t magic = 0;
+	ChunkHeader header;
+	BinaryIO::BinaryRead(file, magic);
+	BinaryIO::BinaryRead(file, header.id);
+	BinaryIO::BinaryRead(file, header.chunkVersion);
+	BinaryIO::BinaryRead(file, header.chunkType);
+	BinaryIO::BinaryRead(file, header.size);
+	BinaryIO::BinaryRead(file, header.startPosition);
+	return header;
 }
 
 void LevelFile::ReadFileInfoChunk(std::istream& file, ChunkHeader& header) {

dCommon/LevelFile.h

@@ -62,6 +62,7 @@ struct LevelFile {
 	void Read(std::istream& file);
 
 private:
+	static ChunkHeader ReadChunkHeader(std::istream& file, uint32_t start);
 	void ReadFileInfoChunk(std::istream& file, ChunkHeader& header);
 	void ReadSceneObjectDataChunk(std::istream& file, uint32_t version);
 };

tests/dCommonTests/ZoneFileTests.cpp

@@ -416,6 +416,7 @@ TEST(LevelFileTests, ReadsChunkedObjects) {
 	w.Put<uint32_t>(41).Put<uint32_t>(9).Put<uint32_t>(0).Put<uint32_t>(0).Put<uint32_t>(0);
 	end(info);
 	const auto objects = chunk(LevelFile::SceneObjectData);
+	w.At<uint32_t>(info + 20 + 12, static_cast<uint32_t>(objects)); // the file info gives where the objects start
 	w.Put<uint32_t>(2);
 	w.Object(41, 4945, 10, "respawnname=0:NS_LW_Portal\nloadOnClientOnly=7:1");
 	w.Object(41, 176, -4, "spawntemplate=1:6010");
@@ -474,6 +475,36 @@ TEST(LevelFileTests, ReadsObjectsAsTheClient) {
 	EXPECT_EQ(level.objects[1].position.x, 5.0f);
 }
 
+// Editor settings are skipped by their size; a file older than version 3 has no objects for the client
+TEST(LevelFileTests, SkipsEditorSettingsBySize) {
+	ZoneBytes w;
+	w.Put<uint16_t>(37).Put<uint16_t>(0).Put<uint8_t>(0).Put<uint32_t>(4); // version, type, important, revision
+	w.data.append(48 + 8 + 12 + 12 + 12 + 16, '\0');                     // lighting
+	w.Put<uint32_t>(0);                                                   // skydome
+	for (int i = 0; i < 5; i++) w.Put<uint32_t>(0);
+	w.Put<uint32_t>(7);
+	w.data.append(7, '\x55');                                            // editor settings
+	w.Put<uint32_t>(1);
+	w.Object(37, 4945, 3, "a=0:b");
+
+	std::istringstream stream(w.Done());
+	LevelFile level;
+	level.Read(stream);
+	ASSERT_EQ(level.objects.size(), 1u);
+	EXPECT_EQ(level.objects[0].lot, 4945);
+	EXPECT_EQ(level.chunkHeaders.begin()->second.fileInfo.revision, 4u);
+
+	ZoneBytes old;
+	old.Put<uint16_t>(2).Put<uint16_t>(0);
+	old.data.append(48 + 12, '\0');
+	old.Put<uint32_t>(0).Put<uint32_t>(1);
+	old.Object(2, 1, 0, "a=0:b");
+	std::istringstream oldStream(old.Done());
+	LevelFile oldLevel;
+	oldLevel.Read(oldStream);
+	EXPECT_TRUE(oldLevel.objects.empty());
+}
+
 TEST(LevelFileTests, DamagedFilesKeepWhatWasRead) {
 	ZoneBytes w;
 	w.Put<uint16_t>(30).Put<uint16_t>(0);

tests/dWebTests/LevelObjectsTests.cpp

@@ -32,6 +32,7 @@ namespace {
 		w.Put<uint32_t>(41).Put<uint32_t>(1).Put<uint32_t>(0).Put<uint32_t>(0).Put<uint32_t>(0);
 		w.End(info);
 		auto objects = w.Chunk(2001);
+		w.At<uint32_t>(info + 32, static_cast<uint32_t>(objects)); // the file info chunk says where the objects start, as in real files
 		w.Put<uint32_t>(4);
 		w.Object(4945, 10, 20, 30, "respawnname=0:NS_LW_Portal\ncustom_config_names=0:");
 		w.Object(6010, 1, 1, 1, "spawntemplate=1:6010");                                   // not a spawn point

tests/dWebTests/ServerOperationsTests.cpp

@@ -255,6 +255,7 @@ TEST(LevelGatingTests, CountsGatedObjects) {
 	w.Put<uint32_t>(41).Put<uint32_t>(1).Put<uint32_t>(0).Put<uint32_t>(0).Put<uint32_t>(0);
 	w.End(info);
 	auto objects = w.Chunk(2001);
+	w.At<uint32_t>(info + 32, static_cast<uint32_t>(objects)); // the file info chunk says where the objects start, as in real files
 	w.Put<uint32_t>(5);
 	w.Object(1000, "gatingOnFeature=13:oct2011content");
 	w.Object(1001, "custom_config_names=0:\ngatingOnFeature=13:oct2011content\r");

tests/dWebTests/WorldViewTests.cpp

@@ -33,6 +33,7 @@ namespace {
 		w.Put<uint32_t>(41).Put<uint32_t>(1).Put<uint32_t>(0).Put<uint32_t>(0).Put<uint32_t>(0);
 		w.End(info);
 		auto objects = w.Chunk(2001);
+		w.At<uint32_t>(info + 32, static_cast<uint32_t>(objects)); // the file info chunk says where the objects start, as in real files
 		w.Put<uint32_t>(3);
 		w.Object(10, 4945, 1, 2, 3, "respawnname=0:NS_Portal\r");
 		w.Object(11, 176, -4, 0, 8, "spawntemplate=1:6010\nspawner_name=0:Crates");
@@ -121,6 +122,7 @@ TEST(WorldSceneTests, ClientDrawsWhatTheGameDraws) {
 	w.Put<uint32_t>(41).Put<uint32_t>(1).Put<uint32_t>(0).Put<uint32_t>(0).Put<uint32_t>(0);
 	w.End(info);
 	auto objects = w.Chunk(2001);
+	w.At<uint32_t>(info + 32, static_cast<uint32_t>(objects)); // the file info chunk says where the objects start, as in real files
 	w.Put<uint32_t>(6);
 	w.Object(1, 4630, 0, 0, 0, "carver_only=7:1\ncreate_physics=7:1");     // an invisible trigger cube
 	w.Object(2, 5651, 0, 0, 0, "carver_only=7:0");                         // loaded, so drawn