Better Handling Of DataPacks

Author: cev-api

README.md

@@ -170,7 +170,6 @@ I also added the ability to import waypoints from [Wurst7-CevAPI](https://github
 Can now change the default 5 minute render timeout with ```/sm:config ESP Timeout```
 
 ### Loot Table Browser
-
 Can now visually search and browse through the loot table for the given map area. Click the 'Loot Table' button on the seed map to open the browser. You can also make ESP highlights or waypoints to the chests or simply copy the coordinates. Enchantments will be highlighted with colors and icons. 
 
 ![LootTable](https://i.imgur.com/lnT5LsP.png)

src/main/c/cubiomes

@@ -388,9 +388,15 @@ private DatapackWorldgen(CloseableResourceManager resourceManager, RegistryAcces
         }
 
         public static DatapackWorldgen load(Path datapackRoot, long seed) throws IOException {
-            PackResources vanilla = createVanillaPack();
-            PackResources customPack = createPathPack("seedmapper_datapack", datapackRoot, PackSource.WORLD);
-            CloseableResourceManager resourceManager = new MultiPackResourceManager(PackType.SERVER_DATA, List.of(vanilla, customPack));
+                PackResources vanilla = createVanillaPack();
+                // Create a sanitized copy of the datapack that strips worldgen JSON which
+                // commonly fails registry loading (noise_settings, density_function, etc.).
+                Path sanitized = sanitizeDatapack(datapackRoot);
+                PackResources customPack = createPathPack("seedmapper_datapack", sanitized, PackSource.WORLD);
+                // Create a small runtime fallback datapack to supply missing density-function keys
+                Path fallbackDatapack = createTemporaryFallbackDatapack();
+                PackResources fallbackPack = createPathPack("seedmapper_fallback", fallbackDatapack, PackSource.BUILT_IN);
+                CloseableResourceManager resourceManager = new MultiPackResourceManager(PackType.SERVER_DATA, List.of(vanilla, fallbackPack, customPack));
             RegistryAccess.Frozen registryAccess = loadRegistryAccess(resourceManager);
             Set<Identifier> vanillaStructures = loadVanillaStructureIds();
             LevelStorageSource.LevelStorageAccess storageAccess = createTempStorageAccess();
@@ -604,6 +610,45 @@ private static List<CustomStructureSet> buildCustomStructureSets(RegistryAccess
         }
     }
 
+    private static Path createTemporaryFallbackDatapack() throws IOException {
+        Path temp = Files.createTempDirectory("seedmapper_fallback_datapack");
+        Path dataDir = temp.resolve("data").resolve("minecraft").resolve("worldgen").resolve("density_function");
+        Files.createDirectories(dataDir);
+        // Provide a simple constant density function so registry parsing that expects
+        // `preliminary_surface_level` can resolve during datapack import. This is
+        // intentionally minimal; it acts as a fallback only.
+        String json = "{\n  \"type\": \"minecraft:constant\",\n  \"argument\": 64.0\n}\n";
+        Files.writeString(dataDir.resolve("preliminary_surface_level.json"), json);
+        return temp;
+    }
+
+    private static Path sanitizeDatapack(Path baseDir) throws IOException {
+        if (baseDir == null) return null;
+        Path sanitized = Files.createTempDirectory("seedmapper_sanitized_");
+        try (Stream<Path> stream = Files.walk(baseDir)) {
+            stream.forEach(source -> {
+                try {
+                    Path rel = baseDir.relativize(source);
+                    String relStr = rel.toString().replace('\\', '/');
+                    // Skip worldgen-related files under data/*/worldgen/**
+                    if (relStr.startsWith("data/") && relStr.contains("/worldgen/")) {
+                        return;
+                    }
+                    Path target = sanitized.resolve(rel);
+                    if (Files.isDirectory(source)) {
+                        Files.createDirectories(target);
+                    } else {
+                        Files.createDirectories(target.getParent());
+                        Files.copy(source, target, StandardCopyOption.REPLACE_EXISTING);
+                    }
+                } catch (IOException e) {
+                    throw new RuntimeException(e);
+                }
+            });
+        }
+        return sanitized;
+    }
+
     public record DimensionContext(int dimensionId, ChunkGenerator chunkGenerator, BiomeSource biomeSource, RandomState randomState,
                                    ChunkGeneratorStructureState structureState, LevelHeightAccessor heightAccessor) {}
 
@@ -927,6 +972,29 @@ private static RegistryAccess.Frozen loadRegistryAccess(ResourceManager resource
                 new FilteringResourceManager(resourceManager, DatapackStructureManager::isEnchantmentRelatedResource),
                 DatapackStructureManager::isEnchantmentRelatedRegistry
             ),
+            new RegistryLoadAttempt(
+                "skip_worldgen_noise_and_density",
+                resourceManager,
+                key -> {
+                    if (key == null) return false;
+                    // Avoid loading worldgen noise settings and density functions from the datapack
+                    if (Registries.NOISE_SETTINGS.equals(key) || Registries.DENSITY_FUNCTION.equals(key)) return false;
+                    return true;
+                }
+            ),
+            new RegistryLoadAttempt(
+                "structures_only",
+                new FilteringResourceManager(resourceManager, DatapackStructureManager::isWorldgenResource),
+                key -> {
+                    if (key == null) return false;
+                    return Registries.STRUCTURE.equals(key)
+                        || Registries.STRUCTURE_SET.equals(key)
+                        || Registries.BIOME.equals(key)
+                        || Registries.CONFIGURED_CARVER.equals(key)
+                        || Registries.PLACED_FEATURE.equals(key)
+                        || Registries.CONFIGURED_FEATURE.equals(key);
+                }
+            ),
             new RegistryLoadAttempt(
                 "unfiltered",
                 resourceManager,
@@ -986,6 +1054,19 @@ private static List<RegistryDataLoader.RegistryData<?>> filterRegistryData(
             .toList();
     }
 
+    private static boolean isWorldgenResource(Identifier id) {
+        if (id == null) return false;
+        String path = id.getPath();
+        if (path == null) return false;
+        return path.startsWith("worldgen/noise_settings")
+            || path.startsWith("worldgen/density_function")
+            || path.startsWith("worldgen/world_preset")
+            || path.startsWith("worldgen/configured_carver")
+            || path.startsWith("worldgen/placed_feature")
+            || path.startsWith("worldgen/configured_feature")
+            || path.startsWith("worldgen/configured_carver");
+    }
+
     private static boolean isEnchantmentResource(Identifier id) {
         if (id == null) {
             return false;