[1.21] Resource Conditions in Pack Overlays

fabric-resource-conditions-api-v1/build.gradle

@@ -4,4 +4,8 @@ loom {
 	accessWidenerPath = file("src/main/resources/fabric-resource-conditions-api-v1.accesswidener")
 }
 
-testDependencies(project, [':fabric-gametest-api-v1'])
+testDependencies(project, [
+	':fabric-gametest-api-v1',
+	':fabric-lifecycle-events-v1',
+	':fabric-resource-loader-v0'
+])

fabric-resource-conditions-api-v1/src/main/java/net/fabricmc/fabric/api/resource/conditions/v1/ResourceConditions.java

@@ -48,6 +48,11 @@ public final class ResourceConditions {
 	 */
 	public static final String CONDITIONS_KEY = "fabric:load_conditions";
 
+	/**
+	 * The JSON key for conditional overlays in pack.mcmeta files.
+	 */
+	public static final String OVERLAYS_KEY = "fabric:overlays";
+
 	private ResourceConditions() {
 	}
 

fabric-resource-conditions-api-v1/src/main/java/net/fabricmc/fabric/impl/resource/conditions/OverlayConditionsMetadata.java

@@ -0,0 +1,60 @@
+/*
+ * Copyright (c) 2016, 2017, 2018, 2019 FabricMC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.fabricmc.fabric.impl.resource.conditions;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.regex.Pattern;
+
+import com.mojang.serialization.Codec;
+import com.mojang.serialization.DataResult;
+import com.mojang.serialization.codecs.RecordCodecBuilder;
+
+import net.minecraft.resource.metadata.ResourceMetadataSerializer;
+
+import net.fabricmc.fabric.api.resource.conditions.v1.ResourceCondition;
+import net.fabricmc.fabric.api.resource.conditions.v1.ResourceConditions;
+
+public record OverlayConditionsMetadata(List<Entry> overlays) {
+	public static final Codec<OverlayConditionsMetadata> CODEC = Entry.CODEC.listOf().fieldOf("entries").xmap(OverlayConditionsMetadata::new, OverlayConditionsMetadata::overlays).codec();
+	public static final ResourceMetadataSerializer<OverlayConditionsMetadata> SERIALIZER = ResourceMetadataSerializer.fromCodec(ResourceConditions.OVERLAYS_KEY, CODEC);
+
+	public List<String> appliedOverlays() {
+		List<String> appliedOverlays = new ArrayList<>();
+
+		for (Entry entry : this.overlays()) {
+			if (entry.condition().test(null)) {
+				appliedOverlays.add(entry.directory());
+			}
+		}
+
+		return appliedOverlays;
+	}
+
+	public record Entry(String directory, ResourceCondition condition) {
+		public static final Codec<Entry> CODEC = RecordCodecBuilder.create(instance -> instance.group(
+				Codec.STRING.validate(Entry::validateDirectory).fieldOf("directory").forGetter(Entry::directory),
+				ResourceCondition.CODEC.fieldOf("condition").forGetter(Entry::condition)
+		).apply(instance, Entry::new));
+		private static final Pattern DIRECTORY_NAME_PATTERN = Pattern.compile("[-_a-zA-Z0-9.]+");
+
+		private static DataResult<String> validateDirectory(String directory) {
+			boolean valid = DIRECTORY_NAME_PATTERN.matcher(directory).matches();
+			return valid ? DataResult.success(directory) : DataResult.error(() -> "Directory name is invalid");
+		}
+	}
+}

fabric-resource-conditions-api-v1/src/main/java/net/fabricmc/fabric/mixin/resource/conditions/ResourcePackProfileMixin.java

@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2016, 2017, 2018, 2019 FabricMC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.fabricmc.fabric.mixin.resource.conditions;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
+
+import com.llamalad7.mixinextras.sugar.Local;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.ModifyVariable;
+
+import net.minecraft.resource.ResourcePack;
+import net.minecraft.resource.ResourcePackProfile;
+
+import net.fabricmc.fabric.impl.resource.conditions.OverlayConditionsMetadata;
+
+@Mixin(ResourcePackProfile.class)
+public class ResourcePackProfileMixin {
+	@ModifyVariable(method = "loadMetadata", at = @At("STORE"))
+	private static List<String> applyOverlayConditions(List<String> overlays, @Local ResourcePack resourcePack) throws IOException {
+		List<String> appliedOverlays = new ArrayList<>(overlays);
+		OverlayConditionsMetadata overlayMetadata = resourcePack.parseMetadata(OverlayConditionsMetadata.SERIALIZER);
+
+		if (overlayMetadata != null) {
+			appliedOverlays.addAll(overlayMetadata.appliedOverlays());
+		}
+
+		return List.copyOf(appliedOverlays);
+	}
+}

fabric-resource-conditions-api-v1/src/main/resources/fabric-resource-conditions-api-v1.mixins.json

@@ -9,6 +9,7 @@
     "RecipeManagerMixin",
     "RegistryLoaderMixin",
     "ReloadableRegistriesMixin",
+    "ResourcePackProfileMixin",
     "ServerAdvancementLoaderMixin",
     "SinglePreparationResourceReloaderMixin",
     "TagManagerLoaderMixin"

fabric-resource-conditions-api-v1/src/testmod/java/net/fabricmc/fabric/test/resource/conditions/ConditionalResourcesTest.java

@@ -121,4 +121,19 @@ public void conditionalDynamicRegistry(TestContext context) {
 
 		context.complete();
 	}
+
+	@GameTest(templateName = FabricGameTest.EMPTY_STRUCTURE)
+	public void conditionalOverlays(TestContext context) {
+		ReloadableRegistries.Lookup registries = context.getWorld().getServer().getReloadableRegistries();
+
+		if (!registries.getRegistryManager().get(RegistryKeys.PREDICATE).containsId(id("do_overlay"))) {
+			throw new AssertionError("do_overlay predicate should have been overlayed.");
+		}
+
+		if (registries.getRegistryManager().get(RegistryKeys.PREDICATE).containsId(id("dont_overlay"))) {
+			throw new AssertionError("dont_overlay predicate should not have been overlayed.");
+		}
+
+		context.complete();
+	}
 }

fabric-resource-conditions-api-v1/src/testmod/resources/do_overlay/data/fabric-resource-conditions-api-v1-testmod/predicate/do_overlay.json

@@ -0,0 +1,3 @@
+{
+  "condition": "minecraft:survives_explosion"
+}

fabric-resource-conditions-api-v1/src/testmod/resources/dont_overlay/data/fabric-resource-conditions-api-v1-testmod/predicate/dont_overlay.json

@@ -0,0 +1,3 @@
+{
+  "condition": "minecraft:survives_explosion"
+}

fabric-resource-conditions-api-v1/src/testmod/resources/pack.mcmeta

@@ -0,0 +1,25 @@
+{
+  "pack": {
+    "pack_format": 48,
+    "description": ""
+  },
+  "fabric:overlays": {
+    "entries": [
+      {
+        "directory": "do_overlay",
+        "condition": {
+          "condition": "fabric:true"
+        }
+      },
+      {
+        "directory": "dont_overlay",
+        "condition": {
+          "condition": "fabric:not",
+          "value": {
+            "condition": "fabric:true"
+          }
+        }
+      }
+    ]
+  }
+}

fabric-resource-loader-v0/src/main/java/net/fabricmc/fabric/impl/resource/loader/ResourceManagerHelperImpl.java

@@ -37,6 +37,7 @@
 
 import net.minecraft.recipe.RecipeManager;
 import net.minecraft.registry.RegistryWrapper;
+import net.minecraft.resource.OverlayResourcePack;
 import net.minecraft.resource.ResourcePack;
 import net.minecraft.resource.ResourcePackInfo;
 import net.minecraft.resource.ResourcePackPosition;
@@ -145,8 +146,19 @@ public ResourcePack open(ResourcePackInfo var1) {
 
 					@Override
 					public ResourcePack openWithOverlays(ResourcePackInfo var1, ResourcePackProfile.Metadata metadata) {
-						// Don't support overlays in builtin res packs.
-						return entry.getRight();
+						ModNioResourcePack pack = entry.getRight();
+
+						if (metadata.overlays().isEmpty()) {
+							return pack;
+						}
+
+						List<ResourcePack> overlays = new ArrayList<>(metadata.overlays().size());
+
+						for (String overlay : metadata.overlays()) {
+							overlays.add(pack.createOverlay(overlay));
+						}
+
+						return new OverlayResourcePack(pack, overlays);
 					}
 				}, resourceType, info2);
 				consumer.accept(profile);