Squash all commits down to 1

Allow modders to generate custom EquipentModels using EquipmentModelProvider
Expose helpers EquipmentModels
Allow modders to use ModelProvider
Expose everything from ItemModelGenerators and BlockModelGenerators
Support modded paths in ModelLocationUtils
Expose more helpers
Support modded paths in ModelTemplate.create
Fix model provider not filtering for mod specific blocks/items
Added test mod to validate ModelProvider and EquipmentModelProvider output
Add note to ModelProvider
Add missing AT for record constructor
Validate model and texture information using ExistingFileHelper
Fix typo in parameter name
Allow using vanilla texture slots in neos model builders
Add custom VariantProperty allowing modders to specify block model builders rather then ResLoc
Allow generating custom model files using vanilla model providers
Allow setting custom properties onto model templates
Allow setting render types for model templates
Fix typo with block state model builder generation
Allow looking up existing model files
Always construct new model template when assigning custom data
Merge overloaded methods into vanilla code
Add more custom data to model templates
Allow setting custom data from TexturedModel
Prepend model folders and append namespaces when missing
Allow specifying render typed by strings (defaulting to "minecraft" namespace)
Add mod and minecraft model path helpers
Fix block models generating empty content
Support setting item transforms on model templates
Fix model being generated into incorrect location
Rename serialization methods
Reorder constructors and parameters
Making them more consistent and the patches easier to read
Remove `VariantProperties.MODEL_BUILDER`
Cleanup `ModelTemplate.createBaseTemplate` patch
Assert existence of existing model files
Allow custom render type names when using String overload
Make `IModelTemplateExtension.withCustomData` publicly visible
Tear out existing file helper
Fix incorrect space indentations
Fix incorrect space indentations *again*
Break all the things
Move texture assignment to TextureSlots
Formatting
Let ModelProvider subclass decide which blocks are relevant
Get compiling on 21.4
Tests model generation still requires updating

patches/net/minecraft/client/data/models/ModelProvider.java.patch

@@ -0,0 +1,115 @@
+--- a/net/minecraft/client/data/models/ModelProvider.java
++++ b/net/minecraft/client/data/models/ModelProvider.java
+@@ -34,20 +_,40 @@
+     private final PackOutput.PathProvider blockStatePathProvider;
+     private final PackOutput.PathProvider itemInfoPathProvider;
+     private final PackOutput.PathProvider modelPathProvider;
+-
+-    public ModelProvider(PackOutput p_388260_) {
++    public final String modId;
++
++    // NeoForge: Use the above constructor passing in their mod id
++    @Deprecated
++    public ModelProvider(PackOutput p_252226_) {
++        this(p_252226_, ResourceLocation.DEFAULT_NAMESPACE);
++    }
++
++    public ModelProvider(PackOutput p_388260_, String modId) {
+         this.blockStatePathProvider = p_388260_.createPathProvider(PackOutput.Target.RESOURCE_PACK, "blockstates");
+         this.itemInfoPathProvider = p_388260_.createPathProvider(PackOutput.Target.RESOURCE_PACK, "items");
+         this.modelPathProvider = p_388260_.createPathProvider(PackOutput.Target.RESOURCE_PACK, "models");
++        this.modId = modId;
++    }
++
++    protected void registerModels(BlockModelGenerators blockModels, ItemModelGenerators itemModels) {
++        blockModels.run();
++        itemModels.run();
++    }
++
++    protected Stream<? extends Holder<Block>> getKnownBlocks() {
++        return BuiltInRegistries.BLOCK.listElements().filter(holder -> holder.getKey().location().getNamespace().equals(modId));
++    }
++
++    protected Stream<? extends Holder<Item>> getKnownItems() {
++        return BuiltInRegistries.ITEM.listElements().filter(holder -> holder.getKey().location().getNamespace().equals(modId));
+     }
+
+     @Override
+     public CompletableFuture<?> run(CachedOutput p_387857_) {
+-        ModelProvider.ItemInfoCollector modelprovider$iteminfocollector = new ModelProvider.ItemInfoCollector();
+-        ModelProvider.BlockStateGeneratorCollector modelprovider$blockstategeneratorcollector = new ModelProvider.BlockStateGeneratorCollector();
++        ModelProvider.ItemInfoCollector modelprovider$iteminfocollector = new ModelProvider.ItemInfoCollector(this::getKnownItems);
++        ModelProvider.BlockStateGeneratorCollector modelprovider$blockstategeneratorcollector = new ModelProvider.BlockStateGeneratorCollector(this::getKnownBlocks);
+         ModelProvider.SimpleModelCollector modelprovider$simplemodelcollector = new ModelProvider.SimpleModelCollector();
+-        new BlockModelGenerators(modelprovider$blockstategeneratorcollector, modelprovider$iteminfocollector, modelprovider$simplemodelcollector).run();
+-        new ItemModelGenerators(modelprovider$iteminfocollector, modelprovider$simplemodelcollector).run();
++        registerModels(new BlockModelGenerators(modelprovider$blockstategeneratorcollector, modelprovider$iteminfocollector, modelprovider$simplemodelcollector), new ItemModelGenerators(modelprovider$iteminfocollector, modelprovider$simplemodelcollector));
+         modelprovider$blockstategeneratorcollector.validate();
+         modelprovider$iteminfocollector.finalizeAndValidate();
+         return CompletableFuture.allOf(
+@@ -69,6 +_,15 @@
+     @OnlyIn(Dist.CLIENT)
+     static class BlockStateGeneratorCollector implements Consumer<BlockStateGenerator> {
+         private final Map<Block, BlockStateGenerator> generators = new HashMap<>();
++        private final Supplier<Stream<? extends Holder<Block>>> knownBlocks;
++
++        public BlockStateGeneratorCollector(Supplier<Stream<? extends Holder<Block>>> knownBlocks) {
++            this.knownBlocks = knownBlocks;
++        }
++
++        public BlockStateGeneratorCollector() {
++            this(BuiltInRegistries.BLOCK::listElements);
++        }
+
+         public void accept(BlockStateGenerator p_388748_) {
+             Block block = p_388748_.getBlock();
+@@ -79,9 +_,9 @@
+         }
+
+         public void validate() {
+-            Stream<Holder.Reference<Block>> stream = BuiltInRegistries.BLOCK.listElements().filter(p_388333_ -> true);
++            Stream<? extends Holder<Block>> stream = knownBlocks.get();
+             List<ResourceLocation> list = stream.filter(p_386843_ -> !this.generators.containsKey(p_386843_.value()))
+-                .map(p_386823_ -> p_386823_.key().location())
++                .map(p_386823_ -> p_386823_.unwrapKey().orElseThrow().location())
+                 .toList();
+             if (!list.isEmpty()) {
+                 throw new IllegalStateException("Missing blockstate definitions for: " + list);
+@@ -97,6 +_,15 @@
+     static class ItemInfoCollector implements ItemModelOutput {
+         private final Map<Item, ClientItem> itemInfos = new HashMap<>();
+         private final Map<Item, Item> copies = new HashMap<>();
++        private final Supplier<Stream<? extends Holder<Item>>> knownItems;
++
++        public ItemInfoCollector(Supplier<Stream<? extends Holder<Item>>> knownItems) {
++            this.knownItems = knownItems;
++        }
++
++        public ItemInfoCollector() {
++            this(BuiltInRegistries.ITEM::listElements);
++        }
+
+         @Override
+         public void accept(Item p_387063_, ItemModel.Unbaked p_388578_) {
+@@ -116,7 +_,7 @@
+         }
+
+         public void finalizeAndValidate() {
+-            BuiltInRegistries.ITEM.forEach(p_388426_ -> {
++            knownItems.get().map(Holder::value).forEach(p_388426_ -> {
+                 if (!this.copies.containsKey(p_388426_)) {
+                     if (p_388426_ instanceof BlockItem blockitem && !this.itemInfos.containsKey(blockitem)) {
+                         ResourceLocation resourcelocation = ModelLocationUtils.getModelLocation(blockitem.getBlock());
+@@ -132,10 +_,9 @@
+                     this.register(p_386494_, clientitem);
+                 }
+             });
+-            List<ResourceLocation> list = BuiltInRegistries.ITEM
+-                .listElements()
++            List<ResourceLocation> list = knownItems.get()
+                 .filter(p_388636_ -> !this.itemInfos.containsKey(p_388636_.value()))
+-                .map(p_388278_ -> p_388278_.key().location())
++                .map(p_388278_ -> p_388278_.unwrapKey().orElseThrow().location())
+                 .toList();
+             if (!list.isEmpty()) {
+                 throw new IllegalStateException("Missing item model definitions for: " + list);

patches/net/minecraft/client/data/models/model/ModelLocationUtils.java.patch

@@ -0,0 +1,18 @@
+--- a/net/minecraft/client/data/models/model/ModelLocationUtils.java
++++ b/net/minecraft/client/data/models/model/ModelLocationUtils.java
+@@ -11,11 +_,13 @@
+ public class ModelLocationUtils {
+     @Deprecated
+     public static ResourceLocation decorateBlockModelLocation(String p_388520_) {
+-        return ResourceLocation.withDefaultNamespace("block/" + p_388520_);
++        // NeoForge: Use ResourceLocation.parse to support modded paths
++        return ResourceLocation.parse(p_388520_).withPrefix("block/");
+     }
+
+     public static ResourceLocation decorateItemModelLocation(String p_387226_) {
+-        return ResourceLocation.withDefaultNamespace("item/" + p_387226_);
++        // NeoForge: Use ResourceLocation.parse to support modded paths
++        return ResourceLocation.parse(p_387226_).withPrefix("item/");
+     }
+
+     public static ResourceLocation getModelLocation(Block p_387758_, String p_388221_) {

patches/net/minecraft/client/data/models/model/ModelTemplate.java.patch

@@ -0,0 +1,41 @@
+--- a/net/minecraft/client/data/models/model/ModelTemplate.java
++++ b/net/minecraft/client/data/models/model/ModelTemplate.java
+@@ -51,21 +_,27 @@
+
+     public ResourceLocation create(ResourceLocation p_388380_, TextureMapping p_387099_, BiConsumer<ResourceLocation, ModelInstance> p_387748_) {
+         Map<TextureSlot, ResourceLocation> map = this.createMap(p_387099_);
+-        p_387748_.accept(p_388380_, () -> {
+-            JsonObject jsonobject = new JsonObject();
+-            this.model.ifPresent(p_388657_ -> jsonobject.addProperty("parent", p_388657_.toString()));
+-            if (!map.isEmpty()) {
+-                JsonObject jsonobject1 = new JsonObject();
+-                map.forEach((p_387287_, p_386479_) -> jsonobject1.addProperty(p_387287_.getId(), p_386479_.toString()));
+-                jsonobject.add("textures", jsonobject1);
+-            }
+-
+-            return jsonobject;
+-        });
++        p_387748_.accept(p_388380_, () -> createBaseTemplate(p_388380_, map));
+         return p_388380_;
+     }
+
++    public JsonObject createBaseTemplate(ResourceLocation p_388380_, Map<TextureSlot, ResourceLocation> map) {
++        JsonObject jsonobject = new JsonObject();
++        this.model.ifPresent(p_388657_ -> jsonobject.addProperty("parent", p_388657_.toString()));
++        if (!map.isEmpty()) {
++            JsonObject jsonobject1 = new JsonObject();
++            map.forEach((p_387287_, p_386479_) -> jsonobject1.addProperty(p_387287_.getId(), p_386479_.toString()));
++            jsonobject.add("textures", jsonobject1);
++        }
++
++        return jsonobject;
++    }
++
+     private Map<TextureSlot, ResourceLocation> createMap(TextureMapping p_387972_) {
+         return Streams.concat(this.requiredSlots.stream(), p_387972_.getForced()).collect(ImmutableMap.toImmutableMap(Function.identity(), p_387972_::get));
++    }
++
++    public net.neoforged.neoforge.client.model.generators.ExtendedModelTemplate.Builder extend() {
++        return net.neoforged.neoforge.client.model.generators.ExtendedModelTemplate.Builder.of(this);
+     }
+ }

patches/net/minecraft/client/data/models/model/TextureMapping.java.patch

@@ -0,0 +1,14 @@
+--- a/net/minecraft/client/data/models/model/TextureMapping.java
++++ b/net/minecraft/client/data/models/model/TextureMapping.java
+@@ -412,4 +_,11 @@
+         ResourceLocation resourcelocation = BuiltInRegistries.ITEM.getKey(p_386842_);
+         return resourcelocation.withPath(p_387396_ -> "item/" + p_387396_ + p_386898_);
+     }
++
++    public TextureMapping copy() {
++        TextureMapping texturemapping = new TextureMapping();
++        texturemapping.slots.putAll(this.slots);
++        texturemapping.forcedSlots.addAll(this.forcedSlots);
++        return texturemapping;
++    }
+ }

patches/net/minecraft/client/data/models/model/TexturedModel.java.patch

@@ -0,0 +1,20 @@
+--- a/net/minecraft/client/data/models/model/TexturedModel.java
++++ b/net/minecraft/client/data/models/model/TexturedModel.java
+@@ -9,7 +_,7 @@
+ import net.neoforged.api.distmarker.OnlyIn;
+
+ @OnlyIn(Dist.CLIENT)
+-public class TexturedModel {
++public class TexturedModel implements net.neoforged.neoforge.common.extensions.ITexturedModelExtension {
+     public static final TexturedModel.Provider CUBE = createDefault(TextureMapping::cube, ModelTemplates.CUBE_ALL);
+     public static final TexturedModel.Provider CUBE_INNER_FACES = createDefault(TextureMapping::cube, ModelTemplates.CUBE_ALL_INNER_FACES);
+     public static final TexturedModel.Provider CUBE_MIRRORED = createDefault(TextureMapping::cube, ModelTemplates.CUBE_MIRRORED_ALL);
+@@ -75,7 +_,7 @@
+
+     @FunctionalInterface
+     @OnlyIn(Dist.CLIENT)
+-    public interface Provider {
++    public interface Provider extends net.neoforged.neoforge.common.extensions.ITexturedModelExtension.Provider {
+         TexturedModel get(Block p_386689_);
+
+         default ResourceLocation create(Block p_388828_, BiConsumer<ResourceLocation, ModelInstance> p_386557_) {