feat: Add forward port for legacy predicates

src/main/kotlin/Firmament.kt

@@ -1,5 +1,6 @@
 package moe.nea.firmament
 
+import com.google.gson.Gson
 import com.mojang.brigadier.CommandDispatcher
 import io.ktor.client.HttpClient
 import io.ktor.client.plugins.UserAgent
@@ -70,6 +71,7 @@ object Firmament {
 		ignoreUnknownKeys = true
 		encodeDefaults = true
 	}
+	val gson = Gson()
 	val tightJson = Json(from = json) {
 		prettyPrint = false
 	}

src/texturePacks/java/moe/nea/firmament/features/texturepack/CustomModelOverrideParser.kt

@@ -14,6 +14,7 @@ import moe.nea.firmament.Firmament
 import moe.nea.firmament.annotations.Subscribe
 import moe.nea.firmament.events.FinalizeResourceManagerEvent
 import moe.nea.firmament.features.texturepack.predicates.AndPredicate
+import moe.nea.firmament.features.texturepack.predicates.CastPredicate
 import moe.nea.firmament.features.texturepack.predicates.DisplayNamePredicate
 import moe.nea.firmament.features.texturepack.predicates.ExtraAttributesPredicate
 import moe.nea.firmament.features.texturepack.predicates.ItemPredicate
@@ -71,9 +72,13 @@ object CustomModelOverrideParser {
 		}
 	)
 
-	fun parsePredicates(predicates: JsonObject): List<FirmamentModelPredicate> {
+	fun parsePredicates(predicates: JsonObject?): List<FirmamentModelPredicate> {
+		if (predicates == null) return neverPredicate
 		val parsedPredicates = mutableListOf<FirmamentModelPredicate>()
 		for (predicateName in predicates.keySet()) {
+			if (predicateName == "cast") { // 1.21.4
+				parsedPredicates.add(CastPredicate.Parser.parse(predicates[predicateName]) ?: return neverPredicate)
+			}
 			if (!predicateName.startsWith("firmament:")) continue
 			val identifier = Identifier.of(predicateName)
 			val parser = predicateParsers[identifier] ?: return neverPredicate

src/texturePacks/java/moe/nea/firmament/features/texturepack/PredicateModel.kt

@@ -1,17 +1,22 @@
 package moe.nea.firmament.features.texturepack
 
+import com.google.gson.JsonObject
 import com.mojang.serialization.Codec
 import com.mojang.serialization.MapCodec
 import com.mojang.serialization.codecs.RecordCodecBuilder
 import net.minecraft.client.item.ItemModelManager
 import net.minecraft.client.render.item.ItemRenderState
+import net.minecraft.client.render.item.model.BasicItemModel
 import net.minecraft.client.render.item.model.ItemModel
 import net.minecraft.client.render.item.model.ItemModelTypes
+import net.minecraft.client.render.item.tint.TintSource
 import net.minecraft.client.render.model.ResolvableModel
 import net.minecraft.client.world.ClientWorld
 import net.minecraft.entity.LivingEntity
 import net.minecraft.item.ItemStack
 import net.minecraft.item.ModelTransformationMode
+import net.minecraft.util.Identifier
+import moe.nea.firmament.features.texturepack.predicates.AndPredicate
 
 class PredicateModel {
 	data class Baked(
@@ -46,6 +51,22 @@ class PredicateModel {
 		val overrides: List<Override>,
 	) : ItemModel.Unbaked {
 		companion object {
+			@JvmStatic
+			fun fromLegacyJson(jsonObject: JsonObject, fallback: ItemModel.Unbaked): ItemModel.Unbaked {
+				val legacyOverrides = jsonObject.getAsJsonArray("overrides") ?: return fallback
+				val newOverrides = ArrayList<Override>()
+				for (legacyOverride in legacyOverrides) {
+					legacyOverride as JsonObject
+					val overrideModel = Identifier.tryParse(legacyOverride.get("model")?.asString ?: continue) ?: continue
+					val predicate = CustomModelOverrideParser.parsePredicates(legacyOverride.getAsJsonObject("predicate"))
+					newOverrides.add(Override(
+						BasicItemModel.Unbaked(overrideModel, listOf()),
+						AndPredicate(predicate.toTypedArray())
+					))
+				}
+				return Unbaked(fallback, newOverrides)
+			}
+
 			val OVERRIDE_CODEC: Codec<Override> = RecordCodecBuilder.create {
 				it.group(
 					ItemModelTypes.CODEC.fieldOf("model").forGetter(Override::model),

src/texturePacks/java/moe/nea/firmament/features/texturepack/predicates/CastPredicate.kt

@@ -0,0 +1,20 @@
+package moe.nea.firmament.features.texturepack.predicates
+
+import com.google.gson.JsonElement
+import net.minecraft.item.ItemStack
+import moe.nea.firmament.features.texturepack.FirmamentModelPredicate
+import moe.nea.firmament.features.texturepack.FirmamentModelPredicateParser
+import moe.nea.firmament.util.MC
+
+class CastPredicate : FirmamentModelPredicate {
+	object Parser : FirmamentModelPredicateParser {
+		override fun parse(jsonElement: JsonElement): FirmamentModelPredicate? {
+			if (jsonElement.asDouble >= 1) return CastPredicate()
+			return NotPredicate(arrayOf(CastPredicate()))
+		}
+	}
+
+	override fun test(stack: ItemStack): Boolean {
+		return MC.player?.fishHook != null // TODO pass through more of the model predicate context
+	}
+}

src/texturePacks/java/moe/nea/firmament/mixins/custommodels/SupplyFakeModelPatch.java

@@ -1,10 +1,15 @@
 package moe.nea.firmament.mixins.custommodels;
 
+import com.google.gson.JsonObject;
 import com.llamalad7.mixinextras.injector.ModifyReturnValue;
 import com.llamalad7.mixinextras.sugar.Local;
+import moe.nea.firmament.Firmament;
+import moe.nea.firmament.features.texturepack.PredicateModel;
+import moe.nea.firmament.util.ErrorUtil;
 import net.minecraft.client.item.ItemAsset;
 import net.minecraft.client.item.ItemAssetsLoader;
 import net.minecraft.client.render.item.model.BasicItemModel;
+import net.minecraft.client.render.item.model.ItemModel;
 import net.minecraft.resource.Resource;
 import net.minecraft.resource.ResourceManager;
 import net.minecraft.resource.ResourcePack;
@@ -12,6 +17,10 @@ import net.minecraft.util.Identifier;
 import org.spongepowered.asm.mixin.Mixin;
 import org.spongepowered.asm.mixin.injection.At;
 
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.ArrayList;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -46,16 +55,22 @@ public class SupplyFakeModelPatch {
 		for (Map.Entry<Identifier, Resource> model : resources.entrySet()) {
 			var resource = model.getValue();
 			var itemModelId = model.getKey().withPath(it -> it.substring("models/item/".length(), it.length() - ".json".length()));
-			// TODO: parse json file here and make use of it in order to generate predicate files.
-			// TODO: add a filter using the pack.mcmeta to opt out of this behaviour
 			var genericModelId = itemModelId.withPrefixedPath("item/");
+			// TODO: inject tint indexes based on the json data here
+			ItemModel.Unbaked unbakedModel = new BasicItemModel.Unbaked(genericModelId, List.of());
+			// TODO: add a filter using the pack.mcmeta to opt out of this behaviour
+			try (var is = resource.getInputStream()) {
+				var jsonObject = Firmament.INSTANCE.getGson().fromJson(new InputStreamReader(is), JsonObject.class);
+				unbakedModel = PredicateModel.Unbaked.fromLegacyJson(jsonObject, unbakedModel);
+			} catch (Exception e) {
+				ErrorUtil.INSTANCE.softError("Could not create resource for fake model supplication: " + model.getKey(), e);
+			}
 			if (resourceManager.getResource(itemModelId)
 			                   .map(Resource::getPack)
 			                   .map(it -> isResourcePackNewer(resourceManager, it, resource.getPack()))
 			                   .orElse(true)) {
 				newModels.put(itemModelId, new ItemAsset(
-					// TODO: inject tint indexes based on the json data here
-					new BasicItemModel.Unbaked(genericModelId, List.of()),
+					unbakedModel,
 					new ItemAsset.Properties(true)
 				));
 			}