Add custom texture pack support

src/main/kotlin/moe/nea/firmament/events/CustomItemModelEvent.kt

@@ -0,0 +1,41 @@
+package moe.nea.firmament.events
+
+import java.util.*
+import net.minecraft.client.render.model.BakedModel
+import net.minecraft.client.render.model.BakedModelManager
+import net.minecraft.client.util.ModelIdentifier
+import net.minecraft.item.ItemStack
+
+data class CustomItemModelEvent(
+    val itemStack: ItemStack,
+    var overrideModel: ModelIdentifier? = null,
+) : FirmamentEvent() {
+    companion object : FirmamentEventBus<CustomItemModelEvent>() {
+        private val cache = IdentityHashMap<ItemStack?, Any>()
+        private val sentinelNull = Object()
+
+        fun clearCache() {
+            cache.clear()
+        }
+
+        @JvmStatic
+        fun getModelIdentifier(itemStack: ItemStack?): ModelIdentifier? {
+            if (itemStack == null) return null
+            return publish(CustomItemModelEvent(itemStack)).overrideModel
+        }
+
+        @JvmStatic
+        fun getModel(itemStack: ItemStack?, thing: BakedModelManager): BakedModel? {
+            if (itemStack == null) return null
+            val cachedValue = cache.getOrPut(itemStack) {
+                val modelId = getModelIdentifier(itemStack) ?: return@getOrPut sentinelNull
+                val bakedModel = thing.getModel(modelId)
+                if (bakedModel === thing.missingModel) return@getOrPut sentinelNull
+                bakedModel
+            }
+            if (cachedValue === sentinelNull)
+                return null
+            return cachedValue as BakedModel
+        }
+    }
+}

src/main/kotlin/moe/nea/firmament/features/FeatureManager.kt

@@ -29,6 +29,7 @@ import moe.nea.firmament.features.inventory.CraftingOverlay
 import moe.nea.firmament.features.inventory.SaveCursorPosition
 import moe.nea.firmament.features.inventory.SlotLocking
 import moe.nea.firmament.features.inventory.storageoverlay.StorageOverlay
+import moe.nea.firmament.features.texturepack.CustomSkyBlockTextures
 import moe.nea.firmament.features.world.FairySouls
 import moe.nea.firmament.util.data.DataHolder
 
@@ -58,6 +59,7 @@ object FeatureManager : DataHolder<FeatureManager.Config>(serializer(), "feature
             loadFeature(CraftingOverlay)
             loadFeature(ImagePreview)
             loadFeature(SaveCursorPosition)
+            loadFeature(CustomSkyBlockTextures)
             if (Firmament.DEBUG) {
                 loadFeature(DeveloperFeatures)
                 loadFeature(DebugView)

src/main/kotlin/moe/nea/firmament/features/texturepack/CustomSkyBlockTextures.kt

@@ -0,0 +1,35 @@
+package moe.nea.firmament.features.texturepack
+
+import net.minecraft.client.util.ModelIdentifier
+import moe.nea.firmament.events.CustomItemModelEvent
+import moe.nea.firmament.events.TickEvent
+import moe.nea.firmament.features.FirmamentFeature
+import moe.nea.firmament.gui.config.ManagedConfig
+import moe.nea.firmament.util.extraAttributes
+
+object CustomSkyBlockTextures : FirmamentFeature {
+    override val identifier: String
+        get() = "custom-skyblock-textures"
+
+    object TConfig : ManagedConfig(identifier) {
+        val enabled by toggle("enabled") { true }
+        val cacheDuration by integer("cache-duration", 0, 20) { 1 }
+    }
+
+    override val config: ManagedConfig
+        get() = TConfig
+
+    override fun onLoad() {
+        CustomItemModelEvent.subscribe {
+            if (!TConfig.enabled) return@subscribe
+            val extra = it.itemStack.extraAttributes
+            val id = extra.getString("id")
+            if (id.isNotBlank())
+                it.overrideModel = ModelIdentifier("firmskyblock", id.lowercase(), "inventory")
+        }
+        TickEvent.subscribe {
+            if (it.tickCount % TConfig.cacheDuration == 0)
+                CustomItemModelEvent.clearCache()
+        }
+    }
+}