Fix errors on switching dimensions (#204)

* Fix errors on switching dimensions

* fix other tests

* clippy

* fix log feature in test_simulation

* fix chunks oops

2 files changed, 26 insertions, 1 deletions

diff --git a/azalea-core/src/data_registry.rs b/azalea-core/src/data_registry.rs
index a72d9caf..6e2c29ff 100644
--- a/azalea-core/src/data_registry.rs
+++ b/azalea-core/src/data_registry.rs
@@ -1,4 +1,4 @@
-use std::str::FromStr;
+use std::{io::Cursor, str::FromStr};
 
 use azalea_registry::DataRegistry;
 use simdnbt::owned::NbtCompound;
@@ -23,5 +23,25 @@ pub trait ResolvableDataRegistry: DataRegistry {
         let resolved = registry_values.get_index(self.protocol_id() as usize)?;
         Some(resolved)
     }
+
+    fn resolve_and_deserialize<T: simdnbt::Deserialize>(
+        &self,
+        registries: &RegistryHolder,
+    ) -> Option<Result<(ResourceLocation, T), simdnbt::DeserializeError>> {
+        let (name, value) = self.resolve(registries)?;
+
+        let mut nbt_bytes = Vec::new();
+        value.write(&mut nbt_bytes);
+        let nbt_borrow_compound =
+            simdnbt::borrow::read_compound(&mut Cursor::new(&nbt_bytes)).ok()?;
+        let value = match T::from_compound((&nbt_borrow_compound).into()) {
+            Ok(value) => value,
+            Err(err) => {
+                return Some(Err(err));
+            }
+        };
+
+        Some(Ok((name.clone(), value)))
+    }
 }
 impl<T: DataRegistry> ResolvableDataRegistry for T {}
diff --git a/azalea-core/src/registry_holder.rs b/azalea-core/src/registry_holder.rs
index ec57eacc..b2f1f5b9 100644
--- a/azalea-core/src/registry_holder.rs
+++ b/azalea-core/src/registry_holder.rs
@@ -19,6 +19,11 @@ use crate::resource_location::ResourceLocation;
 /// The base of the registry.
 ///
 /// This is the registry that is sent to the client upon login.
+///
+/// Note that `azalea-client` stores registries per-world instead of per-client
+/// like you might expect. This is an optimization for swarms to reduce memory
+/// usage, since registries are expected to be the same for every client in a
+/// world.
 #[derive(Default, Debug, Clone)]
 pub struct RegistryHolder {
     pub map: HashMap<ResourceLocation, IndexMap<ResourceLocation, NbtCompound>>,