Add HasMeshHandle and impl for MeshHandle

src/mesh/mod.rs

@@ -45,9 +45,9 @@
 //! TODO: make spillover buffers GPU-transferrable on iGPUs
 
 use slab::Slab;
-use std::sync::Arc;
 use smallvec::SmallVec;
 use std::collections::HashMap;
+use std::sync::Arc;
 
 pub mod attr;
 pub mod group;
@@ -93,6 +93,18 @@ pub struct MeshHandle {
     pub(crate) sub: usize,
 }
 
+impl HasMeshHandle for MeshHandle {
+    fn get_mesh_handle(&self) -> &Self {
+        self
+    }
+}
+
+/// A trait for structs containing [MeshHandles][MeshHandle] that are not
+/// themselves handles. Used for iteration.
+pub trait HasMeshHandle {
+    fn get_mesh_handle(&self) -> &MeshHandle;
+}
+
 /// The top-level mesh data pool.
 pub struct MeshPool {
     staging: StagingPool,
@@ -122,7 +134,8 @@ impl MeshPool {
         }
 
         let group_index = self.groups.len();
-        self.groups.push(MeshGroup::new(group_index, self.attr_store.clone()));
+        let attr_store = self.attr_store.clone();
+        self.groups.push(MeshGroup::new(group_index, attr_store));
         let group = self.groups.get_mut(group_index).unwrap();
 
         let (handle, copies) = group.load(buf)?;