refactor(engine): simplify how model materials are handled

1 files changed, 29 insertions, 16 deletions

diff --git a/engine/src/model/asset.rs b/engine/src/model/asset.rs
index 5487203..52a6733 100644
--- a/engine/src/model/asset.rs
+++ b/engine/src/model/asset.rs
@@ -1,9 +1,11 @@
 use std::fs::read_to_string;
 use std::path::{Path, PathBuf};
 
-use crate::asset::{Assets, Submitter as AssetSubmitter};
-use crate::material::asset::Map as MaterialAssetMap;
-use crate::model::{Materials, Spec};
+use ecs::util::Either;
+
+use crate::asset::{Assets, Label as AssetLabel, Submitter as AssetSubmitter};
+use crate::material::Material;
+use crate::model::{MaterialDescription, Spec};
 
 #[derive(Debug, Clone)]
 #[non_exhaustive]
@@ -69,24 +71,32 @@ fn import_wavefront_obj_asset(
 
     let mesh_asset = asset_submitter.submit_store_named("mesh", mesh);
 
-    let mut material_asset_map_assets = Vec::with_capacity(obj.mtl_libs.len());
-
-    for mtl_lib_path in &obj.mtl_libs {
-        let mtl_lib_asset = asset_submitter
-            .submit_load_other::<MaterialAssetMap>(parent_path.join(mtl_lib_path));
-
-        material_asset_map_assets.push(mtl_lib_asset);
+    if obj.mtl_libs.len() > 1 {
+        return Err(Error::MoreThanOneMaterialLibrary);
     }
 
     asset_submitter.submit_store(
         Spec::builder()
             .mesh(mesh_asset)
-            .materials(Materials::Maps(material_asset_map_assets))
-            .material_names(
-                obj.unique_used_material_names
-                    .into_iter()
-                    .map(|material_name| material_name.into_string()),
-            )
+            .materials(if obj.mtl_libs.is_empty() {
+                Either::A([].into_iter())
+            } else {
+                Either::B(
+                    obj.unique_used_material_names
+                        .iter()
+                        .zip(std::iter::repeat(obj.mtl_libs.iter()).flatten())
+                        .map(|(material_name, mtl_lib)| {
+                            MaterialDescription::new(
+                                asset_submitter.submit_load_other::<Material>(
+                                    AssetLabel {
+                                        path: parent_path.join(mtl_lib).into(),
+                                        name: Some(material_name.as_ref().into()),
+                                    },
+                                ),
+                            )
+                        }),
+                )
+            })
             .build(),
     );
 
@@ -102,6 +112,9 @@ enum Error
     #[error("Failed to read file {}", .1.display())]
     ReadFailed(#[source] std::io::Error, PathBuf),
 
+    #[error("More than one material library is specified. This is not supported")]
+    MoreThanOneMaterialLibrary,
+
     #[error(transparent)]
     Other(#[from] crate::file_format::wavefront::obj::Error),
 }