refactor(engine): make models import as multiple asserts

1 files changed, 82 insertions, 0 deletions

diff --git a/engine/src/model/asset.rs b/engine/src/model/asset.rs
new file mode 100644
index 0000000..070200d
--- /dev/null
+++ b/engine/src/model/asset.rs
@@ -0,0 +1,82 @@
+use std::collections::HashSet;
+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};
+
+#[derive(Debug, Clone)]
+#[non_exhaustive]
+pub struct Settings {}
+
+pub fn add_importers(assets: &mut Assets)
+{
+    assets.set_importer(["obj"], import_wavefront_obj_asset);
+}
+
+fn import_wavefront_obj_asset(
+    asset_submitter: &mut AssetSubmitter<'_>,
+    path: &Path,
+    _settings: Option<&'_ Settings>,
+) -> Result<(), Error>
+{
+    let obj = crate::file_format::wavefront::obj::parse(
+        &read_to_string(path)
+            .map_err(|err| Error::ReadFailed(err, path.to_path_buf()))?,
+    )?;
+
+    let mesh = obj.to_mesh()?;
+
+    let mesh_asset = asset_submitter.submit_store_named("mesh", mesh);
+
+    let mut material_asset_map_assets =
+        Vec::with_capacity(obj.mtl_libs.iter().flatten().count());
+
+    for mtl_lib_path in obj.mtl_libs.iter().flatten() {
+        let mtl_lib_asset =
+            asset_submitter.submit_load_other::<MaterialAssetMap>(mtl_lib_path.as_path());
+
+        material_asset_map_assets.push(mtl_lib_asset);
+    }
+
+    let material_names = obj
+        .faces
+        .into_iter()
+        .map(|face| face.material_name)
+        .flatten()
+        .fold(
+            (HashSet::<String>::new(), Vec::<String>::new()),
+            |(mut pushed_mat_names, mut unique_mat_names), material_name| {
+                if pushed_mat_names.contains(&material_name) {
+                    return (pushed_mat_names, unique_mat_names);
+                }
+
+                unique_mat_names.push(material_name.clone());
+                pushed_mat_names.insert(material_name);
+
+                (pushed_mat_names, unique_mat_names)
+            },
+        )
+        .1;
+
+    asset_submitter.submit_store(
+        Spec::builder()
+            .mesh(mesh_asset)
+            .materials(Materials::Maps(material_asset_map_assets))
+            .material_names(material_names)
+            .build(),
+    );
+
+    Ok(())
+}
+
+#[derive(Debug, thiserror::Error)]
+enum Error
+{
+    #[error("Failed to read file {}", .1.display())]
+    ReadFailed(#[source] std::io::Error, PathBuf),
+
+    #[error(transparent)]
+    Other(#[from] crate::file_format::wavefront::obj::Error),
+}