From 5f367c310800e1dfd574f658e25e8a4cee8825cb Mon Sep 17 00:00:00 2001
From: mars <mars@tebibyte.media>
Date: Thu, 30 Jun 2022 00:21:17 -0600
Subject: [PATCH] Parallelize legion::draw_transformed_meshes()

---
 src/legion.rs | 23 +++++++++++++++--------
 1 file changed, 15 insertions(+), 8 deletions(-)

diff --git a/src/legion.rs b/src/legion.rs
index 8fbf92e..4a9e9c1 100644
--- a/src/legion.rs
+++ b/src/legion.rs
@@ -105,18 +105,25 @@ fn present<T: RenderCallbacks>(#[resource] callbacks: &mut T) {
     callbacks.present();
 }
 
-#[system(for_each)]
+#[system]
 fn draw_transformed_meshes(
     #[resource] mesh_pass: &pass::RenderPassBox<mesh::MeshPass>,
-    transform: &scene::Transform,
-    mesh: &scene::Mesh,
+    world: &SubWorld,
+    query: &mut Query<(&scene::Transform, &scene::Mesh)>,
 ) {
-    puffin::profile_function!();
+    query.par_iter_chunks(world).for_each(|mesh_chunk| {
+        puffin::profile_function!();
 
-    mesh_pass.add_transformed_meshes(&[mesh::TransformedMesh {
-        transform: transform.transform,
-        mesh: mesh.mesh,
-    }]);
+        let meshes: Vec<_> = mesh_chunk
+            .into_iter()
+            .map(|(transform, mesh)| mesh::TransformedMesh {
+                transform: transform.transform,
+                mesh: mesh.mesh,
+            })
+            .collect();
+
+        mesh_pass.add_transformed_meshes(&meshes);
+    });
 }
 
 #[system(for_each)]