From b7813793b413e3ca78ec147ff9d3ef2f3f2cb717 Mon Sep 17 00:00:00 2001
From: Robert Swain <robert.swain@gmail.com>
Date: Tue, 8 Mar 2022 17:54:11 +0100
Subject: [PATCH 1/2] bevy_render: Batch insertion for
 prepare_uniform_components

---
 crates/bevy_render/src/render_component.rs | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/crates/bevy_render/src/render_component.rs b/crates/bevy_render/src/render_component.rs
index 1c72786f89f16..bf700a343d868 100644
--- a/crates/bevy_render/src/render_component.rs
+++ b/crates/bevy_render/src/render_component.rs
@@ -107,18 +107,23 @@ fn prepare_uniform_components<C: Component>(
     render_queue: Res<RenderQueue>,
     mut component_uniforms: ResMut<ComponentUniforms<C>>,
     components: Query<(Entity, &C)>,
+    mut prev_len: Local<usize>,
 ) where
     C: AsStd140 + Clone,
 {
     component_uniforms.uniforms.clear();
+    let mut entities = Vec::with_capacity(*prev_len);
     for (entity, component) in components.iter() {
-        commands
-            .get_or_spawn(entity)
-            .insert(DynamicUniformIndex::<C> {
+        entities.push((
+            entity,
+            (DynamicUniformIndex::<C> {
                 index: component_uniforms.uniforms.push(component.clone()),
                 marker: PhantomData,
-            });
+            },),
+        ));
     }
+    *prev_len = entities.len();
+    commands.insert_or_spawn_batch(entities);
 
     component_uniforms
         .uniforms

From cad7c2762503d6c2c4cc582e899d18ca43705292 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Fran=C3=A7ois?= <mockersf@gmail.com>
Date: Fri, 11 Mar 2022 13:35:28 +0100
Subject: [PATCH 2/2] bevy_render: Use iterator and collect for slightly better
 performance

---
 crates/bevy_render/src/render_component.rs | 24 +++++++++++-----------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/crates/bevy_render/src/render_component.rs b/crates/bevy_render/src/render_component.rs
index bf700a343d868..d6a72e337c4c7 100644
--- a/crates/bevy_render/src/render_component.rs
+++ b/crates/bevy_render/src/render_component.rs
@@ -107,22 +107,22 @@ fn prepare_uniform_components<C: Component>(
     render_queue: Res<RenderQueue>,
     mut component_uniforms: ResMut<ComponentUniforms<C>>,
     components: Query<(Entity, &C)>,
-    mut prev_len: Local<usize>,
 ) where
     C: AsStd140 + Clone,
 {
     component_uniforms.uniforms.clear();
-    let mut entities = Vec::with_capacity(*prev_len);
-    for (entity, component) in components.iter() {
-        entities.push((
-            entity,
-            (DynamicUniformIndex::<C> {
-                index: component_uniforms.uniforms.push(component.clone()),
-                marker: PhantomData,
-            },),
-        ));
-    }
-    *prev_len = entities.len();
+    let entities = components
+        .iter()
+        .map(|(entity, component)| {
+            (
+                entity,
+                (DynamicUniformIndex::<C> {
+                    index: component_uniforms.uniforms.push(component.clone()),
+                    marker: PhantomData,
+                },),
+            )
+        })
+        .collect::<Vec<_>>();
     commands.insert_or_spawn_batch(entities);
 
     component_uniforms