From e98258b206327ceae711ce4da4db471660c9ea85 Mon Sep 17 00:00:00 2001
From: James Liu <contact@jamessliu.com>
Date: Sun, 2 Jan 2022 15:31:15 -0500
Subject: [PATCH 01/13] Implement Dereff(Mut) on BufferVec.

---
 .../src/render_resource/buffer_vec.rs         | 68 ++++++++++---------
 1 file changed, 37 insertions(+), 31 deletions(-)

diff --git a/crates/bevy_render/src/render_resource/buffer_vec.rs b/crates/bevy_render/src/render_resource/buffer_vec.rs
index ad8f5ff2adfe1..da2fc6a806de4 100644
--- a/crates/bevy_render/src/render_resource/buffer_vec.rs
+++ b/crates/bevy_render/src/render_resource/buffer_vec.rs
@@ -4,13 +4,15 @@ use crate::{
 };
 use bevy_core::{cast_slice, Pod};
 use copyless::VecHelper;
+use std::ops::{Deref, DerefMut};
 use wgpu::BufferUsages;
 
+/// A user-friendly wrapper around a [`Buffer`] that provides a `Vec`-like
+/// interface for constructing the buffer.
 pub struct BufferVec<T: Pod> {
     values: Vec<T>,
     buffer: Option<Buffer>,
     capacity: usize,
-    item_size: usize,
     buffer_usage: BufferUsages,
 }
 
@@ -21,12 +23,14 @@ impl<T: Pod> Default for BufferVec<T> {
             buffer: None,
             capacity: 0,
             buffer_usage: BufferUsages::all(),
-            item_size: std::mem::size_of::<T>(),
         }
     }
 }
 
 impl<T: Pod> BufferVec<T> {
+    /// Creates a new [`BufferVec`] with the associated [`BufferUsages`].
+    ///
+    /// This does not immediately allocate a buffer.
     pub fn new(buffer_usage: BufferUsages) -> Self {
         Self {
             buffer_usage,
@@ -34,36 +38,41 @@ impl<T: Pod> BufferVec<T> {
         }
     }
 
+    /// Gets the reference to the underlying buffer, if one has been allocated.
     #[inline]
     pub fn buffer(&self) -> Option<&Buffer> {
         self.buffer.as_ref()
     }
 
+    /// Gets the capacity of the underlying buffer.
+    ///
+    /// Will return 0 if no buffer has been allocated yet.
     #[inline]
-    pub fn capacity(&self) -> usize {
+    pub fn buffer_capacity(&self) -> usize {
         self.capacity
     }
 
-    #[inline]
-    pub fn len(&self) -> usize {
-        self.values.len()
-    }
-
-    #[inline]
-    pub fn is_empty(&self) -> bool {
-        self.values.is_empty()
-    }
-
-    pub fn push(&mut self, value: T) -> usize {
-        let index = self.values.len();
-        self.values.alloc().init(value);
-        index
+    /// Queues up a copy of the contents of the [`BufferVec`] into the underlying
+    /// buffer.
+    ///
+    /// If no buffer has been allocated yet or if the current size of the contents
+    /// exceeds the size of the underlying buffer, a new buffer will be allocated.
+    pub fn write_buffer(&mut self, device: &RenderDevice, queue: &RenderQueue) {
+        if self.values.is_empty() {
+            return;
+        }
+        self.reserve_buffer(self.values.len(), device);
+        if let Some(buffer) = &self.buffer {
+            let range = 0..std::mem::size_of::<T>() * self.values.len();
+            let bytes: &[u8] = cast_slice(&self.values);
+            queue.write_buffer(buffer, 0, &bytes[range]);
+        }
     }
 
-    pub fn reserve(&mut self, capacity: usize, device: &RenderDevice) {
+    fn reserve_buffer(&mut self, capacity: usize, device: &RenderDevice) {
         if capacity > self.capacity {
             self.capacity = capacity;
-            let size = self.item_size * capacity;
+            let size = std::mem::size_of::<T>() * capacity;
             self.buffer = Some(device.create_buffer(&wgpu::BufferDescriptor {
                 label: None,
                 size: size as wgpu::BufferAddress,
@@ -72,20 +81,17 @@ impl<T: Pod> BufferVec<T> {
             }));
         }
     }
+}
 
-    pub fn write_buffer(&mut self, device: &RenderDevice, queue: &RenderQueue) {
-        if self.values.is_empty() {
-            return;
-        }
-        self.reserve(self.values.len(), device);
-        if let Some(buffer) = &self.buffer {
-            let range = 0..self.item_size * self.values.len();
-            let bytes: &[u8] = cast_slice(&self.values);
-            queue.write_buffer(buffer, 0, &bytes[range]);
-        }
+impl<T: Pod> Deref for BufferVec<T> {
+    type Target = Vec<T>;
+    fn deref(&self) -> &Self::Target {
+        &self.values
     }
+}
 
-    pub fn clear(&mut self) {
-        self.values.clear();
+impl<T: Pod> DerefMut for BufferVec<T> {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.values
     }
 }

From 53209fe18723f826b8002229b5eaccdcf0fc7e19 Mon Sep 17 00:00:00 2001
From: James Liu <contact@jamessliu.com>
Date: Tue, 4 Jan 2022 18:15:45 -0500
Subject: [PATCH 02/13] Implement Deref(Mut) on UniformVec

---
 crates/bevy_pbr/src/render/light.rs           |  5 +-
 .../src/render_resource/uniform_vec.rs        | 75 +++++++++----------
 2 files changed, 37 insertions(+), 43 deletions(-)

diff --git a/crates/bevy_pbr/src/render/light.rs b/crates/bevy_pbr/src/render/light.rs
index 562c9b6d2031c..cafde310e598d 100644
--- a/crates/bevy_pbr/src/render/light.rs
+++ b/crates/bevy_pbr/src/render/light.rs
@@ -931,7 +931,7 @@ impl ViewClusterBindings {
         let component = self.n_offsets & ((1 << 2) - 1);
         let packed = pack_offset_and_count(offset, count);
 
-        self.cluster_offsets_and_counts.get_mut(0)[array_index][component] = packed;
+        self.cluster_offsets_and_counts[0][array_index][component] = packed;
 
         self.n_offsets += 1;
     }
@@ -946,8 +946,7 @@ impl ViewClusterBindings {
         let sub_index = self.n_indices & ((1 << 2) - 1);
         let index = index as u32 & POINT_LIGHT_INDEX_MASK;
 
-        self.cluster_light_index_lists.get_mut(0)[array_index][component] |=
-            index << (8 * sub_index);
+        self.cluster_light_index_lists[0][array_index][component] |= index << (8 * sub_index);
 
         self.n_indices += 1;
     }
diff --git a/crates/bevy_render/src/render_resource/uniform_vec.rs b/crates/bevy_render/src/render_resource/uniform_vec.rs
index f31e7e258d6a2..bc0e5963565f0 100644
--- a/crates/bevy_render/src/render_resource/uniform_vec.rs
+++ b/crates/bevy_render/src/render_resource/uniform_vec.rs
@@ -3,7 +3,10 @@ use crate::{
     render_resource::Buffer,
     renderer::{RenderDevice, RenderQueue},
 };
-use std::num::NonZeroU64;
+use std::{
+    num::NonZeroU64,
+    ops::{Deref, DerefMut},
+};
 use wgpu::{BindingResource, BufferBinding, BufferDescriptor, BufferUsages};
 
 pub struct UniformVec<T: AsStd140> {
@@ -11,7 +14,6 @@ pub struct UniformVec<T: AsStd140> {
     scratch: Vec<u8>,
     uniform_buffer: Option<Buffer>,
     capacity: usize,
-    item_size: usize,
 }
 
 impl<T: AsStd140> Default for UniformVec<T> {
@@ -21,13 +23,15 @@ impl<T: AsStd140> Default for UniformVec<T> {
             scratch: Vec::new(),
             uniform_buffer: None,
             capacity: 0,
-            item_size: (T::std140_size_static() + <T as AsStd140>::Output::ALIGNMENT - 1)
-                & !(<T as AsStd140>::Output::ALIGNMENT - 1),
         }
     }
 }
 
 impl<T: AsStd140> UniformVec<T> {
+    const ITEM_SIZE: usize =
+        (std::mem::size_of::<T::Output>() + <T as AsStd140>::Output::ALIGNMENT - 1)
+            & !(<T as AsStd140>::Output::ALIGNMENT - 1);
+
     #[inline]
     pub fn uniform_buffer(&self) -> Option<&Buffer> {
         self.uniform_buffer.as_ref()
@@ -38,20 +42,10 @@ impl<T: AsStd140> UniformVec<T> {
         Some(BindingResource::Buffer(BufferBinding {
             buffer: self.uniform_buffer()?,
             offset: 0,
-            size: Some(NonZeroU64::new(self.item_size as u64).unwrap()),
+            size: Some(NonZeroU64::new(Self::ITEM_SIZE as u64).unwrap()),
         }))
     }
 
-    #[inline]
-    pub fn len(&self) -> usize {
-        self.values.len()
-    }
-
-    #[inline]
-    pub fn is_empty(&self) -> bool {
-        self.values.is_empty()
-    }
-
     #[inline]
     pub fn capacity(&self) -> usize {
         self.capacity
@@ -63,14 +57,23 @@ impl<T: AsStd140> UniformVec<T> {
         index
     }
 
-    pub fn get_mut(&mut self, index: usize) -> &mut T {
-        &mut self.values[index]
+    pub fn write_buffer(&mut self, device: &RenderDevice, queue: &RenderQueue) {
+        if self.values.is_empty() {
+            return;
+        }
+        self.reserve_buffer(self.values.len(), device);
+        if let Some(uniform_buffer) = &self.uniform_buffer {
+            let range = 0..Self::ITEM_SIZE * self.values.len();
+            let mut writer = std140::Writer::new(&mut self.scratch[range.clone()]);
+            writer.write(self.values.as_slice()).unwrap();
+            queue.write_buffer(uniform_buffer, 0, &self.scratch[range]);
+        }
     }
 
-    pub fn reserve(&mut self, capacity: usize, device: &RenderDevice) -> bool {
+    fn reserve_buffer(&mut self, capacity: usize, device: &RenderDevice) -> bool {
         if capacity > self.capacity {
             self.capacity = capacity;
-            let size = self.item_size * capacity;
+            let size = Self::ITEM_SIZE * capacity;
             self.scratch.resize(size, 0);
             self.uniform_buffer = Some(device.create_buffer(&BufferDescriptor {
                 label: None,
@@ -84,25 +87,21 @@ impl<T: AsStd140> UniformVec<T> {
         }
     }
 
-    pub fn write_buffer(&mut self, device: &RenderDevice, queue: &RenderQueue) {
-        if self.values.is_empty() {
-            return;
-        }
-        self.reserve(self.values.len(), device);
-        if let Some(uniform_buffer) = &self.uniform_buffer {
-            let range = 0..self.item_size * self.values.len();
-            let mut writer = std140::Writer::new(&mut self.scratch[range.clone()]);
-            writer.write(self.values.as_slice()).unwrap();
-            queue.write_buffer(uniform_buffer, 0, &self.scratch[range]);
-        }
+    pub fn values(&self) -> &[T] {
+        &self.values
     }
+}
 
-    pub fn clear(&mut self) {
-        self.values.clear();
+impl<T: AsStd140> Deref for UniformVec<T> {
+    type Target = Vec<T>;
+    fn deref(&self) -> &Self::Target {
+        &self.values
     }
+}
 
-    pub fn values(&self) -> &[T] {
-        &self.values
+impl<T: AsStd140> DerefMut for UniformVec<T> {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.values
     }
 }
 
@@ -146,12 +145,8 @@ impl<T: AsStd140> DynamicUniformVec<T> {
 
     #[inline]
     pub fn push(&mut self, value: T) -> u32 {
-        (self.uniform_vec.push(DynamicUniform(value)) * self.uniform_vec.item_size) as u32
-    }
-
-    #[inline]
-    pub fn reserve(&mut self, capacity: usize, device: &RenderDevice) {
-        self.uniform_vec.reserve(capacity, device);
+        (self.uniform_vec.push(DynamicUniform(value)) * UniformVec::<DynamicUniform<T>>::ITEM_SIZE)
+            as u32
     }
 
     #[inline]

From 94bc29fd39c70e9a923fd57c40b273707020e16d Mon Sep 17 00:00:00 2001
From: James Liu <contact@jamessliu.com>
Date: Tue, 4 Jan 2022 19:03:50 -0500
Subject: [PATCH 03/13] Add missing documentation to UniformVec

---
 .../src/render_resource/uniform_vec.rs        | 37 +++++++++++++++----
 1 file changed, 29 insertions(+), 8 deletions(-)

diff --git a/crates/bevy_render/src/render_resource/uniform_vec.rs b/crates/bevy_render/src/render_resource/uniform_vec.rs
index bc0e5963565f0..6dfb1f95726aa 100644
--- a/crates/bevy_render/src/render_resource/uniform_vec.rs
+++ b/crates/bevy_render/src/render_resource/uniform_vec.rs
@@ -9,6 +9,11 @@ use std::{
 };
 use wgpu::{BindingResource, BufferBinding, BufferDescriptor, BufferUsages};
 
+/// A user-friendly wrapper around a [`Buffer`] that provides a `Vec`-like
+/// interface for constructing the buffer.
+/// 
+/// Intended strictly for use with uniform buffers. For other use cases, 
+/// see [`BufferVec`] instead.
 pub struct UniformVec<T: AsStd140> {
     values: Vec<T>,
     scratch: Vec<u8>,
@@ -32,20 +37,26 @@ impl<T: AsStd140> UniformVec<T> {
         (std::mem::size_of::<T::Output>() + <T as AsStd140>::Output::ALIGNMENT - 1)
             & !(<T as AsStd140>::Output::ALIGNMENT - 1);
 
+    /// Gets the reference to the underlying buffer, if one has been allocated.
     #[inline]
-    pub fn uniform_buffer(&self) -> Option<&Buffer> {
+    pub fn buffer(&self) -> Option<&Buffer> {
         self.uniform_buffer.as_ref()
     }
 
+    /// Creates a binding for the underlying buffer.
+    /// Returns `None` if no buffer has been allocated.
     #[inline]
     pub fn binding(&self) -> Option<BindingResource> {
         Some(BindingResource::Buffer(BufferBinding {
-            buffer: self.uniform_buffer()?,
+            buffer: self.buffer()?,
             offset: 0,
             size: Some(NonZeroU64::new(Self::ITEM_SIZE as u64).unwrap()),
         }))
     }
 
+    /// Gets the capacity of the underlying buffer.
+    ///
+    /// Will return 0 if no buffer has been allocated yet.
     #[inline]
     pub fn capacity(&self) -> usize {
         self.capacity
@@ -57,6 +68,11 @@ impl<T: AsStd140> UniformVec<T> {
         index
     }
 
+    /// Queues up a copy of the contents of the [`UniformVec`] into the underlying
+    /// buffer.
+    ///
+    /// If no buffer has been allocated yet or if the current size of the contents
+    /// exceeds the size of the underlying buffer, a new buffer will be allocated.
     pub fn write_buffer(&mut self, device: &RenderDevice, queue: &RenderQueue) {
         if self.values.is_empty() {
             return;
@@ -86,10 +102,6 @@ impl<T: AsStd140> UniformVec<T> {
             false
         }
     }
-
-    pub fn values(&self) -> &[T] {
-        &self.values
-    }
 }
 
 impl<T: AsStd140> Deref for UniformVec<T> {
@@ -118,11 +130,14 @@ impl<T: AsStd140> Default for DynamicUniformVec<T> {
 }
 
 impl<T: AsStd140> DynamicUniformVec<T> {
+    /// Gets the reference to the underlying buffer, if one has been allocated.
     #[inline]
-    pub fn uniform_buffer(&self) -> Option<&Buffer> {
-        self.uniform_vec.uniform_buffer()
+    pub fn buffer(&self) -> Option<&Buffer> {
+        self.uniform_vec.buffer()
     }
 
+    /// Creates a binding for the underlying buffer.
+    /// Returns `None` if no buffer has been allocated.
     #[inline]
     pub fn binding(&self) -> Option<BindingResource> {
         self.uniform_vec.binding()
@@ -138,6 +153,7 @@ impl<T: AsStd140> DynamicUniformVec<T> {
         self.uniform_vec.is_empty()
     }
 
+    /// Gets the capacity of the underlying buffer, in bytes.
     #[inline]
     pub fn capacity(&self) -> usize {
         self.uniform_vec.capacity()
@@ -149,6 +165,11 @@ impl<T: AsStd140> DynamicUniformVec<T> {
             as u32
     }
 
+    /// Queues up a copy of the contents of the [`UniformVec`] into the underlying
+    /// buffer.
+    ///
+    /// If no buffer has been allocated yet or if the current size of the contents
+    /// exceeds the size of the underlying buffer, a new buffer will be allocated.
     #[inline]
     pub fn write_buffer(&mut self, device: &RenderDevice, queue: &RenderQueue) {
         self.uniform_vec.write_buffer(device, queue);

From b4a4cc783731c1540c9a7e2353db4022e88ce859 Mon Sep 17 00:00:00 2001
From: James Liu <contact@jamessliu.com>
Date: Tue, 4 Jan 2022 19:29:23 -0500
Subject: [PATCH 04/13] Fix docs and CI checks

---
 crates/bevy_render/src/render_resource/uniform_vec.rs | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/crates/bevy_render/src/render_resource/uniform_vec.rs b/crates/bevy_render/src/render_resource/uniform_vec.rs
index 6dfb1f95726aa..1a86afc03f143 100644
--- a/crates/bevy_render/src/render_resource/uniform_vec.rs
+++ b/crates/bevy_render/src/render_resource/uniform_vec.rs
@@ -11,9 +11,11 @@ use wgpu::{BindingResource, BufferBinding, BufferDescriptor, BufferUsages};
 
 /// A user-friendly wrapper around a [`Buffer`] that provides a `Vec`-like
 /// interface for constructing the buffer.
-/// 
-/// Intended strictly for use with uniform buffers. For other use cases, 
-/// see [`BufferVec`] instead.
+///
+/// Intended strictly for use with uniform buffers. For other use cases,
+/// see [`BufferVec`][buffervec] instead.
+///
+/// [buffervec]: crate::render_resource::BufferVec
 pub struct UniformVec<T: AsStd140> {
     values: Vec<T>,
     scratch: Vec<u8>,

From b2b7a5d995f03793aa24d46dfdf8d5fba59dd0c2 Mon Sep 17 00:00:00 2001
From: James Liu <contact@jamessliu.com>
Date: Tue, 4 Jan 2022 21:05:00 -0500
Subject: [PATCH 05/13] Make the buffer_capacity name consistent

---
 crates/bevy_render/src/render_resource/uniform_vec.rs | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/crates/bevy_render/src/render_resource/uniform_vec.rs b/crates/bevy_render/src/render_resource/uniform_vec.rs
index 1a86afc03f143..4f08478d22ad6 100644
--- a/crates/bevy_render/src/render_resource/uniform_vec.rs
+++ b/crates/bevy_render/src/render_resource/uniform_vec.rs
@@ -60,7 +60,7 @@ impl<T: AsStd140> UniformVec<T> {
     ///
     /// Will return 0 if no buffer has been allocated yet.
     #[inline]
-    pub fn capacity(&self) -> usize {
+    pub fn buffer_capacity(&self) -> usize {
         self.capacity
     }
 
@@ -157,8 +157,8 @@ impl<T: AsStd140> DynamicUniformVec<T> {
 
     /// Gets the capacity of the underlying buffer, in bytes.
     #[inline]
-    pub fn capacity(&self) -> usize {
-        self.uniform_vec.capacity()
+    pub fn buffer_capacity(&self) -> usize {
+        self.uniform_vec.buffer_capacity()
     }
 
     #[inline]

From a01ed4bddda8c4682ab04f9b0e65140092ce76b2 Mon Sep 17 00:00:00 2001
From: james7132 <contact@jamessliu.com>
Date: Fri, 25 Feb 2022 02:26:52 -0800
Subject: [PATCH 06/13] Fix CI

---
 crates/bevy_render/src/render_resource/buffer_vec.rs | 1 -
 1 file changed, 1 deletion(-)

diff --git a/crates/bevy_render/src/render_resource/buffer_vec.rs b/crates/bevy_render/src/render_resource/buffer_vec.rs
index da2fc6a806de4..72a96aeb319a0 100644
--- a/crates/bevy_render/src/render_resource/buffer_vec.rs
+++ b/crates/bevy_render/src/render_resource/buffer_vec.rs
@@ -3,7 +3,6 @@ use crate::{
     renderer::{RenderDevice, RenderQueue},
 };
 use bevy_core::{cast_slice, Pod};
-use copyless::VecHelper;
 use std::ops::{Deref, DerefMut};
 use wgpu::BufferUsages;
 

From 6cb745b9d5e9f75d5c82cbf73436a693e2f6632a Mon Sep 17 00:00:00 2001
From: james7132 <contact@jamessliu.com>
Date: Wed, 2 Mar 2022 03:50:20 -0800
Subject: [PATCH 07/13] Remove capacity from UniformVec

---
 crates/bevy_render/src/render_resource/buffer_vec.rs  | 8 --------
 crates/bevy_render/src/render_resource/uniform_vec.rs | 6 ++----
 2 files changed, 2 insertions(+), 12 deletions(-)

diff --git a/crates/bevy_render/src/render_resource/buffer_vec.rs b/crates/bevy_render/src/render_resource/buffer_vec.rs
index 72a96aeb319a0..3f3e59979d802 100644
--- a/crates/bevy_render/src/render_resource/buffer_vec.rs
+++ b/crates/bevy_render/src/render_resource/buffer_vec.rs
@@ -43,14 +43,6 @@ impl<T: Pod> BufferVec<T> {
         self.buffer.as_ref()
     }
 
-    /// Gets the capacity of the underlying buffer.
-    ///
-    /// Will return 0 if no buffer has been allocated yet.
-    #[inline]
-    pub fn buffer_capacity(&self) -> usize {
-        self.capacity
-    }
-
     /// Queues up a copy of the contents of the [`BufferVec`] into the underlying
     /// buffer.
     ///
diff --git a/crates/bevy_render/src/render_resource/uniform_vec.rs b/crates/bevy_render/src/render_resource/uniform_vec.rs
index 4f08478d22ad6..fb921bb513360 100644
--- a/crates/bevy_render/src/render_resource/uniform_vec.rs
+++ b/crates/bevy_render/src/render_resource/uniform_vec.rs
@@ -20,7 +20,6 @@ pub struct UniformVec<T: AsStd140> {
     values: Vec<T>,
     scratch: Vec<u8>,
     uniform_buffer: Option<Buffer>,
-    capacity: usize,
 }
 
 impl<T: AsStd140> Default for UniformVec<T> {
@@ -29,7 +28,6 @@ impl<T: AsStd140> Default for UniformVec<T> {
             values: Vec::new(),
             scratch: Vec::new(),
             uniform_buffer: None,
-            capacity: 0,
         }
     }
 }
@@ -61,7 +59,7 @@ impl<T: AsStd140> UniformVec<T> {
     /// Will return 0 if no buffer has been allocated yet.
     #[inline]
     pub fn buffer_capacity(&self) -> usize {
-        self.capacity
+        self.values.len()
     }
 
     pub fn push(&mut self, value: T) -> usize {
@@ -89,7 +87,7 @@ impl<T: AsStd140> UniformVec<T> {
     }
 
     fn reserve_buffer(&mut self, capacity: usize, device: &RenderDevice) -> bool {
-        if capacity > self.capacity {
+        if capacity > self.scratch.len() {
             self.capacity = capacity;
             let size = Self::ITEM_SIZE * capacity;
             self.scratch.resize(size, 0);

From 0a45b6d1b533540009c47cb81e466f4450c4703f Mon Sep 17 00:00:00 2001
From: james7132 <contact@jamessliu.com>
Date: Wed, 2 Mar 2022 12:47:52 -0800
Subject: [PATCH 08/13] Fix build and address review comments

---
 crates/bevy_pbr/src/render/light.rs           |  2 +-
 crates/bevy_render/src/render_component.rs    |  2 +-
 .../src/render_resource/buffer_vec.rs         | 17 ++++++++++---
 .../src/render_resource/uniform_vec.rs        | 25 +++++++++++--------
 crates/bevy_render/src/view/mod.rs            |  2 +-
 5 files changed, 30 insertions(+), 18 deletions(-)

diff --git a/crates/bevy_pbr/src/render/light.rs b/crates/bevy_pbr/src/render/light.rs
index cafde310e598d..1181936c3a44a 100644
--- a/crates/bevy_pbr/src/render/light.rs
+++ b/crates/bevy_pbr/src/render/light.rs
@@ -867,7 +867,7 @@ pub fn prepare_lights(
                 lights: view_lights,
             },
             ViewLightsUniformOffset {
-                offset: light_meta.view_gpu_lights.push(gpu_lights),
+                offset: light_meta.view_gpu_lights.push_and_get_offset(gpu_lights),
             },
         ));
     }
diff --git a/crates/bevy_render/src/render_component.rs b/crates/bevy_render/src/render_component.rs
index 1c72786f89f16..ceda8fdbb2e44 100644
--- a/crates/bevy_render/src/render_component.rs
+++ b/crates/bevy_render/src/render_component.rs
@@ -115,7 +115,7 @@ fn prepare_uniform_components<C: Component>(
         commands
             .get_or_spawn(entity)
             .insert(DynamicUniformIndex::<C> {
-                index: component_uniforms.uniforms.push(component.clone()),
+                index: component_uniforms.uniforms.push_and_get_offset(component.clone()),
                 marker: PhantomData,
             });
     }
diff --git a/crates/bevy_render/src/render_resource/buffer_vec.rs b/crates/bevy_render/src/render_resource/buffer_vec.rs
index 3f3e59979d802..03c448b7221db 100644
--- a/crates/bevy_render/src/render_resource/buffer_vec.rs
+++ b/crates/bevy_render/src/render_resource/buffer_vec.rs
@@ -29,7 +29,7 @@ impl<T: Pod> Default for BufferVec<T> {
 impl<T: Pod> BufferVec<T> {
     /// Creates a new [`BufferVec`] with the associated [`BufferUsages`].
     ///
-    /// This does not immediately allocate a buffer.
+    /// This does not immediately allocate a system/video RAM buffers.
     pub fn new(buffer_usage: BufferUsages) -> Self {
         Self {
             buffer_usage,
@@ -43,6 +43,12 @@ impl<T: Pod> BufferVec<T> {
         self.buffer.as_ref()
     }
 
+    /// Gets the capacity of the underlying buffer, returning 0 if it hasn't been allocated.
+    #[inline]
+    pub fn buffer_capacity(&self) -> usize {
+        self.capacity
+    }
+
     /// Queues up a copy of the contents of the [`BufferVec`] into the underlying
     /// buffer.
     ///
@@ -54,7 +60,7 @@ impl<T: Pod> BufferVec<T> {
         }
         self.reserve_buffer(self.values.len(), device);
         if let Some(buffer) = &self.buffer {
-            let range = 0..std::mem::size_of::<T>() * self.values.len();
+            let range = 0..self.size();
             let bytes: &[u8] = cast_slice(&self.values);
             queue.write_buffer(buffer, 0, &bytes[range]);
         }
@@ -63,15 +69,18 @@ impl<T: Pod> BufferVec<T> {
     fn reserve_buffer(&mut self, capacity: usize, device: &RenderDevice) {
         if capacity > self.capacity {
             self.capacity = capacity;
-            let size = std::mem::size_of::<T>() * capacity;
             self.buffer = Some(device.create_buffer(&wgpu::BufferDescriptor {
                 label: None,
-                size: size as wgpu::BufferAddress,
+                size: self.size() as wgpu::BufferAddress,
                 usage: BufferUsages::COPY_DST | self.buffer_usage,
                 mapped_at_creation: false,
             }));
         }
     }
+    
+    fn size(&self) -> usize {
+        std::mem::size_of::<T>() * self.capacity
+    }
 }
 
 impl<T: Pod> Deref for BufferVec<T> {
diff --git a/crates/bevy_render/src/render_resource/uniform_vec.rs b/crates/bevy_render/src/render_resource/uniform_vec.rs
index fb921bb513360..52eb3527cf731 100644
--- a/crates/bevy_render/src/render_resource/uniform_vec.rs
+++ b/crates/bevy_render/src/render_resource/uniform_vec.rs
@@ -62,7 +62,7 @@ impl<T: AsStd140> UniformVec<T> {
         self.values.len()
     }
 
-    pub fn push(&mut self, value: T) -> usize {
+    pub fn push_and_get_offset(&mut self, value: T) -> usize {
         let index = self.values.len();
         self.values.push(value);
         index
@@ -77,23 +77,21 @@ impl<T: AsStd140> UniformVec<T> {
         if self.values.is_empty() {
             return;
         }
-        self.reserve_buffer(self.values.len(), device);
+        self.reserve_buffer(device);
         if let Some(uniform_buffer) = &self.uniform_buffer {
-            let range = 0..Self::ITEM_SIZE * self.values.len();
+            let range = 0..self.size();
             let mut writer = std140::Writer::new(&mut self.scratch[range.clone()]);
             writer.write(self.values.as_slice()).unwrap();
             queue.write_buffer(uniform_buffer, 0, &self.scratch[range]);
         }
     }
 
-    fn reserve_buffer(&mut self, capacity: usize, device: &RenderDevice) -> bool {
-        if capacity > self.scratch.len() {
-            self.capacity = capacity;
-            let size = Self::ITEM_SIZE * capacity;
-            self.scratch.resize(size, 0);
+    fn reserve_buffer(&mut self, device: &RenderDevice) -> bool {
+        if self.size() > self.scratch.len() {
+            self.scratch.resize(self.size(), 0);
             self.uniform_buffer = Some(device.create_buffer(&BufferDescriptor {
                 label: None,
-                size: size as wgpu::BufferAddress,
+                size: self.size() as wgpu::BufferAddress,
                 usage: BufferUsages::COPY_DST | BufferUsages::UNIFORM,
                 mapped_at_creation: false,
             }));
@@ -102,6 +100,10 @@ impl<T: AsStd140> UniformVec<T> {
             false
         }
     }
+
+    fn size(&self) -> usize {
+        Self::ITEM_SIZE * self.values.len()
+    }
 }
 
 impl<T: AsStd140> Deref for UniformVec<T> {
@@ -160,8 +162,9 @@ impl<T: AsStd140> DynamicUniformVec<T> {
     }
 
     #[inline]
-    pub fn push(&mut self, value: T) -> u32 {
-        (self.uniform_vec.push(DynamicUniform(value)) * UniformVec::<DynamicUniform<T>>::ITEM_SIZE)
+    pub fn push_and_get_offset(&mut self, value: T) -> u32 {
+        (self.uniform_vec.push_and_get_offset(DynamicUniform(value)) * 
+         UniformVec::<DynamicUniform<T>>::ITEM_SIZE)
             as u32
     }
 
diff --git a/crates/bevy_render/src/view/mod.rs b/crates/bevy_render/src/view/mod.rs
index 95233083c6f6c..49cda4b966fec 100644
--- a/crates/bevy_render/src/view/mod.rs
+++ b/crates/bevy_render/src/view/mod.rs
@@ -151,7 +151,7 @@ fn prepare_view_uniforms(
         let view = camera.transform.compute_matrix();
         let inverse_view = view.inverse();
         let view_uniforms = ViewUniformOffset {
-            offset: view_uniforms.uniforms.push(ViewUniform {
+            offset: view_uniforms.uniforms.push_and_get_offset(ViewUniform {
                 view_proj: projection * inverse_view,
                 view,
                 inverse_view,

From 2fea3ecb2103f6ace100b8198cb9dbaef7b341b0 Mon Sep 17 00:00:00 2001
From: james7132 <contact@jamessliu.com>
Date: Wed, 2 Mar 2022 12:51:28 -0800
Subject: [PATCH 09/13] Formatting and DynamicUniformVec Deref(Mut)

---
 crates/bevy_render/src/render_component.rs    |  4 ++-
 .../src/render_resource/buffer_vec.rs         |  2 +-
 .../src/render_resource/uniform_vec.rs        | 28 ++++++++++---------
 3 files changed, 19 insertions(+), 15 deletions(-)

diff --git a/crates/bevy_render/src/render_component.rs b/crates/bevy_render/src/render_component.rs
index ceda8fdbb2e44..4530d464b0a24 100644
--- a/crates/bevy_render/src/render_component.rs
+++ b/crates/bevy_render/src/render_component.rs
@@ -115,7 +115,9 @@ fn prepare_uniform_components<C: Component>(
         commands
             .get_or_spawn(entity)
             .insert(DynamicUniformIndex::<C> {
-                index: component_uniforms.uniforms.push_and_get_offset(component.clone()),
+                index: component_uniforms
+                    .uniforms
+                    .push_and_get_offset(component.clone()),
                 marker: PhantomData,
             });
     }
diff --git a/crates/bevy_render/src/render_resource/buffer_vec.rs b/crates/bevy_render/src/render_resource/buffer_vec.rs
index 03c448b7221db..e0a6cf0a8c2a9 100644
--- a/crates/bevy_render/src/render_resource/buffer_vec.rs
+++ b/crates/bevy_render/src/render_resource/buffer_vec.rs
@@ -77,7 +77,7 @@ impl<T: Pod> BufferVec<T> {
             }));
         }
     }
-    
+
     fn size(&self) -> usize {
         std::mem::size_of::<T>() * self.capacity
     }
diff --git a/crates/bevy_render/src/render_resource/uniform_vec.rs b/crates/bevy_render/src/render_resource/uniform_vec.rs
index 52eb3527cf731..9188ee1310745 100644
--- a/crates/bevy_render/src/render_resource/uniform_vec.rs
+++ b/crates/bevy_render/src/render_resource/uniform_vec.rs
@@ -145,16 +145,6 @@ impl<T: AsStd140> DynamicUniformVec<T> {
         self.uniform_vec.binding()
     }
 
-    #[inline]
-    pub fn len(&self) -> usize {
-        self.uniform_vec.len()
-    }
-
-    #[inline]
-    pub fn is_empty(&self) -> bool {
-        self.uniform_vec.is_empty()
-    }
-
     /// Gets the capacity of the underlying buffer, in bytes.
     #[inline]
     pub fn buffer_capacity(&self) -> usize {
@@ -163,9 +153,8 @@ impl<T: AsStd140> DynamicUniformVec<T> {
 
     #[inline]
     pub fn push_and_get_offset(&mut self, value: T) -> u32 {
-        (self.uniform_vec.push_and_get_offset(DynamicUniform(value)) * 
-         UniformVec::<DynamicUniform<T>>::ITEM_SIZE)
-            as u32
+        (self.uniform_vec.push_and_get_offset(DynamicUniform(value))
+            * UniformVec::<DynamicUniform<T>>::ITEM_SIZE) as u32
     }
 
     /// Queues up a copy of the contents of the [`UniformVec`] into the underlying
@@ -183,3 +172,16 @@ impl<T: AsStd140> DynamicUniformVec<T> {
         self.uniform_vec.clear();
     }
 }
+
+impl<T: AsStd140> Deref for DynamicUniformVec<T> {
+    type Target = Vec<DynamicUniform<T>>;
+    fn deref(&self) -> &Self::Target {
+        &self.uniform_vec
+    }
+}
+
+impl<T: AsStd140> DerefMut for DynamicUniformVec<T> {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.uniform_vec
+    }
+}

From ffc1fce24ddca57f451cfd4db51d49060bde22fb Mon Sep 17 00:00:00 2001
From: james7132 <contact@jamessliu.com>
Date: Wed, 2 Mar 2022 13:02:58 -0800
Subject: [PATCH 10/13] Add functions for extracting parts of the *BufferVec

---
 .../src/render_resource/buffer_vec.rs         | 12 +++++++++
 .../src/render_resource/uniform_vec.rs        | 25 ++++++++++++++++---
 2 files changed, 34 insertions(+), 3 deletions(-)

diff --git a/crates/bevy_render/src/render_resource/buffer_vec.rs b/crates/bevy_render/src/render_resource/buffer_vec.rs
index e0a6cf0a8c2a9..b26032ba38cce 100644
--- a/crates/bevy_render/src/render_resource/buffer_vec.rs
+++ b/crates/bevy_render/src/render_resource/buffer_vec.rs
@@ -66,6 +66,18 @@ impl<T: Pod> BufferVec<T> {
         }
     }
 
+    /// Consumes the [`BufferVec`] and returns the underlying [`Vec`].
+    /// If a buffer was allocated, it will be dropped.
+    pub fn take_vec(self) -> Vec<T> {
+        self.values
+    }
+
+    /// Consumes the [`BufferVec`] and returns the underlying [`Buffer`]
+    /// if one was allocated.
+    pub fn take_buffer(self) -> Option<Buffer> {
+        self.buffer
+    }
+
     fn reserve_buffer(&mut self, capacity: usize, device: &RenderDevice) {
         if capacity > self.capacity {
             self.capacity = capacity;
diff --git a/crates/bevy_render/src/render_resource/uniform_vec.rs b/crates/bevy_render/src/render_resource/uniform_vec.rs
index 9188ee1310745..137b1d207bd04 100644
--- a/crates/bevy_render/src/render_resource/uniform_vec.rs
+++ b/crates/bevy_render/src/render_resource/uniform_vec.rs
@@ -86,6 +86,18 @@ impl<T: AsStd140> UniformVec<T> {
         }
     }
 
+    /// Consumes the [`UniformBufferVec`] and returns the underlying [`Vec`].
+    /// If a buffer was allocated, it will be dropped.
+    pub fn take_vec(self) -> Vec<T> {
+        self.values
+    }
+
+    /// Consumes the [`UniformBufferVec`] and returns the underlying [`Buffer`]
+    /// if one was allocated.
+    pub fn take_buffer(self) -> Option<Buffer> {
+        self.uniform_buffer
+    }
+
     fn reserve_buffer(&mut self, device: &RenderDevice) -> bool {
         if self.size() > self.scratch.len() {
             self.scratch.resize(self.size(), 0);
@@ -167,9 +179,16 @@ impl<T: AsStd140> DynamicUniformVec<T> {
         self.uniform_vec.write_buffer(device, queue);
     }
 
-    #[inline]
-    pub fn clear(&mut self) {
-        self.uniform_vec.clear();
+    /// Consumes the [`DynamicUniformBufferVec`] and returns the underlying [`Vec`].
+    /// If a buffer was allocated, it will be dropped.
+    pub fn take_vec(self) -> Vec<DynamicUniform<T>> {
+        self.uniform_vec.take_vec()
+    }
+
+    /// Consumes the [`DynamicUniformBufferVec`] and returns the underlying [`Buffer`]
+    /// if one was allocated.
+    pub fn take_buffer(self) -> Option<Buffer> {
+        self.uniform_vec.take_buffer()
     }
 }
 

From 4218d70bf24fa94f04f347a560a5adf40155be77 Mon Sep 17 00:00:00 2001
From: james7132 <contact@jamessliu.com>
Date: Thu, 3 Mar 2022 11:44:03 -0800
Subject: [PATCH 11/13] fix panic on reserve

---
 crates/bevy_render/src/render_resource/buffer_vec.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/crates/bevy_render/src/render_resource/buffer_vec.rs b/crates/bevy_render/src/render_resource/buffer_vec.rs
index b26032ba38cce..fc1bb45a0f16b 100644
--- a/crates/bevy_render/src/render_resource/buffer_vec.rs
+++ b/crates/bevy_render/src/render_resource/buffer_vec.rs
@@ -91,7 +91,7 @@ impl<T: Pod> BufferVec<T> {
     }
 
     fn size(&self) -> usize {
-        std::mem::size_of::<T>() * self.capacity
+        std::mem::size_of::<T>() * self.values.len()
     }
 }
 

From 118a4adf287bd97ad36c3faf79a25d48a6261b01 Mon Sep 17 00:00:00 2001
From: james7132 <contact@jamessliu.com>
Date: Thu, 3 Mar 2022 15:36:26 -0800
Subject: [PATCH 12/13] Address review comments

---
 .../src/render_resource/buffer_vec.rs         |  6 ------
 .../src/render_resource/uniform_vec.rs        | 19 +++----------------
 2 files changed, 3 insertions(+), 22 deletions(-)

diff --git a/crates/bevy_render/src/render_resource/buffer_vec.rs b/crates/bevy_render/src/render_resource/buffer_vec.rs
index fc1bb45a0f16b..40bef82aab832 100644
--- a/crates/bevy_render/src/render_resource/buffer_vec.rs
+++ b/crates/bevy_render/src/render_resource/buffer_vec.rs
@@ -43,12 +43,6 @@ impl<T: Pod> BufferVec<T> {
         self.buffer.as_ref()
     }
 
-    /// Gets the capacity of the underlying buffer, returning 0 if it hasn't been allocated.
-    #[inline]
-    pub fn buffer_capacity(&self) -> usize {
-        self.capacity
-    }
-
     /// Queues up a copy of the contents of the [`BufferVec`] into the underlying
     /// buffer.
     ///
diff --git a/crates/bevy_render/src/render_resource/uniform_vec.rs b/crates/bevy_render/src/render_resource/uniform_vec.rs
index 137b1d207bd04..5b27a466d1eb2 100644
--- a/crates/bevy_render/src/render_resource/uniform_vec.rs
+++ b/crates/bevy_render/src/render_resource/uniform_vec.rs
@@ -54,14 +54,6 @@ impl<T: AsStd140> UniformVec<T> {
         }))
     }
 
-    /// Gets the capacity of the underlying buffer.
-    ///
-    /// Will return 0 if no buffer has been allocated yet.
-    #[inline]
-    pub fn buffer_capacity(&self) -> usize {
-        self.values.len()
-    }
-
     pub fn push_and_get_offset(&mut self, value: T) -> usize {
         let index = self.values.len();
         self.values.push(value);
@@ -99,11 +91,12 @@ impl<T: AsStd140> UniformVec<T> {
     }
 
     fn reserve_buffer(&mut self, device: &RenderDevice) -> bool {
-        if self.size() > self.scratch.len() {
+        let size = self.size();
+        if size > self.scratch.len() {
             self.scratch.resize(self.size(), 0);
             self.uniform_buffer = Some(device.create_buffer(&BufferDescriptor {
                 label: None,
-                size: self.size() as wgpu::BufferAddress,
+                size: size as wgpu::BufferAddress,
                 usage: BufferUsages::COPY_DST | BufferUsages::UNIFORM,
                 mapped_at_creation: false,
             }));
@@ -157,12 +150,6 @@ impl<T: AsStd140> DynamicUniformVec<T> {
         self.uniform_vec.binding()
     }
 
-    /// Gets the capacity of the underlying buffer, in bytes.
-    #[inline]
-    pub fn buffer_capacity(&self) -> usize {
-        self.uniform_vec.buffer_capacity()
-    }
-
     #[inline]
     pub fn push_and_get_offset(&mut self, value: T) -> u32 {
         (self.uniform_vec.push_and_get_offset(DynamicUniform(value))

From 3951665134c85380c35f06c206a8619c99cbd8c9 Mon Sep 17 00:00:00 2001
From: james7132 <contact@jamessliu.com>
Date: Thu, 3 Mar 2022 15:38:09 -0800
Subject: [PATCH 13/13] fix docs

---
 crates/bevy_render/src/render_resource/uniform_vec.rs | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/crates/bevy_render/src/render_resource/uniform_vec.rs b/crates/bevy_render/src/render_resource/uniform_vec.rs
index 5b27a466d1eb2..0b210362ae4f4 100644
--- a/crates/bevy_render/src/render_resource/uniform_vec.rs
+++ b/crates/bevy_render/src/render_resource/uniform_vec.rs
@@ -78,13 +78,13 @@ impl<T: AsStd140> UniformVec<T> {
         }
     }
 
-    /// Consumes the [`UniformBufferVec`] and returns the underlying [`Vec`].
+    /// Consumes the [`UniformVec`] and returns the underlying [`Vec`].
     /// If a buffer was allocated, it will be dropped.
     pub fn take_vec(self) -> Vec<T> {
         self.values
     }
 
-    /// Consumes the [`UniformBufferVec`] and returns the underlying [`Buffer`]
+    /// Consumes the [`UniformVec`] and returns the underlying [`Buffer`]
     /// if one was allocated.
     pub fn take_buffer(self) -> Option<Buffer> {
         self.uniform_buffer
@@ -166,13 +166,13 @@ impl<T: AsStd140> DynamicUniformVec<T> {
         self.uniform_vec.write_buffer(device, queue);
     }
 
-    /// Consumes the [`DynamicUniformBufferVec`] and returns the underlying [`Vec`].
+    /// Consumes the [`DynamicUniformVec`] and returns the underlying [`Vec`].
     /// If a buffer was allocated, it will be dropped.
     pub fn take_vec(self) -> Vec<DynamicUniform<T>> {
         self.uniform_vec.take_vec()
     }
 
-    /// Consumes the [`DynamicUniformBufferVec`] and returns the underlying [`Buffer`]
+    /// Consumes the [`DynamicUniformVec`] and returns the underlying [`Buffer`]
     /// if one was allocated.
     pub fn take_buffer(self) -> Option<Buffer> {
         self.uniform_vec.take_buffer()