1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462
use std::{iter, marker::PhantomData};
use crate::{
render_resource::Buffer,
renderer::{RenderDevice, RenderQueue},
};
use bytemuck::{must_cast_slice, NoUninit};
use encase::{
internal::{WriteInto, Writer},
ShaderType,
};
use wgpu::{BindingResource, BufferAddress, BufferUsages};
use super::GpuArrayBufferable;
/// A structure for storing raw bytes that have already been properly formatted
/// for use by the GPU.
///
/// "Properly formatted" means that item data already meets the alignment and padding
/// requirements for how it will be used on the GPU. The item type must implement [`NoUninit`]
/// for its data representation to be directly copyable.
///
/// Index, vertex, and instance-rate vertex buffers have no alignment nor padding requirements and
/// so this helper type is a good choice for them.
///
/// The contained data is stored in system RAM. Calling [`reserve`](RawBufferVec::reserve)
/// allocates VRAM from the [`RenderDevice`].
/// [`write_buffer`](RawBufferVec::write_buffer) queues copying of the data
/// from system RAM to VRAM.
///
/// Other options for storing GPU-accessible data are:
/// * [`StorageBuffer`](crate::render_resource::StorageBuffer)
/// * [`DynamicStorageBuffer`](crate::render_resource::DynamicStorageBuffer)
/// * [`UniformBuffer`](crate::render_resource::UniformBuffer)
/// * [`DynamicUniformBuffer`](crate::render_resource::DynamicUniformBuffer)
/// * [`GpuArrayBuffer`](crate::render_resource::GpuArrayBuffer)
/// * [`BufferVec`]
/// * [`Texture`](crate::render_resource::Texture)
pub struct RawBufferVec<T: NoUninit> {
values: Vec<T>,
buffer: Option<Buffer>,
capacity: usize,
item_size: usize,
buffer_usage: BufferUsages,
label: Option<String>,
changed: bool,
}
impl<T: NoUninit> RawBufferVec<T> {
/// Creates a new [`RawBufferVec`] with the given [`BufferUsages`].
pub const fn new(buffer_usage: BufferUsages) -> Self {
Self {
values: Vec::new(),
buffer: None,
capacity: 0,
item_size: std::mem::size_of::<T>(),
buffer_usage,
label: None,
changed: false,
}
}
/// Returns a handle to the buffer, if the data has been uploaded.
#[inline]
pub fn buffer(&self) -> Option<&Buffer> {
self.buffer.as_ref()
}
/// Returns the binding for the buffer if the data has been uploaded.
#[inline]
pub fn binding(&self) -> Option<BindingResource> {
Some(BindingResource::Buffer(
self.buffer()?.as_entire_buffer_binding(),
))
}
/// Returns the amount of space that the GPU will use before reallocating.
#[inline]
pub fn capacity(&self) -> usize {
self.capacity
}
/// Returns the number of items that have been pushed to this buffer.
#[inline]
pub fn len(&self) -> usize {
self.values.len()
}
/// Returns true if the buffer is empty.
#[inline]
pub fn is_empty(&self) -> bool {
self.values.is_empty()
}
/// Adds a new value and returns its index.
pub fn push(&mut self, value: T) -> usize {
let index = self.values.len();
self.values.push(value);
index
}
pub fn append(&mut self, other: &mut RawBufferVec<T>) {
self.values.append(&mut other.values);
}
/// Changes the debugging label of the buffer.
///
/// The next time the buffer is updated (via [`reserve`]), Bevy will inform
/// the driver of the new label.
pub fn set_label(&mut self, label: Option<&str>) {
let label = label.map(str::to_string);
if label != self.label {
self.changed = true;
}
self.label = label;
}
/// Returns the label
pub fn get_label(&self) -> Option<&str> {
self.label.as_deref()
}
/// Creates a [`Buffer`] on the [`RenderDevice`] with size
/// at least `std::mem::size_of::<T>() * capacity`, unless a such a buffer already exists.
///
/// If a [`Buffer`] exists, but is too small, references to it will be discarded,
/// and a new [`Buffer`] will be created. Any previously created [`Buffer`]s
/// that are no longer referenced will be deleted by the [`RenderDevice`]
/// once it is done using them (typically 1-2 frames).
///
/// In addition to any [`BufferUsages`] provided when
/// the `RawBufferVec` was created, the buffer on the [`RenderDevice`]
/// is marked as [`BufferUsages::COPY_DST`](BufferUsages).
pub fn reserve(&mut self, capacity: usize, device: &RenderDevice) {
let size = self.item_size * capacity;
if capacity > self.capacity || (self.changed && size > 0) {
self.capacity = capacity;
self.buffer = Some(device.create_buffer(&wgpu::BufferDescriptor {
label: self.label.as_deref(),
size: size as BufferAddress,
usage: BufferUsages::COPY_DST | self.buffer_usage,
mapped_at_creation: false,
}));
self.changed = false;
}
}
/// Queues writing of data from system RAM to VRAM using the [`RenderDevice`]
/// and the provided [`RenderQueue`].
///
/// Before queuing the write, a [`reserve`](RawBufferVec::reserve) operation
/// is executed.
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] = must_cast_slice(&self.values);
queue.write_buffer(buffer, 0, &bytes[range]);
}
}
/// Reduces the length of the buffer.
pub fn truncate(&mut self, len: usize) {
self.values.truncate(len);
}
/// Removes all elements from the buffer.
pub fn clear(&mut self) {
self.values.clear();
}
pub fn values(&self) -> &Vec<T> {
&self.values
}
pub fn values_mut(&mut self) -> &mut Vec<T> {
&mut self.values
}
}
impl<T: NoUninit> Extend<T> for RawBufferVec<T> {
#[inline]
fn extend<I: IntoIterator<Item = T>>(&mut self, iter: I) {
self.values.extend(iter);
}
}
/// Like [`RawBufferVec`], but doesn't require that the data type `T` be
/// [`NoUninit`].
///
/// This is a high-performance data structure that you should use whenever
/// possible if your data is more complex than is suitable for [`RawBufferVec`].
/// The [`ShaderType`] trait from the `encase` library is used to ensure that
/// the data is correctly aligned for use by the GPU.
///
/// For performance reasons, unlike [`RawBufferVec`], this type doesn't allow
/// CPU access to the data after it's been added via [`BufferVec::push`]. If you
/// need CPU access to the data, consider another type, such as
/// [`StorageBuffer`].
pub struct BufferVec<T>
where
T: ShaderType + WriteInto,
{
data: Vec<u8>,
buffer: Option<Buffer>,
capacity: usize,
buffer_usage: BufferUsages,
label: Option<String>,
label_changed: bool,
phantom: PhantomData<T>,
}
impl<T> BufferVec<T>
where
T: ShaderType + WriteInto,
{
/// Creates a new [`BufferVec`] with the given [`BufferUsages`].
pub const fn new(buffer_usage: BufferUsages) -> Self {
Self {
data: vec![],
buffer: None,
capacity: 0,
buffer_usage,
label: None,
label_changed: false,
phantom: PhantomData,
}
}
/// Returns a handle to the buffer, if the data has been uploaded.
#[inline]
pub fn buffer(&self) -> Option<&Buffer> {
self.buffer.as_ref()
}
/// Returns the binding for the buffer if the data has been uploaded.
#[inline]
pub fn binding(&self) -> Option<BindingResource> {
Some(BindingResource::Buffer(
self.buffer()?.as_entire_buffer_binding(),
))
}
/// Returns the amount of space that the GPU will use before reallocating.
#[inline]
pub fn capacity(&self) -> usize {
self.capacity
}
/// Returns the number of items that have been pushed to this buffer.
#[inline]
pub fn len(&self) -> usize {
self.data.len() / u64::from(T::min_size()) as usize
}
/// Returns true if the buffer is empty.
#[inline]
pub fn is_empty(&self) -> bool {
self.data.is_empty()
}
/// Adds a new value and returns its index.
pub fn push(&mut self, value: T) -> usize {
let element_size = u64::from(T::min_size()) as usize;
let offset = self.data.len();
// TODO: Consider using unsafe code to push uninitialized, to prevent
// the zeroing. It shows up in profiles.
self.data.extend(iter::repeat(0).take(element_size));
// Take a slice of the new data for `write_into` to use. This is
// important: it hoists the bounds check up here so that the compiler
// can eliminate all the bounds checks that `write_into` will emit.
let mut dest = &mut self.data[offset..(offset + element_size)];
value.write_into(&mut Writer::new(&value, &mut dest, 0).unwrap());
offset / u64::from(T::min_size()) as usize
}
/// Changes the debugging label of the buffer.
///
/// The next time the buffer is updated (via [`reserve`]), Bevy will inform
/// the driver of the new label.
pub fn set_label(&mut self, label: Option<&str>) {
let label = label.map(str::to_string);
if label != self.label {
self.label_changed = true;
}
self.label = label;
}
/// Returns the label
pub fn get_label(&self) -> Option<&str> {
self.label.as_deref()
}
/// Creates a [`Buffer`] on the [`RenderDevice`] with size
/// at least `std::mem::size_of::<T>() * capacity`, unless such a buffer already exists.
///
/// If a [`Buffer`] exists, but is too small, references to it will be discarded,
/// and a new [`Buffer`] will be created. Any previously created [`Buffer`]s
/// that are no longer referenced will be deleted by the [`RenderDevice`]
/// once it is done using them (typically 1-2 frames).
///
/// In addition to any [`BufferUsages`] provided when
/// the `BufferVec` was created, the buffer on the [`RenderDevice`]
/// is marked as [`BufferUsages::COPY_DST`](BufferUsages).
pub fn reserve(&mut self, capacity: usize, device: &RenderDevice) {
if capacity <= self.capacity && !self.label_changed {
return;
}
self.capacity = capacity;
let size = u64::from(T::min_size()) as usize * capacity;
self.buffer = Some(device.create_buffer(&wgpu::BufferDescriptor {
label: self.label.as_deref(),
size: size as BufferAddress,
usage: BufferUsages::COPY_DST | self.buffer_usage,
mapped_at_creation: false,
}));
self.label_changed = false;
}
/// Queues writing of data from system RAM to VRAM using the [`RenderDevice`]
/// and the provided [`RenderQueue`].
///
/// Before queuing the write, a [`reserve`](BufferVec::reserve) operation is
/// executed.
pub fn write_buffer(&mut self, device: &RenderDevice, queue: &RenderQueue) {
if self.data.is_empty() {
return;
}
self.reserve(self.data.len() / u64::from(T::min_size()) as usize, device);
let Some(buffer) = &self.buffer else { return };
queue.write_buffer(buffer, 0, &self.data);
}
/// Reduces the length of the buffer.
pub fn truncate(&mut self, len: usize) {
self.data.truncate(u64::from(T::min_size()) as usize * len);
}
/// Removes all elements from the buffer.
pub fn clear(&mut self) {
self.data.clear();
}
}
/// Like a [`BufferVec`], but only reserves space on the GPU for elements
/// instead of initializing them CPU-side.
///
/// This type is useful when you're accumulating "output slots" for a GPU
/// compute shader to write into.
///
/// The type `T` need not be [`NoUninit`], unlike [`RawBufferVec`]; it only has to
/// be [`GpuArrayBufferable`].
pub struct UninitBufferVec<T>
where
T: GpuArrayBufferable,
{
buffer: Option<Buffer>,
len: usize,
capacity: usize,
item_size: usize,
buffer_usage: BufferUsages,
label: Option<String>,
label_changed: bool,
phantom: PhantomData<T>,
}
impl<T> UninitBufferVec<T>
where
T: GpuArrayBufferable,
{
/// Creates a new [`UninitBufferVec`] with the given [`BufferUsages`].
pub const fn new(buffer_usage: BufferUsages) -> Self {
Self {
len: 0,
buffer: None,
capacity: 0,
item_size: std::mem::size_of::<T>(),
buffer_usage,
label: None,
label_changed: false,
phantom: PhantomData,
}
}
/// Returns the buffer, if allocated.
#[inline]
pub fn buffer(&self) -> Option<&Buffer> {
self.buffer.as_ref()
}
/// Returns the binding for the buffer if the data has been uploaded.
#[inline]
pub fn binding(&self) -> Option<BindingResource> {
Some(BindingResource::Buffer(
self.buffer()?.as_entire_buffer_binding(),
))
}
/// Reserves space for one more element in the buffer and returns its index.
pub fn add(&mut self) -> usize {
let index = self.len;
self.len += 1;
index
}
/// Returns true if no elements have been added to this [`UninitBufferVec`].
pub fn is_empty(&self) -> bool {
self.len == 0
}
/// Removes all elements from the buffer.
pub fn clear(&mut self) {
self.len = 0;
}
/// Returns the length of the buffer.
pub fn len(&self) -> usize {
self.len
}
/// Materializes the buffer on the GPU with space for `capacity` elements.
///
/// If the buffer is already big enough, this function doesn't reallocate
/// the buffer.
pub fn reserve(&mut self, capacity: usize, device: &RenderDevice) {
if capacity <= self.capacity && !self.label_changed {
return;
}
self.capacity = capacity;
let size = self.item_size * capacity;
self.buffer = Some(device.create_buffer(&wgpu::BufferDescriptor {
label: self.label.as_deref(),
size: size as wgpu::BufferAddress,
usage: BufferUsages::COPY_DST | self.buffer_usage,
mapped_at_creation: false,
}));
self.label_changed = false;
}
/// Materializes the buffer on the GPU, with an appropriate size for the
/// elements that have been pushed so far.
pub fn write_buffer(&mut self, device: &RenderDevice) {
if !self.is_empty() {
self.reserve(self.len, device);
}
}
}