Source code
Revision control
Copy as Markdown
Other Tools
#[cfg(any(feature = "serde", test))]
use serde::{Deserialize, Serialize};
#[cfg(doc)]
use crate::{DownlevelFlags, COPY_BUFFER_ALIGNMENT};
/// Describes a [`Buffer`](../wgpu/struct.Buffer.html).
///
/// Corresponds to [WebGPU `GPUBufferDescriptor`](
#[repr(C)]
#[derive(Clone, Debug, PartialEq, Eq, Hash)]
#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
pub struct BufferDescriptor<L> {
/// Debug label of a buffer. This will show up in graphics debuggers for easy identification.
pub label: L,
/// Size of a buffer, in bytes.
pub size: crate::BufferAddress,
/// Usages of a buffer. If the buffer is used in any way that isn't specified here, the operation
/// will panic.
///
/// Specifying only usages the application will actually perform may increase performance.
/// Additionally, on the WebGL backend, there are restrictions on [`BufferUsages::INDEX`];
/// see [`DownlevelFlags::UNRESTRICTED_INDEX_BUFFER`] for more information.
pub usage: BufferUsages,
/// Allows a buffer to be mapped immediately after they are made. It does not have to be [`BufferUsages::MAP_READ`] or
/// [`BufferUsages::MAP_WRITE`], all buffers are allowed to be mapped at creation.
///
/// If this is `true`, [`size`](#structfield.size) must be a multiple of
/// [`COPY_BUFFER_ALIGNMENT`].
pub mapped_at_creation: bool,
}
impl<L> BufferDescriptor<L> {
/// Takes a closure and maps the label of the buffer descriptor into another.
#[must_use]
pub fn map_label<K>(&self, fun: impl FnOnce(&L) -> K) -> BufferDescriptor<K> {
BufferDescriptor {
label: fun(&self.label),
size: self.size,
usage: self.usage,
mapped_at_creation: self.mapped_at_creation,
}
}
}
bitflags::bitflags! {
/// Different ways that you can use a buffer.
///
/// The usages determine what kind of memory the buffer is allocated from and what
/// actions the buffer can partake in.
///
/// Specifying only usages the application will actually perform may increase performance.
/// Additionally, on the WebGL backend, there are restrictions on [`BufferUsages::INDEX`];
/// see [`DownlevelFlags::UNRESTRICTED_INDEX_BUFFER`] for more information.
///
/// Corresponds to [WebGPU `GPUBufferUsageFlags`](
#[repr(transparent)]
#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
#[cfg_attr(feature = "serde", serde(transparent))]
#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
pub struct BufferUsages: u32 {
/// Allow a buffer to be mapped for reading using [`Buffer::map_async`] + [`Buffer::get_mapped_range`].
/// This does not include creating a buffer with [`BufferDescriptor::mapped_at_creation`] set.
///
/// If [`Features::MAPPABLE_PRIMARY_BUFFERS`] isn't enabled, the only other usage a buffer
/// may have is COPY_DST.
const MAP_READ = 1 << 0;
/// Allow a buffer to be mapped for writing using [`Buffer::map_async`] + [`Buffer::get_mapped_range_mut`].
/// This does not include creating a buffer with [`BufferDescriptor::mapped_at_creation`] set.
///
/// If [`Features::MAPPABLE_PRIMARY_BUFFERS`] feature isn't enabled, the only other usage a buffer
/// may have is COPY_SRC.
const MAP_WRITE = 1 << 1;
/// Allow a buffer to be the source buffer for a [`CommandEncoder::copy_buffer_to_buffer`] or [`CommandEncoder::copy_buffer_to_texture`]
/// operation.
const COPY_SRC = 1 << 2;
/// Allow a buffer to be the destination buffer for a [`CommandEncoder::copy_buffer_to_buffer`], [`CommandEncoder::copy_texture_to_buffer`],
/// [`CommandEncoder::clear_buffer`] or [`Queue::write_buffer`] operation.
const COPY_DST = 1 << 3;
/// Allow a buffer to be the index buffer in a draw operation.
const INDEX = 1 << 4;
/// Allow a buffer to be the vertex buffer in a draw operation.
const VERTEX = 1 << 5;
/// Allow a buffer to be a [`BufferBindingType::Uniform`] inside a bind group.
const UNIFORM = 1 << 6;
/// Allow a buffer to be a [`BufferBindingType::Storage`] inside a bind group.
const STORAGE = 1 << 7;
/// Allow a buffer to be the indirect buffer in an indirect draw call.
const INDIRECT = 1 << 8;
/// Allow a buffer to be the destination buffer for a [`CommandEncoder::resolve_query_set`] operation.
const QUERY_RESOLVE = 1 << 9;
/// Allows a buffer to be used as input for a bottom level acceleration structure build
const BLAS_INPUT = 1 << 10;
/// Allows a buffer to be used as input for a top level acceleration structure build
const TLAS_INPUT = 1 << 11;
}
}
bitflags::bitflags! {
/// Similar to `BufferUsages`, but used only for `CommandEncoder::transition_resources`.
#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
#[cfg_attr(feature = "serde", serde(transparent))]
#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
pub struct BufferUses: u16 {
/// The argument to a read-only mapping.
const MAP_READ = 1 << 0;
/// The argument to a write-only mapping.
const MAP_WRITE = 1 << 1;
/// The source of a hardware copy.
/// cbindgen:ignore
const COPY_SRC = 1 << 2;
/// The destination of a hardware copy.
/// cbindgen:ignore
const COPY_DST = 1 << 3;
/// The index buffer used for drawing.
const INDEX = 1 << 4;
/// A vertex buffer used for drawing.
const VERTEX = 1 << 5;
/// A uniform buffer bound in a bind group.
const UNIFORM = 1 << 6;
/// A read-only storage buffer used in a bind group.
/// cbindgen:ignore
const STORAGE_READ_ONLY = 1 << 7;
/// A read-write buffer used in a bind group.
/// cbindgen:ignore
const STORAGE_READ_WRITE = 1 << 8;
/// The indirect or count buffer in a indirect draw or dispatch.
const INDIRECT = 1 << 9;
/// A buffer used to store query results.
const QUERY_RESOLVE = 1 << 10;
/// Buffer used for acceleration structure building.
const ACCELERATION_STRUCTURE_SCRATCH = 1 << 11;
/// Buffer used for bottom level acceleration structure building.
const BOTTOM_LEVEL_ACCELERATION_STRUCTURE_INPUT = 1 << 12;
/// Buffer used for top level acceleration structure building.
const TOP_LEVEL_ACCELERATION_STRUCTURE_INPUT = 1 << 13;
/// A buffer used to store the compacted size of an acceleration structure
const ACCELERATION_STRUCTURE_QUERY = 1 << 14;
/// The combination of states that a buffer may be in _at the same time_.
const INCLUSIVE = Self::MAP_READ.bits() | Self::COPY_SRC.bits() |
Self::INDEX.bits() | Self::VERTEX.bits() | Self::UNIFORM.bits() |
Self::STORAGE_READ_ONLY.bits() | Self::INDIRECT.bits() | Self::BOTTOM_LEVEL_ACCELERATION_STRUCTURE_INPUT.bits() | Self::TOP_LEVEL_ACCELERATION_STRUCTURE_INPUT.bits();
/// The combination of states that a buffer must exclusively be in.
const EXCLUSIVE = Self::MAP_WRITE.bits() | Self::COPY_DST.bits() | Self::STORAGE_READ_WRITE.bits() | Self::ACCELERATION_STRUCTURE_SCRATCH.bits();
/// The combination of all usages that the are guaranteed to be be ordered by the hardware.
/// If a usage is ordered, then if the buffer state doesn't change between draw calls, there
/// are no barriers needed for synchronization.
const ORDERED = Self::INCLUSIVE.bits() | Self::MAP_WRITE.bits();
}
}
/// A buffer transition for use with `CommandEncoder::transition_resources`.
#[derive(Clone, Debug)]
#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
pub struct BufferTransition<T> {
/// The buffer to transition.
pub buffer: T,
/// The new state to transition to.
pub state: BufferUses,
}