Struct BufferSlice

pub struct BufferSlice<'a> { /* private fields */ }

A slice of a Buffer, to be mapped, used for vertex or index data, or the like.

You can create a BufferSlice by calling Buffer::slice:

let slice = buffer.slice(10..20);

This returns a slice referring to the second ten bytes of buffer. To get a slice of the entire Buffer:

let whole_buffer_slice = buffer.slice(..);

A BufferSlice is nothing more than a reference to the Buffer and a starting and ending position. To access the slice’s contents on the CPU, you must first map the buffer, and then call BufferSlice::get_mapped_range or BufferSlice::get_mapped_range_mut to obtain a view of the slice’s contents, which dereferences to a &[u8] or &mut [u8].

You can also pass buffer slices to methods like RenderPass::set_vertex_buffer and RenderPass::set_index_buffer to indicate which data a draw call should consume.

The BufferSlice type is unique to the Rust API of wgpu. In the WebGPU specification, an offset and size are specified as arguments to each call working with the Buffer, instead.

Implementations

impl<'a> BufferSlice<'a>

pub fn map_async( &self, mode: MapMode, callback: impl FnOnce(Result<(), BufferAsyncError>) + WasmNotSend + 'static, )

Map the buffer. Buffer is ready to map once the callback is called.

For the callback to complete, either queue.submit(..), instance.poll_all(..), or device.poll(..) must be called elsewhere in the runtime, possibly integrated into an event loop or run on a separate thread.

The callback will be called on the thread that first calls the above functions after the gpu work has completed. There are no restrictions on the code you can run in the callback, however on native the call to the function will not complete until the callback returns, so prefer keeping callbacks short and used to set flags, send messages, etc.

pub fn get_mapped_range(&self) -> BufferView<'a>

Synchronously and immediately map a buffer for reading. If the buffer is not immediately mappable through BufferDescriptor::mapped_at_creation or BufferSlice::map_async, will panic.

pub fn get_mapped_range_mut(&self) -> BufferViewMut<'a>

Synchronously and immediately map a buffer for writing. If the buffer is not immediately mappable through BufferDescriptor::mapped_at_creation or BufferSlice::map_async, will panic.

Trait Implementations

impl<'a> Clone for BufferSlice<'a>

fn clone(&self) -> BufferSlice<'a>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<'a> Debug for BufferSlice<'a>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'a> Copy for BufferSlice<'a>