Struct CommandBuffer 

pub struct CommandBuffer { /* private fields */ }

One in-flight wgpu::CommandEncoder, handed to a renderer under a strict borrowing contract.

Invariant

A renderer handed this encoder records only render passes and staged uploads; it never submits, never begins a pass it does not end before returning, holds no borrow past return; the caller may record its own passes before and after and submit once. Exception: glyph-atlas uploads may submit their OWN encoder so atlas content is committed before the scene pass reads it (vello_hybrid render/wgpu/mod.rs:428-430).

A staged upload may leave one more thing on the encoder: the deferred re-map of the staging slot it was copied from (wgpu::CommandEncoder::map_buffer_on_submit, see crate::staging). It runs only when the caller submits, after the caller’s own work in the same submission, and is dropped harmlessly with an encoder that is never submitted — it asks nothing of the caller beyond the one submit.

A caller recording depth-writing passes of its own around a renderer’s owes the module-level two caller rules on top of this: depth-clear ownership, with the comparison, direction and extent that ride along with it.

Implementations

impl CommandBuffer

pub fn new(device: &Device, label: Option<&str>) -> Self

Begins recording a fresh command buffer on device.

pub fn render_pass<'e>( &'e mut self, target: &RenderTarget<'_>, label: Option<&str>, ) -> RenderPass<'e>

Begins a render pass over target’s color and depth attachments.

The returned wgpu::RenderPass borrows this buffer’s encoder; per the type-level invariant, a caller must end it (drop it, or call .end()) before recording anything else through Self::encoder_mut, starting another pass, or calling Self::finish.

pub fn encoder_mut(&mut self) -> &mut CommandEncoder

The borrowing seam: direct mutable access to the underlying encoder for recording this type does not model — a staged buffer/texture upload, or a pass shape this crate does not own.

A caller reaching for this still owes the type-level invariant: no submit, and no pass left open across a return.

pub fn finish(self) -> CommandBuffer

Ends recording and hands back the finished wgpu::CommandBuffer for the caller to submit — once, alongside anything else it recorded before or after this buffer’s own passes.