Struct OverlayRenderer 

pub struct OverlayRenderer { /* private fields */ }

The overlay’s renderer, free of any surface: a retention-off frust_engine::EngineRenderer that records a command range into a caller-supplied target cleared to transparent.

OverlaySurface wraps one around a swapchain; the spike’s host tests drive one directly against an offscreen target.

Implementations

impl OverlayRenderer

pub fn new( device: &Device, queue: &Queue, caps: &TierCaps, format: TextureFormat, pipeline_cache: Option<&PipelineCache>, ) -> Result<Self, OverlayError>

Builds an overlay renderer for format targets on device.

pipeline_cache is the main surface’s persisted driver cache, when it has one, so the overlay’s pipelines compile as cache hits.

Errors

OverlayError::Engine when the engine cannot be built on caps.

pub fn record( &mut self, device: &Device, queue: &Queue, encoder: &mut CommandEncoder, scene: &Scene, range: Range<usize>, target: EngineTarget<'_>, ) -> Result<RangeCut, OverlayError>

Records the commands of scene in range into encoder, targeting target cleared to transparent, and returns what the cut did.

Shader quads are prepared over the whole scene (the pre-pass is per-scene), so a quad outside the range is rendered to its own offscreen target too and simply never sampled — a spike cost.

Errors

OverlayError::Engine when the engine refuses the frame; nothing was recorded into encoder then.

pub fn end_frame(&mut self, queue: &Queue, submitted: bool)

Closes the frame Self::record recorded, once its encoder was submitted (submitted) or dropped: the engine’s end-of-frame maintenance and the timestamp ring’s frame close — or, for an encoder that was never submitted, the ring’s abandon, so no slot is left waiting on a resolve that will never run.

pub fn last_cut(&self) -> Option<RangeCut>

What the last recorded range’s cut did, None before the first.

pub fn refused_frames(&self) -> u32

How many frames the engine has refused on this overlay.

pub fn gpu_pass_timings(&self) -> Option<GpuPassTimings>

The overlay’s most recent per-pass GPU time, on a device with TIMESTAMP_QUERY (a perf-trace build); None otherwise — the same reading SurfaceRenderer::gpu_pass_timings gives the main surface.