Struct BloomFeature 

pub struct BloomFeature { /* private fields */ }

Persistent bloom feature owning GPU pipelines, layouts, and pre-built static bind groups.

The Composer calls extract_and_prepare once per frame before the render graph is built, then add_to_graph to emit a chain of flattened micro-passes (Extract → Downsample × N → Upsample × N → Composite) into the RDG.

Dual-Layer BindGroup Model

Static bind groups (Group 0) containing samplers and uniform buffers are built here and shared across all micro-pass nodes as cheap clones. Each micro-pass only assembles Group 1 (transient texture views).

Implementations

impl BloomFeature

pub fn new() -> Self

Creates a new bloom feature. All GPU resources are lazily allocated.

pub fn extract_and_prepare( &mut self, ctx: &mut ExtractContext<'_>, upsample_uniform: &CpuBuffer<UpsampleUniforms>, composite_uniform: &CpuBuffer<CompositeUniforms>, )

Ensure all persistent GPU resources (layouts, static buffers, pipelines) are initialised. Build or rebuild static bind groups (Group 0) when the underlying GPU buffer identity changes.

upsample_uniform and composite_uniform are the CpuBuffer IDs whose GPU mirrors have already been uploaded via ensure_buffer().

pub fn add_to_graph<'a>( &'a self, ctx: &mut GraphBuilderContext<'a, '_>, input_color: TextureNodeId, karis_average: bool, max_mip_levels: u32, ) -> TextureNodeId

Emit the full bloom pipeline as a chain of independent RDG passes.

Each downsample and upsample step is a separate pass operating on independent 2D transient textures with progressively halved resolution. The RDG compiler sees fine-grained dependencies between every mip level, enabling:

• Optimal barrier/transition insertion between individual steps.
• Aggressive memory aliasing — textures whose lifetimes don’t overlap are automatically mapped to the same physical GPU memory.

Returns the composited output TextureNodeId (scene HDR with bloom applied) for downstream wiring (e.g. ToneMapping).

Trait Implementations

impl Default for BloomFeature

fn default() -> Self

Returns the “default value” for a type.