Struct BlurPipeline 

pub struct BlurPipeline {
    pipeline: RenderPipeline,
    bind_group_layout: BindGroupLayout,
    sampler: Sampler,
    uniform_buffers: [Buffer; 6],
    bind_groups: [BindGroup; 6],
}

Drives the 6 blur passes (3 levels × H+V). One pipeline, six bind groups — each pass needs its own bind group because the source texture changes between passes.

Fields

pipeline: RenderPipeline

bind_group_layout: BindGroupLayout

sampler: Sampler

uniform_buffers: [Buffer; 6]

One uniform buffer per pass — 6 in total. Cheap; uniform buffers are tiny and writing different sigmas to one buffer mid-frame would require either dynamic offsets or per-pass write_buffer calls with a barrier, neither worth the complexity here.

bind_groups: [BindGroup; 6]

One bind group per pass, holding (uniforms[i], source texture, sampler). Recreated when textures rebind (resize).

Implementations

impl BlurPipeline

pub fn new( device: &Device, target_format: TextureFormat, width: u32, height: u32, render_view: &TextureView, blur1_view: &TextureView, blur2_view: &TextureView, blur3_view: &TextureView, blur1_scratch_view: &TextureView, blur2_scratch_view: &TextureView, blur3_scratch_view: &TextureView, ) -> Self

Build the pipeline against target_format and wire bind groups for the 6 blur passes. The pyramid is downsampled at each level (Blur1 = ½ render, Blur2 = ¼, Blur3 = ⅛); per-level scratches match their level’s resolution.

The pass order is fixed at construction:

• pass 0 (H, σ=σ1): src = render_view, dst = b1_scratch
• pass 1 (V, σ=σ1): src = b1_scratch, dst = blur1_view
• pass 2 (H, σ=σ2): src = blur1_view, dst = b2_scratch
• pass 3 (V, σ=σ2): src = b2_scratch, dst = blur2_view
• pass 4 (H, σ=σ3): src = blur2_view, dst = b3_scratch
• pass 5 (V, σ=σ3): src = b3_scratch, dst = blur3_view

texel_size is set per-pass to 1 / source-resolution, so each Gaussian tap walks one source-texel in UV space regardless of which level we’re at.

fn make_bind_group( device: &Device, layout: &BindGroupLayout, uniforms: &Buffer, source: &TextureView, sampler: &Sampler, idx: usize, ) -> BindGroup

pub fn rebind( &mut self, device: &Device, queue: &Queue, width: u32, height: u32, render_view: &TextureView, blur1_view: &TextureView, blur2_view: &TextureView, blur1_scratch_view: &TextureView, blur2_scratch_view: &TextureView, blur3_scratch_view: &TextureView, )

Recreate the bind groups + refresh per-pass uniform texel_size after the underlying textures are invalidated (resize).

pub fn render( &self, encoder: &mut CommandEncoder, blur1_view: &TextureView, blur2_view: &TextureView, blur3_view: &TextureView, blur1_scratch_view: &TextureView, blur2_scratch_view: &TextureView, blur3_scratch_view: &TextureView, )

Encode the 6 blur passes for this frame. Caller is responsible for submit-ing the encoder; the pipeline assumes the input render_texture already holds the current warp pass output.