Function create_bloom_chain

native/shared/src/renderer/formats.rs:744–772

Create the bloom mip-chain texture + per-mip render views + a full-chain view for sampling. Mip 0 starts at surface/2 size and each subsequent mip halves down to ~surface/2^N. Caller is responsible for deciding N (usually BLOOM_MIP_COUNT). At least 1×1 is enforced per mip. Build the bloom chain as N separate single-mip textures rather than one multi-mip texture. Multi-mip textures with one mip bou

(
    device: &wgpu::Device,
    width: u32,
    height: u32,
    mip_count: u32,
)

/// read/write hits a distinct texture). `bloom_full_view` is a
/// view onto mip 0's texture, kept for backward compatibility.
pub(super) fn create_bloom_chain(
    device: &wgpu::Device,
    width: u32,
    height: u32,
    mip_count: u32,
) -> (Vec<wgpu::Texture>, Vec<wgpu::TextureView>, wgpu::TextureView) {
    let mut textures = Vec::with_capacity(mip_count as usize);
    let mut views = Vec::with_capacity(mip_count as usize);
    for i in 0..mip_count {
        let w = ((width / 2) >> i).max(1);
        let h = ((height / 2) >> i).max(1);
        let tex = device.create_texture(&wgpu::TextureDescriptor {
            label: Some("bloom_mip_tex"),
            size: wgpu::Extent3d { width: w, height: h, depth_or_array_layers: 1 },
            mip_level_count: 1,
            sample_count: 1,
            dimension: wgpu::TextureDimension::D2,
            format: HDR_FORMAT,
            usage: wgpu::TextureUsages::RENDER_ATTACHMENT
                 | wgpu::TextureUsages::TEXTURE_BINDING,
            view_formats: &[],
        });
        let view = tex.create_view(&wgpu::TextureViewDescriptor::default());
        textures.push(tex);
        views.push(view);
    }
    let full_view = textures[0].create_view(&wgpu::TextureViewDescriptor::default());
    (textures, views, full_view)
}