Function build_surface_lods

perro_source/render_stack/perro_meshlets/src/lib.rs:248–269

(
    vertices: &[LodVertex],
    surface_indices: &[u32],
    ratios: &[f32],
)

    vertices: &[LodVertex],
    indices: &[u32],
    surface_ranges: &[LodSurfaceRange],
    target_ratios: &[f32],
) -> Vec<LodSet> {
    try_build_lod_sets(vertices, indices, surface_ranges, target_ratios).unwrap_or_else(|_| {
        vec![LodSet {
            indices: indices.to_vec(),
            surface_ranges: vec![LodSurfaceRange {
                index_start: 0,
                index_count: u32::try_from(indices.len()).unwrap_or(u32::MAX),
            }],
        }]
    })
}

pub fn try_build_lod_sets(
    vertices: &[LodVertex],
    indices: &[u32],
    surface_ranges: &[LodSurfaceRange],
    target_ratios: &[f32],
) -> Result<Vec<LodSet>, MeshletBuildError> {
    let base_surfaces = if surface_ranges.is_empty() {
        vec![LodSurfaceRange {
            index_start: 0,
            index_count: indices.len() as u32,
        }]