Struct GridUpload 

pub struct GridUpload {
    pub vsid: u32,
    pub origin_chunk: [i32; 3],
    pub chunks_dims: [u32; 3],
    pub pool_dims: [u32; 3],
    pub chunks: Vec<([i32; 3], ChunkUpload)>,
}

CPU-side aggregation of a grid’s chunks ready to upload. Host (e.g. roxlap-scene-demo) builds this by iterating its roxlap-scene::Grid and calling crate::decompress_chunk per materialised chunk.

Fields

vsid: u32

Shared XY extent of every chunk in voxels. Matches roxlap-scene::CHUNK_SIZE_XY = 128.

origin_chunk: [i32; 3]

Lowest chunk index present in the grid (min_chx, min_chy, min_chz). The grid’s bounding box runs from origin_chunk to origin_chunk + chunks_dims exclusive.

chunks_dims: [u32; 3]

Chunk-count along each axis = max - min + 1.

pool_dims: [u32; 3]

GPU.7 slot-pool dimensions for modular chunk indexing. Every component MUST be a power of 2. A chunk at index (chx, chy, chz) maps to slot (chx & (pool_dims.x - 1), chy & (pool_dims.y - 1), chz & (pool_dims.z - 1)). As long as pool_dims_axis ≥ active_range_along_axis, no two simultaneously-resident chunks collide. Set this larger than chunks_dims only when streaming may install chunks at indices outside the initial bbox.

chunks: Vec<([i32; 3], ChunkUpload)>

(chunk_idx, decompressed) pairs. Chunks outside the pool’s collision-free active range are still accepted — modular indexing will assign them slots; the caller is responsible for avoiding collisions with other resident chunks.

Implementations

impl GridUpload

pub fn total_chunks(&self) -> u32

pub fn default_pool_dims(chunks_dims: [u32; 3]) -> [u32; 3]

Default GPU.7 Self::pool_dims derived from chunks_dims — each axis rounded up to the next power of 2. Use this when the grid is static + slots map 1:1 to bbox positions; for streaming grids, callers should pick a larger pool that covers 2 × r_active_chunks + 1 along each axis.

pub fn meta_idx_of(&self, chunk_idx: [i32; 3]) -> Option<u32>

Linear chunk index (meta_idx) for (chx, chy, chz) in the grid’s row-major bounding-box order. None if the index is outside the grid.