Struct ChunkXyBacking 

pub struct ChunkXyBacking<'a> {
    pub chunks: Vec<Option<GridView<'a>>>,
    pub origin_chunk_xy: [i32; 2],
    pub origin_chunk_z: i32,
    pub chunks_x: u32,
    pub chunks_y: u32,
    pub chunks_z: u32,
}

S4B.2.c.3: chx/chy chunk table built from a Grid.

Owns the Vec<Option<GridView>> so roxlap_core::ChunkGrid (which borrows the table) can live alongside the GridView constructed from it. Used by the Approach B render path — see Grid::chunk_xy_backing.

S4B.6.a: gained chunks_z + origin_chunk_z for tall-world support. Pre-S4B.6.a chunk_xy_backing always populates these as chunks_z=1 origin_chunk_z=0 (= chz=0 only); S4B.6.c will switch the render path to chunk_xyz_backing once the rasterizer is stack-aware.

Fields

chunks: Vec<Option<GridView<'a>>>

Per-chunk views over the chx/chy/chz extent. Length chunks_x * chunks_y * chunks_z; index layout [(dz * chunks_y + dy) * chunks_x + dx]. None for implicit-air chunks inside the bbox.

origin_chunk_xy: [i32; 2]

XY index of the chunk at chunks[0] — the minimum chx/chy among populated chunks at chz = origin_chunk_z.

origin_chunk_z: i32

Z index of the chunk at chunks[0].

chunks_x: u32

Number of chunks along the X axis. Row stride.

chunks_y: u32

Number of chunks along the Y axis.

chunks_z: u32

Number of chunks along the Z axis. 1 from Grid::chunk_xy_backing; >1 only via the S4B.6.a Grid::chunk_xyz_backing.