Struct SpriteModel 

pub struct SpriteModel {
    pub dims: [u32; 3],
    pub occ_words_per_col: u32,
    pub pivot: [f32; 3],
    pub occupancy: Vec<u32>,
    pub colors: Vec<u32>,
    pub color_offsets: Vec<u32>,
    pub voxel_world_size: f32,
}

CPU-built voxel volume for one KV6 model.

Fields

dims: [u32; 3]

Voxel extent (mx, my, mz).

occ_words_per_col: u32

ceil(mz / 32) — u32 words of occupancy per (x, y) column.

pivot: [f32; 3]

KV6 pivot in model-local voxel space.

occupancy: Vec<u32>

Per-column occupancy bitmask, mx * my * occ_words_per_col.

colors: Vec<u32>

Voxel colours, ascending z within each column.

color_offsets: Vec<u32>

Prefix sums: color_offsets[col] is the first colour index of column col; length mx * my + 1.

voxel_world_size: f32

World-space size of one voxel of this model (GPU.10.4 LOD): 1.0 at mip-0, doubling each SpriteModel::downsample. The shader divides the local ray by this so a coarse voxel spans the right world extent and the march t stays in world units.

Implementations

impl SpriteModel

pub fn recolor(&mut self, f: impl Fn(u32) -> u32)

Recolour every voxel via f(old_rgba) -> new_rgba. Structure (occupancy / offsets) is untouched, so this is a cheap in-place edit — handy on a SpriteModelRegistry::fork to make a tinted variant. For structural edits, mutate the public occupancy / colours / dims directly (via model_mut) then rebuild the LOD.

pub fn set_voxel(&mut self, x: u32, y: u32, z: u32, color: Option<u32>) -> bool

GPU.12 — structural edit of a single voxel within the model’s existing bounds. Some(rgba) sets/replaces the voxel at (x, y, z); None clears it. Maintains the ascending-z colour invariant by inserting/removing at the voxel’s popcount rank and shifting the affected columns’ color_offsets. Returns true if the model changed. Out-of-bounds coordinates are ignored (returns false) — growing dims is a separate concern.

After editing, call SpriteModelRegistry::rebuild_lod to refresh coarser mips, then re-upload via set_sprite_instances.

pub fn bound_radius(&self) -> f32

Radius of a bounding sphere centred at the instance position (the pivot maps there): the farthest bbox corner from the pivot. Used for frustum culling. Assumes a unit basis; scaled instances would multiply this by their max basis length.

pub fn downsample(&self) -> SpriteModel

GPU.10.4 — 2× voxel downsample for the next LOD level. A coarse voxel is solid if any of its 2×2×2 fine voxels is, coloured by their per-channel average. Dims/pivot halve and voxel_world_size doubles, so the coarse model occupies the same world box at half the resolution (origin-corner aligned).

Trait Implementations

impl Clone for SpriteModel

fn clone(&self) -> SpriteModel

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for SpriteModel

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.