Struct Sky 

pub struct Sky {
    pub pixels: Vec<i32>,
    pub xsiz: i32,
    pub ysiz: i32,
    pub bpl: i32,
    pub lng: Vec<[f32; 2]>,
    pub lat: Vec<i32>,
    pub lng_mul: f32,
}

Sky texture + precomputed angle-lookup tables.

pixels are voxlap-style packed BGRA i32s (low byte = blue, high byte = brightness/alpha) — same layout as voxel records. xsiz × ysiz is the texture’s pixel extent.

Fields

pixels: Vec<i32>

Texture pixels, row-major, length xsiz * ysiz.

xsiz: i32

Texel columns. Stored as the post-decrement value (= one less than the physical column count), matching voxlap’s skyxsiz global state after loadsky. The lookup table Self::lat still has xsiz + 1 entries, with lat[0] = 0 as the asm-search lower-bound sentinel.

ysiz: i32

Texel rows.

bpl: i32

Bytes per row (= (xsiz + 1) * 4, matching voxlap’s skybpl).

lng: Vec<[f32; 2]>

Per-row (cos, sin) of the longitude angle. Length ysiz. Voxlap: skylng[y].x = cos(y·2π/ysiz + π), skylng[y].y = sin(...).

lat: Vec<i32>

Per-column packed (xoff << 16) | (-yoff & 0xffff), both 16-bit. Length xsiz + 1 (= original column count). Voxlap: lat[x] = (xoff<<16) | ((-yoff) & 0xffff) where xoff = cos(((2x - xsiz)·π/(2·xsiz))·32767) and yoff = sin(...). lat[0] = 0 is voxlap’s “make sure assembly index never goes < 0” hack.

lng_mul: f32

ysiz / (2π) — converts a longitude angle in radians into a row index. Used by gline’s first-ray atan2 path.

Implementations

impl Sky

pub fn from_pixels(pixels: Vec<i32>, original_xsiz: u32, ysiz: u32) -> Self

Build a Sky from a row-major BGRA pixel grid. Computes the lng / lat lookup tables; mirror of voxlap5.c:3946- 3970 (the post-kpzload table init in loadsky).

pixels.len() must equal original_xsiz * ysiz. original_xsiz is the pre-decrement column count (what voxlap reads from the loaded texture before stamping skyxsiz--). The returned Sky holds xsiz = original_xsiz - 1.

Panics

Panics if pixels.len() != original_xsiz * ysiz or if original_xsiz < 2 or ysiz < 1.

pub fn blue_gradient() -> Self

Voxlap’s “BLUE” fallback sky (voxlap5.c:3920-3944). A 512×1 horizon-gradient texture: dark blue at the horizon fading up to lighter blue, then to a pale top. Useful as a default when no .png is loaded.

Trait Implementations

impl Clone for Sky

fn clone(&self) -> Sky

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Sky

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

Formats the value using the given formatter.