pub fn compose_into(
shared_fb: &mut [u32],
shared_zb: &mut [f32],
temp_fb: &[u32],
temp_zb: &[f32],
)Expand description
Per-pixel “min-z wins” merge of (temp_fb, temp_zb) into
(shared_fb, shared_zb).
Voxlap’s z-buffer convention: z = perpendicular distance from
camera; smaller z = closer to camera. This helper picks
the closer pixel per slot. Sky pixels emerge with a large z
(scratch.skycast.dist, set to gxmax or i32::MAX per
phase_startsky) so they always lose to any hit’s finite
distance.
temp_fb / temp_zb are read-only inputs; both must have the
same length as shared_fb / shared_zb (debug-asserted).