D918 - A draw samples a depth cube from its six drawn slices

Status: decided Date: 2026-10-20

A draw may sample, as a cube, a depth-format image in a depth swizzle whose descriptor is a cube: TYPE CUBE, DEPTH 5 and BASE_ARRAY 0. Each of that image's six faces is the depth target the host drew at that slice of the surface (D909). The backend reads the six back and binds them as a cube's faces in order, compared or read as the draw asks (D817).

A cube is refused where any face was never drawn here, where the faces were drawn at different extents, or where its view is other than one cube's six faces. A flat depth texture is bound as before.

Why: Grand Theft Auto V's loading-screen lighting samples point-light shadows from 16_UNORM cubes in 64KB_Z_X, which draws refused.