D866 - A signed-normalised 8_8_8_8 target is drawn through its own format

Status: decided Date: 2026-10-14

A colour target whose CB_COLOR0_INFO names COLOR_8_8_8_8 and NUMBER_SNORM, in a component order an 8_8_8_8 UNORM target may take, holds four signed-normalised bytes a texel. A drawer draws it through R8G8B8A8_SNORM, for the image and the attachment alike, so a draw's output and blending are signed and the bytes read in and written back are the guest's own, as they are for the other four-byte targets (D773, D848).

Why: NUMBER_SNORM is 1 (gfx103.json, enum SurfaceNumber). Grand Theft Auto V's second submission draws into a 128 x 128 linear target of it, once its first submission completes (D823).

Rejected:

• Drawing it through the UNORM attachment and reinterpreting: a negative output would clamp to zero, and blending would read the bytes as unsigned.