MXGP 26 (PPSA30839): reaches a race; opaque surfaces render black

[milescoviello]

Status: reaches a race with scripted input. Menus and 2D screens render. In the 3D scenes, opaque surfaces (track, bikes, rider, crowd) render black; only the sky and reflections are lit (#9510). About 4.4 FPS in the race on the host below.

Setup

• Title: MXGP 26 (PPSA30839)
• Linux: Ubuntu 26.04.1 (kernel 7.0), i7-13700K, RTX 4070 Ti, NVIDIA 615.71.09, GCC 15.2, release libs on current main, 12 GB memory cap, warm shader cache

What it takes to get to a race (all on main, no extra PRs)

1. Wait for the Nacon logo (about 180 s with a warm cache) and the title screen, then Cross.
2. The MyNacon "Welcome" screen's prompt is a Square inside a ring: hold Square for 3 s. A tap does nothing.
3. Cross through Terms of Use and the gamma screen.
4. On the profile screen, Down to Confirm, then Cross. The same on the manufacturer screen.
5. Cross every 30 s from there. The race starts at about 880 s.

Fixed on main

• AGC: MXGP 26 (PPSA30839) aborts on a compute shader that calls a function pointer read through a V# at the fixed address 0xF_E0040000 #6117, the compute shader that calls a function pointer read through a V#: fixed by feat(agc): link calls through the AGC FS table #6160.
• An intermittent abort right after the boot screens, at a store into partly watched memory: fixed by fix(agc): stamp the watched blocks of a store into partly watched memory #6455.

Open

• AGC: MXGP 26 (PPSA30839) renders opaque surfaces black in its 3D scenes; only the sky and reflections are lit #9510, the black opaque surfaces. The current lead is in this comment: UE5's virtual texture caches get only a handful of pages. The Hot Wheels Infinite Rush capture in Hot Wheels Infinite Rush (PPSA22408): in game on Linux, scenery renders black #6895 is likely related. That title is from the same studio, its static scenery renders black too, and its Nanite-style compute rasterizer gets indirect dispatches with 0 groups. I'm checking MXGP's indirect dispatch counts next.
• AGC: ResourceCache keeps an index entry for a freed list node (MXGP 26 SIGSEGV in ResourceCache::Find) #9497, a SIGSEGV in ResourceCache from an index entry for a freed list node. fix(agc): synchronize ResourceCache index on list node eviction #9592 is the fix.
• AGC: overlapping 2560x1440 storage images in MXGP 26 are recreated and re-uploaded through the CPU path hundreds of times #6998, overlapping 2560x1440 storage images that are recreated and re-uploaded.

Pull requests from this title

• fix(agc): keep a mipmapped DCC color target's keys on its resident image #9597: mipmapped DCC colour targets keep their keys on the resident image. MXGP's mipmapped DCC chains read wrong keys on main. The PR fixes that, but it doesn't change anything visible in the race: the surfaces stay black.

AI-assisted: yes (Claude Code)