[oliverames]

Not fully tested.

What and why

Stacked on seedds#1176 (maxdavidson:feat/switch2-hdr-output): main has no HDR presentation code, so this is meant to be merged into seedds#1176's branch, or rebased onto main when seedds#1176 lands. The base branch pr-1176-head is seedds#1176's head (69676b97).

1. The game is told the display's own peak by model (front_hdr_device_peak, front_ios.m). vi::QueryDisplayHdrStatus answered a fixed 1,000 nits (DM_HDR_PEAK, no launcher setting) on a panel that reaches 1,600. Now: 1,600 for the iPhone 12 Pro and later and the M-series iPad XDR panels, 1,200 for the iPhone X to 11, else 1,000. DM_HDR_PEAK overrides and 0 is automatic. The Mac keeps 1,000.
2. Launcher rows for the peak and the paper white, shown once HDR output is on (oliverames/anygame#27: highlights reported as "super bright" with no control). Both variables existed and are now player-facing.
3. Add an opt-in packed HDR conversion measurement tool seedds/nxnative#1168's measurement tool (Add an opt-in packed HDR conversion measurement tool seedds/nxnative#1168), cherry-picked as is, with one NOT_RUN Makefile line merged; if this lands, Add an opt-in packed HDR conversion measurement tool seedds/nxnative#1168 is redundant.

Update after two more runs: with HDR on the owner saw flicker; with DM_HDR=0 it was mostly gone. So HDR output is probably part of the flicker; this PR does not fix it. The 1,600-nit peak was in effect in the flickering runs, so it is a candidate; a run with DM_HDR_PEAK=1000 would separate it and has not been done. The slow GPU state (26 to 39 ms against 11 to 13) also appeared with HDR off, so it is not an HDR problem.

Checked

• Tests: t_present_hdr passes on this base (31 checks, four new: a known model's peak, the override, automatic, an unknown model); test_settings.py, test_launcher_settings.py, test_env_switches.py, test_docs.py and test_metal_conversion_probe.py pass; front_ios.m syntax-checks against the iPhoneOS SDK.
• Games run, with title ID and version: Mario Kart World (0400C3F00006E000) 1.8.0, built from WIP: Mario Kart World 1.8.0 on iOS - rendering, memory and presentation seedds/nxnative#1383's tree, on the phone (the equivalent change, in WIP: Mario Kart World 1.8.0 on iOS - rendering, memory and presentation seedds/nxnative#1383's tree): the game told 1,600 nits, the owner reports the picture looks good; flicker with HDR on, mostly gone with it off.
• Devices and OS: iPhone 19,4 (2 Performance + 4 Efficiency cores), iOS 27.3; Apple-silicon Mac, macOS 27.3
• scripts/regress.py check --games: not run: this is stacked on an unmerged HDR PR and only changes what a Switch 2 game is told when HDR output is on.
• Not checked: this exact tree was not built into an app or run on a device; the launcher rows were not opened and no value other than Automatic was tried; no comparison against 1,000 nits, no nits measured, and a brightness or heat cost of the higher peak is unmeasured.

Front ends

Front-ends: interface: front_hdr_device_peak() in front.h, the display's peak in nits by hardware model (0 = unknown, answered 1,000); a front end that makes an HDR layer implements it, and a weak default answers 0.

Docs

• The behaviour is in docs/settings.md, docs/env_switches.tsv and the Mario Kart World note; no new general mechanism
• A chain tool changed: dmsh_chain.py --header was run and dm/gfx/nvn/dmsh_chain.h is part of the change. Not applicable: no chain tool changed.
• No game files, keys or data extracted from a game in the change or the attachments

[chatgpt-codex-connector]

Codex Review Summary: ❌ Failed

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	❌ Failed 2026-11-07T17:56:53.722292Z We couldn’t complete this review. Comment @codex review to try again.	dc67952	PR opened

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