HelixSR 2.x support

The app sets up and installs HelixSR 2.x (built 2026-10-20). Until then it held back at 1.x: HelixSR 2.0's setup script, run unattended, installs HelixSR Scaler into every game it finds. The HelixSR author did not answer the request for a build-only switch (issue #90), so the app does the setup's steps itself. Facts below are from the HelixSR 2.0.0 release (2026-10-19, HelixSR-2.0.0.zip, SHA-256 0d60686e...7f52).

What 2.0 changed

Change in 2.0	What the app does
helixsr-setup.ps1 -Yes builds, then runs helixsr_install.py --yes: HelixSR Scaler (OptiScaler) goes into every game the setup finds, with frame generation on.	The .ps1 is never run. Helix::setupDownloads reads its $Downloads table (Python, numpy, DXC: URL and SHA-256, which change per release); HelixSetup::prepareTools fetches, checks and unpacks what is missing into %LOCALAPPDATA%\HelixSR, as the .ps1 does; then python -I setup/helixsr_setup.py <package> --dxc <dxc> --yes --no-fg. Exit 0 or 3 is success; --status must then print network=1.
helixsr_install.py lost install_list and uninstall_safe; games_from moved to helixsr_games.py.	2.x packages are installed through HelixSR's JSON bridge, setup/helixsr_bridge.py (below). resources/helixsr_driver.py stays for 1.x packages still on disk (Helix::hasBridge).
HelixSR's DLL is in HelixSR-fsrfg/amd_fidelityfx_dx12.dll, not in the package root.	Helix::packageDll.
Frame generation is built by default (DLSS Frame Generation DLLs, NVIDIA's NGX core).	--no-fg: only HelixSR Scaler uses it.
helixsr-scaler/ (HelixSR Scaler 1.1.0, GPL) is in the package; the build writes fsr3-drop-in/ copies of the DLL.	Both are deleted by the clean-up (Helix::buildLeftovers).

Unchanged: shader model 6.6 (cs_6_6), Python 3.14.8 and DXC in %LOCALAPPDATA%\HelixSR, the network from NVIDIA's DLSS 310.7.0 DLL, helixsr.ini next to the FSR drop-in, the DLL announcing HelixSR x.y.z (so Helix::scanGame still recognises installs).

The bridge

Every command prints one JSON object (protocol, ok, error, messages, and for game commands game):

python -I setup/helixsr_bridge.py <package> install --game <game root> --way fsr
python -I setup/helixsr_bridge.py <package> remove --game <game root>

• The app always passes --way fsr (Helix::bridgeArgs): the bridge's own auto picks HelixSR Scaler for most games.
• Helix::parseBridgeReply reads the last JSON line; a reply whose protocol is not kBridgeProtocol (1) makes the self-test fail, so installing switches off instead of guessing.
• The bridge looks up the game in a scan of all game libraries first (read-only, about 2 s here), then in the folder.
• An update of a game that had an older drop-in keeps the previous version in HelixSR-previous.zip in the game folder (the bridge's rollback); remove deletes it again.
• Tried on a throw-away game folder with the 2.0 bridge: install replaced the DLL (game's kept as *.original.dll, plus helixsr-install.json and helixsr.ini), remove put the game's DLL back byte for byte.

Status

• Built, 14 test suites pass (tst_helix: .ps1 table, build / status / bridge arguments, bridge replies, package layouts, kSupportedMajor = 2).
• A full set-up in a scratch copy of the app: see Where we left off in CLAUDE.md.
• Not tried yet: a real game (Horizon Forbidden West has HelixSR 1.9.3: update it to 2.0 from the tab, check helixsr.log and the DLL's version, then Remove; make sure no other game folder changed). Updating from the user's 1.9.3 package to 2.0.0 in the real app.

Later, separate decisions

• HelixSR Scaler (--way scaler, plus --scaler <extracted HelixSR-Scaler zip>): covers DLSS / XeSS / FSR 2 games, but is OptiScaler (GPL) as a dxgi.dll proxy, with an anti-cheat risk (the bridge refuses games with anti-cheat without --anticheat-ok yes).
• Frame generation (--fg on): needs the frame-generation build (drop --no-fg, more downloads).
• Linux / Proton: 2.0 ships helixsr-setup.sh, and the bridge is plain Python, which fits the Linux port.

OptiScaler-forceenabled (looked at 2026-10-20)

lonewolf0622/OptiScaler-forceenabled, by the HelixSR author, marked "testing": one squashed commit of OptiScaler 0.9.4 (upstream 7534ad0) plus a 15-line patch, no releases (CI artifacts only). Diffed against upstream, the patch only adds [DLSS] ForceEnabled (default false):

• OptiScaler normally switches its DLSS backend off when the GPU is not NVIDIA. With ForceEnabled=true it keeps it on and loads the library in [Libraries] NvngxPath, meant for a DLSS-compatible (NGX) library that runs on other GPUs, such as HelixSR's earlier nvngx.dll way.
• It also keeps DXGI spoofing on, so the game offers DLSS.
• It does not make NVIDIA's own DLSS run on another GPU, and changes nothing on an NVIDIA GPU (this PC's GTX 1650 passes the check already).

Not taken up: HelixSR 2.0 no longer builds an nvngx.dll, and HelixSR Scaler 1.1.0 (the released successor) plugs HelixSR into OptiScaler as its FidelityFX upscaler instead. Using the fork would mean building and shipping a GPL OptiScaler ourselves, installed as a DLL proxy in games. HelixSR Scaler through the bridge does that job with released, checksummed files.

Working rules

Same as CLAUDE.md: the user does all git operations; never commit, stage or push.