v0.2.0-rc.0 — Phase 3d complete: DX12 + WGC overlay

Tubelight v0.2.0-rc.0

Date: 2026-05-29
Author: Alonso J. Núñez (GS·RUN)
License: PolyForm Noncommercial 1.0.0 — commercial: gsrun.editor@gmail.com
Supersedes: v0.2.0-beta.0

Release candidate: the DX12 overlay path (T5.5) is feature-complete
and smoke-verified on RTX 2080 Ti FL 12_2. This RC is published as a
prerelease for wider testing ahead of v0.2.0 stable (Phase 3e bench).

Highlights

Closes Phase 3d of ADR-0002. The real overlay now runs the full
8-pass CRT pipeline on Direct3D 12 — not just the standalone
--wgc-test smoke. Combine --renderer dx12 with any --overlay*
mode and Tubelight captures via Windows.Graphics.Capture (WGC),
unwraps each frame to a D3D12 resource through D3D11On12 with zero
CPU copy, and drives the same shader cascade that the OpenGL path does.

The OpenGL overlay is unchanged and remains the default.

What's new

DX12 overlay (--overlay* --renderer dx12)

• Full pipeline on D3D12: the 8-pass CRT cascade runs on the D3D12
  backend shipped in v0.2.0-beta.0; the overlay is now wired to it.
• WGC capture by mode:
  • --overlay-target <title|pid> → per-window capture (CreateForWindow).
    The overlay follows the target window's position every frame and
    exits when the target closes.
  • --overlay-fullscreen / --overlay / --overlay-region →
    per-monitor capture (CreateForMonitor), monitor chosen with
    --monitor <index>.
• No self-capture feedback: the overlay window is excluded from WGC
  via WDA_EXCLUDEFROMCAPTURE.
• Global hotkeys (focus-independent, via the low-level keyboard
  hook): Ctrl+Alt+Q quit, Ctrl+Alt+1..8 toggle pass, Ctrl+Alt+0
  all on, Ctrl+Alt+F freeze.
• Non-intrusive window: borderless modes use
  WS_EX_NOACTIVATE | WS_EX_TOOLWINDOW so the overlay doesn't steal
  focus or clutter the taskbar.

CLI

• --renderer dx12 now drives the overlay (was beta-only / shader-only).
• --help and the --renderer error message updated; they previously
  described dx12 as a non-driving skeleton.

Known limitations (deferred to v0.2.1 / Phase 4a)

• No cross-process mouse click-through in DX12 mode. Layered windows
  (WS_EX_LAYERED) are incompatible with the DXGI flip-model swap chain,
  so true click-through requires DirectComposition (Phase 4a). Until
  then the DX12 overlay sits on top without passing clicks through.
• No ImGui menu under DX12 — the in-app menu stays OpenGL-only.
  Control the DX12 overlay with the global hotkeys above.
• Region / windowed modes capture the whole monitor (WGC has monitor
  granularity); a true sub-rect crop lands in v0.2.1.
• Target tracking is position-only — if the target window is
  resized, the overlay keeps its launch size (WGC frame-pool recreate
  deferred).
• HiDPI (>100% scaling) not yet validated for the DX12 swap chain.

Verification

On NVIDIA RTX 2080 Ti, FL 12_2:

• --wgc-test regression smoke green (CRT-processed monitor capture PNG).
• --overlay-fullscreen, --overlay (windowed) and
  --overlay-target all render the first frame and run steadily.
• Injected Ctrl+Alt+Q exits cleanly (147 frames rendered, keyboard
  hook thread joined without hang).
• OpenGL overlay path unchanged (DXGI Desktop Duplication still ready).

Distribution layout

Same as v0.2.0-beta.0. tubelight-0.2.0-rc.0-win64.zip (~55 MB).

Next phases (per ADR-0002)

Phase	Ships in
3e — bench DX12 vs GL + v0.2.0 stable	v0.2.0
4a — DirectComposition chrome/body + DX12 click-through + ImGui	v0.2.1
5a — HDR10 scRGB FP16 pipeline (blocked on phosphor spectra)	v0.3.0
6a — VRS + async compute	v0.3.1
7a — Slang single-source shaders (closes cross-API PSNR gap)	v0.3.2