The animated pattern math (background sweep, moving 24px bar, frame-
counter block) was copy-pasted across all five clear-based backends
(dx9/dx10/dx11/dx12/gl). The backends MUST render an identical image --
the capture test decodes the same frame-counter block from each -- so a
drift between copies would be a silent test hazard.
Factor it into one frame_pattern() helper (plus kBarWidth) in
render_backend.hpp; each backend now consumes the computed bg/bar_x/code
values with its own API's clear/fill. mock_game_test still decodes every
backend correctly.
The mock backends presented with vsync ("a game-like cadence") -- wrong for a
perf/stress fixture: it does trivial work on an RTX 4090, so it must run as fast
as it can. Vsync capped them to tens of fps (dx9 30, dx10 23, dx11 63, dx12 126),
which hid both capture-induced slowdowns and the hook-removal race. Uncapped now:
dx9/dx10 INTERVAL_IMMEDIATE / Present(0,0) (BLT), dx11/dx12 ALLOW_TEARING +
Present(0, ALLOW_TEARING) (flip), gl wglSwapIntervalEXT(0), vk IMMEDIATE/MAILBOX.
Measured no-hook: dx9 ~21000, dx10 ~2800, dx11 ~17000, dx12 ~12000, gl ~26000, vk
~24000 fps.
mock_game_test now adds a present-rate floor per backend (>= 300/s while
capturing): with the hook live every backend stays in the hundreds-thousands
(vk 13500, dx11 9000+, gl 1800, dx9/10 ~1000-1600, dx12 2500). This is the
dimension the frame-advance checks missed -- the Vulkan 144->3 FPS stall still
advanced frames -- so it catches a present-thread stall OR an accidental vsync.
The faster storm exposed the hook-removal UAF fixed in the previous commit.
README roadmap + lessons-learned updated (incl. correcting the old "reset makes
in-flight trampoline calls safe" claim). Full suite 21/21.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Add render_gl.cpp (selectable as `gl`): renders the animated pattern with
scissored clears (glClear + glScissor -- GL 1.1, exported straight from
opengl32) and presents with SwapBuffers. No glad/submodule needed: a legacy
wglCreateContext + <GL/gl.h> suffices, so the planned loader dependency was
dropped. GL is bottom-left origin and the capture flips top-down, so the
frame-counter block is drawn at the GL top to land top-left in the captured
image. Window class gains CS_OWNDC for a stable GL DC; best-effort vsync via a
runtime wglSwapIntervalEXT lookup.
The GL SwapBuffers/wglSwapBuffers hook now bumps the shared present counter
(it's the GL present), so present_calls works for GL games too. mock_game_test
decodes GL frames through the existing glReadPixels capture path; 15/15 ctest.
Roadmap: OpenGL milestone done and removed (Vulkan renumbered to M2);
architecture/lessons/test docs updated.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
