forked from Ports/goldeneye-pc-port
James Dansereau
70bc9d65b5
* D250: fix sysSleep unit-conversion bug in frame-pacing; add GE_D250 lvlRender probe port/fast3d/gfx_sdl2.cpp sync_framerate_with_timer() computed the remaining frame budget in 100ns units (qpc_to_100ns) and passed it straight into sysSleep(), which takes microseconds -- a real 10x oversleep whenever that branch fires. Genuine bug, but only active when target_fps is nonzero (tied to Input/Video FpsCap); confirmed via live testing that it is NOT the active cause of the user's reported ~45-50fps with FpsCap=0/VSync=0, where this pacing path never runs. Added GE_D250 (src/boss.c, #ifdef PORT) to isolate lvlRender()'s DL-building cost (culling/animation/scene traversal) from gfx_run's already-measured software-RSP interpretation cost. Live test on Dam shows lvlRender averaging ~0.5-1.5ms -- also not the bottleneck. Documented in docs/dev/GE-ENV-PROBES.md (GE_D250 row). findings.md D250 update to follow after rebase. Claude-Session: https://claude.ai/code/session_016DQUKGLZxFtPy52MkKXXog * docs(D250): live A/B session -- MSAA/aniso/FOV/resolution/vsync all ruled out Live session with the user driving the game directly, confirmed the sim-healthy/render-sagging pattern from earlier idle testing reproduces under real play on Dam. One-at-a-time A/B via the F10 overlay ruled out MSAA, anisotropy, FOV, resolution (1280x960 fullscreen vs 640x480 windowed), and VSync (render never exceeds ~60 even uncapped) as the cause -- the cost is resolution/GPU-setting-independent. gfx_run (~6-10ms) + lvlRender (~0.5-1.5ms, via the new GE_D250 probe) together don't account for the real ~20-22ms/frame. Leading remaining suspect: the emulated N64 thread-handoff/scheduler round-trip (gesched.c/sched.c) -- real OS context-switch/wake latency standing in for what was free hardware handoff on N64. Needs a real profiler (Visual Studio / WPR) attached during a live bad-fps moment to confirm; ad-hoc per-call timers have now ruled out the two most obvious CPU call sites without finding the cost. Claude-Session: https://claude.ai/code/session_016DQUKGLZxFtPy52MkKXXog * D250: fix uncached getenv() in fast3d hot paths -- root cause of the fps drop A live WPR/xperf CPU trace (tools_pc/perf.ps1, new sister script to debug.ps1) with Microsoft public symbols resolved found the dominant render thread spending only 5.2% of its CPU time in the game's own code -- 43% was in msvcrt.dll, and getenv()/_getenv_helper_nolock alone accounted for ~50% of the thread's total CPU time. Root cause: port/fast3d/gfx_pc.cpp's import_texture() (runs on every texture bind) and several per-triangle/per-G_SETCOMBINE debug-probe checks (GE_DTEX, GE_TEXDUMP, GE_TEXRAW, GE_D229 x2, GE_D172 x2, plus GE_TEXDUMP/GE_PCDUMP in gfx_opengl.cpp) called getenv() uncached on every call, unlike the safe static-cached pattern already used elsewhere in this codebase. On a texture-heavy scene that's tens of thousands of locked, locale-aware Windows CRT environment lookups per second -- invisible to both of the timers added earlier this session (gfx_run's own cost measurement and the new GE_D250 lvlRender probe), since neither isolates CRT/library time from the game's own code. Fix: cache every getenv() site in gfx_pc.cpp/gfx_opengl.cpp with the established static-int pattern. Narrow, mechanical, no logic change. Verified: the exact idle-Dam test that was pinned at 45-50fps before the fix now holds a rock-steady 60-61fps, zero dips. Also explains why the earlier MSAA/aniso/FOV/resolution/vsync A/B pass all showed "no change" -- the getenv() cost was a large per-call constant that swamped any real, smaller resolution-dependent GPU cost at every setting tried. Residual, separate issue found once this was fixed: still runs badly at 1440p+ (640x480 now holds a clean 60fps) -- likely the real GPU fill-rate cost the getenv() bug was masking, now exposed on its own. Not yet investigated. docs/dev/findings.md D250 updated with the full root-cause writeup. docs/porting-notes.md gets a new lesson under section E (cache getenv() in any hot-path probe). tools_pc/perf.ps1 automates the trace-and-analyze workflow for next time. Claude-Session: https://claude.ai/code/session_016DQUKGLZxFtPy52MkKXXog * docs(D250): correct the 1440p+ follow-up -- it was a stale-build false alarm User re-tested 1440p/4K on the actual getenv-fix build and confirmed it holds up fine too. The "still runs badly at 1440p+" report was from before the fix was live, same stale-build class as the DLL-load false alarm earlier in the session. D250 is fully resolved across all resolutions tested, not just 640x480. Claude-Session: https://claude.ai/code/session_016DQUKGLZxFtPy52MkKXXog * docs: add missing GE_D219RAW row to GE-ENV-PROBES.md (CI validate fix) Pre-existing gap unrelated to this branch's own changes -- gen_env_probes.py --check caught it now since it runs on every PR. GE_D219RAW has had live getenv() sites in src/game/image.c since the D219 investigation but was never added to the probe doc.
fast3d — software RSP
A C++ interpreter that consumes the Gfx display list the game builds each
frame and emits OpenGL calls, replacing the Nintendo 64's Reality Signal
Processor and Reality Display Processor.
Origin and license
This code is adapted from the Perfect Dark PC
port (port/fast3d/), which in
turn is the Ship of Harkinian /
libultraship fast3d, itself descended from
sm64-port.
LICENSE.txt in this directory (MIT, © 2020 Emill, MaikelChan) covers that
lineage. glad/ is generated by glad
(© David Herberth, MIT). GoldenEye-specific changes in this directory are
under the repository's top-level MIT license.
Files
| File | Role |
|---|---|
gfx_pc.cpp |
the RSP interpreter — matrices, lights, fog, G_TRI1/G_TRI4, vtx |
gfx_opengl.cpp |
OpenGL backend — shaders, textures, z-buffer, framebuffers |
gfx_cc.cpp |
color-combiner equation -> GLSL shader |
gfx_sdl2.cpp |
SDL2 window-manager backend |
gfx_api.h |
public API (gfx_init / gfx_run / gfx_start_frame / ...) |
gbiex.h |
GoldenEye custom GBI command definitions |
glad/ |
OpenGL loader |
GoldenEye-specific work
The PD fast3d already handles G_TRI4 (GoldenEye uses it too). The GE additions
are the custom color-combiner / render modes and the handling of GE's GBI
extension commands. rsp/graphics/gmain.s (GE's real RSP microcode, in the
repo root) is the ground truth for the exact command encodings.