mirror of
https://github.com/ChuckBuilds/LEDMatrix.git
synced 2026-10-10 09:06:36 +00:00
There was no way to answer "does this hardware present every frame on time?" other than watching the panel. `scripts/render_bench.py` drives the production path -- a real DisplayManager and ScrollHelper, configured through the same `scroll_config` resolver every ticker uses -- and grades the run with a new `src.common.frame_pacing`, exiting non-zero when more than 0.1% of frames slipped a refresh. Exit 2 when the run could not be set up at all, so a rig that was never measured cannot pass by accident. A missed frame is defined exactly: an interval that rounds up to at least one more refresh than its frame hold asked for. The half-refresh rounding boundary keeps a frame that ran 1ms long on a 10ms refresh out of the count, because it still presented on the refresh it was meant to. The verdict that matters more is NOT LOCKED. A loop that never blocked on vsync reports a perfect zero misses while presenting nothing -- 8ms frames on a 100Hz panel all land in the one-refresh bucket while running 25% too fast -- so the report also checks the typical frame is not shorter than the panel could physically present. That is what caught the first version of this benchmark announcing its scrolling state once instead of per frame: the state expires on an inactivity threshold, the dirty-tracking skip then fires mid-scroll, and the loop free-ran at 827fps. And the refresh is read back out of the frames rather than taken from an idle measurement. Driving the matrix is bit-banging on the same machine, so pushing frames slows the refresh: a Pi 4 on 512x64 measures 100.4Hz idle and holds 96.3Hz while scrolling. Both are real, and grading against the idle figure reports a locked loop as 4% slow -- or, once the gap passes half a refresh, as missing every frame. The gap between the two is itself worth watching: a rise in it is a render-cost regression even when nothing is missed. Measured on hdpi (Pi 4, 512x64, pwm_bits 8), two minutes each: plain 95.44 fps, 8 missed of 11,449 (0.070%) PASS --busy 2 95.41 fps, 3 missed of 11,445 (0.026%) PASS Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_014RRtqXDCnvnY6EQwhT5CV9