D988 - A held stick is shown to reach the picture by frame motion between kept flips

Status: decided Date: 2026-10-25

Whether a title answers a stick in its world is measured from the run's own output. The run keeps a sequence of frames from its first heavy frame (ORBISTOUN_FRAME_AT=busy:N,busy-every:K) and captures what the guest read from its pad (run --capture-input). orbistoun-cli motion then takes each pair of consecutive kept frames, measures the mean colour change over a region, and splits the pairs by whether a stick was off centre at any flip between them. The pairs with a stick held changing more than the pairs at rest, by a stated factor (--expect), is the check.

Why: a moving camera changes the whole picture, and a still one leaves it nearly alone, so the comparison needs no knowledge of the title's memory layout. Pairs at rest in the same phase are the control: animation, cutscene cameras and noise move the picture too, and only the difference between the two kinds of pair is the stick's. A script that alternates held and released stretches gives both kinds in one run.

Rejected:

• A per-title player-position address: found by memory scans per title and build, and it says nothing about whether the picture follows.
• Comparing one frame before and one after a press: a single pair cannot tell the stick from a cutscene camera that happens to move.