The coordinate-space confusion (screen px 1080x2400 for input tap/
screencap, display px 900x2000 for reading PNGs, app-local px offset by
the 128px status bar, pt at density 2.625) cost real debugging time.
Wrote it down in doc/README.md as the permanent reference:
- the four spaces + conversions (display x1.2 = screen; screen Y-128 =
app-local; /2.625 = pt)
- the practical tap rule: read (x,y) off the PNG, x1.2, input tap --
screenshot px ARE screen px, no 128 offset for tap-what-you-see
- fixed geometry (status/nav bars, Gboard rows, editor region in pt),
with re-measure guidance
- tap-test pitfalls (first-tap-swallowed, first input text can fail,
wrong-place text = cursor/selection suspect not tap math, don't
memorize drifting content positions)
All keyboard row values re-measured from a fresh screenshot and verified
live: tapping the Q key at (62, 1712) and backspace at (990, 2020) both
landed first try (file content confirmed). This also exposed that the
old notes had mixed display-px row values with screen-px key values in
the same list -- exactly the confusion this section eliminates.
Also fixed the stale Phase 6 'letterboxed window' note in
development_plan.md (window is full-screen; only the 128px status-bar
offset is real; content positions drift; the OpenFileChan logcat line
was removed) and pointed emu.sh's tap help at the x1.2 rule.
Greg Pomerantz
ab60bb7f16