#+TITLE: QA 10 — Scroll & copy_region
#+TODO: TODO | PASS FAIL SKIP

* How to run
  : emacs --no-init-file -l qa/10-scroll/test.el
  : EMACS_GPU_DISABLE=1 emacs --no-init-file -l qa/10-scroll/test.el

  Press =s= to start the auto-scroll demo, =S= to stop.

* Checklist

** TODO 10.1 Scroll down — no artifacts on new content
   Press =C-v= or =C-n= repeatedly. The text that slides up must not leave
   ghost pixels. New content at the bottom must appear cleanly.
   Failure: horizontal bands of garbage at the scroll boundary.

** TODO 10.2 Scroll up — same as above but reversed
   Press =M-v= or =C-p=. New content at the top must appear without artifacts.
   Failure: garbage lines appear at the top when new content is drawn.

** TODO 10.3 Auto-scroll — smooth and continuous
   Press =s= to start the timer-based auto-scroll (1 line per 60ms).
   The text must slide smoothly without jumps or blank frames.
   Failure: text jumps 2–3 lines at a time, or a blank frame flashes.

** TODO 10.4 Horizontal scroll — hscroll, C-e to a long line
   Press =C-e= on the long-line section to hscroll to the end.
   The content must slide horizontally without artifacts.
   Failure: garbled characters or wrong content visible after hscroll.

** TODO 10.5 [Metal] Scroll easing — EASE_OUT_QUAD
   Run with: =(setq gpu-scroll-easing 'ease-out-quad)= then scroll.
   The scroll must decelerate smoothly near the target.
   Failure: scroll is instant (easing not applied) or overshoots.

** TODO 10.6 [Metal] Scroll easing — SPRING
   Run with: =(setq gpu-scroll-easing 'spring)= then scroll.
   The scroll must overshoot slightly and bounce back.
   Failure: no overshoot visible, or motion never settles.

** TODO 10.7 Overlapping copy_region — 1-line scroll
   Scrolling by exactly one line means src and dst regions overlap.
   Content must move correctly (scratch-texture bounce path used internally).
   Failure: the overlapping region shows corrupted or wrong content.

** TODO 10.8 Shift on insert — glyph shift correct
   Go to the middle of a content line and insert a character.
   Text to the right must shift exactly one character width.
   Failure: text after the insertion point overlaps, or a gap appears.