Entry 353

"A Ryu Book reward's flicker is the game's own; the port draws the book once a frame"

ui

Filescrates/piney-fieldui/src/book/mod.rscrates/piney-fieldui/examples/fieldui_probe.rscrates/piney-fieldui/tests/fieldui.rsdocs/engine/field-ui.md

The user saw a Ryu Book "glitch out and in" for an instant when it gives a reward. The cause is the game's own loop. ccThBook (INF gcmn 0x0041a990) runs Breath; BOOK::Draw; BOOK::CheckItemGet; and then PadControl unless a reward ran. A reward's windows breathe inside CheckItemGet, each Draw; Breath until Check(0) answers. So:

  • the frame a reward starts draws the book twice: the loop's Draw, then the first window's;
  • the frame one ends draws no book: the last Check answers, the window closes, the reward is added, and the loop goes on to its next Breath.

Measured with tools/test_fieldui_rs.py's game run (Book I, 15 areas visited, the scenario of test_book_1). Frame 36 sends 36 bookWin and 2 bookBg packets, against 18 and 1 on the frames around it. Frame 102 sends none of either. The port matched that exactly; that is why the harness passed. On screen the book's translucent background flashes darker on the first frame and vanishes on the last.

Smoothed, by the user's choice: Book::frame draws the book exactly once a frame. It keeps the first frame's first draw (skipping a window step's second) and adds one on the frame a reward ends. Over a whole reward the draw calls are the game's count, one taken away and one added, so the book's state keeps the game's timing.

Book::as_the_game (on the book task, Task::as_the_game) restores the game's draws. fieldui_probe sets it, and the 65 harness tests still match the game frame for frame.

a_ryu_book_reward_draws_the_book_once_a_frame (piney-fieldui) opens Book I with its reward due, dismisses the windows, and requires one background on every frame from the book's first draw. With the game's draws it fails at exactly frames 35 (2) and 102 (0). The book's first frame (BOOK::BOOK, drawn after the loop's first breath) is the game's appearance, not a flicker, and is left out.