The whole-row memcmp settled an unchanged row, but on a changed row the cell
loop then read again the prefix memcmp had already compared, and the trailing
trim walked unchanged cells one by one. Chunks of eight cells now find the
first and last changed cell, so no cell is compared twice and only the span
between them is scanned cell by cell. Output is byte-identical.
Measured on frames captured from vif at 60 fps (median of 15, one core):
vanguard 120x40 73.7 -> 66.6 us a frame (-10%), vanguard 240x66
158.8 -> 131.8 (-17%), main with the gun firing 40.0 -> 34.1 (-15%), main
idle 20.3 -> 14.0 (-31%). Dropping the row compare instead costs +15% to
+120% on the same frames.
* mouse: the wheel's four directions and the side buttons
parseSGRMouse read a report's low two bits alone, so a wheel tilted left or
right (66, 67) reported as WheelDown, and a mouse's back and forward buttons
(128, 129) as a left or middle press. It now decodes by bank: bits 0-1 number
a button within the main three and none, the wheel's four directions (bit 6),
or buttons 8 to 11 (bit 7). WheelLeft and WheelRight join MouseButton after
Forward, so every existing value keeps its number; Back and Forward are
reported for buttons 8 and 9; buttons 10 and 11, and a report with both bank
bits set, are dropped as KeyNone. A wheel step is a press with no release in
every direction.
* tui: ScrollThumb and ScrollDrag
ScrollThumb is the thumb ScrollBarStyled draws, its first row and height,
exported so an application hit-tests the bar it drew. ScrollDrag drives a bar
by the pointer, rows counted from the track's top: a press on the thumb takes
hold where it lands, a press on the track moves the thumb's middle there and
takes hold, and each drag keeps the held row under the pointer, clamped at the
track's ends, at the nearest offset when there are fewer offsets than rows.
Each call returns the offset to show.
A table of SGR reports covers each bank and drops the buttons past 9; a
property test over every track of 3 to 10 rows and content up to 30 checks
each press and drag against the thumb ScrollThumb draws.
* tui: titles, labels and buttons drawn a column a rune
Ten places drew each rune of a title or label at its byte offset, so a
string holding runes of more than one byte drew with holes and ran past the
width it was measured and truncated to: the Pane title, the Modal title and
hint, the Divider label, TabBar titles, Table cells, Form labels, the
TextField placeholder, the ConfirmDialog and AlertDialog buttons, and the
ProgressOverlay title. Each now draws through Region.Text, which counts
columns by rune, within the bound its loop kept; a Form label stays within
its label column, as the byte count meant it to.
* an unchanged frame writes nothing
flush closed every frame with SGR 0, so a frame that changed no cell still
sent four bytes, and an app drawing an idle screen kept writing to the
terminal. The reset now follows only a frame that wrote cells: the next
cell written restates its whole style, and Fini resets on its own.
Each widget, given a title such as "● é · ñ", draws it whole where it drew
it with holes before; a frame flushed twice writes nothing the second time,
where it wrote ESC [ 0 m.
Lixen
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