The bitmap font counts runes, and the ellipsis has a glyph

[tannevaled]

Measure did len(text), and its own doc line has always said "every rune (known or unknown) consumes exactly one Advance slot". Draw walked bytes too, indexing the glyph table by byte. So everything outside ASCII was measured two or three times too wide, and drawn as two or three blanks in a row — pushing the rest of the line along by that much.

Measured at Advance 6, before:

"e" 6	"é" 12	"€" 18	"…" 18
"abc" 18	"àbc" 24

⭐ And it explains a rule in another repository

go-xrkit/desk forbids apostrophes in its settings window because "the glasses' own menu bar" came out with a hole in it. The hole was three cells wide: a curly apostrophe is three bytes, so Draw walked three of them and found no glyph for any.

⛔ And the ellipsis could not have a glyph at all

font5x7 was keyed by byte, so no key above 127 could exist — including U+2026, which ellipsize() appends. Ellipsis=true therefore shortened the text and drew nothing in its place: on screen, indistinguishable from text clipped by its bounds.

The table is keyed by rune now (its literals were rune constants already, so the table itself did not change) and carries three dots on the baseline.

The ellipsis test was passing for the wrong reason

Its own comment said so:

"With the bitmap font the ellipsis is 3 bytes (18px) … so the widest prefix p with (len(p)+3)*6 <= 60 is 7 bytes"

The byte count was written into the test as though it were the rule. It now expects nine runes, and asserts that the last cell is inked — which is what distinguishes an ellipsis from a clip.

Its "narrower than the full render" check is gone: the full render is clipped by the bounds, so its width is wherever its last surviving glyph stops, and an ellipsised line can legitimately paint further right.

Proved by sabotage

Restoring len(text) fails both new tests and the ellipsis test, naming the byte counts:

Measure("é") = 12, want 6 (1 cell(s) of 6): 2 bytes were counted instead of 1 runes
the truncated render stops at 47 in a 60-wide box: nothing was painted in the
last cell, so the ellipsis was appended but never drawn

🤖 Generated with Claude Code