Extension supports only locales that use wide characters.

[ohir]

Trying to draw with normal width font under western locales doubles space.

┌───────┬─────────┐
│              │                  │
│              │                  │
└───────┴─────────┤
indent is with spaces, ts=1

There are two spaces produced for each horizontal line above. I know from where likely it came:
VSC with Asia locales (using a mostly wide glyphs font) probably adjust the display, but VSC with western locales does not.

For now it would be good to have a knob to say "boxdraw.use.single": "yes" somewhere
and have boxdraw emit a single space per single horizontal line above, if set.

In vscode, many double-byte symbols are treated as half-width characters internally. As a result, moving the cursor up and down will cause it to rattle left and right. See isFullWidthCharacter() in https://github.com/microsoft/vscode/blob/main/src/vs/base/common/strings.ts

IMO this is not a source of the problem. Frame drawing glyphs in unicode (and fonts) are all "narrow", and how many bytes a codepoint is written with has no correlation to the glyph being wide, half-width, or narrow.

Thanks!

[taizod1024]

コメントありがとうございます。
返信が遅れてすみません。

western localeのことは考慮していませんでした。
（western localeでこの拡張機能を使おうとしてくれたことに感動しています）
提案を取り込みます。しばらくお待ちください。

あなたが言う通り、unicodeでの描画はいつもnarrowですね。
asia localeでは「wide gryphで表示されることが多い」というだけですね。
double-byte symbolについての説明はasia locale限定の現象の見え方です。