Type: Proportional Metrics in vertical type — upright glyphs on the font's proportional heights, vpal (#966)

The second half of #966. With Proportional Metrics on, a vertical segment is
also shaped top to bottom, with and without `vpal`: the difference gives
each glyph's change of advance down the column and its x and y placement.
An upright glyph (not tate-chu-yoko) in a font with vertical metrics takes
them on top of its cell, so it moves with its shorter cell; a font without
vertical metrics keeps `upright_cell`'s cell, and with the switch off
nothing is shaped twice and the column is as before.

As in horizontal type, Line-end Punctuation Half Width takes nothing more
off the punctuation `vpal` re-spaced and trims the punctuation it leaves
full height as before. Docs: mcp.md, and Proportional Metrics leaves the
missing lists in gaps.md, type-parity.md and target-app-parity.md.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

crates/engine/src/cmd/panelcmds.rs

@@ -43,7 +43,7 @@ pub fn specs() -> Vec<CommandSpec> {
             "Character / Paragraph",
             [],
             None,
-            "{ids?|id?, kerning?: 1/1000 em|\"auto\", baselineShift?: pt, hScale?: %, vScale?: %, rotation?: deg, underline?, strikethrough?, allCaps?, smallCaps?: bool, position?: \"normal\"|\"superscript\"|\"subscript\" (sizes from Document Setup), leftIndent?, rightIndent?, firstLineIndent?, spaceBefore?, spaceAfter?: pt (±1296), hyphenate?: bool, mojikumi?: \"none\"|\"lineEndHalf\" (Japanese punctuation spacing), kinsoku?: \"none\"|\"hard\"|\"soft\" (Kinsoku Set: Soft lets 々, ー and small kana start a line), direction?: \"auto\"|\"leftToRight\"|\"rightToLeft\" (paragraph direction; auto: from each paragraph's first strong character), leadingModel?: \"romanBaseline\"|\"emBoxTop\" (leading measured baseline to baseline, or em box top to top), charAlign?: \"romanBaseline\"|\"emBoxTop\"|\"emBoxCenter\"|\"emBoxBottom\"|\"icfTop\"|\"icfBottom\" (where characters smaller than the largest on their line line up with it), proportionalMetrics?: bool (full-width glyphs on the font's proportional widths, `palt`; horizontal type), burasagari?: \"none\"|\"standard\"|\"forced\" (Paragraph panel menu › Burasagari None/Regular/Force: an East Asian comma or full stop ending an area type line hangs outside it: when it doesn't fit, or always; new type: \"standard\"), composer?: \"singleLine\"|\"everyLine\" (line breaking, Every-line by default), start?: byte, end?: byte} (baselineShift is in document points and hScale includes the object transform; groups include their text descendants; with a range: the character attributes style that range and the paragraph attributes apply to the paragraphs it touches; without: all the text)",
+            "{ids?|id?, kerning?: 1/1000 em|\"auto\", baselineShift?: pt, hScale?: %, vScale?: %, rotation?: deg, underline?, strikethrough?, allCaps?, smallCaps?: bool, position?: \"normal\"|\"superscript\"|\"subscript\" (sizes from Document Setup), leftIndent?, rightIndent?, firstLineIndent?, spaceBefore?, spaceAfter?: pt (±1296), hyphenate?: bool, mojikumi?: \"none\"|\"lineEndHalf\" (Japanese punctuation spacing), kinsoku?: \"none\"|\"hard\"|\"soft\" (Kinsoku Set: Soft lets 々, ー and small kana start a line), direction?: \"auto\"|\"leftToRight\"|\"rightToLeft\" (paragraph direction; auto: from each paragraph's first strong character), leadingModel?: \"romanBaseline\"|\"emBoxTop\" (leading measured baseline to baseline, or em box top to top), charAlign?: \"romanBaseline\"|\"emBoxTop\"|\"emBoxCenter\"|\"emBoxBottom\"|\"icfTop\"|\"icfBottom\" (where characters smaller than the largest on their line line up with it), proportionalMetrics?: bool (full-width glyphs on the font's proportional widths: `palt` in horizontal type, `vpal` in vertical type), burasagari?: \"none\"|\"standard\"|\"forced\" (Paragraph panel menu › Burasagari None/Regular/Force: an East Asian comma or full stop ending an area type line hangs outside it: when it doesn't fit, or always; new type: \"standard\"), composer?: \"singleLine\"|\"everyLine\" (line breaking, Every-line by default), start?: byte, end?: byte} (baselineShift is in document points and hScale includes the object transform; groups include their text descendants; with a range: the character attributes style that range and the paragraph attributes apply to the paragraphs it touches; without: all the text)",
             has_doc,
             set_format
         ),

crates/engine/src/cmd/textedit.rs

@@ -27,7 +27,7 @@ pub fn specs() -> Vec<CommandSpec> {
             "Character",
             [],
             None,
-            "{id? (default: the one selected type object), start?: byte, end?: byte (default: all text), font?, style?, size?: pt, leading?: pt|\"auto\", tracking?, kerning?: 1/1000 em|\"auto\", baselineShift?: pt, hScale?: %, vScale?: %, rotation?: deg, fill?: colour|\"none\", stroke?: colour|\"none\", strokeWidth?: pt, strokeOptions?: {weight?, cap?, join?, miterLimit?, dash?, dashOffset?, alignDashes?} (as stroke.set: the character stroke), underline?, strikethrough?, allCaps?: bool, smallCaps?: bool, position?: \"normal\"|\"superscript\"|\"subscript\" (sizes from Document Setup), features?: [\"dlig\", \"-liga\", …], charAlign?: \"romanBaseline\"|\"emBoxTop\"|\"emBoxCenter\"|\"emBoxBottom\"|\"icfTop\"|\"icfBottom\", proportionalMetrics?: bool (full-width glyphs on the font's proportional widths, `palt`; horizontal type)} style a character range (size/leading/baselineShift are document points and hScale includes the object transform; runs are split at the range ends) → {id, runs}",
+            "{id? (default: the one selected type object), start?: byte, end?: byte (default: all text), font?, style?, size?: pt, leading?: pt|\"auto\", tracking?, kerning?: 1/1000 em|\"auto\", baselineShift?: pt, hScale?: %, vScale?: %, rotation?: deg, fill?: colour|\"none\", stroke?: colour|\"none\", strokeWidth?: pt, strokeOptions?: {weight?, cap?, join?, miterLimit?, dash?, dashOffset?, alignDashes?} (as stroke.set: the character stroke), underline?, strikethrough?, allCaps?: bool, smallCaps?: bool, position?: \"normal\"|\"superscript\"|\"subscript\" (sizes from Document Setup), features?: [\"dlig\", \"-liga\", …], charAlign?: \"romanBaseline\"|\"emBoxTop\"|\"emBoxCenter\"|\"emBoxBottom\"|\"icfTop\"|\"icfBottom\", proportionalMetrics?: bool (full-width glyphs on the font's proportional widths: `palt` in horizontal type, `vpal` in vertical type)} style a character range (size/leading/baselineShift are document points and hScale includes the object transform; runs are split at the range ends) → {id, runs}",
             has_doc,
             set_range_style
         ),