Character: Font Size can measure the cap height, x-height or ICF box

Squashed from #5026 onto main.

crates/cad/Cargo.toml

@@ -21,5 +21,6 @@ image = { workspace = true }
 
 [dev-dependencies]
 serde_json = { workspace = true }
-# The tests lay type out in the bundled fonts (the workspace leaves turning them on to the engine).
-vectorcraft-text = { workspace = true, features = ["bundled-fonts"] }
+# The tests lay type out in the bundled fonts (the workspace leaves turning them on to the engine)
+# and in fonts built in code (`vectorcraft_text::test_fonts`).
+vectorcraft-text = { workspace = true, features = ["bundled-fonts", "test-fonts"] }

crates/cad/src/scene.rs

@@ -1062,7 +1062,8 @@ impl<'a> Scene<'a> {
     }
 
     /// Type: glyph outlines (Preserve Appearance, Outline Text, type on a path), else one text
-    /// entity per run of each line.
+    /// entity per run of each line, whose height (group 40) is [`CAP_HEIGHT`] times the em size its
+    /// run is drawn at ([`vectorcraft_text::FontDb::font_heights_resolved`]).
     fn text(&mut self, n: &Node, t: &TextObject) {
         let outline = self.o.preserve == Preserve::Appearance || self.o.outline_text || matches!(t.kind, TextKind::OnPath { .. });
         if outline {
@@ -1074,6 +1075,8 @@ impl<'a> Scene<'a> {
         if !n.appearance.items.is_empty() {
             self.warn(TYPE_ITEMS);
         }
+        let resolved = vectorcraft_text::FontDb::global().font_heights_resolved(t);
+        let t = &*resolved;
         let layout = vectorcraft_text::layout(vectorcraft_text::FontDb::global(), t);
         let plain = t.plain_text();
         let xf = self.to_dxf * t.xf;

crates/cad/src/tests.rs

@@ -906,6 +906,23 @@ fn text_outside_ascii_is_escaped_before_2007() {
     assert_eq!(text(DxfVersion::R2018), "Größe");
 }
 
+/// Type whose font size measures the cap height is written at the em size it is drawn at: 14 pt
+/// measuring a 0.7 em cap height is 20 pt type, whose TEXT height is 14.
+#[test]
+fn a_font_height_reference_is_written_as_the_size_drawn() {
+    use vectorcraft_text::test_fonts::{HEIGHT_FAMILY, height_font};
+    vectorcraft_text::FontDb::global().add_font(height_font(true).unwrap());
+    let mut d = text_doc("Plan A", 14.0);
+    let id = d.layers[0].children().and_then(|c| c.first()).map(|n| n.id).unwrap();
+    if let Some(NodeKind::Text(t)) = d.node_mut(id).map(|n| &mut n.kind) {
+        t.runs[0].style.font_family = HEIGHT_FAMILY.into();
+        t.runs[0].style.font_height_reference = vectorcraft_doc::FontHeightReference::CapHeight;
+    }
+    let editable = export(&d, &DxfOptions { preserve: Preserve::Editability, ..opts(&d) }).unwrap();
+    let e = entities(&editable);
+    assert!((all(&e[0], 40)[0] - 14.0).abs() < 1e-6, "{:?}", all(&e[0], 40));
+}
+
 #[test]
 fn images_link_png_or_jpeg_files() {
     let mut png = vec![];

crates/doc/src/lib.rs

@@ -106,6 +106,7 @@ pub use selection::{AnchorRef, SegmentRef, Selection};
 pub use setup::{Background, DocSetup, ExportText, GridSize, Quotes};
 pub use slices::{CellAlign, CellVAlign, Slice, SliceArea, SliceKind, SliceOptions, SliceSource};
 pub use style_libs::StyleLibrary;
+pub use text::FontHeightReference;
 pub use text::{
     AreaFit, AreaOptions, Burasagari, CharAlign, CharPosition, CharStyle, Composer, Digits, FirstBaseline, HyphenationOptions, InlineArt,
     JustificationOptions, Justify, Kinsoku, LeadingModel, Mojikumi, ParaDirection, ParaStyle, PathAlign, PathEffect, RubyAlign, RubyPosition,

crates/doc/src/text.rs

@@ -15,7 +15,7 @@ mod tabs_lists;
 
 pub use area::{AreaFit, AreaOptions, PathAlign, PathEffect, TextFlow, TextWrap, VerticalAlign, WrapShape};
 use char_style::yes;
-pub use char_style::{CharAlign, CharPosition, CharStyle, Digits, ScriptMetrics};
+pub use char_style::{CharAlign, CharPosition, CharStyle, Digits, FontHeightReference, ScriptMetrics};
 pub use para_style::{
     Burasagari, Composer, FirstBaseline, HyphenationOptions, JustificationOptions, Justify, Kashida, Kinsoku, LeadingModel, Mojikumi, ParaDirection,
     ParaStyle, SingleWordJustify,

crates/doc/src/text/char_style.rs

@@ -116,6 +116,10 @@ pub struct CharStyle {
     /// these characters are drawn in, whatever digits were typed.
     #[serde(default, skip_serializing_if = "crate::skip::is_default")]
     pub digits: Digits,
+    /// Font height reference (Character panel menu › Show Font Height Options): the height of the
+    /// font that [`Self::size`] measures, the em box by default.
+    #[serde(default, rename = "fontHeightReference", skip_serializing_if = "crate::skip::is_default")]
+    pub font_height_reference: FontHeightReference,
     /// No Break (Character panel menu): these characters are not broken across lines, including
     /// at a space or a hyphenation point inside the run. A run longer than the line stays together
     /// and can overflow it.
@@ -130,6 +134,21 @@ pub struct CharStyle {
     pub language: Option<String>,
 }
 
+/// What a character's font size measures ([`CharStyle::font_height_reference`]): the em square
+/// of the font, the height of its capitals or of its lowercase letters (the cap height and x
+/// height of its OS/2 table), or its ideographic character face (ICF, OpenType's `icfb` and
+/// `icft` baselines). Layout sets the characters at the em size at which the chosen height equals
+/// the font size; with a font that has no such value, the size measures the em box.
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Hash, Serialize, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub enum FontHeightReference {
+    #[default]
+    EmBox,
+    CapHeight,
+    XHeight,
+    IcfBox,
+}
+
 /// The numeral system digits are drawn in ([`CharStyle::digits`]): as typed, or every digit of
 /// the Western, Arabic-Indic and Eastern Arabic-Indic sets drawn in one of them or in the digits
 /// of an Indic script. The text keeps the digits that were typed; only the glyphs change (like
@@ -380,6 +399,7 @@ impl Default for CharStyle {
             standard_vertical_roman: false,
             small_caps: None,
             digits: Digits::Default,
+            font_height_reference: FontHeightReference::EmBox,
             no_break: false,
             language: None,
         }

crates/doc/src/text/tests.rs

@@ -60,6 +60,24 @@ fn digits_map_between_the_numeral_systems() {
     assert_eq!(serde_json::from_value::<CharStyle>(serde_json::to_value(&farsi).unwrap()).unwrap(), farsi);
 }
 
+/// The font height reference is the em box by default and is saved only when it is another.
+#[test]
+fn font_height_reference_is_saved_only_when_not_the_em_box() {
+    let st = CharStyle::default();
+    assert_eq!(st.font_height_reference, FontHeightReference::EmBox);
+    assert!(serde_json::to_value(&st).unwrap().get("fontHeightReference").is_none());
+    for (r, key) in
+        [(FontHeightReference::CapHeight, "capHeight"), (FontHeightReference::XHeight, "xHeight"), (FontHeightReference::IcfBox, "icfBox")]
+    {
+        let set = CharStyle { font_height_reference: r, ..CharStyle::default() };
+        assert_eq!(serde_json::to_value(&set).unwrap()["fontHeightReference"], key);
+        assert_eq!(serde_json::from_value::<CharStyle>(serde_json::to_value(&set).unwrap()).unwrap(), set);
+    }
+    // Styles written before the attribute existed read as the em box.
+    let old = serde_json::to_value(&st).unwrap();
+    assert_eq!(serde_json::from_value::<CharStyle>(old).unwrap().font_height_reference, FontHeightReference::EmBox);
+}
+
 /// Each Indic numeral system draws 0–9 (and the Arabic-Indic sets) as the ten digits of its
 /// script's block; every system saves under its id, which reads back, and other names are refused.
 #[test]

crates/engine/src/cmd/textedit.rs

@@ -39,7 +39,7 @@ 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\"|\"optical\", baselineShift?: pt, hScale?: %, vScale?: %, rotation?: deg, fill?: colour|\"none\", stroke?: colour|\"none\", keepModel?: bool (fill and stroke, as paint.setFill), strokeWidth?: pt, strokeOptions?: {weight?, cap?, join?, miterLimit?, align?, 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), tateChuYoko?: bool (Character panel menu › Tate-chu-yoko, with Show East Asian Options: in vertical type those characters stand side by side across one em of the column; kept on the characters and ignored in horizontal type), standardVerticalRoman?: bool (Character panel menu › Standard Vertical Roman Alignment, with Show East Asian Options: in vertical type those half-width characters, such as Latin letters and digits, stand upright one below the other instead of being rotated; spaces and tate-chu-yoko blocks are not changed; kept on the characters and ignored in horizontal type; off by default), noBreak?: bool (Character panel menu › No Break: these characters stay on one line, including across a space inside the run), charDirection?: \"default\"|\"leftToRight\"|\"rightToLeft\" (Character panel menu › Character Direction: the characters are set left to right or right to left inside their paragraph, as a Unicode bidi embedding; default: as the bidi algorithm sets them), digits?: \"default\"|\"arabic\"|\"hindi\"|\"farsi\"|\"devanagari\"|\"bengali\"|\"gurmukhi\"|\"gujarati\"|\"odia\"|\"tamil\"|\"telugu\"|\"kannada\"|\"malayalam\" (Character panel menu › Digits: the numeral system every digit is drawn in, whatever was typed: Western, Arabic-Indic (hindi), Eastern Arabic-Indic (farsi) or an Indic script's own digits), language?: name|tag (Character panel › Language: one of Document Setup's languages by name or BCP 47 tag, case-insensitive, such as \"Turkish\" or \"tr\"; the characters are shaped in it, so the font uses that language's forms (OpenType `locl`); saved as the tag, English: USA, the default, as none; new type takes the document's language), fontAxes?: {\"wght\": 650, …} (Character panel › Variable Font: the setting of each variation axis named, in the axis's units and clamped to its range; null: back to the style's own setting; other axes keep theirs; tags the font has no axis for are left out; a font or style change clears them; text.fontList {family, style} lists the axes)} 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, warning?: text (the font or style set isn't available: its type is drawn in the fallback font or the family's closest style)}",
+            "{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\"|\"optical\", baselineShift?: pt, hScale?: %, vScale?: %, rotation?: deg, fill?: colour|\"none\", stroke?: colour|\"none\", keepModel?: bool (fill and stroke, as paint.setFill), strokeWidth?: pt, strokeOptions?: {weight?, cap?, join?, miterLimit?, align?, 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), tateChuYoko?: bool (Character panel menu › Tate-chu-yoko, with Show East Asian Options: in vertical type those characters stand side by side across one em of the column; kept on the characters and ignored in horizontal type), standardVerticalRoman?: bool (Character panel menu › Standard Vertical Roman Alignment, with Show East Asian Options: in vertical type those half-width characters, such as Latin letters and digits, stand upright one below the other instead of being rotated; spaces and tate-chu-yoko blocks are not changed; kept on the characters and ignored in horizontal type; off by default), noBreak?: bool (Character panel menu › No Break: these characters stay on one line, including across a space inside the run), charDirection?: \"default\"|\"leftToRight\"|\"rightToLeft\" (Character panel menu › Character Direction: the characters are set left to right or right to left inside their paragraph, as a Unicode bidi embedding; default: as the bidi algorithm sets them), digits?: \"default\"|\"arabic\"|\"hindi\"|\"farsi\"|\"devanagari\"|\"bengali\"|\"gurmukhi\"|\"gujarati\"|\"odia\"|\"tamil\"|\"telugu\"|\"kannada\"|\"malayalam\" (Character panel menu › Digits: the numeral system every digit is drawn in, whatever was typed: Western, Arabic-Indic (hindi), Eastern Arabic-Indic (farsi) or an Indic script's own digits), fontHeightReference?: \"emBox\"|\"capHeight\"|\"xHeight\"|\"icfBox\" (Character panel › Set Font Height Reference: the height of the font that size measures, the em box by default; with a font that has no such height, or one outside 0.1 to 2 em, the em box), language?: name|tag (Character panel › Language: one of Document Setup's languages by name or BCP 47 tag, case-insensitive, such as \"Turkish\" or \"tr\"; the characters are shaped in it, so the font uses that language's forms (OpenType `locl`); saved as the tag, English: USA, the default, as none; new type takes the document's language), fontAxes?: {\"wght\": 650, …} (Character panel › Variable Font: the setting of each variation axis named, in the axis's units and clamped to its range; null: back to the style's own setting; other axes keep theirs; tags the font has no axis for are left out; a font or style change clears them; text.fontList {family, style} lists the axes)} 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, warning?: text (the font or style set isn't available: its type is drawn in the fallback font or the family's closest style)}",
             has_doc,
             set_range_style
         ),
@@ -325,6 +325,7 @@ pub(crate) struct CharChange {
     /// The language to set: a tag, or `None` for the default.
     language: Option<Option<String>>,
     font_axes: Option<AxisChange>,
+    font_height_reference: Option<vectorcraft_doc::FontHeightReference>,
 }
 
 /// `charDirection: "default"|"leftToRight"|"rightToLeft"` → the Character Direction to set (`None`
@@ -452,6 +453,20 @@ pub(crate) fn char_align_param(p: &Value, cmd: &str) -> Result<Option<vectorcraf
     }))
 }
 
+/// `fontHeightReference: "emBox"|"capHeight"|"xHeight"|"icfBox"` (Character panel › Set Font Height
+/// Reference): the height of the font that the font size measures.
+pub(crate) fn font_height_reference_param(p: &Value, cmd: &str) -> Result<Option<vectorcraft_doc::FontHeightReference>> {
+    use vectorcraft_doc::FontHeightReference;
+    let Some(v) = p.get("fontHeightReference").filter(|v| !v.is_null()) else { return Ok(None) };
+    Ok(Some(match v.as_str() {
+        Some("emBox") => FontHeightReference::EmBox,
+        Some("capHeight") => FontHeightReference::CapHeight,
+        Some("xHeight") => FontHeightReference::XHeight,
+        Some("icfBox") => FontHeightReference::IcfBox,
+        _ => return Err(bad(cmd, "`fontHeightReference` must be \"emBox\", \"capHeight\", \"xHeight\" or \"icfBox\"")),
+    }))
+}
+
 fn paint_param(p: &Value, k: &str, cmd: &str) -> Result<Option<Paint>> {
     match p.get(k) {
         None | Some(Value::Null) => Ok(None),
@@ -523,6 +538,7 @@ impl CharChange {
             digits: digits_param(p, cmd)?,
             language: language_param(p, cmd)?,
             font_axes: font_axes_param(p, cmd)?,
+            font_height_reference: font_height_reference_param(p, cmd)?,
         };
         if c.size.is_some_and(|v| v <= 0.0) {
             return Err(bad(cmd, "size must be positive"));
@@ -570,6 +586,7 @@ impl CharChange {
             && self.digits.is_none()
             && self.language.is_none()
             && self.font_axes.is_none()
+            && self.font_height_reference.is_none()
     }
 
     fn localize(&mut self, t: &TextObject, cmd: &str) -> Result<()> {
@@ -680,6 +697,9 @@ impl CharChange {
         if let Some(v) = self.digits {
             st.digits = v;
         }
+        if let Some(v) = self.font_height_reference {
+            st.font_height_reference = v;
+        }
         if let Some(v) = &self.language {
             st.language.clone_from(v);
         }
@@ -1216,7 +1236,11 @@ fn type_step(s: &mut Session, p: &Value) -> Result<Value> {
                     match step {
                         Step::Size => st.size = super::typecmd::local_type_value(t, st.size * points + inc, (0.1, 1296.0), false, C)?,
                         Step::Leading => {
-                            let leading = t.para_at(paras.get(i).copied().unwrap_or(0)).effective_leading(st);
+                            // With Auto leading the step starts from the leading the lines are set with:
+                            // the paragraph's Auto Leading share of the em size the font height reference
+                            // gives the characters. An inline graphic keeps its size.
+                            let em = if run.inline.is_some() { st.size } else { vectorcraft_text::FontDb::global().em_size(st, t.vertical) };
+                            let leading = t.para_at(paras.get(i).copied().unwrap_or(0)).effective_leading(&CharStyle { size: em, ..st.clone() });
                             st.leading = Some(super::typecmd::local_type_value(t, leading * points + inc, (0.1, 5000.0), false, C)?);
                         }
                         Step::Tracking => st.tracking = (st.tracking + inc).clamp(-1000.0, 10000.0),

crates/engine/src/cmd/textstyles.rs

@@ -178,6 +178,7 @@ pub fn char_attrs(v: &CharStyle) -> Map<String, Value> {
         ("standardVerticalRoman", json!(v.standard_vertical_roman)),
         ("noBreak", json!(v.no_break)),
         ("digits", json!(v.digits)),
+        ("fontHeightReference", json!(v.font_height_reference)),
         ("language", json!(v.language)),
     ] {
         m.insert(k.into(), x);

crates/engine/src/cmd/typecmd/area_tests.rs

@@ -1306,6 +1306,97 @@ fn digits_are_a_character_attribute_saved_only_when_set() {
     assert_eq!(set, [("صفحة ".to_string(), Digits::Default), ("12".to_string(), Digits::Farsi)]);
 }
 
+/// Font height reference (Character panel › Set Font Height Reference): a character attribute,
+/// saved only when not the em box; the type is laid out again at the em size it gives, so 20 pt
+/// type measuring a 0.7 em cap height grows by 1 / 0.7, and a leading step from Auto starts at
+/// 120% of that em size.
+#[test]
+fn font_height_reference_is_a_character_attribute_saved_only_when_not_the_em_box() {
+    use vectorcraft_doc::FontHeightReference as R;
+    use vectorcraft_text::test_fonts::{HEIGHT_CAP, HEIGHT_FAMILY, height_font};
+    vectorcraft_text::FontDb::global().add_font(height_font(true).unwrap());
+    let mut s = Session::new();
+    s.execute("file.new", &json!({"width": 400, "height": 400})).unwrap();
+    let id =
+        s.execute("text.create", &json!({"x": 10, "y": 50, "text": "Hx Hx", "font": HEIGHT_FAMILY, "size": 20})).unwrap()["id"].as_u64().unwrap();
+    let text = |s: &Session| match &s.doc().unwrap().doc.node(NodeId(id)).unwrap().kind {
+        NodeKind::Text(t) => t.clone(),
+        _ => panic!("text"),
+    };
+    let height = |s: &Session| text(s).cached_bounds.unwrap().height();
+    let em_box = height(&s);
+    assert_eq!(text(&s).runs[0].style.font_height_reference, R::EmBox);
+    s.execute("select.set", &json!({"ids": [id]})).unwrap();
+    for (key, want) in [("capHeight", R::CapHeight), ("xHeight", R::XHeight), ("icfBox", R::IcfBox), ("emBox", R::EmBox)] {
+        s.execute("text.setFormat", &json!({"fontHeightReference": key})).unwrap();
+        assert!(text(&s).runs.iter().all(|r| r.style.font_height_reference == want && r.style.size == 20.0));
+        let saved = serde_json::to_value(&text(&s).runs[0].style).unwrap();
+        assert_eq!(saved.get("fontHeightReference").and_then(|v| v.as_str()), (want != R::EmBox).then_some(key));
+    }
+    s.execute("text.setFormat", &json!({"fontHeightReference": "capHeight"})).unwrap();
+    let grown = height(&s) / em_box;
+    assert!((grown - 1000.0 / f64::from(HEIGHT_CAP)).abs() < 1e-6, "{grown}");
+    // A leading step from Auto starts at the leading the lines are set with: 120% of the em size
+    // (the paragraph's Auto Leading).
+    s.execute("type.step", &json!({"attribute": "leading"})).unwrap();
+    let stepped = text(&s).runs[0].style.leading.unwrap();
+    assert!((stepped - (1.2 * 20.0 * 1000.0 / f64::from(HEIGHT_CAP) + 2.0)).abs() < 1e-9, "{stepped}");
+    s.execute("edit.undo", &json!({})).unwrap();
+    s.execute("edit.undo", &json!({})).unwrap();
+    assert_eq!(text(&s).runs[0].style.font_height_reference, R::EmBox);
+    assert!((height(&s) - em_box).abs() < 1e-9);
+    let err = s.execute("text.setFormat", &json!({"fontHeightReference": "baseline"})).unwrap_err().to_string();
+    assert!(err.contains("`fontHeightReference` must be"), "{err}");
+    // Characters selected with the Type tool: only the range takes it.
+    s.execute("text.setRangeStyle", &json!({"id": id, "start": 3, "end": 5, "fontHeightReference": "xHeight"})).unwrap();
+    let set: Vec<_> = text(&s).runs.iter().map(|r| (r.text.clone(), r.style.font_height_reference)).collect();
+    assert_eq!(set, [("Hx ".to_string(), R::EmBox), ("Hx".to_string(), R::XHeight)]);
+}
+
+/// A leading step from Auto starts at the leading each paragraph's lines are set with, its
+/// Auto Leading share of the em size: 20 pt type in paragraphs at 120% and 150% steps from 24 pt
+/// and from 30 pt.
+#[test]
+fn a_leading_step_from_auto_starts_at_each_paragraphs_auto_leading() {
+    let mut s = Session::new();
+    s.execute("file.new", &json!({"width": 400, "height": 400})).unwrap();
+    let id = s.execute("text.create", &json!({"x": 10, "y": 50, "text": "Ab\nCd", "size": 20})).unwrap()["id"].as_u64().unwrap();
+    s.execute("text.setFormat", &json!({"id": id, "start": 3, "end": 5, "autoLeading": 150})).unwrap();
+    s.execute("select.set", &json!({"ids": [id]})).unwrap();
+    s.execute("type.step", &json!({"attribute": "leading"})).unwrap();
+    let NodeKind::Text(t) = &s.doc().unwrap().doc.node(NodeId(id)).unwrap().kind else {
+        panic!("text");
+    };
+    let leading: Vec<_> = t.runs.iter().map(|r| (r.text.as_str(), r.style.leading)).collect();
+    assert_eq!(leading, [("Ab\n", Some(26.0)), ("Cd", Some(32.0))]);
+}
+
+/// An inline graphic keeps its size whatever the font height reference, so a leading step from
+/// Auto starts at 120% of that size: 20 pt Cap Height type steps from 120% of 20 / 0.7 pt and
+/// the graphic in it from 24 pt.
+#[test]
+fn a_leading_step_from_auto_starts_at_an_inline_graphics_own_size() {
+    use vectorcraft_text::test_fonts::{HEIGHT_CAP, HEIGHT_FAMILY, height_font};
+    vectorcraft_text::FontDb::global().add_font(height_font(true).unwrap());
+    let mut s = Session::new();
+    s.execute("file.new", &json!({"width": 400, "height": 400})).unwrap();
+    s.execute("shape.ellipse", &json!({"x": 300, "y": 300, "width": 10, "height": 10})).unwrap();
+    s.execute("symbol.new", &json!({"name": "Dot"})).unwrap();
+    s.execute("edit.clear", &json!({})).unwrap();
+    let id = s.execute("text.create", &json!({"x": 10, "y": 50, "text": "Hx", "font": HEIGHT_FAMILY, "size": 20})).unwrap()["id"].as_u64().unwrap();
+    s.execute("text.insertInline", &json!({"id": id, "at": 2, "symbol": "Dot"})).unwrap();
+    s.execute("select.set", &json!({"ids": [id]})).unwrap();
+    s.execute("text.setFormat", &json!({"fontHeightReference": "capHeight"})).unwrap();
+    s.execute("type.step", &json!({"attribute": "leading"})).unwrap();
+    let NodeKind::Text(t) = &s.doc().unwrap().doc.node(NodeId(id)).unwrap().kind else {
+        panic!("text");
+    };
+    let leading: Vec<_> = t.runs.iter().map(|r| (r.inline.is_some(), r.style.leading.unwrap())).collect();
+    let text = 1.2 * 20.0 * 1000.0 / f64::from(HEIGHT_CAP) + 2.0;
+    assert_eq!(leading.len(), 2, "{leading:?}");
+    assert!(leading.iter().all(|&(inline, l)| (l - if inline { 26.0 } else { text }).abs() < 1e-9), "{leading:?}");
+}
+
 /// The Indic digits (#4942): each set by its id through text.setFormat and text.setRangeStyle,
 /// saved under it, kept by save and reopen and by character styles; the text stays as typed.
 #[test]

crates/eps/src/legacy_ai/tests.rs

@@ -1017,6 +1017,39 @@ fn variable_font_settings_are_warned_as_left_out() {
     assert!(String::from_utf8(out.bytes).unwrap().contains("(H\\351llo \\2005\\r) Tx\n"), "still written as text");
 }
 
+/// Type whose font size measures the cap height is written at the em size it is drawn at, with
+/// no warning: 14 pt measuring a 0.7 em cap height reads back as 20 pt type.
+#[test]
+fn a_font_height_reference_is_written_as_the_size_drawn() {
+    use vectorcraft_text::test_fonts::{HEIGHT_FAMILY, height_font};
+    vectorcraft_text::FontDb::global().add_font(height_font(true).unwrap());
+    let mut doc = typed();
+    let id = texts(&doc)[0].0.id;
+    if let Some(NodeKind::Text(t)) = doc.node_mut(id).map(|n| &mut n.kind) {
+        let st = &mut t.runs[0].style;
+        (st.font_family, st.size) = (HEIGHT_FAMILY.into(), 14.0);
+        st.font_height_reference = vectorcraft_doc::FontHeightReference::CapHeight;
+    }
+    let out = write(&doc);
+    assert!(!out.warnings.iter().any(|w| w == TYPE_ATTRIBUTES || w == TYPE), "{:?}", out.warnings);
+    let imported = crate::import(&out.bytes).unwrap();
+    let size = texts(&imported.document)[0].1.runs[0].style.size;
+    assert!((size - 20.0).abs() < 1e-6, "{size}");
+}
+
+/// Characters with Auto leading are written with their paragraph's Auto Leading share of the
+/// size: 18 pt type in paragraphs at 150% is written with 27 pt leading.
+#[test]
+fn auto_leading_is_written_at_the_paragraphs_share() {
+    let mut doc = typed();
+    let id = texts(&doc)[0].0.id;
+    if let Some(NodeKind::Text(t)) = doc.node_mut(id).map(|n| &mut n.kind) {
+        t.edit_paras(None, |p| p.justification.auto_leading = 150.0);
+    }
+    let text = String::from_utf8(write(&doc).bytes).unwrap();
+    assert!(text.contains("\n27 0 Tl\n"), "{text}");
+}
+
 /// A legacy `.ai` paragraph has no list: type with a bulleted or numbered list is written as its
 /// text, with the warning that the bullets and numbers are left out.
 #[test]

crates/eps/src/legacy_ai/writer.rs

@@ -719,11 +719,15 @@ impl<'a> Writer<'a> {
 
     // ---------- type ----------
 
-    /// Type: a text object when the format can hold it as text, else its outlines.
+    /// Type: a text object when the format can hold it as text, else its outlines. A run whose
+    /// font size measures a height other than the em box is written at the em size it is drawn
+    /// at ([`vectorcraft_text::FontDb::font_heights_resolved`]).
     fn text(&mut self, t: &TextObject) {
         if !invertible(t.xf) {
             return;
         }
+        let resolved = vectorcraft_text::FontDb::global().font_heights_resolved(t);
+        let t = &*resolved;
         if !self.outline_text {
             if writable(t) {
                 return self.text_object(t);
@@ -849,7 +853,8 @@ impl<'a> Writer<'a> {
         ps::push_num(&mut self.body, finite(st.tracking, 0.0));
         self.line(" Tt");
         self.line(if st.kerning.is_none() { "1 TA" } else { "0 TA" });
-        ps::push_nums(&mut self.body, &[finite(st.effective_leading(), size * 1.2), finite(p.space_before, 0.0)]);
+        let leading = st.leading.unwrap_or_else(|| p.justification.auto_leading_for(st.size));
+        ps::push_nums(&mut self.body, &[finite(leading, size * 1.2), finite(p.space_before, 0.0)]);
         self.line("Tl");
     }
 

crates/svg/src/css.rs

@@ -567,8 +567,12 @@ impl Rules<'_> {
         }
     }
 
-    /// Type: its first character style's font, colour and spacing, its paragraph's alignment.
+    /// Type: its first character style's font, colour and spacing, its paragraph's alignment. The
+    /// font size is the em size the characters are drawn at
+    /// ([`vectorcraft_text::FontDb::font_heights_resolved`]).
     fn type_art(&mut self, n: &Node, t: &vectorcraft_doc::TextObject, art: &mut Art) {
+        let resolved = vectorcraft_text::FontDb::global().font_heights_resolved(t);
+        let t = &*resolved;
         if matches!(t.kind, TextKind::OnPath { .. }) {
             art.unsupported("type on a path");
         }

crates/svg/src/export/text.rs

@@ -73,11 +73,14 @@ impl Writer<'_> {
     /// instances of their symbols (a `<use>` of the symbol's def where it can be shared), all in
     /// one group carrying the object's transparency. The live text skips their characters and
     /// places the text after each one; type on a path with inline graphics is written as outlines
-    /// (a `<textPath>` couldn't leave room for the art).
+    /// (a `<textPath>` couldn't leave room for the art). A run whose font size measures a height
+    /// other than the em box is written at the em size it is drawn at
+    /// ([`vectorcraft_text::FontDb::font_heights_resolved`]).
     pub(super) fn text_node(&mut self, n: &Node, t: &TextObject) {
         let doc = self.doc;
         let resolved = doc.inline_resolved(t);
-        let t = &*resolved;
+        let heights = vectorcraft_text::FontDb::global().font_heights_resolved(&resolved);
+        let t = &*heights;
         let inline = t.runs.iter().any(|r| r.inline.is_some());
         // Ruby is written as outlines with its base text: a reader's <text> can't place it. So are
         // small capitals, superscript and subscript and tab leaders, which SVG text doesn't draw (#3869).

crates/svg/tests/it/css_rules.rs

@@ -148,6 +148,26 @@ fn ellipses_round_fully_and_options_change_units_and_names() {
     assert!(prop(&r, "width").is_none() && prop(&r, "height").is_none());
 }
 
+/// Type whose font size measures the cap height gives the em size it is drawn at: 14 pt measuring
+/// a 0.7 em cap height is `font-size: 20px`, and its Auto leading is not written.
+#[test]
+fn type_gives_the_font_size_it_is_drawn_at() {
+    use vectorcraft_text::test_fonts::{HEIGHT_FAMILY, height_font};
+    vectorcraft_text::FontDb::global().add_font(height_font(true).unwrap());
+    let mut d = doc();
+    let st = CharStyle {
+        font_family: HEIGHT_FAMILY.into(),
+        size: 14.0,
+        font_height_reference: vectorcraft_doc::FontHeightReference::CapHeight,
+        ..CharStyle::default()
+    };
+    let n = text(&mut d, "Hello", st);
+    let id = add(&mut d, n);
+    let r = one(&d, id, &CssOptions::default());
+    assert_eq!(prop(&r, "font-size"), Some("20px"));
+    assert!(prop(&r, "line-height").is_none());
+}
+
 #[test]
 fn type_gives_font_properties() {
     let mut d = doc();

crates/svg/tests/it/text_layout.rs

@@ -176,6 +176,23 @@ fn digits_are_written_as_drawn() {
     assert!(!text.contains("page 4") && !text.contains("page ٥"), "{svg}");
 }
 
+/// A run whose font size measures the cap height is written at the em size it is drawn at: 14 pt
+/// measuring a 0.7 em cap height is `font-size="20"`, after a 12 pt run measuring the em box,
+/// which takes the `<text>` element's 12.
+#[test]
+fn font_height_reference_writes_the_size_drawn() {
+    use vectorcraft_doc::FontHeightReference;
+    use vectorcraft_text::test_fonts::{HEIGHT_FAMILY, height_font};
+    vectorcraft_text::FontDb::global().add_font(height_font(true).unwrap());
+    let em_box = CharStyle { font_family: HEIGHT_FAMILY.into(), ..style(12.0) };
+    let cap = CharStyle { size: 14.0, font_height_reference: FontHeightReference::CapHeight, ..em_box.clone() };
+    let d = area_doc(vec![run("Hx ", em_box), run("Hx", cap)], 280.0, Justify::Left);
+    let svg = export(&d, &ExportOptions::default());
+    assert!(svg.contains("font-size=\"12\" fill"), "{svg}");
+    let sizes: Vec<_> = tspans(&svg).iter().map(|t| attr(t, "font-size")).collect();
+    assert_eq!(sizes, [None, Some(20.0)], "{svg}");
+}
+
 #[test]
 fn fewer_tspans_writes_one_per_line() {
     let bold = CharStyle { font_style: "Bold".into(), ..style(12.0) };

crates/text/src/fontdb/face.rs

@@ -279,6 +279,26 @@ impl FontFace {
         *self.icf_margins.get_or_init(|| self.icf_from_base().or_else(|| self.icf_from_glyphs()).unwrap_or_default())
     }
 
+    /// The height of the face that a font size measures with `reference`, in ems: 1 for the em
+    /// box; the cap height or x height of its OS/2 table; the height of its ideographic character
+    /// face ([`Self::icf_margins`]), or across a `vertical` line its width. None for a face whose
+    /// font has no such value (an OS/2 table without the heights, no ICF), or one outside 0.1 to
+    /// 2 ems.
+    pub fn font_height(&self, reference: vectorcraft_doc::FontHeightReference, vertical: bool) -> Option<f64> {
+        use vectorcraft_doc::FontHeightReference as R;
+        let units = |v: Option<f32>| v.map(f64::from).map(|v| v / self.upem);
+        let h = match reference {
+            R::EmBox => Some(1.0),
+            R::CapHeight => units(self.skrifa()?.metrics(Size::unscaled(), self.location()).cap_height),
+            R::XHeight => units(self.skrifa()?.metrics(Size::unscaled(), self.location()).x_height),
+            R::IcfBox => {
+                let m = self.icf_margins();
+                (m != IcfMargins::default()).then_some(if vertical { 1.0 - m.left - m.right } else { 1.0 - m.top - m.bottom })
+            }
+        };
+        h.filter(|h| (0.1..=2.0).contains(h))
+    }
+
     /// [`Self::icf_margins`] from the BASE table: the ICF's bottom edge `icfb` (top edge `icft`, else
     /// as far below the em box top) against the em box `ideo` .. `idtp` (else the OS/2 typographic
     /// descender, and one em above it); across vertical lines, `icfb` and `icft` of the vertical

crates/text/src/fontdb/lookup.rs

@@ -247,6 +247,37 @@ impl FontDb {
         Some(self.instance(&face, &st.font_axes))
     }
 
+    /// The em size characters of style `st` are set at, in `vertical` type or not: its size, or
+    /// with a font height reference other than the em box ([`vectorcraft_doc::FontHeightReference`])
+    /// the size at which its face ([`Self::style_face`]) has that height
+    /// ([`FontFace::font_height`]). The size itself when the face has no such height.
+    pub fn em_size(&self, st: &vectorcraft_doc::CharStyle, vertical: bool) -> f64 {
+        let reference = st.font_height_reference;
+        if reference == vectorcraft_doc::FontHeightReference::EmBox {
+            return st.size;
+        }
+        self.style_face(st).and_then(|f| f.font_height(reference, vertical)).map_or(st.size, |h| st.size / h)
+    }
+
+    /// `t` as layout sets it: each run takes its [`Self::em_size`] and the em box as its font
+    /// height reference; an inline graphic keeps its size. Explicit leading and baseline shift
+    /// stay in points; Auto leading, tracking and kerning follow the em size. `t` itself when every
+    /// run measures the em box.
+    pub fn font_heights_resolved<'a>(&self, t: &'a vectorcraft_doc::TextObject) -> std::borrow::Cow<'a, vectorcraft_doc::TextObject> {
+        use vectorcraft_doc::FontHeightReference;
+        if t.runs.iter().all(|r| r.style.font_height_reference == FontHeightReference::EmBox) {
+            return std::borrow::Cow::Borrowed(t);
+        }
+        let mut out = t.clone();
+        for r in &mut out.runs {
+            if r.inline.is_none() {
+                r.style.size = self.em_size(&r.style, t.vertical);
+            }
+            r.style.font_height_reference = FontHeightReference::EmBox;
+        }
+        std::borrow::Cow::Owned(out)
+    }
+
     /// `face` with the axis settings `axes` (by tag, in the axes' own units) in place of its own,
     /// each clamped to its axis's range: its outlines, metrics and advances taken there, and its
     /// file embedded instanced there. Tags the font has no axis for are left out. `face` itself

crates/text/src/layout/driver.rs

@@ -106,8 +106,11 @@ pub fn decorations(layout: &TextLayout, db: &FontDb, t: &TextObject) -> Vec<(usi
 const SHRINK_PASSES: usize = 11;
 
 /// Lay out a text object with explicit options (area type rows/columns, inset, first baseline,
-/// fit, composer, OpenType features).
+/// fit, composer, OpenType features). Each run is set at the em size its font height reference
+/// gives it ([`FontDb::font_heights_resolved`]).
 pub fn layout_with(db: &FontDb, t: &TextObject, opts: &LayoutOptions) -> TextLayout {
+    let resolved = db.font_heights_resolved(t);
+    let t = &*resolved;
     let first = layout_once(db, t, opts);
     match (opts.fit.min_scale(), &t.kind) {
         (Some(min), TextKind::Area { .. }) if first.overflow => shrink_to_fit(db, t, opts, min).unwrap_or(first),

crates/text/src/shape.rs

@@ -718,6 +718,7 @@ fn shapes_alike(a: &CharStyle, b: &CharStyle) -> bool {
         tate_chu_yoko,
         standard_vertical_roman: _,
         digits,
+        font_height_reference,
         no_break,
         language,
     } = a;
@@ -735,6 +736,7 @@ fn shapes_alike(a: &CharStyle, b: &CharStyle) -> bool {
         && *proportional_metrics == b.proportional_metrics
         && *tate_chu_yoko == b.tate_chu_yoko
         && *digits == b.digits
+        && *font_height_reference == b.font_height_reference
         && *no_break == b.no_break
         && *language == b.language
         && ligatures_suppressed_by(*tracking) == ligatures_suppressed_by(b.tracking)

crates/text/src/test_fonts.rs

@@ -254,6 +254,86 @@ pub fn vertical_font(vorg: bool) -> Option<Vec<u8>> {
     Some(builder.build())
 }
 
+/// The family of [`height_font`] with its heights.
+pub const HEIGHT_FAMILY: &str = "Heighttest Sans";
+
+/// The family of [`height_font`] without them.
+pub const HEIGHTLESS_FAMILY: &str = "Heightlesstest Sans";
+
+/// The cap height and x height [`height_font`] gives, in font units (1,000 to the em).
+pub const HEIGHT_CAP: i16 = 700;
+pub const HEIGHT_X: i16 = 500;
+
+/// The height (and the width across a vertical line) of [`height_font`]'s ideographic character
+/// face, in ems.
+pub const HEIGHT_ICF: f64 = 0.9;
+
+/// The family of [`height_outside_font`].
+pub const HEIGHT_OUTSIDE_FAMILY: &str = "Heightoutsidetest Sans";
+
+/// The cap height and x height [`height_outside_font`] gives, in font units (1,000 to the em):
+/// 2.5 em and 0.05 em, outside the 0.1 to 2 ems a font size measures.
+pub const HEIGHT_OUTSIDE_CAP: i16 = 2500;
+pub const HEIGHT_OUTSIDE_X: i16 = 50;
+
+/// The bundled Source Sans 3 Regular as family [`HEIGHT_FAMILY`], with the cap height
+/// [`HEIGHT_CAP`] and x height [`HEIGHT_X`] in its OS/2 table and a `BASE` table whose Han
+/// baselines put the ideographic character face [`HEIGHT_ICF`] em high inside the em box (`ideo`
+/// -120, `idtp` 880, `icfb` -70, `icft` 830). Without `heights`: family [`HEIGHTLESS_FAMILY`],
+/// with a version 1 OS/2 table, which holds neither height, and no `BASE` table. `None` when it
+/// can't be built.
+pub fn height_font(heights: bool) -> Option<Vec<u8>> {
+    if heights { heights_font(HEIGHT_FAMILY, Some((HEIGHT_X, HEIGHT_CAP)), true) } else { heights_font(HEIGHTLESS_FAMILY, None, false) }
+}
+
+/// The bundled Source Sans 3 Regular as family [`HEIGHT_OUTSIDE_FAMILY`], with the cap height
+/// [`HEIGHT_OUTSIDE_CAP`] and x height [`HEIGHT_OUTSIDE_X`] in its OS/2 table and no `BASE`
+/// table. `None` when it can't be built.
+pub fn height_outside_font() -> Option<Vec<u8>> {
+    heights_font(HEIGHT_OUTSIDE_FAMILY, Some((HEIGHT_OUTSIDE_X, HEIGHT_OUTSIDE_CAP)), false)
+}
+
+/// The bundled Source Sans 3 Regular as `family`: with the x height and cap height `heights` in
+/// its OS/2 table, else a version 1 OS/2 table, which holds neither; with `base`, the `BASE`
+/// table of [`height_font`].
+fn heights_font(family: &str, heights: Option<(i16, i16)>, base: bool) -> Option<Vec<u8>> {
+    use write_fonts::tables::base::{Axis, Base, BaseCoord, BaseScript, BaseScriptList, BaseScriptRecord, BaseTagList, BaseValues};
+
+    const BASE: &[u8] = include_bytes!("../../../assets/fonts/SourceSans3-Regular.ttf");
+    let font = skrifa::FontRef::new(BASE).ok()?;
+    let full = format!("{family} Regular");
+    let postscript = format!("{}-Regular", family.replace(' ', ""));
+    let name = name_table(&[(1, family), (2, "Regular"), (4, &full), (6, &postscript)])?;
+    let mut builder = FontBuilder::new();
+    builder.add_raw(Tag::new(b"name"), name);
+    if base {
+        let tags = BaseTagList::new([b"icfb", b"icft", b"ideo", b"idtp"].map(Tag::new).to_vec());
+        let values = BaseValues::new(2, [-70, 830, -120, 880].map(BaseCoord::format_1).to_vec());
+        let hani = BaseScriptRecord::new(Tag::new(b"hani"), BaseScript::new(Some(values), None, vec![]));
+        let axis = Axis::new(Some(tags), BaseScriptList::new(vec![hani]));
+        builder.add_table(&Base::new(Some(axis), None)).ok()?;
+    }
+    for r in font.table_directory.table_records() {
+        let tag = Tag::new(&r.tag().to_be_bytes());
+        if builder.contains(tag) {
+            continue;
+        }
+        let mut data = font.table_data(r.tag())?.as_bytes().to_vec();
+        if tag == Tag::new(b"OS/2") {
+            if let Some((x, cap)) = heights {
+                // sxHeight and sCapHeight, at bytes 86 and 88 of a version 2 or later table.
+                data.get_mut(86..90)?.copy_from_slice(&[x.to_be_bytes(), cap.to_be_bytes()].concat());
+            } else {
+                // Version 1 ends before sxHeight.
+                data.truncate(86);
+                data.get_mut(0..2)?.copy_from_slice(&1_u16.to_be_bytes());
+            }
+        }
+        builder.add_raw(tag, data);
+    }
+    Some(builder.build())
+}
+
 /// The family of [`vertical_punctuation_font`].
 pub const VERTICAL_PUNCTUATION_FAMILY: &str = "Punctuationtest Sans";
 

crates/text/src/tests.rs

@@ -1347,6 +1347,62 @@ fn character_alignment_on_the_icf_lines_small_characters_up_with_the_largest_fac
     }
 }
 
+/// The font height reference: 20 pt type that measures the cap height is set at the em size at
+/// which the font's cap height (OS/2) is 20 pt, and the same for the x height and for the ideographic
+/// character face's height (its width in vertical type); the em box keeps 20 pt to the em, and
+/// so does every reference in a font without these values. Auto leading follows the em size,
+/// and two runs that measure different heights each take their own em size.
+#[test]
+fn font_size_measures_the_font_height_reference() {
+    use crate::test_fonts::{HEIGHT_CAP, HEIGHT_FAMILY, HEIGHT_ICF, HEIGHT_X, HEIGHTLESS_FAMILY, height_font};
+    use vectorcraft_doc::FontHeightReference as R;
+    let db = FontDb::with_font_dirs(vec![]);
+    db.add_font(height_font(true).unwrap());
+    db.add_font(height_font(false).unwrap());
+    let st = |family: &str, r: R| CharStyle { font_family: family.into(), font_height_reference: r, ..style(20.0) };
+    // The em size each glyph of `t` is drawn at (its transform's scale times 1,000 units).
+    let ems = |t: &TextObject| layout(&db, t).glyphs.iter().map(|g| g.xf.determinant().abs().sqrt() * 1000.0).collect::<Vec<_>>();
+    let near = |a: f64, b: f64| (a - b).abs() < 1e-6;
+    let (cap, x) = (f64::from(HEIGHT_CAP) / 1000.0, f64::from(HEIGHT_X) / 1000.0);
+    for vertical_type in [false, true] {
+        for (r, h) in [(R::EmBox, 1.0), (R::CapHeight, cap), (R::XHeight, x), (R::IcfBox, HEIGHT_ICF)] {
+            let mut t = point("Hx", st(HEIGHT_FAMILY, r));
+            t.vertical = vertical_type;
+            assert!(ems(&t).iter().all(|e| near(*e, 20.0 / h)), "{r:?} vertical {vertical_type}: {:?}", ems(&t));
+            t.runs[0].style.font_family = HEIGHTLESS_FAMILY.into();
+            assert!(ems(&t).iter().all(|e| near(*e, 20.0)), "{r:?} without the value, vertical {vertical_type}: {:?}", ems(&t));
+        }
+    }
+    let face = db.face(HEIGHT_FAMILY, "Regular").unwrap();
+    assert_eq!(face.font_height(R::CapHeight, false), Some(cap));
+    assert_eq!(db.face(HEIGHTLESS_FAMILY, "Regular").unwrap().font_height(R::XHeight, false), None);
+    // Auto leading: 120% of the em size the line is set at.
+    let lines = layout(&db, &point("H\nH", st(HEIGHT_FAMILY, R::CapHeight))).lines;
+    assert!(near(lines[1].baseline - lines[0].baseline, 1.2 * 20.0 / cap), "{lines:?}");
+    // One run at the em box, the next at the cap height.
+    let mut t = point("H", st(HEIGHT_FAMILY, R::EmBox));
+    t.runs.push(TextRun { text: "H".into(), style: st(HEIGHT_FAMILY, R::CapHeight), inline: None });
+    let set = ems(&t);
+    assert!(set.len() == 2 && near(set[0], 20.0) && near(set[1], 20.0 / cap), "{set:?}");
+}
+
+/// A font height outside 0.1 to 2 ems is not used: 20 pt type that measures a font's 2.5 em cap
+/// height or its 0.05 em x height is set at 20 pt to the em.
+#[test]
+fn a_font_height_outside_a_tenth_to_two_ems_measures_the_em_box() {
+    use crate::test_fonts::{HEIGHT_OUTSIDE_FAMILY, height_outside_font};
+    use vectorcraft_doc::FontHeightReference as R;
+    let db = FontDb::with_font_dirs(vec![]);
+    db.add_font(height_outside_font().unwrap());
+    let face = db.face(HEIGHT_OUTSIDE_FAMILY, "Regular").unwrap();
+    for r in [R::CapHeight, R::XHeight] {
+        assert_eq!(face.font_height(r, false), None, "{r:?}");
+        let st = CharStyle { font_family: HEIGHT_OUTSIDE_FAMILY.into(), font_height_reference: r, ..style(20.0) };
+        let ems = layout(&db, &point("Hx", st)).glyphs.iter().map(|g| g.xf.determinant().abs().sqrt() * 1000.0).collect::<Vec<_>>();
+        assert!(!ems.is_empty() && ems.iter().all(|e| (e - 20.0).abs() < 1e-6), "{r:?}: {ems:?}");
+    }
+}
+
 /// Burasagari leaves Latin punctuation alone: in a measure of exactly "abcd", the full stop of
 /// "abcd. ef" doesn't hang with Standard or Forced (the line breaks as it does with None), and a
 /// Latin line ending in a full stop isn't shortened by Forced.

crates/ui-egui/src/i18n/bg.tsv

@@ -4500,6 +4500,12 @@ axis	Both	И двете
 	Insert Inline Symbol	Вграждане на вграден символ
 	ICF Top/Right	ICF горе/дясно
 	ICF Bottom/Left	ICF долу/ляво
+	Show Font Height Options	Показване на опциите за височина на шрифта
+	Hide Font Height Options	Скриване на опциите за височина на шрифта
+	Set Font Height Reference	Задаване на референтна височина на шрифта
+	Em Box	Квадратна касетка (Em Box)
+	x-Height	Височина на x
+	ICF Box	Касетка ICF
 @msg	`id` is the step reference {r}, which only `run` and `command_batch` resolve	`id` е референцията за стъпка {r}, която се разрешава само от `run` и `command_batch`
 @msg	`ids` must be an array of object ids, not {v}	`ids` трябва да бъде масив от идентификатори на обекти, а не {v}
 @msg	`corners` must be an array of anchor indices, not {v}	`corners` трябва да бъде масив от индекси на опорни точки, а не {v}

crates/ui-egui/src/i18n/bs.tsv

@@ -1454,6 +1454,12 @@ digits	Malayalam	Malajalam
 	Axis	Osa
 	ICF Top/Right	ICF vrh/desno
 	ICF Bottom/Left	ICF dno/lijevo
+	Show Font Height Options	Prikaži opcije visine fonta
+	Hide Font Height Options	Sakrij opcije visine fonta
+	Set Font Height Reference	Postavi referentnu visinu fonta
+	Em Box	Em okvir
+	x-Height	Visina malih slova
+	ICF Box	ICF okvir
 	Copy Color Value (Hex)	Kopiraj vrijednost boje (hex)
 	Create New Swatch…	Kreiraj novi uzorak boje…
 	Name 40%	Naziv 40%

crates/ui-egui/src/i18n/ca.tsv

@@ -5735,6 +5735,12 @@ theme	Appearance	Aparença
 	Glyph Bounds	Límits del glif
 	Proximity Guides	Guies de proximitat
 	Angular Guides	Guies angulars
+	Show Font Height Options	Mostra les opcions d’alçada de la font
+	Hide Font Height Options	Amaga les opcions d’alçada de la font
+	Set Font Height Reference	Estableix la referència d’alçada de la font
+	Em Box	Caixa em
+	x-Height	Alçada de la x
+	ICF Box	Caixa ICF
 # Average & Join (Object › Path, Cmd+Alt+Shift+J).
 	Average & Join…	Mitjana i unió…
 	Average & Join	Mitjana i unió

crates/ui-egui/src/i18n/cs.tsv

@@ -1478,6 +1478,12 @@ digits	Malayalam	Malajálamské
 	Axis	Osa
 	ICF Top/Right	ICF horní/pravý
 	ICF Bottom/Left	ICF dolní/levý
+	Show Font Height Options	Zobrazit možnosti výšky písma
+	Hide Font Height Options	Skrýt možnosti výšky písma
+	Set Font Height Reference	Nastavit referenční výšku písma
+	Em Box	Čtverčík
+	x-Height	Výška x
+	ICF Box	Rámeček ICF
 	Copy Color Value (Hex)	Kopírovat hodnotu barvy (hex)
 	Create New Swatch…	Vytvořit novou položku vzorníku…
 	Name 40%	Název 40 %
@@ -4209,6 +4215,7 @@ imageTrace	Outline	Obrys
 @msg	the file's layers weren't read ({_1}): it comes in as its page, in one layer	vrstvy souboru nebyly načteny ({_1}): soubor se otevře jako jeho stránka v jedné vrstvě
 @msg	the file's layers weren't read from its editing data ({_1}): they come from its PDF part	vrstvy souboru nebyly načteny z jeho dat pro úpravy ({_1}): pocházejí z jeho části PDF
 @msg	`to` must be "corner" or "smooth"	`to` musí být "corner" nebo "smooth"
+@msg	`fontHeightReference` must be "emBox", "capHeight", "xHeight" or "icfBox"	`fontHeightReference` musí být "emBox", "capHeight", "xHeight" nebo "icfBox"
 @msg	BMP files are RGB or grayscale: colorModel rgb or gray	soubory BMP jsou RGB nebo ve stupních šedi: colorModel rgb nebo gray
 @msg	Blend colors: select at least three objects with filled colours	Prolnout barvy: vyberte alespoň tři objekty s barevnou výplní
 @msg	Combine Slices: the slices have no bounds	Spojit řezy: řezy nemají hranice

crates/ui-egui/src/i18n/da.tsv

@@ -1388,6 +1388,12 @@ digits	Malayalam	Malayalam
 	Axis	Akse
 	ICF Top/Right	ICF øverst/højre
 	ICF Bottom/Left	ICF nederst/venstre
+	Show Font Height Options	Vis indstillinger for skrifthøjde
+	Hide Font Height Options	Skjul indstillinger for skrifthøjde
+	Set Font Height Reference	Angiv reference for skrifthøjde
+	Em Box	Em-felt
+	x-Height	x-højde
+	ICF Box	ICF-felt
 	Copy Color Value (Hex)	Kopiér farveværdi (hex)
 	Create New Swatch…	Opret ny farveprøve…
 	Name 40%	Navn 40%

crates/ui-egui/src/i18n/de.tsv

@@ -3821,6 +3821,7 @@ theme	Appearance	Erscheinungsbild
 @msg	the file's layers weren't read ({_1}): it comes in as its page, in one layer	die Ebenen der Datei wurden nicht gelesen ({_1}): sie wird als ihre Seite in einer Ebene geöffnet
 @msg	the file's layers weren't read from its editing data ({_1}): they come from its PDF part	die Ebenen der Datei wurden nicht aus ihren Bearbeitungsdaten gelesen ({_1}): sie stammen aus ihrem PDF-Teil
 @msg	`to` must be "corner" or "smooth"	`to` muss "corner" oder "smooth" sein
+@msg	`fontHeightReference` must be "emBox", "capHeight", "xHeight" or "icfBox"	`fontHeightReference` muss "emBox", "capHeight", "xHeight" oder "icfBox" sein
 @msg	BMP files are RGB or grayscale: colorModel rgb or gray	BMP-Dateien sind RGB oder Graustufen: colorModel rgb oder gray
 @msg	Blend colors: select at least three objects with filled colours	Farben angleichen: Wählen Sie mindestens drei Objekte mit Flächenfarbe aus
 @msg	Combine Slices: the slices have no bounds	Slices kombinieren: Die Slices haben keine Begrenzung
@@ -4555,6 +4556,13 @@ theme	Appearance	Erscheinungsbild
 	Insert Inline Symbol	Inline-Symbol einfügen
 	ICF Top/Right	ICF oben/rechts
 	ICF Bottom/Left	ICF unten/links
+	Show Font Height Options	Optionen für Schrifthöhe einblenden
+	Hide Font Height Options	Optionen für Schrifthöhe ausblenden
+	Set Font Height Reference	Bezugsgröße der Schrifthöhe festlegen
+	Em Box	Geviert
+	Cap Height	Versalhöhe
+	x-Height	x-Höhe
+	ICF Box	ICF-Rahmen
 @msg	`id` is the step reference {r}, which only `run` and `command_batch` resolve	`id` ist der Schrittverweis {r}, den nur `run` und `command_batch` auflösen
 @msg	`ids` must be an array of object ids, not {v}	`ids` muss ein Array von Objekt-IDs sein, nicht {v}
 @msg	`corners` must be an array of anchor indices, not {v}	`corners` muss ein Array von Ankerpunkt-Indizes sein, nicht {v}

crates/ui-egui/src/i18n/el.tsv

@@ -2123,6 +2123,7 @@ axis	Both	Και τα δύο
 @msg	the art on them differs from the page's in {_1}% of it: they come from its editing data all the same	Τα γραφικά τους διαφέρουν από εκείνα της σελίδας κατά {_1}%, αλλά θα χρησιμοποιηθούν τα δεδομένα επεξεργασίας
 @msg	`Custom` stands for changed settings: save the preset under another name	Το `Custom` αντιστοιχεί σε αλλαγμένες ρυθμίσεις: αποθηκεύστε την προεπιλογή με άλλο όνομα
 @msg	`to` must be "corner" or "smooth"	Το `to` πρέπει να είναι "corner" ή "smooth"
+@msg	`fontHeightReference` must be "emBox", "capHeight", "xHeight" or "icfBox"	Το `fontHeightReference` πρέπει να είναι "emBox", "capHeight", "xHeight" ή "icfBox"
 @msg	BMP files are RGB or grayscale: colorModel rgb or gray	Τα αρχεία BMP πρέπει να είναι RGB ή σε κλίμακα του γκρι: colorModel rgb ή gray
 @msg	Blend colors: select at least three objects with filled colours	Ανάμειξη χρωμάτων: επιλέξτε τουλάχιστον τρία αντικείμενα με χρώμα γεμίσματος
 @msg	Combine Slices: the slices have no bounds	Συνδυασμός τομών: οι τομές δεν έχουν όρια
@@ -4580,6 +4581,12 @@ digits	Malayalam	Μαλαγιάλαμ
 	Insert Inline Symbol	Εισαγωγή ενσωματωμένου συμβόλου
 	ICF Top/Right	ICF επάνω/δεξιά
 	ICF Bottom/Left	ICF κάτω/αριστερά
+	Show Font Height Options	Εμφάνιση επιλογών ύψους γραμματοσειράς
+	Hide Font Height Options	Απόκρυψη επιλογών ύψους γραμματοσειράς
+	Set Font Height Reference	Ορισμός αναφοράς ύψους γραμματοσειράς
+	Em Box	Τετράγωνο em
+	x-Height	Ύψος x
+	ICF Box	Πλαίσιο ICF
 @msg	`id` is the step reference {r}, which only `run` and `command_batch` resolve	το `id` είναι η αναφορά βήματος {r}, την οποία αναλύουν μόνο τα `run` και `command_batch`
 @msg	`ids` must be an array of object ids, not {v}	το `ids` πρέπει να είναι πίνακας αναγνωριστικών αντικειμένων, όχι {v}
 @msg	`corners` must be an array of anchor indices, not {v}	το `corners` πρέπει να είναι πίνακας δεικτών αγκύρωσης, όχι {v}

crates/ui-egui/src/i18n/es.tsv

@@ -949,6 +949,12 @@ font-technology	Variable	Variables
 	Em Box Top/Right	Arriba/derecha del cuadro eme
 	ICF Top/Right	Arriba/derecha del ICF
 	ICF Bottom/Left	Abajo/izquierda del ICF
+	Show Font Height Options	Mostrar opciones de altura de fuente
+	Hide Font Height Options	Ocultar opciones de altura de fuente
+	Set Font Height Reference	Definir la referencia de altura de fuente
+	Em Box	Cuadro eme
+	x-Height	Altura de la x
+	ICF Box	Cuadro ICF
 	Em Dash	Raya
 	Em Space	Espacio eme
 	Embed	Incrustar
@@ -3901,6 +3907,7 @@ axis	Both	Ambos
 @msg	the file's layers weren't read ({_1}): it comes in as its page, in one layer	no se leyeron las capas del archivo ({_1}): se abre como su página, en una sola capa
 @msg	the file's layers weren't read from its editing data ({_1}): they come from its PDF part	no se leyeron las capas del archivo desde sus datos de edición ({_1}): proceden de su parte PDF
 @msg	`to` must be "corner" or "smooth"	`to` debe ser "corner" o "smooth"
+@msg	`fontHeightReference` must be "emBox", "capHeight", "xHeight" or "icfBox"	`fontHeightReference` debe ser "emBox", "capHeight", "xHeight" o "icfBox"
 @msg	BMP files are RGB or grayscale: colorModel rgb or gray	los archivos BMP son RGB o en escala de grises: colorModel rgb o gray
 @msg	Blend colors: select at least three objects with filled colours	Fusionar colores: selecciona al menos tres objetos con relleno de color
 @msg	Combine Slices: the slices have no bounds	Combinar sectores: los sectores no tienen límites

crates/ui-egui/src/i18n/fi.tsv

@@ -1451,6 +1451,12 @@ digits	Malayalam	Malajalam
 	Axis	Akseli
 	ICF Top/Right	ICF ylä/oikea
 	ICF Bottom/Left	ICF ala/vasen
+	Show Font Height Options	Näytä fontin korkeuden asetukset
+	Hide Font Height Options	Piilota fontin korkeuden asetukset
+	Set Font Height Reference	Aseta fontin korkeuden viite
+	Em Box	Em-laatikko
+	x-Height	x-korkeus
+	ICF Box	ICF-laatikko
 	Copy Color Value (Hex)	Kopioi väriarvo (heksa)
 	Create New Swatch…	Luo uusi värimalli…
 	Name 40%	Nimi 40%
@@ -4123,6 +4129,7 @@ imageTrace	Outline	Ääriviiva
 @msg	the art on them differs from the page's in {_1}% of it: they come from its editing data all the same	niiden kuvitus eroaa sivun kuvituksesta {_1} %:n osalta: ne tuodaan silti sen muokkaustiedoista
 @msg	`Custom` stands for changed settings: save the preset under another name	`Custom` tarkoittaa muutettuja asetuksia: tallenna esiasetus toisella nimellä
 @msg	`to` must be "corner" or "smooth"	`to` on oltava "corner" tai "smooth"
+@msg	`fontHeightReference` must be "emBox", "capHeight", "xHeight" or "icfBox"	`fontHeightReference` on oltava "emBox", "capHeight", "xHeight" tai "icfBox"
 @msg	BMP files are RGB or grayscale: colorModel rgb or gray	BMP-tiedostot ovat RGB- tai harmaasävykuvia: colorModel rgb tai gray
 @msg	Blend colors: select at least three objects with filled colours	Sulauta värit: valitse vähintään kolme objektia, joilla on väritäyttö
 @msg	Combine Slices: the slices have no bounds	Yhdistä viipaleet: viipaleilla ei ole rajoja

crates/ui-egui/src/i18n/fr.tsv

@@ -3897,6 +3897,7 @@ axis	Both	Les deux
 @msg	the file's layers weren't read ({_1}): it comes in as its page, in one layer	les calques du fichier n’ont pas été lus ({_1}) : il est ouvert tel que sa page, sur un seul calque
 @msg	the file's layers weren't read from its editing data ({_1}): they come from its PDF part	les calques du fichier n’ont pas été lus depuis ses données de modification ({_1}) : ils proviennent de sa partie PDF
 @msg	`to` must be "corner" or "smooth"	`to` doit être "corner" ou "smooth"
+@msg	`fontHeightReference` must be "emBox", "capHeight", "xHeight" or "icfBox"	`fontHeightReference` doit être "emBox", "capHeight", "xHeight" ou "icfBox"
 @msg	BMP files are RGB or grayscale: colorModel rgb or gray	Les fichiers BMP sont en RVB ou en niveaux de gris : colorModel rgb ou gray
 @msg	Blend colors: select at least three objects with filled colours	Fusion des couleurs : sélectionnez au moins trois objets dotés d’un fond de couleur
 @msg	Combine Slices: the slices have no bounds	Combiner les tranches : les tranches n’ont pas de limites
@@ -4628,6 +4629,12 @@ axis	Both	Les deux
 	Free Transform	Transformation manuelle
 	Perspective Distort	Distorsion de perspective
 	Insert Inline Symbol	Insérer un symbole dans le texte
+	Show Font Height Options	Afficher les options de hauteur de police
+	Hide Font Height Options	Masquer les options de hauteur de police
+	Set Font Height Reference	Définir la référence de hauteur de police
+	Em Box	Cadratin
+	x-Height	Hauteur d’x
+	ICF Box	Cadre ICF
 	ICF Top/Right	ICF haut/droite
 	ICF Bottom/Left	ICF bas/gauche
 @msg	`id` is the step reference {r}, which only `run` and `command_batch` resolve	`id` est la référence d’étape {r}, que seuls `run` et `command_batch` résolvent

crates/ui-egui/src/i18n/hu.tsv

@@ -1937,6 +1937,12 @@ file-filter	Templates	Sablonok
 	Hyphenate Capitalized Words	Nagybetűs szavak elválasztása
 	ICC Profile	ICC-profil
 	ICF Bottom/Left	ICF alja/bal oldala
+	Show Font Height Options	Betűmagasság-beállítások megjelenítése
+	Hide Font Height Options	Betűmagasság-beállítások elrejtése
+	Set Font Height Reference	Betűmagasság viszonyítási alapjának beállítása
+	Em Box	Kvirtmező
+	x-Height	x-magasság
+	ICF Box	ICF-mező
 	ICF Top/Right	ICF teteje/jobb oldala
 	Identify Objects By	Objektumok azonosítása
 	Ignore	Kihagy
@@ -4518,6 +4524,7 @@ imageTrace	Outline	Körvonal
 @msg	`stops` must be an array	`stops`: tömb kell
 @msg	`svg` must be an object of SVG options (see document.formats)	`svg`: SVG-beállításokat tartalmazó objektum kell (lásd: document.formats)
 @msg	`to` must be "corner" or "smooth"	`to`: "corner" vagy "smooth" kell
+@msg	`fontHeightReference` must be "emBox", "capHeight", "xHeight" or "icfBox"	`fontHeightReference`: "emBox", "capHeight", "xHeight" vagy "icfBox" kell
 @msg	`{_1}` is no save command	nem mentési parancs: `{_1}`
 @msg	`{area}` is no recovery area name	nem helyreállítási terület neve: `{area}`
 @msg	`{color}` is not a colour (#rrggbb or a preset name)	nem szín: `{color}` (#rrggbb vagy előbeállítás neve)

crates/ui-egui/src/i18n/id.tsv

@@ -1388,6 +1388,12 @@ digits	Malayalam	Malayalam
 	Axis	Sumbu
 	ICF Top/Right	ICF atas/kanan
 	ICF Bottom/Left	ICF bawah/kiri
+	Show Font Height Options	Tampilkan opsi tinggi font
+	Hide Font Height Options	Sembunyikan opsi tinggi font
+	Set Font Height Reference	Atur acuan tinggi font
+	Em Box	Em Box
+	x-Height	Tinggi x
+	ICF Box	Kotak ICF
 	Copy Color Value (Hex)	Salin nilai warna (Hex)
 	Create New Swatch…	Buat swatch baru…
 	Name 40%	Nama 40%

crates/ui-egui/src/i18n/it.tsv

@@ -949,6 +949,13 @@ font-technology	Variable	Variabili
 	Em Box Top/Right	Riquadro em in alto/a destra
 	ICF Top/Right	ICF in alto/a destra
 	ICF Bottom/Left	ICF in basso/a sinistra
+	Show Font Height Options	Mostra opzioni altezza font
+	Hide Font Height Options	Nascondi opzioni altezza font
+	Set Font Height Reference	Imposta riferimento altezza font
+	Em Box	Riquadro em
+	Cap Height	Altezza maiuscole
+	x-Height	Altezza x
+	ICF Box	Riquadro ICF
 	Em Dash	Lineetta
 	Em Space	Spazio em
 	Embed	Incorpora
@@ -3941,6 +3948,7 @@ axis	Both	Entrambi
 @msg	the file's layers weren't read ({_1}): it comes in as its page, in one layer	i livelli del file non sono stati letti ({_1}): si apre come la sua pagina, in un solo livello
 @msg	the file's layers weren't read from its editing data ({_1}): they come from its PDF part	i livelli del file non sono stati letti dai suoi dati di modifica ({_1}): provengono dalla sua parte PDF
 @msg	`to` must be "corner" or "smooth"	`to` deve essere "corner" o "smooth"
+@msg	`fontHeightReference` must be "emBox", "capHeight", "xHeight" or "icfBox"	`fontHeightReference` deve essere "emBox", "capHeight", "xHeight" o "icfBox"
 @msg	BMP files are RGB or grayscale: colorModel rgb or gray	I file BMP sono RGB o in scala di grigi: colorModel rgb o gray
 @msg	Blend colors: select at least three objects with filled colours	Fondi colori: seleziona almeno tre oggetti con riempimento colore
 @msg	Combine Slices: the slices have no bounds	Combina sezioni: le sezioni non hanno limiti

crates/ui-egui/src/i18n/ja.tsv

@@ -42,6 +42,13 @@ font-technology	Variable	バリアブル
 	Em Box Top/Right	仮想ボディの上 / 右
 	ICF Top/Right	平均字面の上 / 右
 	ICF Bottom/Left	平均字面の下 / 左
+	Show Font Height Options	フォントの高さオプションを表示
+	Hide Font Height Options	フォントの高さオプションを隠す
+	Set Font Height Reference	フォントの高さの基準を設定
+	Em Box	仮想ボディ
+	Cap Height	キャップハイト
+	x-Height	x ハイト
+	ICF Box	平均字面
 	Proportional Metrics	プロポーショナルメトリクス
 	Character Direction	文字の方向
 	Digits	数字
@@ -3983,6 +3990,7 @@ swatch	Bright Violet	ビビッドバイオレット
 @msg	Saving {_1}	{_1} を保存中
 @msg	Sent to {_1}	{_1} に送信しました
 @msg	`to` must be "corner" or "smooth"	`to` には "corner" または "smooth" を指定してください
+@msg	`fontHeightReference` must be "emBox", "capHeight", "xHeight" or "icfBox"	`fontHeightReference` には "emBox"、"capHeight"、"xHeight"、"icfBox" のいずれかを指定してください
 @msg	a layer couldn't be read	読み込めなかったレイヤーがあります
 @msg	it has more than one artboard	アートボードが複数あります
 @msg	its editing data has no layers	編集データにレイヤーがありません

crates/ui-egui/src/i18n/ka.tsv

@@ -1305,6 +1305,12 @@ digits	Malayalam	მალაიალამური
 	Axis	ღერძი
 	ICF Top/Right	ICF ზედა/მარჯვენა
 	ICF Bottom/Left	ICF ქვედა/მარცხენა
+	Show Font Height Options	შრიფტის სიმაღლის პარამეტრების ჩვენება
+	Hide Font Height Options	შრიფტის სიმაღლის პარამეტრების დამალვა
+	Set Font Height Reference	შრიფტის სიმაღლის საზომის დაყენება
+	Em Box	Em-ბლოკი
+	x-Height	x-სიმაღლე
+	ICF Box	ICF-ბლოკი
 	Copy Color Value (Hex)	ფერის მნიშვნელობის კოპირება (Hex)
 	Create New Swatch…	ახალი ფერის ნიმუშის შექმნა…
 	Name 40%	სახელი 40%
@@ -3692,6 +3698,7 @@ font-technology	Variable	ცვლადი
 @msg	the art on them differs from the page's in {_1}% of it	მათზე არსებული ნახატი გვერდისას {_1}%-ით განსხვავდება
 @msg	`Custom` stands for changed settings: save the preset under another name	`Custom` შეცვლილ პარამეტრებს ნიშნავს: შეინახეთ პრესეტი სხვა სახელით
 @msg	`to` must be "corner" or "smooth"	`to` უნდა იყოს "corner" ან "smooth"
+@msg	`fontHeightReference` must be "emBox", "capHeight", "xHeight" or "icfBox"	`fontHeightReference` უნდა იყოს "emBox", "capHeight", "xHeight" ან "icfBox"
 @msg	BMP files are RGB or grayscale: colorModel rgb or gray	BMP ფაილები RGB-ა ან ნაცრისფერი: colorModel rgb ან gray
 @msg	Blend colors: select at least three objects with filled colours	ფერების შერევა: მონიშნეთ მინიმუმ სამი ობიექტი ფერადი შევსებით
 @msg	Combine Slices: the slices have no bounds	ნაჭრების გაერთიანება: ნაჭრებს საზღვრები არ აქვს

crates/ui-egui/src/i18n/ko.tsv

@@ -36,6 +36,13 @@ font-technology	Variable	가변
 	Em Box Top/Right	엠 박스 위/오른쪽
 	ICF Top/Right	ICF 위/오른쪽
 	ICF Bottom/Left	ICF 아래/왼쪽
+	Show Font Height Options	글꼴 높이 옵션 표시
+	Hide Font Height Options	글꼴 높이 옵션 숨기기
+	Set Font Height Reference	글꼴 높이 기준 설정
+	Em Box	엠 박스
+	Cap Height	대문자 높이
+	x-Height	x 높이
+	ICF Box	ICF 박스
 	Proportional Metrics	비례 메트릭
 	Character Direction	문자 방향
 	Digits	숫자
@@ -3910,6 +3917,7 @@ theme	Appearance	외관
 @msg	Saving {_1}	{_1} 저장 중
 @msg	Sent to {_1}	{_1}(으)로 보냈습니다
 @msg	`to` must be "corner" or "smooth"	`to`는 "corner" 또는 "smooth"여야 합니다
+@msg	`fontHeightReference` must be "emBox", "capHeight", "xHeight" or "icfBox"	`fontHeightReference`는 "emBox", "capHeight", "xHeight" 또는 "icfBox"여야 합니다
 @msg	a layer couldn't be read	레이어를 읽을 수 없습니다
 @msg	it has more than one artboard	아트보드가 둘 이상입니다
 @msg	its editing data has no layers	편집 데이터에 레이어가 없습니다

crates/ui-egui/src/i18n/nl.tsv

@@ -1402,6 +1402,12 @@ digits	Malayalam	Malayalam
 	Axis	As
 	ICF Top/Right	ICF boven/rechts
 	ICF Bottom/Left	ICF onder/links
+	Show Font Height Options	Opties voor letterhoogte tonen
+	Hide Font Height Options	Opties voor letterhoogte verbergen
+	Set Font Height Reference	Referentie voor letterhoogte instellen
+	Em Box	Em-vak
+	x-Height	x-hoogte
+	ICF Box	ICF-vak
 	Copy Color Value (Hex)	Kleurwaarde kopiëren (Hex)
 	Create New Swatch…	Nieuw staal maken…
 	Name 40%	Naam 40%

crates/ui-egui/src/i18n/pl.tsv

@@ -1391,6 +1391,12 @@ digits	Malayalam	Malajalam
 	Axis	Oś
 	ICF Top/Right	ICF góra/prawo
 	ICF Bottom/Left	ICF dół/lewo
+	Show Font Height Options	Pokaż opcje wysokości czcionki
+	Hide Font Height Options	Ukryj opcje wysokości czcionki
+	Set Font Height Reference	Ustaw odniesienie wysokości czcionki
+	Em Box	Ramka firetowa
+	x-Height	Wysokość x
+	ICF Box	Ramka ICF
 	Copy Color Value (Hex)	Kopiuj wartość koloru (hex)
 	Create New Swatch…	Utwórz nową próbkę…
 	Name 40%	Nazwa 40%
@@ -4032,6 +4038,7 @@ imageTrace	Outline	Kontur
 @msg	the file's layers weren't read ({_1}): it comes in as its page, in one layer	nie odczytano warstw pliku ({_1}): plik jest wczytywany jako jego strona, na jednej warstwie
 @msg	the file's layers weren't read from its editing data ({_1}): they come from its PDF part	nie odczytano warstw pliku z jego danych edycyjnych ({_1}): pochodzą z jego części PDF
 @msg	`to` must be "corner" or "smooth"	`to` musi mieć wartość "corner" lub "smooth"
+@msg	`fontHeightReference` must be "emBox", "capHeight", "xHeight" or "icfBox"	`fontHeightReference` musi mieć wartość "emBox", "capHeight", "xHeight" lub "icfBox"
 @msg	BMP files are RGB or grayscale: colorModel rgb or gray	Pliki BMP są w RGB lub skali szarości: colorModel rgb lub gray
 @msg	Blend colors: select at least three objects with filled colours	Przejście kolorów: zaznacz co najmniej trzy obiekty z wypełnieniem kolorem
 @msg	Combine Slices: the slices have no bounds	Połącz plasterki: plasterki nie mają granic

crates/ui-egui/src/i18n/pt-br.tsv

@@ -840,6 +840,12 @@
 	Em Box Top/Right	Topo/Direita da Caixa Eme
 	ICF Top/Right	Topo/Direita do ICF
 	ICF Bottom/Left	Base/Esquerda do ICF
+	Show Font Height Options	Mostrar Opções de Altura da Fonte
+	Hide Font Height Options	Ocultar Opções de Altura da Fonte
+	Set Font Height Reference	Definir Referência de Altura da Fonte
+	Em Box	Caixa Eme
+	x-Height	Altura do x
+	ICF Box	Caixa ICF
 	Em Dash	Travessão
 	Em Space	Espaço Em
 	Embed	Incorporar
@@ -3485,6 +3491,7 @@ axis	Both	Ambos
 @msg	the file's layers weren't read ({_1}): it comes in as its page, in one layer	as camadas do arquivo não foram lidas ({_1}): ele entra como sua página, em uma só camada
 @msg	the file's layers weren't read from its editing data ({_1}): they come from its PDF part	as camadas do arquivo não foram lidas dos seus dados de edição ({_1}): elas vêm da sua parte PDF
 @msg	`to` must be "corner" or "smooth"	`to` deve ser "corner" ou "smooth"
+@msg	`fontHeightReference` must be "emBox", "capHeight", "xHeight" or "icfBox"	`fontHeightReference` deve ser "emBox", "capHeight", "xHeight" ou "icfBox"
 @msg	BMP files are RGB or grayscale: colorModel rgb or gray	arquivos BMP são RGB ou em tons de cinza: colorModel rgb ou gray
 @msg	Blend colors: select at least three objects with filled colours	Mesclar cores: selecione pelo menos três objetos com preenchimento de cor
 @msg	Combine Slices: the slices have no bounds	Combinar fatias: as fatias não têm limites

crates/ui-egui/src/i18n/ru.tsv

@@ -947,6 +947,12 @@ font-technology	Variable	Вариативные
 	Em Box Top/Right	Верх/право кегельной площадки
 	ICF Top/Right	Верх/право ICF
 	ICF Bottom/Left	Низ/лево ICF
+	Show Font Height Options	Показать параметры высоты шрифта
+	Hide Font Height Options	Скрыть параметры высоты шрифта
+	Set Font Height Reference	Задать опорную высоту шрифта
+	Em Box	Кегельная площадка
+	x-Height	Высота строчных
+	ICF Box	Рамка ICF
 	Em Dash	Длинное тире
 	Em Space	Круглая шпация
 	Embed	Внедрить
@@ -3937,6 +3943,7 @@ axis	Both	Оба
 @msg	the file's layers weren't read ({_1}): it comes in as its page, in one layer	слои файла не прочитаны ({_1}): он открывается как его страница, на одном слое
 @msg	the file's layers weren't read from its editing data ({_1}): they come from its PDF part	слои файла не прочитаны из его данных для редактирования ({_1}): они взяты из его PDF-части
 @msg	`to` must be "corner" or "smooth"	`to` должно быть "corner" или "smooth"
+@msg	`fontHeightReference` must be "emBox", "capHeight", "xHeight" or "icfBox"	`fontHeightReference` должно быть "emBox", "capHeight", "xHeight" или "icfBox"
 @msg	BMP files are RGB or grayscale: colorModel rgb or gray	файлы BMP бывают RGB или в оттенках серого: colorModel rgb или gray
 @msg	Blend colors: select at least three objects with filled colours	Смешивание цветов: выберите не менее трёх объектов с цветными заливками
 @msg	Combine Slices: the slices have no bounds	Объединение фрагментов: у фрагментов нет границ

crates/ui-egui/src/i18n/sv.tsv

@@ -3818,6 +3818,7 @@ axis	Both	Båda
 @msg	the art on them differs from the page's in {_1}% of it: they come from its editing data all the same	grafiken på dem skiljer sig från sidans i {_1} % av ytan: de hämtas ändå från dess redigeringsdata
 @msg	`Custom` stands for changed settings: save the preset under another name	`Custom` står för ändrade inställningar: spara förinställningen med ett annat namn
 @msg	`to` must be "corner" or "smooth"	`to` måste vara "corner" eller "smooth"
+@msg	`fontHeightReference` must be "emBox", "capHeight", "xHeight" or "icfBox"	`fontHeightReference` måste vara "emBox", "capHeight", "xHeight" eller "icfBox"
 @msg	BMP files are RGB or grayscale: colorModel rgb or gray	BMP-filer är RGB eller gråskala: colorModel rgb eller gray
 @msg	Blend colors: select at least three objects with filled colours	Blanda färger: markera minst tre objekt med färgfyllning
 @msg	Combine Slices: the slices have no bounds	Kombinera skivor: skivorna har inga gränser
@@ -4537,6 +4538,12 @@ axis	Both	Båda
 	Insert Inline Symbol	Infoga symbol i texten
 	ICF Top/Right	ICF överkant/höger
 	ICF Bottom/Left	ICF nederkant/vänster
+	Show Font Height Options	Visa alternativ för teckenhöjd
+	Hide Font Height Options	Dölj alternativ för teckenhöjd
+	Set Font Height Reference	Ange referens för teckenhöjd
+	Em Box	Em-ruta
+	x-Height	x-höjd
+	ICF Box	ICF-ruta
 @msg	`id` is the step reference {r}, which only `run` and `command_batch` resolve	`id` är stegreferensen {r}, som bara `run` och `command_batch` löser upp
 @msg	`ids` must be an array of object ids, not {v}	`ids` måste vara en array med objekt-id:n, inte {v}
 @msg	`corners` must be an array of anchor indices, not {v}	`corners` måste vara en array med index för ankarpunkter, inte {v}

crates/ui-egui/src/i18n/tests.rs

@@ -144,6 +144,17 @@ fn catalan_reads_as_catalan() {
     assert_eq!(message(ca, nested), "l’ordre `object.group` no està disponible ara mateix: no hi ha res seleccionat");
 }
 
+#[test]
+fn font_height_reference_labels_are_in_complete_catalogs() {
+    for lang in LANGUAGES.iter().filter(|lang| lang.complete_menus) {
+        for label in
+            ["Show Font Height Options", "Hide Font Height Options", "Set Font Height Reference", "Em Box", "Cap Height", "x-Height", "ICF Box"]
+        {
+            assert!(lang.catalog().plain(label).is_some(), "{} is missing {label}", lang.code);
+        }
+    }
+}
+
 /// Each language counts with its own plural rule: the form a count picks (`one`, then `few`, then
 /// `other`/`many`).
 #[test]

crates/ui-egui/src/i18n/tr.tsv

@@ -3703,6 +3703,7 @@ axis	Both	Her İkisi
 @msg	the file's layers weren't read ({_1}): it comes in as its page, in one layer	dosyanın katmanları okunmadı ({_1}): tek katmanda kendi sayfası olarak geliyor
 @msg	the file's layers weren't read from its editing data ({_1}): they come from its PDF part	dosyanın katmanları düzenleme verilerinden okunmadı ({_1}): PDF kısmından geliyorlar
 @msg	`to` must be "corner" or "smooth"	"to" "köşe" veya "pürüzsüz" olmalıdır
+@msg	`fontHeightReference` must be "emBox", "capHeight", "xHeight" or "icfBox"	`fontHeightReference` "emBox", "capHeight", "xHeight" veya "icfBox" olmalıdır
 @msg	BMP files are RGB or grayscale: colorModel rgb or gray	BMP dosyaları RGB veya gri tonlamalıdır: colorModel rgb veya gri
 @msg	Blend colors: select at least three objects with filled colours	Renkleri karıştır: dolgulu renklere sahip en az üç nesne seçin
 @msg	Combine Slices: the slices have no bounds	Dilimleri Birleştir: dilimlerin sınırları yoktur
@@ -4380,6 +4381,12 @@ axis	Both	Her İkisi
 	Insert Inline Symbol	Satır İçi Sembol Ekle
 	ICF Top/Right	ICF Üst/Sağ
 	ICF Bottom/Left	ICF Alt/Sol
+	Show Font Height Options	Yazı Tipi Yüksekliği Seçeneklerini Göster
+	Hide Font Height Options	Yazı Tipi Yüksekliği Seçeneklerini Gizle
+	Set Font Height Reference	Yazı Tipi Yüksekliği Referansını Ayarla
+	Em Box	Em Kutusu
+	x-Height	x-Yüksekliği
+	ICF Box	ICF Kutusu
 @msg	`id` is the step reference {r}, which only `run` and `command_batch` resolve	"id", yalnızca "run" ve "command_batch" çözümleyen {r} adım referansıdır
 @msg	`ids` must be an array of object ids, not {v}	"kimlikler" {v} değil, bir nesne kimlikleri dizisi olmalıdır
 @msg	`corners` must be an array of anchor indices, not {v}	"köşeler" {v} değil, bir bağlantı indeksleri dizisi olmalıdır

crates/ui-egui/src/i18n/uk.tsv

@@ -943,6 +943,13 @@ font-technology	Variable	Варіативні
 	Em Box Top/Right	Верх/право кегельного майданчика
 	ICF Top/Right	Верх/право ICF
 	ICF Bottom/Left	Нижній/лівий край ICF
+	Show Font Height Options	Показати параметри висоти шрифту
+	Hide Font Height Options	Приховати параметри висоти шрифту
+	Set Font Height Reference	Задати опорну висоту шрифту
+	Em Box	Кегельний майданчик
+	Cap Height	Висота великих літер
+	x-Height	Висота малих літер
+	ICF Box	Рамка ICF
 	Em Dash	Довге тире
 	Em Space	Кругла шпація
 	Embed	Вбудувати
@@ -3925,6 +3932,7 @@ axis	Both	Обидві
 @msg	the file's layers weren't read ({_1}): it comes in as its page, in one layer	шари файлу не прочитано ({_1}): він відкривається як його сторінка, на одному шарі
 @msg	the file's layers weren't read from its editing data ({_1}): they come from its PDF part	шари файлу не прочитано з його даних для редагування ({_1}): їх взято з його PDF-частини
 @msg	`to` must be "corner" or "smooth"	`to` має бути "corner" або "smooth"
+@msg	`fontHeightReference` must be "emBox", "capHeight", "xHeight" or "icfBox"	`fontHeightReference` має бути "emBox", "capHeight", "xHeight" або "icfBox"
 @msg	BMP files are RGB or grayscale: colorModel rgb or gray	Файли BMP бувають RGB або у відтінках сірого: colorModel rgb або gray
 @msg	Blend colors: select at least three objects with filled colours	Змішування кольорів: виберіть не менше трьох об’єктів із кольоровими заливками
 @msg	Combine Slices: the slices have no bounds	Об’єднання фрагментів: фрагменти не мають кордонів

crates/ui-egui/src/i18n/vi.tsv

@@ -1781,6 +1781,13 @@ digits	Hindi	Hindi
 	Hyphenate Capitalized Words	Gạch nối từ viết hoa chữ đầu
 	ICC Profile	Hồ sơ ICC
 	ICF Bottom/Left	ICF Dưới/Trái
+	Show Font Height Options	Hiện tùy chọn chiều cao phông chữ
+	Hide Font Height Options	Ẩn tùy chọn chiều cao phông chữ
+	Set Font Height Reference	Đặt tham chiếu chiều cao phông chữ
+	Em Box	Ô em
+	Cap Height	Chiều cao chữ hoa
+	x-Height	Chiều cao chữ x
+	ICF Box	Ô ICF
 	ICF Top/Right	ICF Trên/Phải
 	Identify Objects By	Nhận diện đối tượng theo
 	Ignore	Bỏ qua
@@ -4169,6 +4176,7 @@ theme	Appearance	Giao diện
 @msg	`stops` must be an array	`stops` phải là một mảng
 @msg	`svg` must be an object of SVG options (see document.formats)	`svg` phải là đối tượng tùy chọn SVG (xem document.formats)
 @msg	`to` must be "corner" or "smooth"	`to` phải là "corner" hoặc "smooth"
+@msg	`fontHeightReference` must be "emBox", "capHeight", "xHeight" or "icfBox"	`fontHeightReference` phải là "emBox", "capHeight", "xHeight" hoặc "icfBox"
 @msg	`{_1}` is no save command	`{_1}` không phải là lệnh lưu
 @msg	`{area}` is no recovery area name	`{area}` không phải là tên vùng phục hồi
 @msg	`{color}` is not a colour (#rrggbb or a preset name)	`{color}` không phải là màu (#rrggbb hoặc tên thiết lập sẵn)

crates/ui-egui/src/i18n/zh-hans.tsv

@@ -889,6 +889,13 @@
 	Em Box Top/Right	全角字框上 / 右
 	ICF Top/Right	ICF 上 / 右
 	ICF Bottom/Left	ICF 下 / 左
+	Show Font Height Options	显示字体高度选项
+	Hide Font Height Options	隐藏字体高度选项
+	Set Font Height Reference	设置字体高度参考
+	Em Box	全角字框
+	Cap Height	大写字母高度
+	x-Height	x 字高
+	ICF Box	ICF 框
 	Em Dash	长破折号
 	Em Space	全角空格
 	Embed	嵌入
@@ -3720,6 +3727,7 @@ imageTrace	Outline	轮廓
 @msg	Saving {_1}	正在保存 {_1}
 @msg	Sent to {_1}	已发送到 {_1}
 @msg	`to` must be "corner" or "smooth"	`to` 必须是 "corner" 或 "smooth"
+@msg	`fontHeightReference` must be "emBox", "capHeight", "xHeight" or "icfBox"	`fontHeightReference` 必须是 "emBox"、"capHeight"、"xHeight" 或 "icfBox"
 @msg	a layer couldn't be read	无法读取某个图层
 @msg	it has more than one artboard	它有多个画板
 @msg	its editing data has no layers	其编辑数据中没有图层

crates/ui-egui/src/i18n/zh-hant.tsv

@@ -911,6 +911,13 @@ font-technology	Variable	可變
 	Em Box Top/Right	全形字框上 / 右
 	ICF Top/Right	ICF 上 / 右
 	ICF Bottom/Left	ICF 下 / 左
+	Show Font Height Options	顯示字體高度選項
+	Hide Font Height Options	隱藏字體高度選項
+	Set Font Height Reference	設定字體高度參考
+	Em Box	全形字框
+	Cap Height	大寫字母高度
+	x-Height	x 字高
+	ICF Box	ICF 框
 	Em Dash	長破折號
 	Em Space	全形空格
 	Embed	嵌入
@@ -1645,6 +1652,7 @@ file-filter	Templates	範本
 @msg	Saving {_1}	正在儲存 {_1}
 @msg	Sent to {_1}	已傳送至 {_1}
 @msg	`to` must be "corner" or "smooth"	`to` 必須是 "corner" 或 "smooth"
+@msg	`fontHeightReference` must be "emBox", "capHeight", "xHeight" or "icfBox"	`fontHeightReference` 必須是 "emBox"、"capHeight"、"xHeight" 或 "icfBox"
 @msg	a layer couldn't be read	有一個圖層無法讀取
 @msg	it has more than one artboard	它有多個工作區域
 @msg	its editing data has no layers	其編輯資料中沒有圖層

crates/ui-egui/src/panels/character.rs

@@ -91,20 +91,27 @@ pub(crate) fn shared_text_flag(app: &VectorcraftApp, f: impl Fn(&vectorcraft_doc
 /// caret's style at a caret), else every run of the selected type, groups' included. `None` (a
 /// blank field) where they differ, or with no type.
 pub(crate) fn shared<T: PartialEq>(app: &VectorcraftApp, f: impl Fn(&CharStyle) -> T) -> Option<T> {
-    shared_styles(app, |_, _, style| Some(f(style)))
+    shared_styles(app, |_, _, style, _| Some(f(style)))
 }
 
 /// Dimensional controls use document units and tolerate arithmetic roundoff when comparing
 /// compensated runs. Keep raw styles available to font/paragraph controls and style definitions,
 /// even if a collapsed affine prevents editing dimensions.
 fn shared_effective(app: &VectorcraftApp, f: impl Fn(&CharStyle) -> f64) -> Option<f64> {
-    shared_styles(app, |t, _, style| t.effective_char_style(style).map(|s| Metric(f(&s)))).map(|v| v.0)
+    shared_styles(app, |t, _, style, _| t.effective_char_style(style).map(|s| Metric(f(&s)))).map(|v| v.0)
 }
 
-/// The Leading shown: each character's own, or for Auto leading the share of its size its
-/// paragraph's Justification › Auto Leading sets, as the layout uses.
+/// The Leading shown: each character's own, or for Auto leading the share of the em size their
+/// font height reference gives them ([`vectorcraft_text::FontDb::em_size`]) that their paragraph's
+/// Justification › Auto Leading sets, as the layout uses. An inline graphic keeps its size.
 fn shared_leading(app: &VectorcraftApp) -> Option<f64> {
-    shared_styles(app, |t, para, style| t.effective_char_style(style).map(|s| Metric(para.effective_leading(&s)))).map(|v| v.0)
+    let db = vectorcraft_text::FontDb::global();
+    shared_styles(app, |t, para, style, inline| {
+        let s = t.effective_char_style(style)?;
+        let em = if inline { s.size } else { db.em_size(&s, t.vertical) };
+        Some(Metric(para.effective_leading(&CharStyle { size: em, ..s })))
+    })
+    .map(|v| v.0)
 }
 
 pub(crate) struct Metric(pub(crate) f64);
@@ -115,11 +122,12 @@ impl PartialEq for Metric {
     }
 }
 
-/// `f` of each character style in the selection, with its text object and the paragraph the
-/// characters are in (a run that spans paragraphs counts once for each).
+/// `f` of each character style in the selection, with its text object, the paragraph the
+/// characters are in (a run that spans paragraphs counts once for each) and whether the run is an
+/// inline graphic.
 fn shared_styles<T: PartialEq>(
     app: &VectorcraftApp,
-    f: impl Fn(&vectorcraft_doc::TextObject, &vectorcraft_doc::ParaStyle, &CharStyle) -> Option<T>,
+    f: impl Fn(&vectorcraft_doc::TextObject, &vectorcraft_doc::ParaStyle, &CharStyle, bool) -> Option<T>,
 ) -> Option<T> {
     let st = app.session.active()?;
     let text = |id: NodeId| match st.doc.node(id).map(|n| &n.kind) {
@@ -131,14 +139,14 @@ fn shared_styles<T: PartialEq>(
         let t = text(id)?;
         if b <= a {
             let para = t.plain_text().get(..a).map_or(0, |s| s.bytes().filter(|&c| c == b'\n').count());
-            return f(t, t.para_at(para), &vectorcraft_text::edit::insertion_style(&t.runs, a, b));
+            return f(t, t.para_at(para), &vectorcraft_text::edit::insertion_style(&t.runs, a, b), false);
         }
-        each_paragraph_run(t, Some((a, b)), |para, style| acc.add(f(t, para, style)));
+        each_paragraph_run(t, Some((a, b)), |para, style, inline| acc.add(f(t, para, style, inline)));
     } else {
         for n in st.selection.objects.iter().filter_map(|id| st.doc.node(*id)) {
             n.walk(&mut |c| {
                 if let NodeKind::Text(t) = &c.kind {
-                    each_paragraph_run(t, None, |para, style| acc.add(f(t, para, style)));
+                    each_paragraph_run(t, None, |para, style, inline| acc.add(f(t, para, style, inline)));
                 }
             });
         }
@@ -147,13 +155,14 @@ fn shared_styles<T: PartialEq>(
 }
 
 /// `f` of the paragraph and style of each piece of `t`'s runs that lies in one paragraph (a
-/// paragraph's closing line break belongs to it): the pieces within bytes `a..b`, or with no
-/// range every run's, empty ones included. With no range, a final empty paragraph (the text ends
-/// in a line break) counts too, with the style of the run before it, as the caret there types.
+/// paragraph's closing line break belongs to it), and whether the run is an inline graphic: the
+/// pieces within bytes `a..b`, or with no range every run's, empty ones included. With no range, a
+/// final empty paragraph (the text ends in a line break) counts too, with the style of the run
+/// before it, as the caret there types.
 fn each_paragraph_run<'a>(
     t: &'a vectorcraft_doc::TextObject,
     range: Option<(usize, usize)>,
-    mut f: impl FnMut(&'a vectorcraft_doc::ParaStyle, &'a CharStyle),
+    mut f: impl FnMut(&'a vectorcraft_doc::ParaStyle, &'a CharStyle, bool),
 ) {
     let (mut end, mut para) = (0, 0);
     // The style of the last character and whether it is a line break: the paragraph after it has
@@ -162,7 +171,7 @@ fn each_paragraph_run<'a>(
     for r in &t.runs {
         if r.text.is_empty() {
             if range.is_none_or(|(a, b)| a < end && end < b) {
-                f(t.para_at(para), &r.style);
+                f(t.para_at(para), &r.style, r.inline.is_some());
             }
             continue;
         }
@@ -170,7 +179,7 @@ fn each_paragraph_run<'a>(
             let start = end;
             end += piece.len();
             if range.is_none_or(|(a, b)| start < b && end > a) {
-                f(t.para_at(para), &r.style);
+                f(t.para_at(para), &r.style, r.inline.is_some());
             }
             para += usize::from(piece.ends_with('\n'));
             last = Some((&r.style, piece.ends_with('\n')));
@@ -179,7 +188,7 @@ fn each_paragraph_run<'a>(
     if range.is_none()
         && let Some((style, true)) = last
     {
-        f(t.para_at(para), style);
+        f(t.para_at(para), style, false);
     }
 }
 
@@ -657,7 +666,8 @@ fn cell(ui: &mut Ui, label: &str, tip: &str, add: impl FnOnce(&mut Ui)) {
 
 /// The Character panel's grid of numeric fields, `w` wide: Font Size, Leading, Kerning and
 /// Tracking, then with `more` the scales, Baseline Shift and Character Rotation (`s`: the style
-/// shown). The Properties panel shows its first rows.
+/// shown). With Show Font Height Options on, a row under Font Size holds the Set Font Height
+/// Reference dropdown. The Properties panel shows its first rows.
 pub(crate) fn metrics_grid(app: &mut VectorcraftApp, ui: &mut Ui, id: &str, s: &CharStyle, w: f32, more: bool) {
     let fw = ((w - 66.0) / 2.0).clamp(60.0, 100.0);
     let unit = app.session.type_unit();
@@ -674,6 +684,10 @@ pub(crate) fn metrics_grid(app: &mut VectorcraftApp, ui: &mut Ui, id: &str, s: &
             }
         });
         ui.end_row();
+        if pstate::<bool>(ui.ctx(), FONT_HEIGHT_OPTIONS) {
+            cell(ui, "T↕", tl!("Set Font Height Reference"), |ui| font_height_reference(app, ui, fw));
+            ui.end_row();
+        }
         cell(ui, "VA", tl!("Kerning"), |ui| {
             let mode = shared(app, |s| (s.optical_kerning, s.kerning));
             let caret = text_editing(app).is_some_and(|(_, a, b)| a == b);
@@ -741,6 +755,30 @@ pub(crate) fn size_field(app: &mut VectorcraftApp, ui: &mut Ui, id: &str, width:
     }
 }
 
+/// The panel state of the Character panel menu's Show Font Height Options.
+const FONT_HEIGHT_OPTIONS: &str = "ch-font-height-options";
+
+/// The font height references the Set Font Height Reference dropdown lists, with their
+/// `text.setFormat` values.
+const FONT_HEIGHT_REFERENCES: [(vectorcraft_doc::FontHeightReference, &str); 4] = [
+    (vectorcraft_doc::FontHeightReference::EmBox, "emBox"),
+    (vectorcraft_doc::FontHeightReference::CapHeight, "capHeight"),
+    (vectorcraft_doc::FontHeightReference::XHeight, "xHeight"),
+    (vectorcraft_doc::FontHeightReference::IcfBox, "icfBox"),
+];
+
+/// The Set Font Height Reference dropdown, `width` wide: the height of the font that the Font Size
+/// measures, blank where the characters the panel acts on differ.
+fn font_height_reference(app: &mut VectorcraftApp, ui: &mut Ui, width: f32) {
+    // The labels of [`FONT_HEIGHT_REFERENCES`], in its order.
+    let labels = [tl!("Em Box"), tl!("Cap Height"), tl!("x-Height"), tl!("ICF Box")];
+    let current = shared(app, |s| s.font_height_reference);
+    let shown = FONT_HEIGHT_REFERENCES.iter().zip(labels).find(|(r, _)| Some(r.0) == current).map_or("", |(_, l)| l);
+    if let Some((_, key)) = widgets::dropdown_names(ui, "ch-font-height", shown, &labels, width).and_then(|i| FONT_HEIGHT_REFERENCES.get(i)) {
+        format(app, json!({"fontHeightReference": key}));
+    }
+}
+
 /// The font family menu and the font style dropdown of style `s` (Character and Properties panels,
 /// Control bar), with their `ids` and `widths`.
 pub(crate) fn font_pickers(app: &mut VectorcraftApp, ui: &mut Ui, s: &CharStyle, ids: (&str, &str), widths: (f32, f32)) {
@@ -1065,6 +1103,11 @@ pub fn menu(app: &mut VectorcraftApp, ui: &mut Ui) {
     if menu_item(ui, if glyph { tl!("Hide Snap to Glyph Options") } else { tl!("Show Snap to Glyph Options") }, true, false) {
         set_pstate(ui.ctx(), SNAP_TO_GLYPH_OPTIONS, !glyph);
     }
+    // Show Font Height Options shows the Set Font Height Reference dropdown under Font Size.
+    let heights: bool = pstate(ui.ctx(), FONT_HEIGHT_OPTIONS);
+    if menu_item(ui, if heights { tl!("Hide Font Height Options") } else { tl!("Show Font Height Options") }, true, false) {
+        set_pstate(ui.ctx(), FONT_HEIGHT_OPTIONS, !heights);
+    }
     ui.separator();
     let s = st.map(|x| x.0);
     for (label, key, on) in [
@@ -1191,8 +1234,9 @@ fn fractional_widths_on(app: &VectorcraftApp) -> bool {
 /// kerning, no baseline shift, 100% scales, no rotation, no underline or strikethrough, All Caps
 /// and Small Caps off, the normal position (neither superscript nor subscript), Roman Baseline
 /// character alignment, Proportional Metrics, Tate-chu-yoko, Standard Vertical Roman Alignment and
-/// No Break off, the Default character direction and the Default digits, whether or not Show East
-/// Asian Options and Show Indic Options are on.
+/// No Break off, the Default character direction, the Default digits and the Em Box font height
+/// reference, whether or not Show East Asian Options, Show Indic Options and Show Font Height
+/// Options are on.
 fn reset_panel(app: &mut VectorcraftApp) {
     let d = CharStyle::default();
     style(app, json!({"tracking": 0, "leading": "auto"}));
@@ -1203,7 +1247,7 @@ fn reset_panel(app: &mut VectorcraftApp) {
             "allCaps": false, "smallCaps": d.small_caps.is_some(), "position": d.position.id(), "charAlign": d.char_align,
             "proportionalMetrics": d.proportional_metrics, "tateChuYoko": d.tate_chu_yoko,
             "standardVerticalRoman": d.standard_vertical_roman, "noBreak": d.no_break, "charDirection": "default",
-            "digits": d.digits
+            "digits": d.digits, "fontHeightReference": d.font_height_reference
         }),
     );
 }

crates/ui-egui/src/panels/character/tests.rs

@@ -89,6 +89,102 @@ fn scaled_character_fields_show_document_sizes_and_mixed_group_values() {
     assert_eq!(shared_effective(&app, |s| s.h_scale), Some(100.0));
 }
 
+/// The Leading field shows the Auto leading the characters are set with, their paragraph's Auto
+/// Leading share (120% by default) of their em size: 20 pt type measuring a 0.7 em cap height
+/// is set at 20 / 0.7 pt. Paragraphs whose Auto leading differs show a blank field, and an
+/// explicit leading shows as it is.
+#[test]
+fn leading_shows_the_auto_leading_of_the_em_size() {
+    use vectorcraft_text::test_fonts::{HEIGHT_CAP, HEIGHT_FAMILY, height_font};
+    vectorcraft_text::FontDb::global().add_font(height_font(true).unwrap());
+    let mut app = VectorcraftApp::new(Session::new(), Default::default());
+    app.run("file.new", json!({"width": 300, "height": 200})).unwrap();
+    let id = app.run("text.create", json!({"x": 20, "y": 50, "text": "Hx", "size": 20, "font": HEIGHT_FAMILY})).unwrap()["id"].clone();
+    app.run("select.set", json!({"ids": [id]})).unwrap();
+    let near = |l: Option<f64>, want: f64| l.is_some_and(|l| (l - want).abs() < 1e-9);
+    assert!(near(shared_leading(&app), 24.0), "{:?}", shared_leading(&app));
+    app.run("text.setFormat", json!({"fontHeightReference": "capHeight"})).unwrap();
+    let cap = f64::from(HEIGHT_CAP) / 1000.0;
+    assert!(near(shared_leading(&app), 1.2 * 20.0 / cap), "{:?}", shared_leading(&app));
+    app.run("text.setFormat", json!({"autoLeading": 150})).unwrap();
+    assert!(near(shared_leading(&app), 1.5 * 20.0 / cap), "{:?}", shared_leading(&app));
+    // The second paragraph ends in a two-byte character.
+    let two = app.run("text.create", json!({"x": 20, "y": 120, "text": "Hx\nHé", "size": 20, "font": HEIGHT_FAMILY})).unwrap()["id"].clone();
+    app.run("select.set", json!({"ids": [two]})).unwrap();
+    assert!(near(shared_leading(&app), 24.0), "{:?}", shared_leading(&app));
+    app.run("text.setFormat", json!({"id": two, "start": 3, "end": 6, "autoLeading": 150})).unwrap();
+    assert_eq!(shared_leading(&app), None, "the second paragraph's Auto leading is 30 pt");
+    app.run("select.set", json!({"ids": [id]})).unwrap();
+    app.run("text.setStyle", json!({"leading": 30})).unwrap();
+    assert!(near(shared_leading(&app), 30.0), "{:?}", shared_leading(&app));
+}
+
+/// An inline graphic keeps its size whatever the font height reference, so the Leading field
+/// shows 120% of that size for it: blank for 20 pt Cap Height type with a graphic in it, and
+/// 24 pt for the graphic alone.
+#[test]
+fn leading_of_an_inline_graphic_follows_its_own_size() {
+    use vectorcraft_text::test_fonts::{HEIGHT_FAMILY, height_font};
+    vectorcraft_text::FontDb::global().add_font(height_font(true).unwrap());
+    let mut app = VectorcraftApp::new(Session::new(), Default::default());
+    app.run("file.new", json!({"width": 300, "height": 200})).unwrap();
+    app.run("shape.ellipse", json!({"x": 200, "y": 150, "width": 10, "height": 10})).unwrap();
+    app.run("symbol.new", json!({"name": "Dot"})).unwrap();
+    app.run("edit.clear", json!({})).unwrap();
+    app.session.select_tool("type", Default::default()).unwrap();
+    let id = app.run("text.create", json!({"x": 20, "y": 50, "text": "Hx", "size": 20, "font": HEIGHT_FAMILY})).unwrap()["id"].clone();
+    app.session.apply_actions(vec![vectorcraft_tools::Action::Notify("text.editNew".into())]).unwrap();
+    app.run("text.insertInline", json!({"id": id, "at": 2, "symbol": "Dot"})).unwrap();
+    app.run("text.setRangeStyle", json!({"id": id, "start": 0, "end": 5, "fontHeightReference": "capHeight"})).unwrap();
+    app.session.set_tool_option("select", &json!({"start": 0, "end": 5}));
+    assert_eq!(shared_leading(&app), None, "the type is set with 34.3 pt Auto leading and the graphic with 24 pt");
+    app.session.set_tool_option("select", &json!({"start": 2, "end": 5}));
+    assert_eq!(text_editing(&app).map(|(_, a, b)| (a, b)), Some((2, 5)));
+    let shown = shared_leading(&app);
+    assert!(shown.is_some_and(|l| (l - 24.0).abs() < 1e-9), "{shown:?}");
+}
+
+/// A selected text object that ends in a line break has an empty last paragraph, which the
+/// Leading field takes in; a Type tool selection of all the text does not.
+#[test]
+fn leading_of_a_whole_object_takes_in_the_empty_last_paragraph() {
+    let mut app = VectorcraftApp::new(Session::new(), Default::default());
+    app.run("file.new", json!({"width": 300, "height": 200})).unwrap();
+    let id = app.run("text.create", json!({"x": 20, "y": 50, "text": "Ab\n", "size": 20})).unwrap()["id"].clone();
+    app.run("select.set", json!({"ids": [id]})).unwrap();
+    let near = |l: Option<f64>, want: f64| l.is_some_and(|l| (l - want).abs() < 1e-9);
+    assert!(near(shared_leading(&app), 24.0), "{:?}", shared_leading(&app));
+    app.run("text.setFormat", json!({"id": id, "start": 3, "end": 3, "autoLeading": 150})).unwrap();
+    assert_eq!(shared_leading(&app), None, "the empty last paragraph's Auto leading is 30 pt");
+    app.session.select_tool("type", Default::default()).unwrap();
+    app.session.apply_actions(vec![vectorcraft_tools::Action::Notify("text.editNew".into())]).unwrap();
+    app.session.set_tool_option("select", &json!({"start": 0, "end": 3}));
+    assert_eq!(text_editing(&app).map(|(_, a, b)| (a, b)), Some((0, 3)));
+    assert!(near(shared_leading(&app), 24.0), "a line break belongs to the paragraph it ends: {:?}", shared_leading(&app));
+}
+
+/// With the Type tool, the Leading field shows the Auto leading of the paragraphs the selection
+/// covers (a line break belongs to the paragraph it ends), and at a caret that of the caret's
+/// paragraph.
+#[test]
+fn leading_follows_the_paragraphs_the_type_tool_selection_covers() {
+    let mut app = VectorcraftApp::new(Session::new(), Default::default());
+    app.run("file.new", json!({"width": 300, "height": 200})).unwrap();
+    app.session.select_tool("type", Default::default()).unwrap();
+    // é is two bytes, 4..6.
+    let id = app.run("text.create", json!({"x": 20, "y": 50, "text": "Ab\nCé", "size": 20})).unwrap()["id"].clone();
+    app.session.apply_actions(vec![vectorcraft_tools::Action::Notify("text.editNew".into())]).unwrap();
+    app.run("text.setFormat", json!({"id": id, "start": 3, "end": 6, "autoLeading": 150})).unwrap();
+    let ranges = [((0, 2), Some(24.0)), ((0, 3), Some(24.0)), ((3, 6), Some(30.0)), ((1, 4), None), ((1, 6), None), ((4, 4), Some(30.0))];
+    for ((start, end), want) in ranges {
+        app.session.set_tool_option("select", &json!({"start": start, "end": end}));
+        assert_eq!(text_editing(&app).map(|(_, a, b)| (a, b)), Some((start, end)));
+        let shown = shared_leading(&app);
+        assert_eq!(shown.is_some(), want.is_some(), "{start}..{end}: {shown:?}");
+        assert!(shown.zip(want).is_none_or(|(l, w)| (l - w).abs() < 1e-9), "{start}..{end}: {shown:?}");
+    }
+}
+
 #[test]
 fn scaled_range_fields_follow_the_type_tool_selection() {
     let mut app = VectorcraftApp::new(Session::new(), Default::default());
@@ -498,6 +594,48 @@ fn character_alignment_shows_with_the_east_asian_options() {
     assert_eq!(shown(&mut app), (true, true));
 }
 
+/// The panel menu's Show Font Height Options shows the Set Font Height Reference dropdown,
+/// which shows the selected type's reference and sets the one picked (one undo step); Hide
+/// Font Height Options hides it again.
+#[test]
+fn show_font_height_options_shows_the_font_height_reference() {
+    use super::super::tests_appearance::{click, frame_events, text_rect};
+    use vectorcraft_doc::FontHeightReference as R;
+    let mut app = VectorcraftApp::new(Session::new(), Default::default());
+    app.run("file.new", json!({"width": 300, "height": 200})).unwrap();
+    let id = app.run("text.create", json!({"x": 20, "y": 50, "text": "Hx", "size": 12})).unwrap()["id"].as_u64().unwrap();
+    app.run("select.set", json!({"ids": [id]})).unwrap();
+    let reference = |app: &VectorcraftApp| match &app.session.active().unwrap().doc.node(NodeId(id)).unwrap().kind {
+        NodeKind::Text(t) => t.runs.iter().map(|r| r.style.font_height_reference).collect::<Vec<_>>(),
+        _ => panic!("text"),
+    };
+    let ctx = egui::Context::default();
+    crate::theme::install_fonts(&ctx);
+    let texts = |ctx: &egui::Context, app: &mut VectorcraftApp, f: fn(&mut VectorcraftApp, &mut Ui)| {
+        frame_events(ctx, app, vec![], f);
+        frame_events(ctx, app, vec![], f)
+    };
+    // A menu item's label is drawn after its check column (a check mark or spaces).
+    let item = |texts: &[(String, egui::Rect)], s: &str| texts.iter().find(|(t, _)| t.trim_start_matches(['✓', ' ']) == s).map(|(_, r)| r.center());
+    assert!(item(&texts(&ctx, &mut app, show), "Em Box").is_none());
+    let at = item(&texts(&ctx, &mut app, menu), "Show Font Height Options").unwrap();
+    click(&ctx, &mut app, at, menu);
+    assert!(item(&texts(&ctx, &mut app, menu), "Hide Font Height Options").is_some());
+    let panel = texts(&ctx, &mut app, show);
+    assert!(item(&panel, "Em Box").is_some(), "{panel:?}");
+    // Pick Cap Height from the dropdown.
+    click(&ctx, &mut app, text_rect(&panel, "Em Box").center(), show);
+    let undo = app.session.active().unwrap().history.undo.len();
+    let open = texts(&ctx, &mut app, show);
+    click(&ctx, &mut app, text_rect(&open, "Cap Height").center(), show);
+    assert_eq!(reference(&app), [R::CapHeight]);
+    assert_eq!(app.session.active().unwrap().history.undo.len(), undo + 1);
+    assert!(item(&texts(&ctx, &mut app, show), "Cap Height").is_some());
+    let at = item(&texts(&ctx, &mut app, menu), "Hide Font Height Options").unwrap();
+    click(&ctx, &mut app, at, menu);
+    assert!(item(&texts(&ctx, &mut app, show), "Cap Height").is_none());
+}
+
 /// Tate-chu-yoko is in the panel menu with the East Asian options, and choosing it marks the
 /// selected characters.
 #[test]
@@ -723,8 +861,8 @@ fn no_break_menu_item_toggles_the_selected_characters() {
 
 /// Reset Panel sets every character attribute the panel shows, except the font family, style
 /// and size, back to its default (Small Caps, the position, Character Alignment, Proportional
-/// Metrics, Tate-chu-yoko, No Break, Character Direction and Digits included), in the selected
-/// type and in the text the Type tool has selected while it edits.
+/// Metrics, Tate-chu-yoko, No Break, Character Direction, Digits and the font height reference
+/// included), in the selected type and in the text the Type tool has selected while it edits.
 #[test]
 fn reset_panel_resets_every_attribute_but_the_font() {
     let mut app = VectorcraftApp::new(Session::new(), Default::default());
@@ -755,6 +893,7 @@ fn reset_panel_resets_every_attribute_but_the_font() {
             s.no_break != d.no_break,
             s.char_direction != d.char_direction,
             s.digits != d.digits,
+            s.font_height_reference != d.font_height_reference,
         ]
     };
     let custom = |app: &mut VectorcraftApp| {
@@ -764,16 +903,16 @@ fn reset_panel_resets_every_attribute_but_the_font() {
                 "id": id, "tracking": 50, "leading": 30, "kerning": 20, "baselineShift": 3, "hScale": 120, "vScale": 90, "rotation": 15,
                 "underline": true, "strikethrough": true, "allCaps": true, "smallCaps": true, "position": "superscript",
                 "charAlign": "emBoxCenter", "proportionalMetrics": true, "tateChuYoko": true, "standardVerticalRoman": true,
-                "noBreak": true, "charDirection": "rightToLeft", "digits": "hindi"
+                "noBreak": true, "charDirection": "rightToLeft", "digits": "hindi", "fontHeightReference": "capHeight"
             }),
         )
         .unwrap();
     };
     let plain = runs(&app)[0].1.clone();
-    assert_eq!(differs(&plain, &CharStyle::default()), [false; 19]);
+    assert_eq!(differs(&plain, &CharStyle::default()), [false; 20]);
     custom(&mut app);
     let styled = runs(&app)[0].1.clone();
-    assert_eq!(differs(&styled, &CharStyle::default()), [true; 19]);
+    assert_eq!(differs(&styled, &CharStyle::default()), [true; 20]);
     app.run("select.set", json!({"ids": [id]})).unwrap();
     reset_panel(&mut app);
     assert_eq!(runs(&app), [("One 12".to_string(), plain.clone())]);

docs/mcp.md

@@ -5119,6 +5119,27 @@ A digit the font lacks comes from a fallback font. Default and saved only when s
 {"name":"run_command","arguments":{"command":"text.setFormat","params":{"digits":"hindi"}}}
 ```
 
+## Font height reference
+
+`text.setFormat {fontHeightReference: "emBox"|"capHeight"|"xHeight"|"icfBox"}` (the selected type, or `ids`) and
+`text.setRangeStyle {id, start, end, fontHeightReference}` (a range) set the height of the font that the characters' font
+size measures, as the Character panel's Set Font Height Reference dropdown does (panel menu › Show Font Height Options).
+With `emBox`, the default, the font size is the size of the em square. With `capHeight`, `xHeight` or `icfBox`, the
+characters are set at the em size at which the font's cap height or x height (OS/2 `sCapHeight`, `sxHeight`), or the
+height of its ideographic character face (the BASE table's `icfb` and `icft`, else the ink of some ideographs and kana;
+across a vertical line, its width), equals the font size: 20 pt Cap Height type in a font whose capitals are 0.7 em
+tall is set at about 28.6 pt, and its font size stays 20 pt. With a font that has no such value, or one outside 0.1 to 2
+em, the size measures the em box. Auto leading, tracking and kerning follow the em size the characters are set at (the
+Character panel's Leading field shows that Auto leading, and `type.step {attribute: "leading"}` starts from it);
+explicit leading and baseline shift stay in points, and an inline graphic keeps its size.
+SVG, PDF and legacy `.ai` export and the CSS Properties rules write the em size. DXF export writes 0.7 times the em
+size as each TEXT entity's height (group 40, the height of its capitals).
+Saved only when not `emBox`. One undo step.
+
+```json
+{"name":"run_command","arguments":{"command":"text.setFormat","params":{"fontHeightReference":"capHeight"}}}
+```
+
 ## Language
 
 `text.setFormat {language}` (the selected type, or `ids`) and `text.setRangeStyle {id, start, end, language}` (a range)