Use the shaper in math (#6336)

crates/typst-layout/src/inline/mod.rs

@@ -9,6 +9,7 @@ mod prepare;
 mod shaping;
 
 pub use self::box_::layout_box;
+pub use self::shaping::create_shape_plan;
 
 use comemo::{Track, Tracked, TrackedMut};
 use typst_library::diag::SourceResult;

crates/typst-layout/src/inline/shaping.rs

@@ -1,18 +1,16 @@
 use std::borrow::Cow;
 use std::fmt::{self, Debug, Formatter};
-use std::str::FromStr;
 use std::sync::Arc;
 
 use az::SaturatingAs;
-use ecow::EcoString;
 use rustybuzz::{BufferFlags, ShapePlan, UnicodeBuffer};
 use ttf_parser::Tag;
 use typst_library::engine::Engine;
 use typst_library::foundations::{Smart, StyleChain};
 use typst_library::layout::{Abs, Dir, Em, Frame, FrameItem, Point, Size};
 use typst_library::text::{
-    families, features, is_default_ignorable, variant, Font, FontFamily, FontVariant,
+    families, features, is_default_ignorable, language, variant, Font, FontFamily,
-    Glyph, Lang, Region, TextEdgeBounds, TextElem, TextItem,
+    FontVariant, Glyph, Lang, Region, TextEdgeBounds, TextElem, TextItem,
 };
 use typst_library::World;
 use typst_utils::SliceExt;
@@ -295,6 +293,8 @@ impl<'a> ShapedText<'a> {
                             + justification_left
                             + justification_right,
                         x_offset: shaped.x_offset + justification_left,
+                        y_advance: Em::zero(),
+                        y_offset: Em::zero(),
                         range: (shaped.range.start - range.start).saturating_as()
                             ..(shaped.range.end - range.start).saturating_as(),
                         span,
@@ -934,7 +934,7 @@ fn shape_segment<'a>(
 
 /// Create a shape plan.
 #[comemo::memoize]
-fn create_shape_plan(
+pub fn create_shape_plan(
     font: &Font,
     direction: rustybuzz::Direction,
     script: rustybuzz::Script,
@@ -952,7 +952,7 @@ fn create_shape_plan(
 
 /// Shape the text with tofus from the given font.
 fn shape_tofus(ctx: &mut ShapingContext, base: usize, text: &str, font: Font) {
-    let x_advance = font.advance(0).unwrap_or_default();
+    let x_advance = font.x_advance(0).unwrap_or_default();
     let add_glyph = |(cluster, c): (usize, char)| {
         let start = base + cluster;
         let end = start + c.len_utf8();
@@ -1044,20 +1044,8 @@ fn calculate_adjustability(ctx: &mut ShapingContext, lang: Lang, region: Option<
 
 /// Difference between non-breaking and normal space.
 fn nbsp_delta(font: &Font) -> Option<Em> {
-    let space = font.ttf().glyph_index(' ')?.0;
     let nbsp = font.ttf().glyph_index('\u{00A0}')?.0;
-    Some(font.advance(nbsp)? - font.advance(space)?)
+    Some(font.x_advance(nbsp)? - font.space_width()?)
-}
-
-/// Process the language and region of a style chain into a
-/// rustybuzz-compatible BCP 47 language.
-fn language(styles: StyleChain) -> rustybuzz::Language {
-    let mut bcp: EcoString = TextElem::lang_in(styles).as_str().into();
-    if let Some(region) = TextElem::region_in(styles) {
-        bcp.push('-');
-        bcp.push_str(region.as_str());
-    }
-    rustybuzz::Language::from_str(&bcp).unwrap()
 }
 
 /// Returns true if all glyphs in `glyphs` have ranges within the range `range`.

crates/typst-layout/src/math/accent.rs

@@ -3,7 +3,10 @@ use typst_library::foundations::{Packed, StyleChain};
 use typst_library::layout::{Em, Frame, Point, Size};
 use typst_library::math::AccentElem;
 
-use super::{style_cramped, FrameFragment, GlyphFragment, MathContext, MathFragment};
+use super::{
+    style_cramped, style_dtls, style_flac, FrameFragment, GlyphFragment, MathContext,
+    MathFragment,
+};
 
 /// How much the accent can be shorter than the base.
 const ACCENT_SHORT_FALL: Em = Em::new(0.5);
@@ -15,40 +18,40 @@ pub fn layout_accent(
     ctx: &mut MathContext,
     styles: StyleChain,
 ) -> SourceResult<()> {
-    let cramped = style_cramped();
-    let mut base = ctx.layout_into_fragment(&elem.base, styles.chain(&cramped))?;
-
     let accent = elem.accent;
     let top_accent = !accent.is_bottom();
 
-    // Try to replace base glyph with its dotless variant.
+    // Try to replace the base glyph with its dotless variant.
-    if top_accent && elem.dotless(styles) {
+    let dtls = style_dtls();
-        if let MathFragment::Glyph(glyph) = &mut base {
+    let base_styles =
-            glyph.make_dotless_form(ctx);
+        if top_accent && elem.dotless(styles) { styles.chain(&dtls) } else { styles };
-        }
+
-    }
+    let cramped = style_cramped();
+    let base = ctx.layout_into_fragment(&elem.base, base_styles.chain(&cramped))?;
 
     // Preserve class to preserve automatic spacing.
     let base_class = base.class();
     let base_attach = base.accent_attach();
 
-    let mut glyph = GlyphFragment::new(ctx, styles, accent.0, elem.span());
+    // Try to replace the accent glyph with its flattened variant.
+    let flattened_base_height = scaled!(ctx, styles, flattened_accent_base_height);
+    let flac = style_flac();
+    let accent_styles = if top_accent && base.ascent() > flattened_base_height {
+        styles.chain(&flac)
+    } else {
+        styles
+    };
 
-    // Try to replace accent glyph with its flattened variant.
+    let mut glyph =
-    if top_accent {
+        GlyphFragment::new_char(ctx.font, accent_styles, accent.0, elem.span())?;
-        let flattened_base_height = scaled!(ctx, styles, flattened_accent_base_height);
-        if base.ascent() > flattened_base_height {
-            glyph.make_flattened_accent_form(ctx);
-        }
-    }
 
-    // Forcing the accent to be at least as large as the base makes it too
+    // Forcing the accent to be at least as large as the base makes it too wide
-    // wide in many case.
+    // in many cases.
     let width = elem.size(styles).relative_to(base.width());
-    let short_fall = ACCENT_SHORT_FALL.at(glyph.font_size);
+    let short_fall = ACCENT_SHORT_FALL.at(glyph.item.size);
-    let variant = glyph.stretch_horizontal(ctx, width - short_fall);
+    glyph.stretch_horizontal(ctx, width - short_fall);
-    let accent = variant.frame;
+    let accent_attach = glyph.accent_attach.0;
-    let accent_attach = variant.accent_attach.0;
+    let accent = glyph.into_frame();
 
     let (gap, accent_pos, base_pos) = if top_accent {
         // Descent is negative because the accent's ink bottom is above the

crates/typst-layout/src/math/attach.rs

@@ -66,7 +66,6 @@ pub fn layout_attach(
         let relative_to_width = measure!(t, width).max(measure!(b, width));
         stretch_fragment(
             ctx,
-            styles,
             &mut base,
             Some(Axis::X),
             Some(relative_to_width),
@@ -220,7 +219,6 @@ fn layout_attachments(
     // Calculate the distance each pre-script extends to the left of the base's
     // width.
     let (tl_pre_width, bl_pre_width) = compute_pre_script_widths(
-        ctx,
         &base,
         [tl.as_ref(), bl.as_ref()],
         (tx_shift, bx_shift),
@@ -231,7 +229,6 @@ fn layout_attachments(
     // base's width. Also calculate each post-script's kerning (we need this for
     // its position later).
     let ((tr_post_width, tr_kern), (br_post_width, br_kern)) = compute_post_script_widths(
-        ctx,
         &base,
         [tr.as_ref(), br.as_ref()],
         (tx_shift, bx_shift),
@@ -287,14 +284,13 @@ fn layout_attachments(
 /// post-script's kerning value. The first tuple is for the post-superscript,
 /// and the second is for the post-subscript.
 fn compute_post_script_widths(
-    ctx: &MathContext,
     base: &MathFragment,
     [tr, br]: [Option<&MathFragment>; 2],
     (tr_shift, br_shift): (Abs, Abs),
     space_after_post_script: Abs,
 ) -> ((Abs, Abs), (Abs, Abs)) {
     let tr_values = tr.map_or_default(|tr| {
-        let kern = math_kern(ctx, base, tr, tr_shift, Corner::TopRight);
+        let kern = math_kern(base, tr, tr_shift, Corner::TopRight);
         (space_after_post_script + tr.width() + kern, kern)
     });
 
@@ -302,7 +298,7 @@ fn compute_post_script_widths(
     // need to shift the post-subscript left by the base's italic correction
     // (see the kerning algorithm as described in the OpenType MATH spec).
     let br_values = br.map_or_default(|br| {
-        let kern = math_kern(ctx, base, br, br_shift, Corner::BottomRight)
+        let kern = math_kern(base, br, br_shift, Corner::BottomRight)
             - base.italics_correction();
         (space_after_post_script + br.width() + kern, kern)
     });
@@ -317,19 +313,18 @@ fn compute_post_script_widths(
 /// extends left of the base's width and the second being the distance the
 /// pre-subscript extends left of the base's width.
 fn compute_pre_script_widths(
-    ctx: &MathContext,
     base: &MathFragment,
     [tl, bl]: [Option<&MathFragment>; 2],
     (tl_shift, bl_shift): (Abs, Abs),
     space_before_pre_script: Abs,
 ) -> (Abs, Abs) {
     let tl_pre_width = tl.map_or_default(|tl| {
-        let kern = math_kern(ctx, base, tl, tl_shift, Corner::TopLeft);
+        let kern = math_kern(base, tl, tl_shift, Corner::TopLeft);
         space_before_pre_script + tl.width() + kern
     });
 
     let bl_pre_width = bl.map_or_default(|bl| {
-        let kern = math_kern(ctx, base, bl, bl_shift, Corner::BottomLeft);
+        let kern = math_kern(base, bl, bl_shift, Corner::BottomLeft);
         space_before_pre_script + bl.width() + kern
     });
 
@@ -471,13 +466,7 @@ fn compute_script_shifts(
 /// a negative value means shifting the script closer to the base. Requires the
 /// distance from the base's baseline to the script's baseline, as well as the
 /// script's corner (tl, tr, bl, br).
-fn math_kern(
+fn math_kern(base: &MathFragment, script: &MathFragment, shift: Abs, pos: Corner) -> Abs {
-    ctx: &MathContext,
-    base: &MathFragment,
-    script: &MathFragment,
-    shift: Abs,
-    pos: Corner,
-) -> Abs {
     // This process is described under the MathKernInfo table in the OpenType
     // MATH spec.
 
@@ -502,8 +491,8 @@ fn math_kern(
 
     // Calculate the sum of kerning values for each correction height.
     let summed_kern = |height| {
-        let base_kern = base.kern_at_height(ctx, pos, height);
+        let base_kern = base.kern_at_height(pos, height);
-        let attach_kern = script.kern_at_height(ctx, pos.inv(), height);
+        let attach_kern = script.kern_at_height(pos.inv(), height);
         base_kern + attach_kern
     };
 

crates/typst-layout/src/math/frac.rs

@@ -109,14 +109,14 @@ fn layout_frac_like(
     frame.push_frame(denom_pos, denom);
 
     if binom {
-        let mut left = GlyphFragment::new(ctx, styles, '(', span)
+        let mut left = GlyphFragment::new_char(ctx.font, styles, '(', span)?;
-            .stretch_vertical(ctx, height - short_fall);
+        left.stretch_vertical(ctx, height - short_fall);
-        left.center_on_axis(ctx);
+        left.center_on_axis();
         ctx.push(left);
         ctx.push(FrameFragment::new(styles, frame));
-        let mut right = GlyphFragment::new(ctx, styles, ')', span)
+        let mut right = GlyphFragment::new_char(ctx.font, styles, ')', span)?;
-            .stretch_vertical(ctx, height - short_fall);
+        right.stretch_vertical(ctx, height - short_fall);
-        right.center_on_axis(ctx);
+        right.center_on_axis();
         ctx.push(right);
     } else {
         frame.push(

crates/typst-layout/src/math/lr.rs

@@ -45,20 +45,20 @@ pub fn layout_lr(
 
     // Scale up fragments at both ends.
     match inner_fragments {
-        [one] => scale(ctx, styles, one, relative_to, height, None),
+        [one] => scale(ctx, one, relative_to, height, None),
         [first, .., last] => {
-            scale(ctx, styles, first, relative_to, height, Some(MathClass::Opening));
+            scale(ctx, first, relative_to, height, Some(MathClass::Opening));
-            scale(ctx, styles, last, relative_to, height, Some(MathClass::Closing));
+            scale(ctx, last, relative_to, height, Some(MathClass::Closing));
         }
         _ => {}
     }
 
-    // Handle MathFragment::Variant fragments that should be scaled up.
+    // Handle MathFragment::Glyph fragments that should be scaled up.
     for fragment in inner_fragments.iter_mut() {
-        if let MathFragment::Variant(ref mut variant) = fragment {
+        if let MathFragment::Glyph(ref mut glyph) = fragment {
-            if variant.mid_stretched == Some(false) {
+            if glyph.mid_stretched == Some(false) {
-                variant.mid_stretched = Some(true);
+                glyph.mid_stretched = Some(true);
-                scale(ctx, styles, fragment, relative_to, height, Some(MathClass::Large));
+                scale(ctx, fragment, relative_to, height, Some(MathClass::Large));
             }
         }
     }
@@ -95,18 +95,9 @@ pub fn layout_mid(
     let mut fragments = ctx.layout_into_fragments(&elem.body, styles)?;
 
     for fragment in &mut fragments {
-        match fragment {
+        if let MathFragment::Glyph(ref mut glyph) = fragment {
-            MathFragment::Glyph(glyph) => {
+            glyph.mid_stretched = Some(false);
-                let mut new = glyph.clone().into_variant();
+            glyph.class = MathClass::Fence;
-                new.mid_stretched = Some(false);
-                new.class = MathClass::Fence;
-                *fragment = MathFragment::Variant(new);
-            }
-            MathFragment::Variant(variant) => {
-                variant.mid_stretched = Some(false);
-                variant.class = MathClass::Fence;
-            }
-            _ => {}
         }
     }
 
@@ -117,7 +108,6 @@ pub fn layout_mid(
 /// Scale a math fragment to a height.
 fn scale(
     ctx: &mut MathContext,
-    styles: StyleChain,
     fragment: &mut MathFragment,
     relative_to: Abs,
     height: Rel<Abs>,
@@ -132,7 +122,6 @@ fn scale(
         let short_fall = DELIM_SHORT_FALL.at(fragment.font_size().unwrap_or_default());
         stretch_fragment(
             ctx,
-            styles,
             fragment,
             Some(Axis::Y),
             Some(relative_to),

crates/typst-layout/src/math/mat.rs

@@ -9,8 +9,8 @@ use typst_library::visualize::{FillRule, FixedStroke, Geometry, LineCap, Shape};
 use typst_syntax::Span;
 
 use super::{
-    alignments, delimiter_alignment, style_for_denominator, AlignmentResult,
+    alignments, style_for_denominator, AlignmentResult, FrameFragment, GlyphFragment,
-    FrameFragment, GlyphFragment, LeftRightAlternator, MathContext, DELIM_SHORT_FALL,
+    LeftRightAlternator, MathContext, DELIM_SHORT_FALL,
 };
 
 const VERTICAL_PADDING: Ratio = Ratio::new(0.1);
@@ -183,8 +183,12 @@ fn layout_body(
     // We pad ascent and descent with the ascent and descent of the paren
     // to ensure that normal matrices are aligned with others unless they are
     // way too big.
-    let paren =
+    let paren = GlyphFragment::new_char(
-        GlyphFragment::new(ctx, styles.chain(&denom_style), '(', Span::detached());
+        ctx.font,
+        styles.chain(&denom_style),
+        '(',
+        Span::detached(),
+    )?;
 
     for (column, col) in columns.iter().zip(&mut cols) {
         for (cell, (ascent, descent)) in column.iter().zip(&mut heights) {
@@ -202,8 +206,8 @@ fn layout_body(
                 ));
             }
 
-            ascent.set_max(cell.ascent().max(paren.ascent));
+            ascent.set_max(cell.ascent().max(paren.ascent()));
-            descent.set_max(cell.descent().max(paren.descent));
+            descent.set_max(cell.descent().max(paren.descent()));
 
             col.push(cell);
         }
@@ -312,19 +316,19 @@ fn layout_delimiters(
     let target = height + VERTICAL_PADDING.of(height);
     frame.set_baseline(height / 2.0 + axis);
 
-    if let Some(left) = left {
+    if let Some(left_c) = left {
-        let mut left = GlyphFragment::new(ctx, styles, left, span)
+        let mut left = GlyphFragment::new_char(ctx.font, styles, left_c, span)?;
-            .stretch_vertical(ctx, target - short_fall);
+        left.stretch_vertical(ctx, target - short_fall);
-        left.align_on_axis(ctx, delimiter_alignment(left.c));
+        left.center_on_axis();
         ctx.push(left);
     }
 
     ctx.push(FrameFragment::new(styles, frame));
 
-    if let Some(right) = right {
+    if let Some(right_c) = right {
-        let mut right = GlyphFragment::new(ctx, styles, right, span)
+        let mut right = GlyphFragment::new_char(ctx.font, styles, right_c, span)?;
-            .stretch_vertical(ctx, target - short_fall);
+        right.stretch_vertical(ctx, target - short_fall);
-        right.align_on_axis(ctx, delimiter_alignment(right.c));
+        right.center_on_axis();
         ctx.push(right);
     }
 

crates/typst-layout/src/math/mod.rs

@@ -13,8 +13,6 @@ mod stretch;
 mod text;
 mod underover;
 
-use rustybuzz::Feature;
-use ttf_parser::Tag;
 use typst_library::diag::{bail, SourceResult};
 use typst_library::engine::Engine;
 use typst_library::foundations::{
@@ -30,7 +28,7 @@ use typst_library::math::*;
 use typst_library::model::ParElem;
 use typst_library::routines::{Arenas, RealizationKind};
 use typst_library::text::{
-    families, features, variant, Font, LinebreakElem, SpaceElem, TextEdgeBounds, TextElem,
+    families, variant, Font, LinebreakElem, SpaceElem, TextEdgeBounds, TextElem,
 };
 use typst_library::World;
 use typst_syntax::Span;
@@ -38,11 +36,11 @@ use typst_utils::Numeric;
 use unicode_math_class::MathClass;
 
 use self::fragment::{
-    FrameFragment, GlyphFragment, GlyphwiseSubsts, Limits, MathFragment, VariantFragment,
+    has_dtls_feat, stretch_axes, FrameFragment, GlyphFragment, Limits, MathFragment,
 };
 use self::run::{LeftRightAlternator, MathRun, MathRunFrameBuilder};
 use self::shared::*;
-use self::stretch::{stretch_fragment, stretch_glyph};
+use self::stretch::stretch_fragment;
 
 /// Layout an inline equation (in a paragraph).
 #[typst_macros::time(span = elem.span())]
@@ -58,7 +56,7 @@ pub fn layout_equation_inline(
     let font = find_math_font(engine, styles, elem.span())?;
 
     let mut locator = locator.split();
-    let mut ctx = MathContext::new(engine, &mut locator, styles, region, &font);
+    let mut ctx = MathContext::new(engine, &mut locator, region, &font);
 
     let scale_style = style_for_script_scale(&ctx);
     let styles = styles.chain(&scale_style);
@@ -113,7 +111,7 @@ pub fn layout_equation_block(
     let font = find_math_font(engine, styles, span)?;
 
     let mut locator = locator.split();
-    let mut ctx = MathContext::new(engine, &mut locator, styles, regions.base(), &font);
+    let mut ctx = MathContext::new(engine, &mut locator, regions.base(), &font);
 
     let scale_style = style_for_script_scale(&ctx);
     let styles = styles.chain(&scale_style);
@@ -374,14 +372,7 @@ struct MathContext<'a, 'v, 'e> {
     region: Region,
     // Font-related.
     font: &'a Font,
-    ttf: &'a ttf_parser::Face<'a>,
-    table: ttf_parser::math::Table<'a>,
     constants: ttf_parser::math::Constants<'a>,
-    dtls_table: Option<GlyphwiseSubsts<'a>>,
-    flac_table: Option<GlyphwiseSubsts<'a>>,
-    ssty_table: Option<GlyphwiseSubsts<'a>>,
-    glyphwise_tables: Option<Vec<GlyphwiseSubsts<'a>>>,
-    space_width: Em,
     // Mutable.
     fragments: Vec<MathFragment>,
 }
@@ -391,46 +382,20 @@ impl<'a, 'v, 'e> MathContext<'a, 'v, 'e> {
     fn new(
         engine: &'v mut Engine<'e>,
         locator: &'v mut SplitLocator<'a>,
-        styles: StyleChain<'a>,
         base: Size,
         font: &'a Font,
     ) -> Self {
-        let math_table = font.ttf().tables().math.unwrap();
+        // These unwraps are safe as the font given is one returned by the
-        let gsub_table = font.ttf().tables().gsub;
+        // find_math_font function, which only returns fonts that have a math
-        let constants = math_table.constants.unwrap();
+        // constants table.
-
+        let constants = font.ttf().tables().math.unwrap().constants.unwrap();
-        let feat = |tag: &[u8; 4]| {
-            GlyphwiseSubsts::new(gsub_table, Feature::new(Tag::from_bytes(tag), 0, ..))
-        };
-
-        let features = features(styles);
-        let glyphwise_tables = Some(
-            features
-                .into_iter()
-                .filter_map(|feature| GlyphwiseSubsts::new(gsub_table, feature))
-                .collect(),
-        );
-
-        let ttf = font.ttf();
-        let space_width = ttf
-            .glyph_index(' ')
-            .and_then(|id| ttf.glyph_hor_advance(id))
-            .map(|advance| font.to_em(advance))
-            .unwrap_or(THICK);
 
         Self {
             engine,
             locator,
             region: Region::new(base, Axes::splat(false)),
             font,
-            ttf,
-            table: math_table,
             constants,
-            dtls_table: feat(b"dtls"),
-            flac_table: feat(b"flac"),
-            ssty_table: feat(b"ssty"),
-            glyphwise_tables,
-            space_width,
             fragments: vec![],
         }
     }
@@ -529,7 +494,8 @@ fn layout_realized(
     if let Some(elem) = elem.to_packed::<TagElem>() {
         ctx.push(MathFragment::Tag(elem.tag.clone()));
     } else if elem.is::<SpaceElem>() {
-        ctx.push(MathFragment::Space(ctx.space_width.resolve(styles)));
+        let space_width = ctx.font.space_width().unwrap_or(THICK);
+        ctx.push(MathFragment::Space(space_width.resolve(styles)));
     } else if elem.is::<LinebreakElem>() {
         ctx.push(MathFragment::Linebreak);
     } else if let Some(elem) = elem.to_packed::<HElem>() {

crates/typst-layout/src/math/root.rs

@@ -49,9 +49,9 @@ pub fn layout_root(
 
     // Layout root symbol.
     let target = radicand.height() + thickness + gap;
-    let sqrt = GlyphFragment::new(ctx, styles, '√', span)
+    let mut sqrt = GlyphFragment::new_char(ctx.font, styles, '√', span)?;
-        .stretch_vertical(ctx, target)
+    sqrt.stretch_vertical(ctx, target);
-        .frame;
+    let sqrt = sqrt.into_frame();
 
     // Layout the index.
     let sscript = EquationElem::set_size(MathSize::ScriptScript).wrap();

crates/typst-layout/src/math/shared.rs

@@ -1,7 +1,9 @@
 use ttf_parser::math::MathValue;
+use ttf_parser::Tag;
 use typst_library::foundations::{Style, StyleChain};
-use typst_library::layout::{Abs, Em, FixedAlignment, Frame, Point, Size, VAlignment};
+use typst_library::layout::{Abs, Em, FixedAlignment, Frame, Point, Size};
 use typst_library::math::{EquationElem, MathSize};
+use typst_library::text::{FontFeatures, TextElem};
 use typst_utils::LazyHash;
 
 use super::{LeftRightAlternator, MathContext, MathFragment, MathRun};
@@ -59,6 +61,16 @@ pub fn style_cramped() -> LazyHash<Style> {
     EquationElem::set_cramped(true).wrap()
 }
 
+/// Sets flac OpenType feature.
+pub fn style_flac() -> LazyHash<Style> {
+    TextElem::set_features(FontFeatures(vec![(Tag::from_bytes(b"flac"), 1)])).wrap()
+}
+
+/// Sets dtls OpenType feature.
+pub fn style_dtls() -> LazyHash<Style> {
+    TextElem::set_features(FontFeatures(vec![(Tag::from_bytes(b"dtls"), 1)])).wrap()
+}
+
 /// The style for subscripts in the current style.
 pub fn style_for_subscript(styles: StyleChain) -> [LazyHash<Style>; 2] {
     [style_for_superscript(styles), EquationElem::set_cramped(true).wrap()]
@@ -97,15 +109,6 @@ pub fn style_for_script_scale(ctx: &MathContext) -> LazyHash<Style> {
     .wrap()
 }
 
-/// How a delimieter should be aligned when scaling.
-pub fn delimiter_alignment(delimiter: char) -> VAlignment {
-    match delimiter {
-        '⌜' | '⌝' => VAlignment::Top,
-        '⌞' | '⌟' => VAlignment::Bottom,
-        _ => VAlignment::Horizon,
-    }
-}
-
 /// Stack rows on top of each other.
 ///
 /// Add a `gap` between each row and uses the baseline of the `baseline`-th

crates/typst-layout/src/math/stretch.rs

@@ -1,19 +1,10 @@
-use ttf_parser::math::{GlyphAssembly, GlyphConstruction, GlyphPart};
-use ttf_parser::LazyArray16;
 use typst_library::diag::{warning, SourceResult};
 use typst_library::foundations::{Packed, StyleChain};
-use typst_library::layout::{Abs, Axis, Frame, Point, Rel, Size};
+use typst_library::layout::{Abs, Axis, Rel};
 use typst_library::math::StretchElem;
 use typst_utils::Get;
 
-use super::{
+use super::{stretch_axes, MathContext, MathFragment};
-    delimiter_alignment, GlyphFragment, MathContext, MathFragment, Scaled,
-    VariantFragment,
-};
-use crate::modifiers::FrameModify;
-
-/// Maximum number of times extenders can be repeated.
-const MAX_REPEATS: usize = 1024;
 
 /// Lays out a [`StretchElem`].
 #[typst_macros::time(name = "math.stretch", span = elem.span())]
@@ -23,15 +14,7 @@ pub fn layout_stretch(
     styles: StyleChain,
 ) -> SourceResult<()> {
     let mut fragment = ctx.layout_into_fragment(&elem.body, styles)?;
-    stretch_fragment(
+    stretch_fragment(ctx, &mut fragment, None, None, elem.size(styles), Abs::zero());
-        ctx,
-        styles,
-        &mut fragment,
-        None,
-        None,
-        elem.size(styles),
-        Abs::zero(),
-    );
     ctx.push(fragment);
     Ok(())
 }
@@ -39,266 +22,49 @@ pub fn layout_stretch(
 /// Attempts to stretch the given fragment by/to the amount given in stretch.
 pub fn stretch_fragment(
     ctx: &mut MathContext,
-    styles: StyleChain,
     fragment: &mut MathFragment,
     axis: Option<Axis>,
     relative_to: Option<Abs>,
     stretch: Rel<Abs>,
     short_fall: Abs,
 ) {
-    let glyph = match fragment {
+    let size = fragment.size();
-        MathFragment::Glyph(glyph) => glyph.clone(),
+
-        MathFragment::Variant(variant) => {
+    let MathFragment::Glyph(ref mut glyph) = fragment else { return };
-            GlyphFragment::new(ctx, styles, variant.c, variant.span)
-        }
-        _ => return,
-    };
 
     // Return if we attempt to stretch along an axis which isn't stretchable,
     // so that the original fragment isn't modified.
-    let Some(stretch_axis) = stretch_axis(ctx, &glyph) else { return };
+    let axes = stretch_axes(&glyph.item.font, glyph.base_glyph.id);
-    let axis = axis.unwrap_or(stretch_axis);
+    let stretch_axis = if let Some(axis) = axis {
-    if axis != stretch_axis {
+        if !axes.get(axis) {
-        return;
+            return;
-    }
-
-    let relative_to_size = relative_to.unwrap_or_else(|| fragment.size().get(axis));
-
-    let mut variant = stretch_glyph(
-        ctx,
-        glyph,
-        stretch.relative_to(relative_to_size) - short_fall,
-        axis,
-    );
-
-    if axis == Axis::Y {
-        variant.align_on_axis(ctx, delimiter_alignment(variant.c));
-    }
-
-    *fragment = MathFragment::Variant(variant);
-}
-
-/// Return whether the glyph is stretchable and if it is, along which axis it
-/// can be stretched.
-fn stretch_axis(ctx: &mut MathContext, base: &GlyphFragment) -> Option<Axis> {
-    let base_id = base.id;
-    let vertical = ctx
-        .table
-        .variants
-        .and_then(|variants| variants.vertical_constructions.get(base_id))
-        .map(|_| Axis::Y);
-    let horizontal = ctx
-        .table
-        .variants
-        .and_then(|variants| variants.horizontal_constructions.get(base_id))
-        .map(|_| Axis::X);
-
-    match (vertical, horizontal) {
-        (vertical, None) => vertical,
-        (None, horizontal) => horizontal,
-        _ => {
-            // As far as we know, there aren't any glyphs that have both
-            // vertical and horizontal constructions. So for the time being, we
-            // will assume that a glyph cannot have both.
-            ctx.engine.sink.warn(warning!(
-               base.span,
-               "glyph has both vertical and horizontal constructions";
-               hint: "this is probably a font bug";
-               hint: "please file an issue at https://github.com/typst/typst/issues"
-            ));
-
-            None
         }
-    }
+        axis
-}
+    } else {
-
+        match (axes.x, axes.y) {
-/// Try to stretch a glyph to a desired width or height.
+            (true, false) => Axis::X,
-///
+            (false, true) => Axis::Y,
-/// The resulting frame may not have the exact desired width.
+            (false, false) => return,
-pub fn stretch_glyph(
+            (true, true) => {
-    ctx: &mut MathContext,
+                // As far as we know, there aren't any glyphs that have both
-    mut base: GlyphFragment,
+                // vertical and horizontal constructions. So for the time being, we
-    target: Abs,
+                // will assume that a glyph cannot have both.
-    axis: Axis,
+                ctx.engine.sink.warn(warning!(
-) -> VariantFragment {
+                   glyph.item.glyphs[0].span.0,
-    // If the base glyph is good enough, use it.
+                   "glyph has both vertical and horizontal constructions";
-    let advance = match axis {
+                   hint: "this is probably a font bug";
-        Axis::X => base.width,
+                   hint: "please file an issue at https://github.com/typst/typst/issues"
-        Axis::Y => base.height(),
+                ));
-    };
+                return;
-    if target <= advance {
-        return base.into_variant();
-    }
-
-    let mut min_overlap = Abs::zero();
-    let construction = ctx
-        .table
-        .variants
-        .and_then(|variants| {
-            min_overlap = variants.min_connector_overlap.scaled(ctx, base.font_size);
-            match axis {
-                Axis::X => variants.horizontal_constructions,
-                Axis::Y => variants.vertical_constructions,
             }
-            .get(base.id)
-        })
-        .unwrap_or(GlyphConstruction { assembly: None, variants: LazyArray16::new(&[]) });
-
-    // Search for a pre-made variant with a good advance.
-    let mut best_id = base.id;
-    let mut best_advance = base.width;
-    for variant in construction.variants {
-        best_id = variant.variant_glyph;
-        best_advance = base.font.to_em(variant.advance_measurement).at(base.font_size);
-        if target <= best_advance {
-            break;
         }
-    }
-
-    // This is either good or the best we've got.
-    if target <= best_advance || construction.assembly.is_none() {
-        base.set_id(ctx, best_id);
-        return base.into_variant();
-    }
-
-    // Assemble from parts.
-    let assembly = construction.assembly.unwrap();
-    assemble(ctx, base, assembly, min_overlap, target, axis)
-}
-
-/// Assemble a glyph from parts.
-fn assemble(
-    ctx: &mut MathContext,
-    base: GlyphFragment,
-    assembly: GlyphAssembly,
-    min_overlap: Abs,
-    target: Abs,
-    axis: Axis,
-) -> VariantFragment {
-    // Determine the number of times the extenders need to be repeated as well
-    // as a ratio specifying how much to spread the parts apart
-    // (0 = maximal overlap, 1 = minimal overlap).
-    let mut full;
-    let mut ratio;
-    let mut repeat = 0;
-    loop {
-        full = Abs::zero();
-        ratio = 0.0;
-
-        let mut parts = parts(assembly, repeat).peekable();
-        let mut growable = Abs::zero();
-
-        while let Some(part) = parts.next() {
-            let mut advance = part.full_advance.scaled(ctx, base.font_size);
-            if let Some(next) = parts.peek() {
-                let max_overlap = part
-                    .end_connector_length
-                    .min(next.start_connector_length)
-                    .scaled(ctx, base.font_size);
-                if max_overlap < min_overlap {
-                    // This condition happening is indicative of a bug in the
-                    // font.
-                    ctx.engine.sink.warn(warning!(
-                       base.span,
-                       "glyph has assembly parts with overlap less than minConnectorOverlap";
-                       hint: "its rendering may appear broken - this is probably a font bug";
-                       hint: "please file an issue at https://github.com/typst/typst/issues"
-                    ));
-                }
-
-                advance -= max_overlap;
-                growable += max_overlap - min_overlap;
-            }
-
-            full += advance;
-        }
-
-        if full < target {
-            let delta = target - full;
-            ratio = (delta / growable).min(1.0);
-            full += ratio * growable;
-        }
-
-        if target <= full || repeat >= MAX_REPEATS {
-            break;
-        }
-
-        repeat += 1;
-    }
-
-    let mut selected = vec![];
-    let mut parts = parts(assembly, repeat).peekable();
-    while let Some(part) = parts.next() {
-        let mut advance = part.full_advance.scaled(ctx, base.font_size);
-        if let Some(next) = parts.peek() {
-            let max_overlap = part
-                .end_connector_length
-                .min(next.start_connector_length)
-                .scaled(ctx, base.font_size);
-            advance -= max_overlap;
-            advance += ratio * (max_overlap - min_overlap);
-        }
-
-        let mut fragment = base.clone();
-        fragment.set_id(ctx, part.glyph_id);
-        selected.push((fragment, advance));
-    }
-
-    let size;
-    let baseline;
-    match axis {
-        Axis::X => {
-            let height = base.ascent + base.descent;
-            size = Size::new(full, height);
-            baseline = base.ascent;
-        }
-        Axis::Y => {
-            let axis = ctx.constants.axis_height().scaled(ctx, base.font_size);
-            let width = selected.iter().map(|(f, _)| f.width).max().unwrap_or_default();
-            size = Size::new(width, full);
-            baseline = full / 2.0 + axis;
-        }
-    }
-
-    let mut frame = Frame::soft(size);
-    let mut offset = Abs::zero();
-    frame.set_baseline(baseline);
-    frame.modify(&base.modifiers);
-
-    for (fragment, advance) in selected {
-        let pos = match axis {
-            Axis::X => Point::new(offset, frame.baseline() - fragment.ascent),
-            Axis::Y => Point::with_y(full - offset - fragment.height()),
-        };
-        frame.push_frame(pos, fragment.into_frame());
-        offset += advance;
-    }
-
-    let accent_attach = match axis {
-        Axis::X => (frame.width() / 2.0, frame.width() / 2.0),
-        Axis::Y => base.accent_attach,
     };
 
-    VariantFragment {
+    let relative_to_size = relative_to.unwrap_or_else(|| size.get(stretch_axis));
-        c: base.c,
+
-        frame,
+    glyph.stretch(ctx, stretch.relative_to(relative_to_size) - short_fall, stretch_axis);
-        font_size: base.font_size,
+
-        italics_correction: Abs::zero(),
+    if stretch_axis == Axis::Y {
-        accent_attach,
+        glyph.center_on_axis();
-        class: base.class,
-        math_size: base.math_size,
-        span: base.span,
-        limits: base.limits,
-        mid_stretched: None,
-        extended_shape: true,
     }
 }
-
-/// Return an iterator over the assembly's parts with extenders repeated the
-/// specified number of times.
-fn parts(assembly: GlyphAssembly, repeat: usize) -> impl Iterator<Item = GlyphPart> + '_ {
-    assembly.parts.into_iter().flat_map(move |part| {
-        let count = if part.part_flags.extender() { repeat } else { 1 };
-        std::iter::repeat_n(part, count)
-    })
-}

crates/typst-layout/src/math/text.rs

@@ -12,7 +12,10 @@ use typst_syntax::{is_newline, Span};
 use unicode_math_class::MathClass;
 use unicode_segmentation::UnicodeSegmentation;
 
-use super::{FrameFragment, GlyphFragment, MathContext, MathFragment, MathRun};
+use super::{
+    has_dtls_feat, style_dtls, FrameFragment, GlyphFragment, MathContext, MathFragment,
+    MathRun,
+};
 
 /// Lays out a [`TextElem`].
 pub fn layout_text(
@@ -67,12 +70,7 @@ fn layout_inline_text(
         let mut fragments = vec![];
         for unstyled_c in text.chars() {
             let c = styled_char(styles, unstyled_c, false);
-            let mut glyph = GlyphFragment::new(ctx, styles, c, span);
+            let glyph = GlyphFragment::new_char(ctx.font, styles, c, span)?;
-            match EquationElem::size_in(styles) {
-                MathSize::Script => glyph.make_script_size(ctx),
-                MathSize::ScriptScript => glyph.make_script_script_size(ctx),
-                _ => {}
-            }
             fragments.push(glyph.into());
         }
         let frame = MathRun::new(fragments).into_frame(styles);
@@ -121,54 +119,45 @@ pub fn layout_symbol(
 ) -> SourceResult<()> {
     // Switch dotless char to normal when we have the dtls OpenType feature.
     // This should happen before the main styling pass.
-    let (unstyled_c, dtls) = match try_dotless(elem.text) {
+    let dtls = style_dtls();
-        Some(c) if ctx.dtls_table.is_some() => (c, true),
+    let (unstyled_c, symbol_styles) = match try_dotless(elem.text) {
-        _ => (elem.text, false),
+        Some(c) if has_dtls_feat(ctx.font) => (c, styles.chain(&dtls)),
+        _ => (elem.text, styles),
     };
     let c = styled_char(styles, unstyled_c, true);
-    let fragment = match GlyphFragment::try_new(ctx, styles, c, elem.span()) {
+    let fragment: MathFragment =
-        Some(glyph) => layout_glyph(glyph, dtls, ctx, styles),
+        match GlyphFragment::new_char(ctx.font, symbol_styles, c, elem.span()) {
-        None => {
+            Ok(mut glyph) => {
-            // Not in the math font, fallback to normal inline text layout.
+                adjust_glyph_layout(&mut glyph, ctx, styles);
-            layout_inline_text(c.encode_utf8(&mut [0; 4]), elem.span(), ctx, styles)?
+                glyph.into()
-                .into()
+            }
-        }
+            Err(_) => {
-    };
+                // Not in the math font, fallback to normal inline text layout.
+                // TODO: Should replace this with proper fallback in [`GlyphFragment::new`].
+                layout_inline_text(c.encode_utf8(&mut [0; 4]), elem.span(), ctx, styles)?
+                    .into()
+            }
+        };
     ctx.push(fragment);
     Ok(())
 }
 
-/// Layout a [`GlyphFragment`].
+/// Centers large glyphs vertically on the axis, scaling them if in display
-fn layout_glyph(
+/// style.
-    mut glyph: GlyphFragment,
+fn adjust_glyph_layout(
-    dtls: bool,
+    glyph: &mut GlyphFragment,
     ctx: &mut MathContext,
     styles: StyleChain,
-) -> MathFragment {
+) {
-    if dtls {
-        glyph.make_dotless_form(ctx);
-    }
-    let math_size = EquationElem::size_in(styles);
-    match math_size {
-        MathSize::Script => glyph.make_script_size(ctx),
-        MathSize::ScriptScript => glyph.make_script_script_size(ctx),
-        _ => {}
-    }
-
     if glyph.class == MathClass::Large {
-        let mut variant = if math_size == MathSize::Display {
+        if EquationElem::size_in(styles) == MathSize::Display {
             let height = scaled!(ctx, styles, display_operator_min_height)
-                .max(SQRT_2 * glyph.height());
+                .max(SQRT_2 * glyph.size.y);
-            glyph.stretch_vertical(ctx, height)
+            glyph.stretch_vertical(ctx, height);
-        } else {
-            glyph.into_variant()
         };
         // TeXbook p 155. Large operators are always vertically centered on the
         // axis.
-        variant.center_on_axis(ctx);
+        glyph.center_on_axis();
-        variant.into()
-    } else {
-        glyph.into()
     }
 }
 

crates/typst-layout/src/math/underover.rs

@@ -285,14 +285,14 @@ fn layout_underoverspreader(
     let body = ctx.layout_into_run(body, styles)?;
     let body_class = body.class();
     let body = body.into_fragment(styles);
-    let glyph = GlyphFragment::new(ctx, styles, c, span);
+    let mut glyph = GlyphFragment::new_char(ctx.font, styles, c, span)?;
-    let stretched = glyph.stretch_horizontal(ctx, body.width());
+    glyph.stretch_horizontal(ctx, body.width());
 
     let mut rows = vec![];
     let baseline = match position {
         Position::Under => {
             rows.push(MathRun::new(vec![body]));
-            rows.push(stretched.into());
+            rows.push(glyph.into());
             if let Some(annotation) = annotation {
                 let under_style = style_for_subscript(styles);
                 let annotation_styles = styles.chain(&under_style);
@@ -306,7 +306,7 @@ fn layout_underoverspreader(
                 let annotation_styles = styles.chain(&over_style);
                 rows.extend(ctx.layout_into_run(annotation, annotation_styles)?.rows());
             }
-            rows.push(stretched.into());
+            rows.push(glyph.into());
             rows.push(MathRun::new(vec![body]));
             rows.len() - 1
         }

crates/typst-library/src/text/font/mod.rs

@@ -106,13 +106,26 @@ impl Font {
     }
 
     /// Look up the horizontal advance width of a glyph.
-    pub fn advance(&self, glyph: u16) -> Option<Em> {
+    pub fn x_advance(&self, glyph: u16) -> Option<Em> {
         self.0
             .ttf
             .glyph_hor_advance(GlyphId(glyph))
             .map(|units| self.to_em(units))
     }
 
+    /// Look up the vertical advance width of a glyph.
+    pub fn y_advance(&self, glyph: u16) -> Option<Em> {
+        self.0
+            .ttf
+            .glyph_ver_advance(GlyphId(glyph))
+            .map(|units| self.to_em(units))
+    }
+
+    /// Look up the width of a space.
+    pub fn space_width(&self) -> Option<Em> {
+        self.0.ttf.glyph_index(' ').and_then(|id| self.x_advance(id.0))
+    }
+
     /// Lookup a name by id.
     pub fn find_name(&self, id: u16) -> Option<String> {
         find_name(&self.0.ttf, id)

crates/typst-library/src/text/item.rs

@@ -35,6 +35,11 @@ impl TextItem {
     pub fn width(&self) -> Abs {
         self.glyphs.iter().map(|g| g.x_advance).sum::<Em>().at(self.size)
     }
+
+    /// The height of the text run.
+    pub fn height(&self) -> Abs {
+        self.glyphs.iter().map(|g| g.y_advance).sum::<Em>().at(self.size)
+    }
 }
 
 impl Debug for TextItem {
@@ -54,6 +59,10 @@ pub struct Glyph {
     pub x_advance: Em,
     /// The horizontal offset of the glyph.
     pub x_offset: Em,
+    /// The advance height (Y-up) of the glyph.
+    pub y_advance: Em,
+    /// The vertical offset (Y-up) of the glyph.
+    pub y_offset: Em,
     /// The range of the glyph in its item's text. The range's length may
     /// be more than one due to multi-byte UTF-8 encoding or ligatures.
     pub range: Range<u16>,
@@ -115,4 +124,13 @@ impl<'a> TextItemView<'a> {
             .sum::<Em>()
             .at(self.item.size)
     }
+
+    /// The total height of this text slice
+    pub fn height(&self) -> Abs {
+        self.glyphs()
+            .iter()
+            .map(|g| g.y_advance)
+            .sum::<Em>()
+            .at(self.item.size)
+    }
 }

crates/typst-library/src/text/mod.rs

@@ -30,6 +30,7 @@ pub use self::space::*;
 
 use std::fmt::{self, Debug, Formatter};
 use std::hash::Hash;
+use std::str::FromStr;
 use std::sync::LazyLock;
 
 use ecow::{eco_format, EcoString};
@@ -1283,6 +1284,12 @@ pub fn features(styles: StyleChain) -> Vec<Feature> {
         feat(b"frac", 1);
     }
 
+    match EquationElem::size_in(styles) {
+        MathSize::Script => feat(b"ssty", 1),
+        MathSize::ScriptScript => feat(b"ssty", 2),
+        _ => {}
+    }
+
     for (tag, value) in TextElem::features_in(styles).0 {
         tags.push(Feature::new(tag, value, ..))
     }
@@ -1290,6 +1297,17 @@ pub fn features(styles: StyleChain) -> Vec<Feature> {
     tags
 }
 
+/// Process the language and region of a style chain into a
+/// rustybuzz-compatible BCP 47 language.
+pub fn language(styles: StyleChain) -> rustybuzz::Language {
+    let mut bcp: EcoString = TextElem::lang_in(styles).as_str().into();
+    if let Some(region) = TextElem::region_in(styles) {
+        bcp.push('-');
+        bcp.push_str(region.as_str());
+    }
+    rustybuzz::Language::from_str(&bcp).unwrap()
+}
+
 /// A toggle that turns on and off alternatingly if folded.
 #[derive(Debug, Copy, Clone, Eq, PartialEq, Hash)]
 pub struct ItalicToggle(pub bool);

crates/typst-pdf/src/text.rs

@@ -120,13 +120,15 @@ impl krilla::text::Glyph for PdfGlyph {
     }
 
     #[inline(always)]
-    fn y_offset(&self, _: f32) -> f32 {
+    fn y_offset(&self, size: f32) -> f32 {
-        0.0
+        // Don't use `Em::at`, because it contains an expensive check whether the result is finite.
+        self.0.y_offset.get() as f32 * size
     }
 
     #[inline(always)]
-    fn y_advance(&self, _: f32) -> f32 {
+    fn y_advance(&self, size: f32) -> f32 {
-        0.0
+        // Don't use `Em::at`, because it contains an expensive check whether the result is finite.
+        self.0.y_advance.get() as f32 * size
     }
 
     fn location(&self) -> Option<Location> {

crates/typst-render/src/text.rs

@@ -14,18 +14,20 @@ use crate::{shape, AbsExt, State};
 /// Render a text run into the canvas.
 pub fn render_text(canvas: &mut sk::Pixmap, state: State, text: &TextItem) {
     let mut x = Abs::zero();
+    let mut y = Abs::zero();
     for glyph in &text.glyphs {
         let id = GlyphId(glyph.id);
-        let offset = x + glyph.x_offset.at(text.size);
+        let x_offset = x + glyph.x_offset.at(text.size);
+        let y_offset = y + glyph.y_offset.at(text.size);
 
         if should_outline(&text.font, glyph) {
-            let state = state.pre_translate(Point::with_x(offset));
+            let state = state.pre_translate(Point::new(x_offset, -y_offset));
             render_outline_glyph(canvas, state, text, id);
         } else {
             let upem = text.font.units_per_em();
             let text_scale = text.size / upem;
             let state = state
-                .pre_translate(Point::new(offset, -text.size))
+                .pre_translate(Point::new(x_offset, -y_offset - text.size))
                 .pre_scale(Axes::new(text_scale, text_scale));
 
             let (glyph_frame, _) = glyph_frame(&text.font, glyph.id);
@@ -33,6 +35,7 @@ pub fn render_text(canvas: &mut sk::Pixmap, state: State, text: &TextItem) {
         }
 
         x += glyph.x_advance.at(text.size);
+        y += glyph.y_advance.at(text.size);
     }
 }
 

crates/typst-svg/src/text.rs

@@ -25,25 +25,32 @@ impl SVGRenderer {
         self.xml.write_attribute("transform", "scale(1, -1)");
 
         let mut x: f64 = 0.0;
+        let mut y: f64 = 0.0;
         for glyph in &text.glyphs {
             let id = GlyphId(glyph.id);
-            let offset = x + glyph.x_offset.at(text.size).to_pt();
+            let x_offset = x + glyph.x_offset.at(text.size).to_pt();
+            let y_offset = y + glyph.y_offset.at(text.size).to_pt();
 
-            self.render_svg_glyph(text, id, offset, scale)
+            self.render_svg_glyph(text, id, x_offset, y_offset, scale)
-                .or_else(|| self.render_bitmap_glyph(text, id, offset))
+                .or_else(|| self.render_bitmap_glyph(text, id, x_offset, y_offset))
                 .or_else(|| {
                     self.render_outline_glyph(
                         state
                             .pre_concat(Transform::scale(Ratio::one(), -Ratio::one()))
-                            .pre_translate(Point::new(Abs::pt(offset), Abs::zero())),
+                            .pre_translate(Point::new(
+                                Abs::pt(x_offset),
+                                Abs::pt(y_offset),
+                            )),
                         text,
                         id,
-                        offset,
+                        x_offset,
+                        y_offset,
                         scale,
                     )
                 });
 
             x += glyph.x_advance.at(text.size).to_pt();
+            y += glyph.y_advance.at(text.size).to_pt();
         }
 
         self.xml.end_element();
@@ -55,6 +62,7 @@ impl SVGRenderer {
         text: &TextItem,
         id: GlyphId,
         x_offset: f64,
+        y_offset: f64,
         scale: f64,
     ) -> Option<()> {
         let data_url = convert_svg_glyph_to_base64_url(&text.font, id)?;
@@ -73,6 +81,7 @@ impl SVGRenderer {
         self.xml.start_element("use");
         self.xml.write_attribute_fmt("xlink:href", format_args!("#{id}"));
         self.xml.write_attribute("x", &x_offset);
+        self.xml.write_attribute("y", &y_offset);
         self.xml.end_element();
 
         Some(())
@@ -84,6 +93,7 @@ impl SVGRenderer {
         text: &TextItem,
         id: GlyphId,
         x_offset: f64,
+        y_offset: f64,
     ) -> Option<()> {
         let (image, bitmap_x_offset, bitmap_y_offset) =
             convert_bitmap_glyph_to_image(&text.font, id)?;
@@ -109,6 +119,7 @@ impl SVGRenderer {
         // it.
         let scale_factor = target_height / image.height();
         self.xml.write_attribute("x", &(x_offset / scale_factor));
+        self.xml.write_attribute("y", &(y_offset / scale_factor));
         self.xml.write_attribute_fmt(
             "transform",
             format_args!("scale({scale_factor} -{scale_factor})",),
@@ -125,6 +136,7 @@ impl SVGRenderer {
         text: &TextItem,
         glyph_id: GlyphId,
         x_offset: f64,
+        y_offset: f64,
         scale: f64,
     ) -> Option<()> {
         let scale = Ratio::new(scale);
@@ -139,6 +151,7 @@ impl SVGRenderer {
         self.xml.start_element("use");
         self.xml.write_attribute_fmt("xlink:href", format_args!("#{id}"));
         self.xml.write_attribute_fmt("x", format_args!("{x_offset}"));
+        self.xml.write_attribute_fmt("y", format_args!("{y_offset}"));
         self.write_fill(
             &text.fill,
             FillRule::default(),

tests/suite/math/accent.typ

@@ -51,6 +51,12 @@ $hat(i), hat(i, dotless: #false), accent(j, tilde), accent(j, tilde, dotless: #f
 #set math.accent(dotless: false)
 $ hat(i) $
 
+--- math-accent-dotless-greedy ---
+// Currently the dotless style propogates to everything in the accent's base,
+// even though it shouldn't.
+$ arrow(P_(c, i dot j) P_(1, i) j) \
+  arrow(P_(c, i dot j) P_(1, i) j, dotless: #false) $
+
 --- math-accent-flattened ---
 // Test flattened accent glyph variants.
 #show math.equation: set text(font: "STIX Two Math")