Merge branch 'typst:main' into main

README.md

@@ -240,6 +240,26 @@ instant preview. To achieve these goals, we follow three core design principles:
   Luckily we have [`comemo`], a system for incremental compilation which does
   most of the hard work in the background.
 
+## Acknowledgements
+
+We'd like to thank everyone who is supporting Typst's development, be it via
+[GitHub sponsors] or elsewhere. In particular, special thanks[^1] go to:
+
+- [Posit](https://posit.co/blog/posit-and-typst/) for financing a full-time
+  compiler engineer
+- [NLnet](https://nlnet.nl/) for supporting work on Typst via multiple grants
+  through the [NGI Zero Core](https://nlnet.nl/core) fund:
+  - Work on [HTML export](https://nlnet.nl/project/Typst-HTML/)
+  - Work on [PDF accessibility](https://nlnet.nl/project/Typst-Accessibility/)
+- [Science & Startups](https://www.science-startups.berlin/) for having financed
+  Typst development from January through June 2023 via the Berlin Startup
+  Scholarship
+- [Zerodha](https://zerodha.tech/blog/1-5-million-pdfs-in-25-minutes/) for their
+  generous one-time sponsorship
+
+[^1]: This list only includes contributions for our open-source work that exceed
+    or are expected to exceed €10K.
+
 [docs]: https://typst.app/docs/
 [app]: https://typst.app/
 [discord]: https://discord.gg/2uDybryKPe
@@ -259,3 +279,4 @@ instant preview. To achieve these goals, we follow three core design principles:
 [packages]: https://github.com/typst/packages/
 [`comemo`]: https://github.com/typst/comemo/
 [snap]: https://snapcraft.io/typst
+[GitHub sponsors]: https://github.com/sponsors/typst/

crates/typst-cli/src/args.rs

@@ -491,7 +491,7 @@ pub enum PdfStandard {
     /// PDF/A-2u.
     #[value(name = "a-2u")]
     A_2u,
-    /// PDF/A-3u.
+    /// PDF/A-3b.
     #[value(name = "a-3b")]
     A_3b,
     /// PDF/A-3u.

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

@@ -206,7 +206,7 @@ pub fn collect<'a>(
                     }
                     InlineItem::Frame(mut frame) => {
                         frame.modify(&FrameModifiers::get_in(styles));
-                        apply_baseline_shift(&mut frame, styles);
+                        apply_shift(&engine.world, &mut frame, styles);
                         collector.push_item(Item::Frame(frame));
                     }
                 }
@@ -221,7 +221,7 @@ pub fn collect<'a>(
                 let mut frame = layout_and_modify(styles, |styles| {
                     layout_box(elem, engine, loc, styles, region)
                 })?;
-                apply_baseline_shift(&mut frame, styles);
+                apply_shift(&engine.world, &mut frame, styles);
                 collector.push_item(Item::Frame(frame));
             }
         } else if let Some(elem) = child.to_packed::<TagElem>() {

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

@@ -5,7 +5,7 @@ use typst_library::engine::Engine;
 use typst_library::introspection::{SplitLocator, Tag};
 use typst_library::layout::{Abs, Dir, Em, Fr, Frame, FrameItem, Point};
 use typst_library::model::ParLineMarker;
-use typst_library::text::{Lang, TextElem};
+use typst_library::text::{variant, Lang, TextElem};
 use typst_utils::Numeric;
 
 use super::*;
@@ -330,7 +330,7 @@ fn adjust_cj_at_line_start(p: &Preparation, items: &mut Items) {
         let glyph = shaped.glyphs.to_mut().first_mut().unwrap();
         let shrink = glyph.shrinkability().0;
         glyph.shrink_left(shrink);
-        shaped.width -= shrink.at(shaped.size);
+        shaped.width -= shrink.at(glyph.size);
     } else if p.config.cjk_latin_spacing
         && glyph.is_cj_script()
         && glyph.x_offset > Em::zero()
@@ -342,7 +342,7 @@ fn adjust_cj_at_line_start(p: &Preparation, items: &mut Items) {
         glyph.x_advance -= shrink;
         glyph.x_offset = Em::zero();
         glyph.adjustability.shrinkability.0 = Em::zero();
-        shaped.width -= shrink.at(shaped.size);
+        shaped.width -= shrink.at(glyph.size);
     }
 }
 
@@ -360,7 +360,7 @@ fn adjust_cj_at_line_end(p: &Preparation, items: &mut Items) {
         let shrink = glyph.shrinkability().1;
         let punct = shaped.glyphs.to_mut().last_mut().unwrap();
         punct.shrink_right(shrink);
-        shaped.width -= shrink.at(shaped.size);
+        shaped.width -= shrink.at(punct.size);
     } else if p.config.cjk_latin_spacing
         && glyph.is_cj_script()
         && (glyph.x_advance - glyph.x_offset) > Em::one()
@@ -371,7 +371,7 @@ fn adjust_cj_at_line_end(p: &Preparation, items: &mut Items) {
         let glyph = shaped.glyphs.to_mut().last_mut().unwrap();
         glyph.x_advance -= shrink;
         glyph.adjustability.shrinkability.1 = Em::zero();
-        shaped.width -= shrink.at(shaped.size);
+        shaped.width -= shrink.at(glyph.size);
     }
 }
 
@@ -412,9 +412,30 @@ fn should_repeat_hyphen(pred_line: &Line, text: &str) -> bool {
     }
 }
 
-/// Apply the current baseline shift to a frame.
+/// Apply the current baseline shift and italic compensation to a frame.
-pub fn apply_baseline_shift(frame: &mut Frame, styles: StyleChain) {
+pub fn apply_shift<'a>(
-    frame.translate(Point::with_y(TextElem::baseline_in(styles)));
+    world: &Tracked<'a, dyn World + 'a>,
+    frame: &mut Frame,
+    styles: StyleChain,
+) {
+    let mut baseline = TextElem::baseline_in(styles);
+    let mut compensation = Abs::zero();
+    if let Some(scripts) = TextElem::shift_settings_in(styles) {
+        let font_metrics = TextElem::font_in(styles)
+            .into_iter()
+            .find_map(|family| {
+                world
+                    .book()
+                    .select(family.as_str(), variant(styles))
+                    .and_then(|id| world.font(id))
+            })
+            .map_or(*scripts.kind.default_metrics(), |f| {
+                *scripts.kind.read_metrics(f.metrics())
+            });
+        baseline -= scripts.shift.unwrap_or(font_metrics.vertical_offset).resolve(styles);
+        compensation += font_metrics.horizontal_offset.resolve(styles);
+    }
+    frame.translate(Point::new(compensation, baseline));
 }
 
 /// Commit to a line and build its frame.
@@ -444,7 +465,7 @@ pub fn commit(
                 && TextElem::overhang_in(text.styles)
                 && (line.items.len() > 1 || text.glyphs.len() > 1)
             {
-                let amount = overhang(glyph.c) * glyph.x_advance.at(text.size);
+                let amount = overhang(glyph.c) * glyph.x_advance.at(glyph.size);
                 offset -= amount;
                 remaining += amount;
             }
@@ -458,7 +479,7 @@ pub fn commit(
                 && TextElem::overhang_in(text.styles)
                 && (line.items.len() > 1 || text.glyphs.len() > 1)
             {
-                let amount = overhang(glyph.c) * glyph.x_advance.at(text.size);
+                let amount = overhang(glyph.c) * glyph.x_advance.at(glyph.size);
                 remaining += amount;
             }
         }
@@ -519,7 +540,7 @@ pub fn commit(
                     let mut frame = layout_and_modify(*styles, |styles| {
                         layout_box(elem, engine, loc.relayout(), styles, region)
                     })?;
-                    apply_baseline_shift(&mut frame, *styles);
+                    apply_shift(&engine.world, &mut frame, *styles);
                     push(&mut offset, frame, idx);
                 } else {
                     offset += amount;

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

@@ -927,9 +927,9 @@ impl Estimates {
                     let byte_len = g.range.len();
                     let stretch = g.stretchability().0 + g.stretchability().1;
                     let shrink = g.shrinkability().0 + g.shrinkability().1;
-                    widths.push(byte_len, g.x_advance.at(shaped.size));
+                    widths.push(byte_len, g.x_advance.at(g.size));
-                    stretchability.push(byte_len, stretch.at(shaped.size));
+                    stretchability.push(byte_len, stretch.at(g.size));
-                    shrinkability.push(byte_len, shrink.at(shaped.size));
+                    shrinkability.push(byte_len, shrink.at(g.size));
                     justifiables.push(byte_len, g.is_justifiable() as usize);
                 }
             } else {

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

@@ -29,7 +29,7 @@ use typst_utils::{Numeric, SliceExt};
 use self::collect::{collect, Item, Segment, SpanMapper};
 use self::deco::decorate;
 use self::finalize::finalize;
-use self::line::{apply_baseline_shift, commit, line, Line};
+use self::line::{apply_shift, commit, line, Line};
 use self::linebreak::{linebreak, Breakpoint};
 use self::prepare::{prepare, Preparation};
 use self::shaping::{

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

@@ -144,7 +144,7 @@ fn add_cjk_latin_spacing(items: &mut [(Range, Item)]) {
                 // The spacing is default to 1/4 em, and can be shrunk to 1/8 em.
                 glyph.x_advance += Em::new(0.25);
                 glyph.adjustability.shrinkability.1 += Em::new(0.125);
-                text.width += Em::new(0.25).at(text.size);
+                text.width += Em::new(0.25).at(glyph.size);
             }
 
             // Case 2: Latin followed by a CJ character
@@ -152,7 +152,7 @@ fn add_cjk_latin_spacing(items: &mut [(Range, Item)]) {
                 glyph.x_advance += Em::new(0.25);
                 glyph.x_offset += Em::new(0.25);
                 glyph.adjustability.shrinkability.0 += Em::new(0.125);
-                text.width += Em::new(0.25).at(text.size);
+                text.width += Em::new(0.25).at(glyph.size);
             }
 
             prev = Some(glyph);

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

@@ -3,14 +3,15 @@ use std::fmt::{self, Debug, Formatter};
 use std::sync::Arc;
 
 use az::SaturatingAs;
-use rustybuzz::{BufferFlags, ShapePlan, UnicodeBuffer};
+use rustybuzz::{BufferFlags, Feature, ShapePlan, UnicodeBuffer};
+use ttf_parser::gsub::SubstitutionSubtable;
 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, language, variant, Font, FontFamily,
-    FontVariant, Glyph, Lang, Region, TextEdgeBounds, TextElem, TextItem,
+    FontVariant, Glyph, Lang, Region, ShiftSettings, TextEdgeBounds, TextElem, TextItem,
 };
 use typst_library::World;
 use typst_utils::SliceExt;
@@ -41,8 +42,6 @@ pub struct ShapedText<'a> {
     pub styles: StyleChain<'a>,
     /// The font variant.
     pub variant: FontVariant,
-    /// The font size.
-    pub size: Abs,
     /// The width of the text's bounding box.
     pub width: Abs,
     /// The shaped glyphs.
@@ -62,6 +61,8 @@ pub struct ShapedGlyph {
     pub x_offset: Em,
     /// The vertical offset of the glyph.
     pub y_offset: Em,
+    /// The font size for the glyph.
+    pub size: Abs,
     /// The adjustability of the glyph.
     pub adjustability: Adjustability,
     /// The byte range of this glyph's cluster in the full inline layout. A
@@ -222,14 +223,17 @@ impl<'a> ShapedText<'a> {
         let mut frame = Frame::soft(size);
         frame.set_baseline(top);
 
+        let size = TextElem::size_in(self.styles);
         let shift = TextElem::baseline_in(self.styles);
         let decos = TextElem::deco_in(self.styles);
         let fill = TextElem::fill_in(self.styles);
         let stroke = TextElem::stroke_in(self.styles);
         let span_offset = TextElem::span_offset_in(self.styles);
 
-        for ((font, y_offset), group) in
+        for ((font, y_offset, glyph_size), group) in self
-            self.glyphs.as_ref().group_by_key(|g| (g.font.clone(), g.y_offset))
+            .glyphs
+            .as_ref()
+            .group_by_key(|g| (g.font.clone(), g.y_offset, g.size))
         {
             let mut range = group[0].range.clone();
             for glyph in group {
@@ -237,7 +241,7 @@ impl<'a> ShapedText<'a> {
                 range.end = range.end.max(glyph.range.end);
             }
 
-            let pos = Point::new(offset, top + shift - y_offset.at(self.size));
+            let pos = Point::new(offset, top + shift - y_offset.at(size));
             let glyphs: Vec<Glyph> = group
                 .iter()
                 .map(|shaped: &ShapedGlyph| {
@@ -257,11 +261,11 @@ impl<'a> ShapedText<'a> {
                         adjustability_right * justification_ratio;
                     if shaped.is_justifiable() {
                         justification_right +=
-                            Em::from_length(extra_justification, self.size)
+                            Em::from_abs(extra_justification, glyph_size)
                     }
 
-                    frame.size_mut().x += justification_left.at(self.size)
+                    frame.size_mut().x += justification_left.at(glyph_size)
-                        + justification_right.at(self.size);
+                        + justification_right.at(glyph_size);
 
                     // We may not be able to reach the offset completely if
                     // it exceeds u16, but better to have a roughly correct
@@ -304,7 +308,7 @@ impl<'a> ShapedText<'a> {
 
             let item = TextItem {
                 font,
-                size: self.size,
+                size: glyph_size,
                 lang: self.lang,
                 region: self.region,
                 fill: fill.clone(),
@@ -336,12 +340,13 @@ impl<'a> ShapedText<'a> {
         let mut top = Abs::zero();
         let mut bottom = Abs::zero();
 
+        let size = TextElem::size_in(self.styles);
         let top_edge = TextElem::top_edge_in(self.styles);
         let bottom_edge = TextElem::bottom_edge_in(self.styles);
 
         // Expand top and bottom by reading the font's vertical metrics.
         let mut expand = |font: &Font, bounds: TextEdgeBounds| {
-            let (t, b) = font.edges(top_edge, bottom_edge, self.size, bounds);
+            let (t, b) = font.edges(top_edge, bottom_edge, size, bounds);
             top.set_max(t);
             bottom.set_max(b);
         };
@@ -388,18 +393,16 @@ impl<'a> ShapedText<'a> {
     pub fn stretchability(&self) -> Abs {
         self.glyphs
             .iter()
-            .map(|g| g.stretchability().0 + g.stretchability().1)
+            .map(|g| (g.stretchability().0 + g.stretchability().1).at(g.size))
-            .sum::<Em>()
+            .sum()
-            .at(self.size)
     }
 
     /// The shrinkability of the text
     pub fn shrinkability(&self) -> Abs {
         self.glyphs
             .iter()
-            .map(|g| g.shrinkability().0 + g.shrinkability().1)
+            .map(|g| (g.shrinkability().0 + g.shrinkability().1).at(g.size))
-            .sum::<Em>()
+            .sum()
-            .at(self.size)
     }
 
     /// Reshape a range of the shaped text, reusing information from this
@@ -418,9 +421,8 @@ impl<'a> ShapedText<'a> {
                 lang: self.lang,
                 region: self.region,
                 styles: self.styles,
-                size: self.size,
                 variant: self.variant,
-                width: glyphs.iter().map(|g| g.x_advance).sum::<Em>().at(self.size),
+                width: glyphs_width(glyphs),
                 glyphs: Cow::Borrowed(glyphs),
             }
         } else {
@@ -484,13 +486,15 @@ impl<'a> ShapedText<'a> {
             // that subtracting either of the endpoints by self.base doesn't
             // underflow. See <https://github.com/typst/typst/issues/2283>.
             .unwrap_or_else(|| self.base..self.base);
-            self.width += x_advance.at(self.size);
+            let size = TextElem::size_in(self.styles);
+            self.width += x_advance.at(size);
             let glyph = ShapedGlyph {
                 font,
                 glyph_id: glyph_id.0,
                 x_advance,
                 x_offset: Em::zero(),
                 y_offset: Em::zero(),
+                size,
                 adjustability: Adjustability::default(),
                 range,
                 safe_to_break: true,
@@ -666,6 +670,7 @@ fn shape<'a>(
     region: Option<Region>,
 ) -> ShapedText<'a> {
     let size = TextElem::size_in(styles);
+    let shift_settings = TextElem::shift_settings_in(styles);
     let mut ctx = ShapingContext {
         engine,
         size,
@@ -676,6 +681,7 @@ fn shape<'a>(
         features: features(styles),
         fallback: TextElem::fallback_in(styles),
         dir,
+        shift_settings,
     };
 
     if !text.is_empty() {
@@ -698,12 +704,17 @@ fn shape<'a>(
         region,
         styles,
         variant: ctx.variant,
-        size,
+        width: glyphs_width(&ctx.glyphs),
-        width: ctx.glyphs.iter().map(|g| g.x_advance).sum::<Em>().at(size),
         glyphs: Cow::Owned(ctx.glyphs),
     }
 }
 
+/// Computes the width of a run of glyphs relative to the font size, accounting
+/// for their individual scaling factors and other font metrics.
+fn glyphs_width(glyphs: &[ShapedGlyph]) -> Abs {
+    glyphs.iter().map(|g| g.x_advance.at(g.size)).sum()
+}
+
 /// Holds shaping results and metadata common to all shaped segments.
 struct ShapingContext<'a, 'v> {
     engine: &'a Engine<'v>,
@@ -715,6 +726,7 @@ struct ShapingContext<'a, 'v> {
     features: Vec<rustybuzz::Feature>,
     fallback: bool,
     dir: Dir,
+    shift_settings: Option<ShiftSettings>,
 }
 
 /// Shape text with font fallback using the `families` iterator.
@@ -789,6 +801,18 @@ fn shape_segment<'a>(
     // text extraction.
     buffer.set_flags(BufferFlags::REMOVE_DEFAULT_IGNORABLES);
 
+    let (script_shift, script_compensation, scale, shift_feature) = ctx
+        .shift_settings
+        .map_or((Em::zero(), Em::zero(), Em::one(), None), |settings| {
+            determine_shift(text, &font, settings)
+        });
+
+    let has_shift_feature = shift_feature.is_some();
+    if let Some(feat) = shift_feature {
+        // Temporarily push the feature.
+        ctx.features.push(feat)
+    }
+
     // Prepare the shape plan. This plan depends on direction, script, language,
     // and features, but is independent from the text and can thus be memoized.
     let plan = create_shape_plan(
@@ -799,6 +823,10 @@ fn shape_segment<'a>(
         &ctx.features,
     );
 
+    if has_shift_feature {
+        ctx.features.pop();
+    }
+
     // Shape!
     let buffer = rustybuzz::shape_with_plan(font.rusty(), &plan, buffer);
     let infos = buffer.glyph_infos();
@@ -869,8 +897,9 @@ fn shape_segment<'a>(
                 glyph_id: info.glyph_id as u16,
                 // TODO: Don't ignore y_advance.
                 x_advance,
-                x_offset: font.to_em(pos[i].x_offset),
+                x_offset: font.to_em(pos[i].x_offset) + script_compensation,
-                y_offset: font.to_em(pos[i].y_offset),
+                y_offset: font.to_em(pos[i].y_offset) + script_shift,
+                size: scale.at(ctx.size),
                 adjustability: Adjustability::default(),
                 range: start..end,
                 safe_to_break: !info.unsafe_to_break(),
@@ -932,6 +961,64 @@ fn shape_segment<'a>(
     ctx.used.pop();
 }
 
+/// Returns a `(script_shift, script_compensation, scale, feature)` quadruplet
+/// describing how to produce scripts.
+///
+/// Those values determine how the rendered text should be transformed to
+/// display sub-/super-scripts. If the OpenType feature can be used, the
+/// rendered text should not be transformed in any way, and so those values are
+/// neutral (`(0, 0, 1, None)`). If scripts should be synthesized, those values
+/// determine how to transform the rendered text to display scripts as expected.
+fn determine_shift(
+    text: &str,
+    font: &Font,
+    settings: ShiftSettings,
+) -> (Em, Em, Em, Option<Feature>) {
+    settings
+        .typographic
+        .then(|| {
+            // If typographic scripts are enabled (i.e., we want to use the
+            // OpenType feature instead of synthesizing if possible), we add
+            // "subs"/"sups" to the feature list if supported by the font.
+            // In case of a problem, we just early exit
+            let gsub = font.rusty().tables().gsub?;
+            let subtable_index =
+                gsub.features.find(settings.kind.feature())?.lookup_indices.get(0)?;
+            let coverage = gsub
+                .lookups
+                .get(subtable_index)?
+                .subtables
+                .get::<SubstitutionSubtable>(0)?
+                .coverage();
+            text.chars()
+                .all(|c| {
+                    font.rusty().glyph_index(c).is_some_and(|i| coverage.contains(i))
+                })
+                .then(|| {
+                    // If we can use the OpenType feature, we can keep the text
+                    // as is.
+                    (
+                        Em::zero(),
+                        Em::zero(),
+                        Em::one(),
+                        Some(Feature::new(settings.kind.feature(), 1, ..)),
+                    )
+                })
+        })
+        // Reunite the cases where `typographic` is `false` or where using the
+        // OpenType feature would not work.
+        .flatten()
+        .unwrap_or_else(|| {
+            let script_metrics = settings.kind.read_metrics(font.metrics());
+            (
+                settings.shift.unwrap_or(script_metrics.vertical_offset),
+                script_metrics.horizontal_offset,
+                settings.size.unwrap_or(script_metrics.height),
+                None,
+            )
+        })
+}
+
 /// Create a shape plan.
 #[comemo::memoize]
 pub fn create_shape_plan(
@@ -963,6 +1050,7 @@ fn shape_tofus(ctx: &mut ShapingContext, base: usize, text: &str, font: Font) {
             x_advance,
             x_offset: Em::zero(),
             y_offset: Em::zero(),
+            size: ctx.size,
             adjustability: Adjustability::default(),
             range: start..end,
             safe_to_break: true,
@@ -985,9 +1073,8 @@ fn shape_tofus(ctx: &mut ShapingContext, base: usize, text: &str, font: Font) {
 
 /// Apply tracking and spacing to the shaped glyphs.
 fn track_and_space(ctx: &mut ShapingContext) {
-    let tracking = Em::from_length(TextElem::tracking_in(ctx.styles), ctx.size);
+    let tracking = Em::from_abs(TextElem::tracking_in(ctx.styles), ctx.size);
-    let spacing =
+    let spacing = TextElem::spacing_in(ctx.styles).map(|abs| Em::from_abs(abs, ctx.size));
-        TextElem::spacing_in(ctx.styles).map(|abs| Em::from_length(abs, ctx.size));
 
     let mut glyphs = ctx.glyphs.iter_mut().peekable();
     while let Some(glyph) = glyphs.next() {

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

@@ -215,7 +215,7 @@ impl MathFragment {
                     &glyph.item.font,
                     GlyphId(glyph.item.glyphs[glyph_index].id),
                     corner,
-                    Em::from_length(height, glyph.item.size),
+                    Em::from_abs(height, glyph.item.size),
                 )
                 .unwrap_or_default()
                 .at(glyph.item.size)
@@ -767,8 +767,8 @@ fn assemble(
             advance += ratio * (max_overlap - min_overlap);
         }
         let (x, y) = match axis {
-            Axis::X => (Em::from_length(advance, base.item.size), Em::zero()),
+            Axis::X => (Em::from_abs(advance, base.item.size), Em::zero()),
-            Axis::Y => (Em::zero(), Em::from_length(advance, base.item.size)),
+            Axis::Y => (Em::zero(), Em::from_abs(advance, base.item.size)),
         };
         glyphs.push(Glyph {
             id: part.glyph_id.0,

crates/typst-library/src/foundations/array.rs

@@ -604,7 +604,7 @@ impl Array {
         Ok(acc)
     }
 
-    /// Calculates the product all items (works for all types that can be
+    /// Calculates the product of all items (works for all types that can be
     /// multiplied).
     #[func]
     pub fn product(

crates/typst-library/src/foundations/calc.rs

@@ -207,9 +207,9 @@ pub fn sqrt(
 /// ```
 #[func]
 pub fn root(
-    /// The expression to take the root of
+    /// The expression to take the root of.
     radicand: f64,
-    /// Which root of the radicand to take
+    /// Which root of the radicand to take.
     index: Spanned<i64>,
 ) -> SourceResult<f64> {
     if index.v == 0 {
@@ -317,7 +317,7 @@ pub fn asin(
 /// ```
 #[func(title = "Arccosine")]
 pub fn acos(
-    /// The number whose arcsine to calculate. Must be between -1 and 1.
+    /// The number whose arccosine to calculate. Must be between -1 and 1.
     value: Spanned<Num>,
 ) -> SourceResult<Angle> {
     let val = value.v.float();
@@ -387,7 +387,7 @@ pub fn cosh(
     value.cosh()
 }
 
-/// Calculates the hyperbolic tangent of an hyperbolic angle.
+/// Calculates the hyperbolic tangent of a hyperbolic angle.
 ///
 /// ```example
 /// #calc.tanh(0) \

crates/typst-library/src/layout/em.rs

@@ -6,7 +6,7 @@ use ecow::EcoString;
 use typst_utils::{Numeric, Scalar};
 
 use crate::foundations::{cast, repr, Repr, Resolve, StyleChain, Value};
-use crate::layout::Abs;
+use crate::layout::{Abs, Length};
 use crate::text::TextElem;
 
 /// A length that is relative to the font size.
@@ -26,18 +26,18 @@ impl Em {
         Self(Scalar::ONE)
     }
 
-    /// Create a font-relative length.
+    /// Creates a font-relative length.
     pub const fn new(em: f64) -> Self {
         Self(Scalar::new(em))
     }
 
-    /// Create an em length from font units at the given units per em.
+    /// Creates an em length from font units at the given units per em.
     pub fn from_units(units: impl Into<f64>, units_per_em: f64) -> Self {
         Self(Scalar::new(units.into() / units_per_em))
     }
 
-    /// Create an em length from a length at the given font size.
+    /// Creates an em length from an absolute length at the given font size.
-    pub fn from_length(length: Abs, font_size: Abs) -> Self {
+    pub fn from_abs(length: Abs, font_size: Abs) -> Self {
         let result = length / font_size;
         if result.is_finite() {
             Self(Scalar::new(result))
@@ -46,6 +46,11 @@ impl Em {
         }
     }
 
+    /// Creates an em length from a length at the given font size.
+    pub fn from_length(length: Length, font_size: Abs) -> Em {
+        length.em + Self::from_abs(length.abs, font_size)
+    }
+
     /// The number of em units.
     pub const fn get(self) -> f64 {
         (self.0).get()
@@ -56,7 +61,7 @@ impl Em {
         Self::new(self.get().abs())
     }
 
-    /// Convert to an absolute length at the given font size.
+    /// Converts to an absolute length at the given font size.
     pub fn at(self, font_size: Abs) -> Abs {
         let resolved = font_size * self.get();
         if resolved.is_finite() {

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

@@ -228,6 +228,10 @@ pub struct FontMetrics {
     pub underline: LineMetrics,
     /// Recommended metrics for an overline.
     pub overline: LineMetrics,
+    /// Metrics for subscripts, if provided by the font.
+    pub subscript: Option<ScriptMetrics>,
+    /// Metrics for superscripts, if provided by the font.
+    pub superscript: Option<ScriptMetrics>,
 }
 
 impl FontMetrics {
@@ -240,6 +244,7 @@ impl FontMetrics {
         let cap_height = ttf.capital_height().filter(|&h| h > 0).map_or(ascender, to_em);
         let x_height = ttf.x_height().filter(|&h| h > 0).map_or(ascender, to_em);
         let descender = to_em(ttf.typographic_descender().unwrap_or(ttf.descender()));
+
         let strikeout = ttf.strikeout_metrics();
         let underline = ttf.underline_metrics();
 
@@ -262,6 +267,20 @@ impl FontMetrics {
             thickness: underline.thickness,
         };
 
+        let subscript = ttf.subscript_metrics().map(|metrics| ScriptMetrics {
+            width: to_em(metrics.x_size),
+            height: to_em(metrics.y_size),
+            horizontal_offset: to_em(metrics.x_offset),
+            vertical_offset: -to_em(metrics.y_offset),
+        });
+
+        let superscript = ttf.superscript_metrics().map(|metrics| ScriptMetrics {
+            width: to_em(metrics.x_size),
+            height: to_em(metrics.y_size),
+            horizontal_offset: to_em(metrics.x_offset),
+            vertical_offset: to_em(metrics.y_offset),
+        });
+
         Self {
             units_per_em,
             ascender,
@@ -271,6 +290,8 @@ impl FontMetrics {
             strikethrough,
             underline,
             overline,
+            superscript,
+            subscript,
         }
     }
 
@@ -296,6 +317,24 @@ pub struct LineMetrics {
     pub thickness: Em,
 }
 
+/// Metrics for subscripts or superscripts.
+#[derive(Debug, Copy, Clone)]
+pub struct ScriptMetrics {
+    /// The width of those scripts, relative to the outer font size.
+    pub width: Em,
+    /// The height of those scripts, relative to the outer font size.
+    pub height: Em,
+    /// The horizontal (to the right) offset of those scripts, relative to the
+    /// outer font size.
+    ///
+    /// This is used for italic correction.
+    pub horizontal_offset: Em,
+    /// The vertical (to the top) offset of those scripts, relative to the outer font size.
+    ///
+    /// For superscripts, this is positive. For subscripts, this is negative.
+    pub vertical_offset: Em,
+}
+
 /// Identifies a vertical metric of a font.
 #[derive(Debug, Copy, Clone, Eq, PartialEq, Hash, Cast)]
 pub enum VerticalFontMetric {

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

@@ -755,6 +755,12 @@ pub struct TextElem {
     #[internal]
     #[ghost]
     pub smallcaps: Option<Smallcaps>,
+
+    /// The configuration for superscripts or subscripts, if one of them is
+    /// enabled.
+    #[internal]
+    #[ghost]
+    pub shift_settings: Option<ShiftSettings>,
 }
 
 impl TextElem {

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

@@ -1,14 +1,13 @@
-use ecow::EcoString;
-
 use crate::diag::SourceResult;
 use crate::engine::Engine;
 use crate::foundations::{
-    elem, Content, NativeElement, Packed, SequenceElem, Show, StyleChain, TargetElem,
+    elem, Content, NativeElement, Packed, Show, Smart, StyleChain, TargetElem,
 };
 use crate::html::{tag, HtmlElem};
 use crate::layout::{Em, Length};
-use crate::text::{variant, SpaceElem, TextElem, TextSize};
+use crate::text::{FontMetrics, TextElem, TextSize};
-use crate::World;
+use ttf_parser::Tag;
+use typst_library::text::ScriptMetrics;
 
 /// Renders text in subscript.
 ///
@@ -20,11 +19,16 @@ use crate::World;
 /// ```
 #[elem(title = "Subscript", Show)]
 pub struct SubElem {
-    /// Whether to prefer the dedicated subscript characters of the font.
+    /// Whether to create artificial subscripts by lowering and scaling down
+    /// regular glyphs.
     ///
-    /// If this is enabled, Typst first tries to transform the text to subscript
+    /// Ideally, subscripts glyphs are provided by the font (using the `subs`
-    /// codepoints. If that fails, it falls back to rendering lowered and shrunk
+    /// OpenType feature). Otherwise, Typst is able to synthesize subscripts.
-    /// normal letters.
+    ///
+    /// When this is set to `{false}`, synthesized glyphs will be used
+    /// regardless of whether the font provides dedicated subscript glyphs. When
+    /// `{true}`, synthesized glyphs may still be used in case the font does not
+    /// provide the necessary subscript glyphs.
     ///
     /// ```example
     /// N#sub(typographic: true)[1]
@@ -33,17 +37,27 @@ pub struct SubElem {
     #[default(true)]
     pub typographic: bool,
 
-    /// The baseline shift for synthetic subscripts. Does not apply if
+    /// The downward baseline shift for synthesized subscripts.
-    /// `typographic` is true and the font has subscript codepoints for the
+    ///
-    /// given `body`.
+    /// This only applies to synthesized subscripts. In other words, this has no
-    #[default(Em::new(0.2).into())]
+    /// effect if `typographic` is `{true}` and the font provides the necessary
-    pub baseline: Length,
+    /// subscript glyphs.
+    ///
+    /// If set to `{auto}`, the baseline is shifted according to the metrics
+    /// provided by the font, with a fallback to `{0.2em}` in case the font does
+    /// not define the necessary metrics.
+    pub baseline: Smart<Length>,
 
-    /// The font size for synthetic subscripts. Does not apply if
+    /// The font size for synthesized subscripts.
-    /// `typographic` is true and the font has subscript codepoints for the
+    ///
-    /// given `body`.
+    /// This only applies to synthesized subscripts. In other words, this has no
-    #[default(TextSize(Em::new(0.6).into()))]
+    /// effect if `typographic` is `{true}` and the font provides the necessary
-    pub size: TextSize,
+    /// subscript glyphs.
+    ///
+    /// If set to `{auto}`, the size is scaled according to the metrics provided
+    /// by the font, with a fallback to `{0.6em}` in case the font does not
+    /// define the necessary metrics.
+    pub size: Smart<TextSize>,
 
     /// The text to display in subscript.
     #[required]
@@ -52,7 +66,7 @@ pub struct SubElem {
 
 impl Show for Packed<SubElem> {
     #[typst_macros::time(name = "sub", span = self.span())]
-    fn show(&self, engine: &mut Engine, styles: StyleChain) -> SourceResult<Content> {
+    fn show(&self, _: &mut Engine, styles: StyleChain) -> SourceResult<Content> {
         let body = self.body.clone();
 
         if TargetElem::target_in(styles).is_html() {
@@ -62,17 +76,14 @@ impl Show for Packed<SubElem> {
                 .spanned(self.span()));
         }
 
-        if self.typographic(styles) {
+        show_script(
-            if let Some(text) = convert_script(&body, true) {
+            styles,
-                if is_shapable(engine, &text, styles) {
+            body,
-                    return Ok(TextElem::packed(text));
+            self.typographic(styles),
-                }
+            self.baseline(styles),
-            }
+            self.size(styles),
-        };
+            ScriptKind::Sub,
-
+        )
-        Ok(body
-            .styled(TextElem::set_baseline(self.baseline(styles)))
-            .styled(TextElem::set_size(self.size(styles))))
     }
 }
 
@@ -86,11 +97,16 @@ impl Show for Packed<SubElem> {
 /// ```
 #[elem(title = "Superscript", Show)]
 pub struct SuperElem {
-    /// Whether to prefer the dedicated superscript characters of the font.
+    /// Whether to create artificial superscripts by raising and scaling down
+    /// regular glyphs.
     ///
-    /// If this is enabled, Typst first tries to transform the text to
+    /// Ideally, superscripts glyphs are provided by the font (using the `sups`
-    /// superscript codepoints. If that fails, it falls back to rendering
+    /// OpenType feature). Otherwise, Typst is able to synthesize superscripts.
-    /// raised and shrunk normal letters.
+    ///
+    /// When this is set to `{false}`, synthesized glyphs will be used
+    /// regardless of whether the font provides dedicated superscript glyphs.
+    /// When `{true}`, synthesized glyphs may still be used in case the font
+    /// does not provide the necessary superscript glyphs.
     ///
     /// ```example
     /// N#super(typographic: true)[1]
@@ -99,17 +115,31 @@ pub struct SuperElem {
     #[default(true)]
     pub typographic: bool,
 
-    /// The baseline shift for synthetic superscripts. Does not apply if
+    /// The downward baseline shift for synthesized superscripts.
-    /// `typographic` is true and the font has superscript codepoints for the
+    ///
-    /// given `body`.
+    /// This only applies to synthesized superscripts. In other words, this has
-    #[default(Em::new(-0.5).into())]
+    /// no effect if `typographic` is `{true}` and the font provides the
-    pub baseline: Length,
+    /// necessary superscript glyphs.
+    ///
+    /// If set to `{auto}`, the baseline is shifted according to the metrics
+    /// provided by the font, with a fallback to `{-0.5em}` in case the font
+    /// does not define the necessary metrics.
+    ///
+    /// Note that, since the baseline shift is applied downward, you will need
+    /// to provide a negative value for the content to appear as raised above
+    /// the normal baseline.
+    pub baseline: Smart<Length>,
 
-    /// The font size for synthetic superscripts. Does not apply if
+    /// The font size for synthesized superscripts.
-    /// `typographic` is true and the font has superscript codepoints for the
+    ///
-    /// given `body`.
+    /// This only applies to synthesized superscripts. In other words, this has
-    #[default(TextSize(Em::new(0.6).into()))]
+    /// no effect if `typographic` is `{true}` and the font provides the
-    pub size: TextSize,
+    /// necessary superscript glyphs.
+    ///
+    /// If set to `{auto}`, the size is scaled according to the metrics provided
+    /// by the font, with a fallback to `{0.6em}` in case the font does not
+    /// define the necessary metrics.
+    pub size: Smart<TextSize>,
 
     /// The text to display in superscript.
     #[required]
@@ -118,7 +148,7 @@ pub struct SuperElem {
 
 impl Show for Packed<SuperElem> {
     #[typst_macros::time(name = "super", span = self.span())]
-    fn show(&self, engine: &mut Engine, styles: StyleChain) -> SourceResult<Content> {
+    fn show(&self, _: &mut Engine, styles: StyleChain) -> SourceResult<Content> {
         let body = self.body.clone();
 
         if TargetElem::target_in(styles).is_html() {
@@ -128,104 +158,102 @@ impl Show for Packed<SuperElem> {
                 .spanned(self.span()));
         }
 
-        if self.typographic(styles) {
+        show_script(
-            if let Some(text) = convert_script(&body, false) {
+            styles,
-                if is_shapable(engine, &text, styles) {
+            body,
-                    return Ok(TextElem::packed(text));
+            self.typographic(styles),
-                }
+            self.baseline(styles),
-            }
+            self.size(styles),
-        };
+            ScriptKind::Super,
-
+        )
-        Ok(body
-            .styled(TextElem::set_baseline(self.baseline(styles)))
-            .styled(TextElem::set_size(self.size(styles))))
     }
 }
 
-/// Find and transform the text contained in `content` to the given script kind
+fn show_script(
-/// if and only if it only consists of `Text`, `Space`, and `Empty` leaves.
+    styles: StyleChain,
-fn convert_script(content: &Content, sub: bool) -> Option<EcoString> {
+    body: Content,
-    if content.is::<SpaceElem>() {
+    typographic: bool,
-        Some(' '.into())
+    baseline: Smart<Length>,
-    } else if let Some(elem) = content.to_packed::<TextElem>() {
+    size: Smart<TextSize>,
-        if sub {
+    kind: ScriptKind,
-            elem.text.chars().map(to_subscript_codepoint).collect()
+) -> SourceResult<Content> {
-        } else {
+    let font_size = TextElem::size_in(styles);
-            elem.text.chars().map(to_superscript_codepoint).collect()
+    Ok(body.styled(TextElem::set_shift_settings(Some(ShiftSettings {
-        }
+        typographic,
-    } else if let Some(sequence) = content.to_packed::<SequenceElem>() {
+        shift: baseline.map(|l| -Em::from_length(l, font_size)),
-        sequence
+        size: size.map(|t| Em::from_length(t.0, font_size)),
-            .children
+        kind,
-            .iter()
+    }))))
-            .map(|item| convert_script(item, sub))
-            .collect()
-    } else {
-        None
-    }
 }
 
-/// Checks whether the first retrievable family contains all code points of the
+/// Configuration values for sub- or superscript text.
-/// given string.
+#[derive(Debug, Copy, Clone, Eq, PartialEq, Hash)]
-fn is_shapable(engine: &Engine, text: &str, styles: StyleChain) -> bool {
+pub struct ShiftSettings {
-    let world = engine.world;
+    /// Whether the OpenType feature should be used if possible.
-    for family in TextElem::font_in(styles) {
+    pub typographic: bool,
-        if let Some(font) = world
+    /// The baseline shift of the script, relative to the outer text size.
-            .book()
+    ///
-            .select(family.as_str(), variant(styles))
+    /// For superscripts, this is positive. For subscripts, this is negative. A
-            .and_then(|id| world.font(id))
+    /// value of [`Smart::Auto`] indicates that the value should be obtained
-        {
+    /// from font metrics.
-            let covers = family.covers();
+    pub shift: Smart<Em>,
-            return text.chars().all(|c| {
+    /// The size of the script, relative to the outer text size.
-                covers.is_none_or(|cov| cov.is_match(c.encode_utf8(&mut [0; 4])))
+    ///
-                    && font.ttf().glyph_index(c).is_some()
+    /// A value of [`Smart::Auto`] indicates that the value should be obtained
-            });
+    /// from font metrics.
+    pub size: Smart<Em>,
+    /// The kind of script (either a subscript, or a superscript).
+    ///
+    /// This is used to know which OpenType table to use to resolve
+    /// [`Smart::Auto`] values.
+    pub kind: ScriptKind,
+}
+
+#[derive(Debug, Copy, Clone, Eq, PartialEq, Hash)]
+pub enum ScriptKind {
+    Sub,
+    Super,
+}
+
+impl ScriptKind {
+    /// Returns the default metrics for this script kind.
+    ///
+    /// This can be used as a last resort if neither the user nor the font
+    /// provided those metrics.
+    pub fn default_metrics(self) -> &'static ScriptMetrics {
+        match self {
+            Self::Sub => &DEFAULT_SUBSCRIPT_METRICS,
+            Self::Super => &DEFAULT_SUPERSCRIPT_METRICS,
         }
     }
 
-    false
+    /// Reads the script metrics from the font table for to this script kind.
-}
+    pub fn read_metrics(self, font_metrics: &FontMetrics) -> &ScriptMetrics {
+        match self {
+            Self::Sub => font_metrics.subscript.as_ref(),
+            Self::Super => font_metrics.superscript.as_ref(),
+        }
+        .unwrap_or(self.default_metrics())
+    }
 
-/// Convert a character to its corresponding Unicode superscript.
+    /// The corresponding OpenType feature.
-fn to_superscript_codepoint(c: char) -> Option<char> {
+    pub const fn feature(self) -> Tag {
-    match c {
+        match self {
-        '1' => Some('¹'),
+            Self::Sub => Tag::from_bytes(b"subs"),
-        '2' => Some('²'),
+            Self::Super => Tag::from_bytes(b"sups"),
-        '3' => Some('³'),
+        }
-        '0' | '4'..='9' => char::from_u32(c as u32 - '0' as u32 + '⁰' as u32),
-        '+' => Some('⁺'),
-        '−' => Some('⁻'),
-        '=' => Some('⁼'),
-        '(' => Some('⁽'),
-        ')' => Some('⁾'),
-        'n' => Some('ⁿ'),
-        'i' => Some('ⁱ'),
-        ' ' => Some(' '),
-        _ => None,
     }
 }
+static DEFAULT_SUBSCRIPT_METRICS: ScriptMetrics = ScriptMetrics {
+    width: Em::new(0.6),
+    height: Em::new(0.6),
+    horizontal_offset: Em::zero(),
+    vertical_offset: Em::new(-0.2),
+};
 
-/// Convert a character to its corresponding Unicode subscript.
+static DEFAULT_SUPERSCRIPT_METRICS: ScriptMetrics = ScriptMetrics {
-fn to_subscript_codepoint(c: char) -> Option<char> {
+    width: Em::new(0.6),
-    match c {
+    height: Em::new(0.6),
-        '0'..='9' => char::from_u32(c as u32 - '0' as u32 + '₀' as u32),
+    horizontal_offset: Em::zero(),
-        '+' => Some('₊'),
+    vertical_offset: Em::new(0.5),
-        '−' => Some('₋'),
+};
-        '=' => Some('₌'),
-        '(' => Some('₍'),
-        ')' => Some('₎'),
-        'a' => Some('ₐ'),
-        'e' => Some('ₑ'),
-        'o' => Some('ₒ'),
-        'x' => Some('ₓ'),
-        'h' => Some('ₕ'),
-        'k' => Some('ₖ'),
-        'l' => Some('ₗ'),
-        'm' => Some('ₘ'),
-        'n' => Some('ₙ'),
-        'p' => Some('ₚ'),
-        's' => Some('ₛ'),
-        't' => Some('ₜ'),
-        ' ' => Some(' '),
-        _ => None,
-    }
-}

crates/typst-pdf/src/lib.rs

@@ -172,7 +172,7 @@ pub enum PdfStandard {
     /// PDF/A-2u.
     #[serde(rename = "a-2u")]
     A_2u,
-    /// PDF/A-3u.
+    /// PDF/A-3b.
     #[serde(rename = "a-3b")]
     A_3b,
     /// PDF/A-3u.

crates/typst-utils/src/lib.rs

@@ -395,6 +395,10 @@ pub fn default_math_class(c: char) -> Option<MathClass> {
         // https://github.com/typst/typst/issues/5764
         '⟇' => Some(MathClass::Binary),
 
+        // Arabic comma.
+        // https://github.com/latex3/unicode-math/pull/633#issuecomment-2028936135
+        '،' => Some(MathClass::Punctuation),
+
         c => unicode_math_class::class(c),
     }
 }

docs/tutorial/3-advanced.md

@@ -79,7 +79,7 @@ the right.
 
 Last but not least is the `numbering` argument. Here, we can provide a
 [numbering pattern]($numbering) that defines how to number the pages. By
-setting into to `{"1"}`, Typst only displays the bare page number. Setting it to
+setting it to `{"1"}`, Typst only displays the bare page number. Setting it to
 `{"(1/1)"}` would have displayed the current page and total number of pages
 surrounded by parentheses. And we could even have provided a completely custom
 function here to format things to our liking.

tests/suite/text/shift.typ

@@ -1,22 +1,89 @@
 // Test sub- and superscript shifts.
 
 --- sub-super ---
+#let sq = box(square(size: 4pt))
 #table(
   columns: 3,
-  [Typo.], [Fallb.], [Synth],
+  [Typo.], [Fallb.], [Synth.],
-  [x#super[1]], [x#super[5n]], [x#super[2 #box(square(size: 6pt))]],
+  [x#super[1#sq]], [x#super[5: #sq]], [x#super(typographic: false)[2 #sq]],
-  [x#sub[1]], [x#sub[5n]], [x#sub[2 #box(square(size: 6pt))]],
+  [x#sub[1#sq]], [x#sub[5: #sq]], [x#sub(typographic: false)[2 #sq]],
 )
 
+--- sub-super-typographic ---
+#set text(size: 20pt)
+// Libertinus Serif supports "subs" and "sups" for `typo` and `sq`, but not for
+// `synth`.
+#let synth = [1,2,3]
+#let typo = [123]
+#let sq = [1#box(square(size: 4pt))2]
+x#super(synth) x#super(typo) x#super(sq) \
+x#sub(synth) x#sub(typo) x#sub(sq)
+
+--- sub-super-italic-compensation ---
+#set text(size: 20pt, style: "italic")
+// Libertinus Serif supports "subs" and "sups" for `typo`, but not for `synth`.
+#let synth = [1,2,3]
+#let typo = [123]
+#let sq = [1#box(square(size: 4pt))2]
+x#super(synth) x#super(typo) x#super(sq) \
+x#sub(synth) x#sub(typo) x#sub(sq)
+
 --- sub-super-non-typographic ---
 #set super(typographic: false, baseline: -0.25em, size: 0.7em)
 n#super[1], n#sub[2], ... n#super[N]
 
 --- super-underline ---
 #set underline(stroke: 0.5pt, offset: 0.15em)
-#underline[The claim#super[\[4\]]] has been disputed. \
+#set super(typographic: false)
-The claim#super[#underline[\[4\]]] has been disputed. \
+#underline[A#super[4]] B \
-It really has been#super(box(text(baseline: 0pt, underline[\[4\]]))) \
+A#super[#underline[4]] B \
+A #underline(super[4]) B \
+#set super(typographic: true)
+#underline[A#super[4]] B \
+A#super[#underline[4]] B \
+A #underline(super[4]) B
+
+--- super-highlight ---
+#set super(typographic: false)
+#highlight[A#super[4]] B \
+A#super[#highlight[4]] B \
+A#super(highlight[4]) \
+#set super(typographic: true)
+#highlight[A#super[4]] B \
+A#super[#highlight[4]] B \
+A#super(highlight[4])
+
+--- super-1em ---
+#set text(size: 10pt)
+#super(context test(1em.to-absolute(), 10pt))
+
+--- long-scripts ---
+|longscript| \
+|#super(typographic: true)[longscript]| \
+|#super(typographic: false)[longscript]| \
+|#sub(typographic: true)[longscript]| \
+|#sub(typographic: false)[longscript]|
+
+--- script-metrics-bundeled-fonts ---
+// Tests whether the script metrics are used properly by synthesizing
+// superscripts and subscripts for all bundled fonts.
+
+#set super(typographic: false)
+#set sub(typographic: false)
+
+#let test(font, weights, styles) = {
+  for weight in weights {
+    for style in styles {
+      text(font: font, weight: weight, style: style)[Xx#super[Xx]#sub[Xx]]
+      linebreak()
+    }
+  }
+}
+
+#test("DejaVu Sans Mono", ("regular", "bold"), ("normal", "oblique"))
+#test("Libertinus Serif", ("regular", "semibold", "bold"), ("normal", "italic"))
+#test("New Computer Modern", ("regular", "bold"), ("normal", "italic"))
+#test("New Computer Modern Math", (400, 450, "bold"), ("normal",))
 
 --- basic-sup-sub html ---
 1#super[st], 2#super[nd], 3#super[rd].

tools/test-helper/package.json

@@ -94,9 +94,12 @@
 		"watch": "tsc -watch -p ./"
 	},
 	"devDependencies": {
-		"@types/node": "18.x",
+		"@types/node": "^24.0.4",
-		"@types/vscode": "^1.88.0",
+		"@types/vscode": "^1.101.0",
-		"typescript": "^5.3.3"
+		"typescript": "^5.8.3"
+	},
+	"dependencies": {
+		"shiki": "^3.7.0"
 	},
 	"engines": {
 		"vscode": "^1.88.0"

tools/test-helper/src/extension.ts

@@ -1,6 +1,7 @@
 import * as vscode from "vscode";
 import * as cp from "child_process";
 import { clearInterval } from "timers";
+const shiki = import("shiki"); // Normal import causes TypeScript problems.
 
 // Called when an activation event is triggered. Our activation event is the
 // presence of "tests/suite/playground.typ".
@@ -17,6 +18,8 @@ class TestHelper {
   opened?: {
     // The tests's name.
     name: string;
+    // The test's attributes.
+    attrs: string[];
     // The WebView panel that displays the test images and output.
     panel: vscode.WebviewPanel;
   };
@@ -44,18 +47,18 @@ class TestHelper {
     );
 
     // Triggered when clicking "View" in the lens.
-    this.registerCommand("typst-test-helper.viewFromLens", (name) =>
+    this.registerCommand("typst-test-helper.viewFromLens", (name, attrs) =>
-      this.viewFromLens(name)
+      this.viewFromLens(name, attrs)
     );
 
     // Triggered when clicking "Run" in the lens.
-    this.registerCommand("typst-test-helper.runFromLens", (name) =>
+    this.registerCommand("typst-test-helper.runFromLens", (name, attrs) =>
-      this.runFromLens(name)
+      this.runFromLens(name, attrs)
     );
 
     // Triggered when clicking "Save" in the lens.
-    this.registerCommand("typst-test-helper.saveFromLens", (name) =>
+    this.registerCommand("typst-test-helper.saveFromLens", (name, attrs) =>
-      this.saveFromLens(name)
+      this.saveFromLens(name, attrs)
     );
 
     // Triggered when clicking "Terminal" in the lens.
@@ -121,31 +124,32 @@ class TestHelper {
     const lenses = [];
     for (let nr = 0; nr < document.lineCount; nr++) {
       const line = document.lineAt(nr);
-      const re = /^--- ([\d\w-]+)( [\d\w-]+)* ---$/;
+      const re = /^--- ([\d\w-]+)(( [\d\w-]+)*) ---$/;
       const m = line.text.match(re);
       if (!m) {
         continue;
       }
 
       const name = m[1];
+      const attrs = m[2].trim().split(" ");
       lenses.push(
         new vscode.CodeLens(line.range, {
           title: "View",
           tooltip: "View the test output and reference in a new tab",
           command: "typst-test-helper.viewFromLens",
-          arguments: [name],
+          arguments: [name, attrs],
         }),
         new vscode.CodeLens(line.range, {
           title: "Run",
           tooltip: "Run the test and view the results in a new tab",
           command: "typst-test-helper.runFromLens",
-          arguments: [name],
+          arguments: [name, attrs],
         }),
         new vscode.CodeLens(line.range, {
           title: "Save",
           tooltip: "Run and view the test and save the reference output",
           command: "typst-test-helper.saveFromLens",
-          arguments: [name],
+          arguments: [name, attrs],
         }),
         new vscode.CodeLens(line.range, {
           title: "Terminal",
@@ -159,40 +163,49 @@ class TestHelper {
   }
 
   // Triggered when clicking "View" in the lens.
-  private viewFromLens(name: string) {
+  private viewFromLens(name: string, attrs: string[]) {
-    if (this.opened?.name == name) {
+    if (
+      this.opened?.name == name &&
+      this.opened.attrs.join(" ") == attrs.join(" ")
+    ) {
       this.opened.panel.reveal();
       return;
     }
 
     if (this.opened) {
       this.opened.name = name;
+      this.opened.attrs = attrs;
       this.opened.panel.title = name;
     } else {
       const panel = vscode.window.createWebviewPanel(
         "typst-test-helper.preview",
         name,
         vscode.ViewColumn.Beside,
-        { enableFindWidget: true }
+        { enableFindWidget: true, enableScripts: true }
       );
 
       panel.onDidDispose(() => (this.opened = undefined));
+      panel.webview.onDidReceiveMessage((message) => {
+        if (message.command === "openFile") {
+          vscode.env.openExternal(vscode.Uri.parse(message.uri));
+        }
+      });
 
-      this.opened = { name, panel };
+      this.opened = { name, attrs, panel };
     }
 
     this.refreshWebView();
   }
 
   // Triggered when clicking "Run" in the lens.
-  private runFromLens(name: string) {
+  private runFromLens(name: string, attrs: string[]) {
-    this.viewFromLens(name);
+    this.viewFromLens(name, attrs);
     this.runFromPreview();
   }
 
   // Triggered when clicking "Run" in the lens.
-  private saveFromLens(name: string) {
+  private saveFromLens(name: string, attrs: string[]) {
-    this.viewFromLens(name);
+    this.viewFromLens(name, attrs);
     this.saveFromPreview();
   }
 
@@ -288,41 +301,37 @@ class TestHelper {
   private copyImageFilePathFromPreviewContext(webviewSection: string) {
     if (!this.opened) return;
     const { name } = this.opened;
-    const { png, ref } = getImageUris(name);
+    const [bucket, format] = webviewSection.split("/");
-    switch (webviewSection) {
+    vscode.env.clipboard.writeText(
-      case "png":
+      getUri(name, bucket as Bucket, format as Format).fsPath
-        vscode.env.clipboard.writeText(png.fsPath);
+    );
-        break;
-      case "ref":
-        vscode.env.clipboard.writeText(ref.fsPath);
-        break;
-      default:
-        break;
-    }
   }
 
   // Reloads the web view.
   private refreshWebView(output?: { stdout: string; stderr: string }) {
     if (!this.opened) return;
 
-    const { name, panel } = this.opened;
+    const { name, attrs, panel } = this.opened;
-    const { png, ref } = getImageUris(name);
 
     if (panel) {
       console.log(
-        `Refreshing WebView for ${name}` + (panel.visible ? " in background" : ""));
+        `Refreshing WebView for ${name}` +
-      const webViewSrcs = {
+          (panel.visible ? " in background" : "")
-        png: panel.webview.asWebviewUri(png),
+      );
-        ref: panel.webview.asWebviewUri(ref),
+
-      };
       panel.webview.html = "";
 
       // Make refresh notable.
-      setTimeout(() => {
+      setTimeout(async () => {
         if (!panel) {
           throw new Error("panel to refresh is falsy after waiting");
         }
-        panel.webview.html = getWebviewContent(webViewSrcs, output);
+        panel.webview.html = await getWebviewContent(
+          panel,
+          name,
+          attrs,
+          output
+        );
       }, 50);
     }
   }
@@ -386,30 +395,43 @@ function getWorkspaceRoot() {
   return vscode.workspace.workspaceFolders![0].uri;
 }
 
-// Returns the URIs for a test's images.
+const EXTENSION = { html: "html", render: "png" };
-function getImageUris(name: string) {
+
-  const root = getWorkspaceRoot();
+type Bucket = "store" | "ref";
-  const png = vscode.Uri.joinPath(root, `tests/store/render/${name}.png`);
+type Format = "html" | "render";
-  const ref = vscode.Uri.joinPath(root, `tests/ref/${name}.png`);
+
-  return { png, ref };
+function getUri(name: string, bucket: Bucket, format: Format) {
+  let path;
+  if (bucket === "ref" && format === "render") {
+    path = `tests/ref/${name}.png`;
+  } else {
+    path = `tests/${bucket}/${format}/${name}.${EXTENSION[format]}`;
+  }
+  return vscode.Uri.joinPath(getWorkspaceRoot(), path);
 }
 
 // Produces the content of the WebView.
-function getWebviewContent(
+async function getWebviewContent(
-  webViewSrcs: { png: vscode.Uri; ref: vscode.Uri },
+  panel: vscode.WebviewPanel,
+  name: string,
+  attrs: string[],
   output?: {
     stdout: string;
     stderr: string;
   }
-): string {
+): Promise<string> {
-  const escape = (text: string) =>
+  const showHtml = attrs.includes("html");
-    text.replace(/</g, "&lt;").replace(/>/g, "&gt;");
+  const showRender = !showHtml || attrs.includes("render");
 
-  const stdoutHtml = output?.stdout
+  const stdout = output?.stdout
-    ? `<h1>Standard output</h1><pre>${escape(output.stdout)}</pre>`
+    ? `<h2>Standard output</h2><pre class="output">${escape(
+        output.stdout
+      )}</pre>`
     : "";
-  const stderrHtml = output?.stderr
+  const stderr = output?.stderr
-    ? `<h1>Standard error</h1><pre>${escape(output.stderr)}</pre>`
+    ? `<h2>Standard error</h2><pre class="output">${escape(
+        output.stderr
+      )}</pre>`
     : "";
 
   return `
@@ -449,46 +471,169 @@ function getWebviewContent(
           color: #bebebe;
           content: "Not present";
         }
-        pre {
+        h2 {
-          display: inline-block;
+          margin-bottom: 12px;
-          font-family: var(--vscode-editor-font-family);
+        }
-          text-align: left;
+        h2 a {
-          width: 80%;
+          color: var(--vscode-editor-foreground);
+          text-decoration: underline;
+        }
+        h2 a:hover {
+          cursor: pointer;
         }
         .flex {
           display: flex;
           flex-wrap: wrap;
           justify-content: center;
         }
+        .vertical {
+          flex-direction: column;
+        }
+        .top-bottom {
+          display: flex;
+          flex-direction: column;
+          padding-inline: 32px;
+          width: calc(100vw - 64px);
+        }
+        pre {
+          font-family: var(--vscode-editor-font-family);
+          text-align: left;
+          white-space: pre-wrap;
+        }
+        pre.output {
+          display: inline-block;
+          width: 80%;
+          margin-block-start: 0;
+        }
+        pre.shiki {
+          background-color: transparent !important;
+          padding: 12px;
+          margin-block-start: 0;
+        }
+        pre.shiki code {
+          --vscode-textPreformat-background: transparent;
+        }
+        iframe, pre.shiki {
+          border: 1px solid rgb(189, 191, 204);
+          border-radius: 6px;
+        }
+        iframe {
+          background: white;
+        }
+        .vscode-dark iframe {
+          filter: invert(1) hue-rotate(180deg);
+        }
       </style>
+      <script>
+        const api = acquireVsCodeApi()
+        function openFile(uri) {
+          api.postMessage({ command: 'openFile', uri });
+        }
+        function sizeIframe(obj){
+          obj.style.height = 0;
+          obj.style.height = obj.contentWindow.document.body.scrollHeight + 'px';
+        }
+      </script>
     </head>
     <body>
-      <div
+      ${showRender ? renderSection(panel, name) : ""}
-        class="flex"
+      ${showHtml ? await htmlSection(name) : ""}
-        data-vscode-context='{"preventDefaultContextMenuItems": true}'
+      ${stdout}
-      >
+      ${stderr}
-        <div>
-          <h1>Output</h1>
-          <img
-            class="output"
-            data-vscode-context='{"webviewSection":"png"}'
-            src="${webViewSrcs.png}"
-            alt="Placeholder"
-          >
-        </div>
-
-        <div>
-          <h1>Reference</h1>
-          <img
-            class="ref"
-            data-vscode-context='{"webviewSection":"ref"}'
-            src="${webViewSrcs.ref}"
-            alt="Placeholder"
-          >
-        </div>
-      </div>
-      ${stdoutHtml}
-      ${stderrHtml}
     </body>
   </html>`;
 }
+
+function renderSection(panel: vscode.WebviewPanel, name: string) {
+  const outputUri = getUri(name, "store", "render");
+  const refUri = getUri(name, "ref", "render");
+  return `<div
+    class="flex"
+    data-vscode-context='{"preventDefaultContextMenuItems": true}'
+  >
+    <div>
+      ${linkedTitle("Output", outputUri)}
+      <img
+        class="output"
+        data-vscode-context='{"bucket":"store", format: "render"}'
+        src="${panel.webview.asWebviewUri(outputUri)}"
+        alt="Placeholder"
+      >
+    </div>
+
+    <div>
+      ${linkedTitle("Reference", refUri)}
+      <img
+        class="ref"
+        data-vscode-context='{"bucket":"ref", format: "render"}'
+        src="${panel.webview.asWebviewUri(refUri)}"
+        alt="Placeholder"
+      >
+    </div>
+  </div>`;
+}
+
+async function htmlSection(name: string) {
+  const storeHtml = await htmlSnippet(
+    "HTML Output",
+    getUri(name, "store", "html")
+  );
+  const refHtml = await htmlSnippet(
+    "HTML Reference",
+    getUri(name, "ref", "html")
+  );
+  return `<div
+    class="flex vertical"
+    data-vscode-context='{"preventDefaultContextMenuItems": true}'
+  >
+    ${storeHtml}
+    ${refHtml}
+  </div>`;
+}
+
+async function htmlSnippet(title: string, uri: vscode.Uri): Promise<string> {
+  try {
+    const data = await vscode.workspace.fs.readFile(uri);
+    const code = new TextDecoder("utf-8").decode(data);
+    return `<div>
+      ${linkedTitle(title, uri)}
+      <div class="top-bottom">
+        ${await highlight(code)}
+        <iframe srcdoc="${escape(code)}"></iframe>
+      </div>
+    </div>`;
+  } catch {
+    return `<div><h2>${title}</h2>Not present</div>`;
+  }
+}
+
+function linkedTitle(title: string, uri: vscode.Uri) {
+  return `<h2><a onclick="openFile('${uri.toString()}')">${title}</a></h2>`;
+}
+
+async function highlight(code: string): Promise<string> {
+  return (await shiki).codeToHtml(code, {
+    lang: "html",
+    theme: selectTheme(),
+  });
+}
+
+function selectTheme() {
+  switch (vscode.window.activeColorTheme.kind) {
+    case vscode.ColorThemeKind.Light:
+    case vscode.ColorThemeKind.HighContrastLight:
+      return "github-light";
+    case vscode.ColorThemeKind.Dark:
+    case vscode.ColorThemeKind.HighContrast:
+      return "github-dark";
+  }
+}
+
+function escape(text: string) {
+  return text
+    .replace(/&/g, "&amp;")
+    .replace(/</g, "&lt;")
+    .replace(/>/g, "&gt;")
+    .replace(/"/g, "&quot;")
+    .replace(/'/g, "&apos;");
+}

tools/test-helper/tsconfig.json

@@ -1,9 +1,10 @@
 {
   "compilerOptions": {
-    "module": "Node16",
+    "module": "nodenext",
+    "lib": ["ES2022", "DOM"],
     "target": "ES2022",
+    "moduleResolution": "nodenext",
     "outDir": "dist",
-    "lib": ["ES2022"],
     "sourceMap": true,
     "rootDir": "src",
     "strict": true