Emojis in PDF (#3853)

Cargo.lock

@@ -1612,9 +1612,9 @@ checksum = "8835116a5c179084a830efb3adc117ab007512b535bc1a21c991d3b32a6b44dd"
 
 [[package]]
 name = "pdf-writer"
-version = "0.9.2"
+version = "0.9.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "644b654f2de28457bf1e25a4905a76a563d1128a33ce60cf042f721f6818feaf"
+checksum = "24e9127455063c816e661caac9ecd9043ad2871f55be93014e6838a8ced2332b"
 dependencies = [
  "bitflags 1.3.2",
  "itoa",
@@ -2525,6 +2525,7 @@ dependencies = [
  "comemo",
  "csv",
  "ecow",
+ "flate2",
  "fontdb",
  "hayagriva",
  "hypher",
@@ -2571,6 +2572,7 @@ dependencies = [
  "unicode-math-class",
  "unicode-script",
  "unicode-segmentation",
+ "unscanny",
  "usvg",
  "wasmi",
 ]
@@ -2702,6 +2704,7 @@ dependencies = [
  "comemo",
  "ecow",
  "image",
+ "indexmap 2.2.5",
  "miniz_oxide",
  "once_cell",
  "pdf-writer",
@@ -2723,7 +2726,6 @@ version = "0.11.0"
 dependencies = [
  "bytemuck",
  "comemo",
- "flate2",
  "image",
  "pixglyph",
  "resvg",

Cargo.toml

@@ -73,7 +73,7 @@ oxipng = { version = "9.0", default-features = false, features = ["filetime", "p
 palette = { version = "0.7.3", default-features = false, features = ["approx", "libm"] }
 parking_lot = "0.12.1"
 pathdiff = "0.2"
-pdf-writer = "0.9.2"
+pdf-writer = "0.9.3"
 phf = { version = "0.11", features = ["macros"] }
 pixglyph = "0.3"
 png = "0.17"

crates/typst-pdf/Cargo.toml

@@ -22,6 +22,7 @@ bytemuck = { workspace = true }
 comemo = { workspace = true }
 ecow = { workspace = true }
 image = { workspace = true }
+indexmap = { workspace = true }
 miniz_oxide = { workspace = true }
 once_cell = { workspace = true }
 pdf-writer = { workspace = true }

crates/typst-pdf/src/font.rs

@@ -3,13 +3,16 @@ use std::sync::Arc;
 
 use ecow::{eco_format, EcoString};
 use pdf_writer::types::{CidFontType, FontFlags, SystemInfo, UnicodeCmap};
+use pdf_writer::writers::FontDescriptor;
 use pdf_writer::{Filter, Finish, Name, Rect, Str};
 use ttf_parser::{name_id, GlyphId, Tag};
+use typst::layout::{Abs, Em, Ratio, Transform};
 use typst::text::Font;
 use typst::util::SliceExt;
 use unicode_properties::{GeneralCategory, UnicodeGeneralCategory};
 
-use crate::{deflate, EmExt, PdfContext};
+use crate::page::{write_frame, PageContext};
+use crate::{deflate, AbsExt, EmExt, PdfContext};
 
 const CFF: Tag = Tag::from_bytes(b"CFF ");
 const CFF2: Tag = Tag::from_bytes(b"CFF2");
@@ -23,6 +26,8 @@ const SYSTEM_INFO: SystemInfo = SystemInfo {
 /// Embed all used fonts into the PDF.
 #[typst_macros::time(name = "write fonts")]
 pub(crate) fn write_fonts(ctx: &mut PdfContext) {
+    write_color_fonts(ctx);
+
     for font in ctx.font_map.items() {
         let type0_ref = ctx.alloc.bump();
         let cid_ref = ctx.alloc.bump();
@@ -32,7 +37,6 @@ pub(crate) fn write_fonts(ctx: &mut PdfContext) {
         ctx.font_refs.push(type0_ref);
 
         let glyph_set = ctx.glyph_sets.get_mut(font).unwrap();
-        let metrics = font.metrics();
         let ttf = font.ttf();
 
         // Do we have a TrueType or CFF font?
@@ -103,47 +107,6 @@ pub(crate) fn write_fonts(ctx: &mut PdfContext) {
         width_writer.finish();
         cid.finish();
 
-        let mut flags = FontFlags::empty();
-        flags.set(FontFlags::SERIF, postscript_name.contains("Serif"));
-        flags.set(FontFlags::FIXED_PITCH, ttf.is_monospaced());
-        flags.set(FontFlags::ITALIC, ttf.is_italic());
-        flags.insert(FontFlags::SYMBOLIC);
-        flags.insert(FontFlags::SMALL_CAP);
-
-        let global_bbox = ttf.global_bounding_box();
-        let bbox = Rect::new(
-            font.to_em(global_bbox.x_min).to_font_units(),
-            font.to_em(global_bbox.y_min).to_font_units(),
-            font.to_em(global_bbox.x_max).to_font_units(),
-            font.to_em(global_bbox.y_max).to_font_units(),
-        );
-
-        let italic_angle = ttf.italic_angle().unwrap_or(0.0);
-        let ascender = metrics.ascender.to_font_units();
-        let descender = metrics.descender.to_font_units();
-        let cap_height = metrics.cap_height.to_font_units();
-        let stem_v = 10.0 + 0.244 * (f32::from(ttf.weight().to_number()) - 50.0);
-
-        // Write the font descriptor (contains metrics about the font).
-        let mut font_descriptor = ctx.pdf.font_descriptor(descriptor_ref);
-        font_descriptor
-            .name(Name(base_font.as_bytes()))
-            .flags(flags)
-            .bbox(bbox)
-            .italic_angle(italic_angle)
-            .ascent(ascender)
-            .descent(descender)
-            .cap_height(cap_height)
-            .stem_v(stem_v);
-
-        if is_cff {
-            font_descriptor.font_file3(data_ref);
-        } else {
-            font_descriptor.font_file2(data_ref);
-        }
-
-        font_descriptor.finish();
-
         // Write the /ToUnicode character map, which maps glyph ids back to
         // unicode codepoints to enable copying out of the PDF.
         let cmap = create_cmap(font, glyph_set);
@@ -160,9 +123,173 @@ pub(crate) fn write_fonts(ctx: &mut PdfContext) {
         }
 
         stream.finish();
+
+        let mut font_descriptor =
+            write_font_descriptor(&mut ctx.pdf, descriptor_ref, font, &base_font);
+        if is_cff {
+            font_descriptor.font_file3(data_ref);
+        } else {
+            font_descriptor.font_file2(data_ref);
+        }
     }
 }
 
+/// Writes color fonts as Type3 fonts
+fn write_color_fonts(ctx: &mut PdfContext) {
+    let color_font_map = ctx.color_font_map.take_map();
+    for (font, color_font) in color_font_map {
+        // For each Type3 font that is part of this family…
+        for (font_index, subfont_id) in color_font.refs.iter().enumerate() {
+            // Allocate some IDs.
+            let cmap_ref = ctx.alloc.bump();
+            let descriptor_ref = ctx.alloc.bump();
+            let widths_ref = ctx.alloc.bump();
+            // And a map between glyph IDs and the instructions to draw this
+            // glyph.
+            let mut glyphs_to_instructions = Vec::new();
+
+            let start = font_index * 256;
+            let end = (start + 256).min(color_font.glyphs.len());
+            let glyph_count = end - start;
+            let subset = &color_font.glyphs[start..end];
+            let mut widths = Vec::new();
+
+            let scale_factor = font.ttf().units_per_em() as f32;
+
+            // Write the instructions for each glyph.
+            for color_glyph in subset {
+                let instructions_stream_ref = ctx.alloc.bump();
+                let width =
+                    font.advance(color_glyph.gid).unwrap_or(Em::new(0.0)).to_font_units();
+                widths.push(width);
+                // Create a fake page context for `write_frame`. We are only
+                // interested in the contents of the page.
+                let size = color_glyph.frame.size();
+                let mut page_ctx = PageContext::new(ctx, size);
+                page_ctx.bottom = size.y.to_f32();
+                page_ctx.content.start_color_glyph(width);
+                page_ctx.transform(
+                    // Make the Y axis go upwards, while preserving aspect ratio
+                    Transform::scale(Ratio::one(), -size.aspect_ratio())
+                        // Also move the origin to the top left corner
+                        .post_concat(Transform::translate(Abs::zero(), size.y)),
+                );
+                write_frame(&mut page_ctx, &color_glyph.frame);
+
+                // Retrieve the stream of the page and write it.
+                let stream = page_ctx.content.finish();
+                ctx.pdf.stream(instructions_stream_ref, &stream);
+
+                // Use this stream as instructions to draw the glyph.
+                glyphs_to_instructions.push(instructions_stream_ref);
+            }
+
+            // Write the Type3 font object.
+            let mut pdf_font = ctx.pdf.type3_font(*subfont_id);
+            pdf_font.pair(Name(b"Resources"), ctx.type3_font_resources_ref);
+            pdf_font.bbox(color_font.bbox);
+            pdf_font.matrix([1.0 / scale_factor, 0.0, 0.0, 1.0 / scale_factor, 0.0, 0.0]);
+            pdf_font.first_char(0);
+            pdf_font.last_char((glyph_count - 1) as u8);
+            pdf_font.pair(Name(b"Widths"), widths_ref);
+            pdf_font.to_unicode(cmap_ref);
+            pdf_font.font_descriptor(descriptor_ref);
+
+            // Write the /CharProcs dictionary, that maps glyph names to
+            // drawing instructions.
+            let mut char_procs = pdf_font.char_procs();
+            for (gid, instructions_ref) in glyphs_to_instructions.iter().enumerate() {
+                char_procs
+                    .pair(Name(eco_format!("glyph{gid}").as_bytes()), *instructions_ref);
+            }
+            char_procs.finish();
+
+            // Write the /Encoding dictionary.
+            let names = (0..glyph_count)
+                .map(|gid| eco_format!("glyph{gid}"))
+                .collect::<Vec<_>>();
+            pdf_font
+                .encoding_custom()
+                .differences()
+                .consecutive(0, names.iter().map(|name| Name(name.as_bytes())));
+            pdf_font.finish();
+
+            // Encode a CMAP to make it possible to search or copy glyphs.
+            let glyph_set = ctx.glyph_sets.get_mut(&font).unwrap();
+            let mut cmap = UnicodeCmap::new(CMAP_NAME, SYSTEM_INFO);
+            for (index, glyph) in subset.iter().enumerate() {
+                let Some(text) = glyph_set.get(&glyph.gid) else {
+                    continue;
+                };
+
+                if !text.is_empty() {
+                    cmap.pair_with_multiple(index as u8, text.chars());
+                }
+            }
+            ctx.pdf.cmap(cmap_ref, &cmap.finish());
+
+            // Write the font descriptor.
+            let postscript_name = font
+                .find_name(name_id::POST_SCRIPT_NAME)
+                .unwrap_or_else(|| "unknown".to_string());
+            let base_font = eco_format!("COLOR{font_index:x}+{postscript_name}");
+            write_font_descriptor(&mut ctx.pdf, descriptor_ref, &font, &base_font);
+
+            // Write the widths array
+            ctx.pdf.indirect(widths_ref).array().items(widths);
+        }
+    }
+}
+
+/// Writes a FontDescriptor dictionary.
+fn write_font_descriptor<'a>(
+    pdf: &'a mut pdf_writer::Pdf,
+    descriptor_ref: pdf_writer::Ref,
+    font: &'a Font,
+    base_font: &EcoString,
+) -> FontDescriptor<'a> {
+    let ttf = font.ttf();
+    let metrics = font.metrics();
+    let postscript_name = font
+        .find_name(name_id::POST_SCRIPT_NAME)
+        .unwrap_or_else(|| "unknown".to_string());
+
+    let mut flags = FontFlags::empty();
+    flags.set(FontFlags::SERIF, postscript_name.contains("Serif"));
+    flags.set(FontFlags::FIXED_PITCH, ttf.is_monospaced());
+    flags.set(FontFlags::ITALIC, ttf.is_italic());
+    flags.insert(FontFlags::SYMBOLIC);
+    flags.insert(FontFlags::SMALL_CAP);
+
+    let global_bbox = ttf.global_bounding_box();
+    let bbox = Rect::new(
+        font.to_em(global_bbox.x_min).to_font_units(),
+        font.to_em(global_bbox.y_min).to_font_units(),
+        font.to_em(global_bbox.x_max).to_font_units(),
+        font.to_em(global_bbox.y_max).to_font_units(),
+    );
+
+    let italic_angle = ttf.italic_angle().unwrap_or(0.0);
+    let ascender = metrics.ascender.to_font_units();
+    let descender = metrics.descender.to_font_units();
+    let cap_height = metrics.cap_height.to_font_units();
+    let stem_v = 10.0 + 0.244 * (f32::from(ttf.weight().to_number()) - 50.0);
+
+    // Write the font descriptor (contains metrics about the font).
+    let mut font_descriptor = pdf.font_descriptor(descriptor_ref);
+    font_descriptor
+        .name(Name(base_font.as_bytes()))
+        .flags(flags)
+        .bbox(bbox)
+        .italic_angle(italic_angle)
+        .ascent(ascender)
+        .descent(descender)
+        .cap_height(cap_height)
+        .stem_v(stem_v);
+
+    font_descriptor
+}
+
 /// Subset a font to the given glyphs.
 ///
 /// - For a font with TrueType outlines, this returns the whole OpenType font.

crates/typst-pdf/src/lib.rs

@@ -15,13 +15,15 @@ use std::sync::Arc;
 
 use base64::Engine;
 use ecow::{eco_format, EcoString};
+use indexmap::IndexMap;
 use pdf_writer::types::Direction;
 use pdf_writer::writers::Destination;
-use pdf_writer::{Finish, Name, Pdf, Ref, Str, TextStr};
+use pdf_writer::{Finish, Name, Pdf, Rect, Ref, Str, TextStr};
 use typst::foundations::{Datetime, Label, NativeElement, Smart};
 use typst::introspection::Location;
-use typst::layout::{Abs, Dir, Em, Transform};
+use typst::layout::{Abs, Dir, Em, Frame, Transform};
 use typst::model::{Document, HeadingElem};
+use typst::text::color::frame_for_glyph;
 use typst::text::{Font, Lang};
 use typst::util::Deferred;
 use typst::visualize::Image;
@@ -68,6 +70,7 @@ pub fn pdf(
     pattern::write_patterns(&mut ctx);
     write_named_destinations(&mut ctx);
     page::write_page_tree(&mut ctx);
+    page::write_global_resources(&mut ctx);
     write_catalog(&mut ctx, ident, timestamp);
     ctx.pdf.finish()
 }
@@ -96,6 +99,15 @@ struct PdfContext<'a> {
     alloc: Ref,
     /// The ID of the page tree.
     page_tree_ref: Ref,
+    /// The ID of the globally shared Resources dictionary.
+    global_resources_ref: Ref,
+    /// The ID of the resource dictionary shared by Type3 fonts.
+    ///
+    /// Type3 fonts cannot use the global resources, as it would create some
+    /// kind of infinite recursion (they are themselves present in that
+    /// dictionary), which Acrobat doesn't appreciate (it fails to parse the
+    /// font) even if the specification seems to allow it.
+    type3_font_resources_ref: Ref,
     /// The IDs of written pages.
     page_refs: Vec<Ref>,
     /// The IDs of written fonts.
@@ -123,6 +135,8 @@ struct PdfContext<'a> {
     pattern_map: Remapper<PdfPattern>,
     /// Deduplicates external graphics states used across the document.
     extg_map: Remapper<ExtGState>,
+    /// Deduplicates color glyphs.
+    color_font_map: ColorFontMap,
 
     /// A sorted list of all named destinations.
     dests: Vec<(Label, Ref)>,
@@ -134,6 +148,8 @@ impl<'a> PdfContext<'a> {
     fn new(document: &'a Document) -> Self {
         let mut alloc = Ref::new(1);
         let page_tree_ref = alloc.bump();
+        let global_resources_ref = alloc.bump();
+        let type3_font_resources_ref = alloc.bump();
         Self {
             document,
             pdf: Pdf::new(),
@@ -142,6 +158,8 @@ impl<'a> PdfContext<'a> {
             languages: BTreeMap::new(),
             alloc,
             page_tree_ref,
+            global_resources_ref,
+            type3_font_resources_ref,
             page_refs: vec![],
             font_refs: vec![],
             image_refs: vec![],
@@ -155,6 +173,7 @@ impl<'a> PdfContext<'a> {
             gradient_map: Remapper::new(),
             pattern_map: Remapper::new(),
             extg_map: Remapper::new(),
+            color_font_map: ColorFontMap::new(),
             dests: vec![],
             loc_to_dest: HashMap::new(),
         }
@@ -455,6 +474,98 @@ where
     }
 }
 
+/// A mapping between `Font`s and all the corresponding `ColorFont`s.
+///
+/// This mapping is one-to-many because there can only be 256 glyphs in a Type 3
+/// font, and fonts generally have more color glyphs than that.
+struct ColorFontMap {
+    /// The mapping itself
+    map: IndexMap<Font, ColorFont>,
+    /// A list of all PDF indirect references to Type3 font objects.
+    all_refs: Vec<Ref>,
+}
+
+/// A collection of Type3 font, belonging to the same TTF font.
+struct ColorFont {
+    /// A list of references to Type3 font objects for this font family.
+    refs: Vec<Ref>,
+    /// The list of all color glyphs in this family.
+    ///
+    /// The index in this vector modulo 256 corresponds to the index in one of
+    /// the Type3 fonts in `refs` (the `n`-th in the vector, where `n` is the
+    /// quotient of the index divided by 256).
+    glyphs: Vec<ColorGlyph>,
+    /// The global bounding box of the font.
+    bbox: Rect,
+    /// A mapping between glyph IDs and character indices in the `glyphs`
+    /// vector.
+    glyph_indices: HashMap<u16, usize>,
+}
+
+/// A single color glyph.
+struct ColorGlyph {
+    /// The ID of the glyph.
+    gid: u16,
+    /// A frame that contains the glyph.
+    frame: Frame,
+}
+
+impl ColorFontMap {
+    /// Creates a new empty mapping
+    fn new() -> Self {
+        Self { map: IndexMap::new(), all_refs: Vec::new() }
+    }
+
+    /// Takes the contents of the mapping.
+    ///
+    /// After calling this function, the mapping will be empty.
+    fn take_map(&mut self) -> IndexMap<Font, ColorFont> {
+        std::mem::take(&mut self.map)
+    }
+
+    /// Obtains the reference to a Type3 font, and an index in this font
+    /// that can be used to draw a color glyph.
+    ///
+    /// The glyphs will be de-duplicated if needed.
+    fn get(&mut self, alloc: &mut Ref, font: &Font, gid: u16) -> (Ref, u8) {
+        let color_font = self.map.entry(font.clone()).or_insert_with(|| {
+            let global_bbox = font.ttf().global_bounding_box();
+            let bbox = Rect::new(
+                font.to_em(global_bbox.x_min).to_font_units(),
+                font.to_em(global_bbox.y_min).to_font_units(),
+                font.to_em(global_bbox.x_max).to_font_units(),
+                font.to_em(global_bbox.y_max).to_font_units(),
+            );
+            ColorFont {
+                bbox,
+                refs: Vec::new(),
+                glyphs: Vec::new(),
+                glyph_indices: HashMap::new(),
+            }
+        });
+
+        if let Some(index_of_glyph) = color_font.glyph_indices.get(&gid) {
+            // If we already know this glyph, return it.
+            (color_font.refs[index_of_glyph / 256], *index_of_glyph as u8)
+        } else {
+            // Otherwise, allocate a new ColorGlyph in the font, and a new Type3 font
+            // if needed
+            let index = color_font.glyphs.len();
+            if index % 256 == 0 {
+                let new_ref = alloc.bump();
+                self.all_refs.push(new_ref);
+                color_font.refs.push(new_ref);
+            }
+
+            let instructions = frame_for_glyph(font, gid);
+            color_font.glyphs.push(ColorGlyph { gid, frame: instructions });
+            color_font.glyph_indices.insert(gid, index);
+
+            (color_font.refs[index / 256], index as u8)
+        }
+    }
+}
+
 /// Additional methods for [`Abs`].
 trait AbsExt {
     /// Convert an to a number of points.

crates/typst-pdf/src/page.rs

@@ -1,6 +1,10 @@
 use std::collections::HashMap;
 use std::num::NonZeroUsize;
 
+use crate::color::PaintEncode;
+use crate::extg::ExtGState;
+use crate::image::deferred_image;
+use crate::{deflate_deferred, AbsExt, EmExt, PdfContext};
 use ecow::{eco_format, EcoString};
 use pdf_writer::types::{
     ActionType, AnnotationFlags, AnnotationType, ColorSpaceOperand, LineCapStyle,
@@ -13,17 +17,13 @@ use typst::layout::{
     Abs, Em, Frame, FrameItem, GroupItem, Page, Point, Ratio, Size, Transform,
 };
 use typst::model::{Destination, Numbering};
-use typst::text::{Case, Font, TextItem};
-use typst::util::{Deferred, Numeric};
+use typst::text::color::is_color_glyph;
+use typst::text::{Case, Font, TextItem, TextItemView};
+use typst::util::{Deferred, Numeric, SliceExt};
 use typst::visualize::{
     FixedStroke, Geometry, Image, LineCap, LineJoin, Paint, Path, PathItem, Shape,
 };
 
-use crate::color::PaintEncode;
-use crate::extg::ExtGState;
-use crate::image::deferred_image;
-use crate::{deflate_deferred, AbsExt, EmExt, PdfContext};
-
 /// Construct page objects.
 #[typst_macros::time(name = "construct pages")]
 pub(crate) fn construct_pages(ctx: &mut PdfContext, pages: &[Page]) {
@@ -44,17 +44,7 @@ pub(crate) fn construct_page(ctx: &mut PdfContext, frame: &Frame) -> (Ref, Encod
     let page_ref = ctx.alloc.bump();
 
     let size = frame.size();
-    let mut ctx = PageContext {
-        parent: ctx,
-        page_ref,
-        uses_opacities: false,
-        content: Content::new(),
-        state: State::new(size),
-        saves: vec![],
-        bottom: 0.0,
-        links: vec![],
-        resources: HashMap::default(),
-    };
+    let mut ctx = PageContext::new(ctx, size);
 
     // Make the coordinate system start at the top-left.
     ctx.bottom = size.y.to_f32();
@@ -73,7 +63,7 @@ pub(crate) fn construct_page(ctx: &mut PdfContext, frame: &Frame) -> (Ref, Encod
     let page = EncodedPage {
         size,
         content: deflate_deferred(ctx.content.finish()),
-        id: ctx.page_ref,
+        id: page_ref,
         uses_opacities: ctx.uses_opacities,
         links: ctx.links,
         label: None,
@@ -85,10 +75,8 @@ pub(crate) fn construct_page(ctx: &mut PdfContext, frame: &Frame) -> (Ref, Encod
 
 /// Write the page tree.
 pub(crate) fn write_page_tree(ctx: &mut PdfContext) {
-    let resources_ref = write_global_resources(ctx);
-
     for i in 0..ctx.pages.len() {
-        write_page(ctx, i, resources_ref);
+        write_page(ctx, i);
     }
 
     ctx.pdf
@@ -102,30 +90,20 @@ pub(crate) fn write_page_tree(ctx: &mut PdfContext) {
 /// We add a reference to this dictionary to each page individually instead of
 /// to the root node of the page tree because using the resource inheritance
 /// feature breaks PDF merging with Apple Preview.
-fn write_global_resources(ctx: &mut PdfContext) -> Ref {
-    let resource_ref = ctx.alloc.bump();
+pub(crate) fn write_global_resources(ctx: &mut PdfContext) {
+    let images_ref = ctx.alloc.bump();
+    let patterns_ref = ctx.alloc.bump();
+    let ext_gs_states_ref = ctx.alloc.bump();
+    let color_spaces_ref = ctx.alloc.bump();
 
-    let mut resources = ctx.pdf.indirect(resource_ref).start::<Resources>();
-    ctx.colors
-        .write_color_spaces(resources.color_spaces(), &mut ctx.alloc);
-
-    let mut fonts = resources.fonts();
-    for (font_ref, f) in ctx.font_map.pdf_indices(&ctx.font_refs) {
-        let name = eco_format!("F{}", f);
-        fonts.pair(Name(name.as_bytes()), font_ref);
-    }
-
-    fonts.finish();
-
-    let mut images = resources.x_objects();
+    let mut images = ctx.pdf.indirect(images_ref).dict();
     for (image_ref, im) in ctx.image_map.pdf_indices(&ctx.image_refs) {
         let name = eco_format!("Im{}", im);
         images.pair(Name(name.as_bytes()), image_ref);
     }
-
     images.finish();
 
-    let mut patterns = resources.patterns();
+    let mut patterns = ctx.pdf.indirect(patterns_ref).dict();
     for (gradient_ref, gr) in ctx.gradient_map.pdf_indices(&ctx.gradient_refs) {
         let name = eco_format!("Gr{}", gr);
         patterns.pair(Name(name.as_bytes()), gradient_ref);
@@ -135,26 +113,64 @@ fn write_global_resources(ctx: &mut PdfContext) -> Ref {
         let name = eco_format!("P{}", p);
         patterns.pair(Name(name.as_bytes()), pattern_ref);
     }
-
     patterns.finish();
 
-    let mut ext_gs_states = resources.ext_g_states();
+    let mut ext_gs_states = ctx.pdf.indirect(ext_gs_states_ref).dict();
     for (gs_ref, gs) in ctx.extg_map.pdf_indices(&ctx.ext_gs_refs) {
         let name = eco_format!("Gs{}", gs);
         ext_gs_states.pair(Name(name.as_bytes()), gs_ref);
     }
     ext_gs_states.finish();
 
+    let color_spaces = ctx.pdf.indirect(color_spaces_ref).dict();
+    ctx.colors.write_color_spaces(color_spaces, &mut ctx.alloc);
+
+    let mut resources = ctx.pdf.indirect(ctx.global_resources_ref).start::<Resources>();
+    resources.pair(Name(b"XObject"), images_ref);
+    resources.pair(Name(b"Pattern"), patterns_ref);
+    resources.pair(Name(b"ExtGState"), ext_gs_states_ref);
+    resources.pair(Name(b"ColorSpace"), color_spaces_ref);
+
+    let mut fonts = resources.fonts();
+    for (font_ref, f) in ctx.font_map.pdf_indices(&ctx.font_refs) {
+        let name = eco_format!("F{}", f);
+        fonts.pair(Name(name.as_bytes()), font_ref);
+    }
+
+    for font in &ctx.color_font_map.all_refs {
+        let name = eco_format!("Cf{}", font.get());
+        fonts.pair(Name(name.as_bytes()), font);
+    }
+    fonts.finish();
+
     resources.finish();
 
+    // Also write the resources for Type3 fonts, that only contains images,
+    // color spaces and regular fonts (COLR glyphs depend on them).
+    if !ctx.color_font_map.all_refs.is_empty() {
+        let mut resources =
+            ctx.pdf.indirect(ctx.type3_font_resources_ref).start::<Resources>();
+        resources.pair(Name(b"XObject"), images_ref);
+        resources.pair(Name(b"Pattern"), patterns_ref);
+        resources.pair(Name(b"ExtGState"), ext_gs_states_ref);
+        resources.pair(Name(b"ColorSpace"), color_spaces_ref);
+
+        let mut fonts = resources.fonts();
+        for (font_ref, f) in ctx.font_map.pdf_indices(&ctx.font_refs) {
+            let name = eco_format!("F{}", f);
+            fonts.pair(Name(name.as_bytes()), font_ref);
+        }
+        fonts.finish();
+
+        resources.finish();
+    }
+
     // Write all of the functions used by the document.
     ctx.colors.write_functions(&mut ctx.pdf);
-
-    resource_ref
 }
 
 /// Write a page tree node.
-fn write_page(ctx: &mut PdfContext, i: usize, resources_ref: Ref) {
+fn write_page(ctx: &mut PdfContext, i: usize) {
     let page = &ctx.pages[i];
     let content_id = ctx.alloc.bump();
 
@@ -165,7 +181,7 @@ fn write_page(ctx: &mut PdfContext, i: usize, resources_ref: Ref) {
     let h = page.size.y.to_f32();
     page_writer.media_box(Rect::new(0.0, 0.0, w, h));
     page_writer.contents(content_id);
-    page_writer.pair(Name(b"Resources"), resources_ref);
+    page_writer.pair(Name(b"Resources"), ctx.global_resources_ref);
 
     if page.uses_opacities {
         page_writer
@@ -434,17 +450,31 @@ impl PageResource {
 /// An exporter for the contents of a single PDF page.
 pub struct PageContext<'a, 'b> {
     pub(crate) parent: &'a mut PdfContext<'b>,
-    page_ref: Ref,
     pub content: Content,
     state: State,
     saves: Vec<State>,
-    bottom: f32,
+    pub bottom: f32,
     uses_opacities: bool,
     links: Vec<(Destination, Rect)>,
     /// Keep track of the resources being used in the page.
     pub resources: HashMap<PageResource, usize>,
 }
 
+impl<'a, 'b> PageContext<'a, 'b> {
+    pub fn new(parent: &'a mut PdfContext<'b>, size: Size) -> Self {
+        PageContext {
+            parent,
+            uses_opacities: false,
+            content: Content::new(),
+            state: State::new(size),
+            saves: vec![],
+            bottom: 0.0,
+            links: vec![],
+            resources: HashMap::default(),
+        }
+    }
+}
+
 /// A simulated graphics state used to deduplicate graphics state changes and
 /// keep track of the current transformation matrix for link annotations.
 #[derive(Debug, Clone)]
@@ -555,7 +585,7 @@ impl PageContext<'_, '_> {
         self.set_external_graphics_state(&ExtGState { stroke_opacity, fill_opacity });
     }
 
-    fn transform(&mut self, transform: Transform) {
+    pub fn transform(&mut self, transform: Transform) {
         let Transform { sx, ky, kx, sy, tx, ty } = transform;
         self.state.transform = self.state.transform.pre_concat(transform);
         if self.state.container_transform.is_identity() {
@@ -670,7 +700,7 @@ impl PageContext<'_, '_> {
 }
 
 /// Encode a frame into the content stream.
-fn write_frame(ctx: &mut PageContext, frame: &Frame) {
+pub(crate) fn write_frame(ctx: &mut PageContext, frame: &Frame) {
     for &(pos, ref item) in frame.items() {
         let x = pos.x.to_f32();
         let y = pos.y.to_f32();
@@ -718,21 +748,71 @@ fn write_group(ctx: &mut PageContext, pos: Point, group: &GroupItem) {
 
 /// Encode a text run into the content stream.
 fn write_text(ctx: &mut PageContext, pos: Point, text: &TextItem) {
+    let ttf = text.font.ttf();
+    let tables = ttf.tables();
+
+    // If the text run contains either only color glyphs (used for emojis for
+    // example) or normal text we can render it directly
+    let has_color_glyphs = tables.sbix.is_some()
+        || tables.cbdt.is_some()
+        || tables.svg.is_some()
+        || tables.colr.is_some();
+    if !has_color_glyphs {
+        write_normal_text(ctx, pos, TextItemView::all_of(text));
+        return;
+    }
+
+    let color_glyph_count =
+        text.glyphs.iter().filter(|g| is_color_glyph(&text.font, g)).count();
+
+    if color_glyph_count == text.glyphs.len() {
+        write_color_glyphs(ctx, pos, TextItemView::all_of(text));
+    } else if color_glyph_count == 0 {
+        write_normal_text(ctx, pos, TextItemView::all_of(text));
+    } else {
+        // Otherwise we need to split it in smaller text runs
+        let mut offset = 0;
+        let mut position_in_run = Abs::zero();
+        for (color, sub_run) in
+            text.glyphs.group_by_key(|g| is_color_glyph(&text.font, g))
+        {
+            let end = offset + sub_run.len();
+
+            // Build a sub text-run
+            let text_item_view = TextItemView::from_glyph_range(text, offset..end);
+
+            // Adjust the position of the run on the line
+            let pos = pos + Point::new(position_in_run, Abs::zero());
+            position_in_run += text_item_view.width();
+            offset = end;
+            // Actually write the sub text-run
+            if color {
+                write_color_glyphs(ctx, pos, text_item_view);
+            } else {
+                write_normal_text(ctx, pos, text_item_view);
+            }
+        }
+    }
+}
+
+// Encodes a text run (without any color glyph) into the content stream.
+fn write_normal_text(ctx: &mut PageContext, pos: Point, text: TextItemView) {
     let x = pos.x.to_f32();
     let y = pos.y.to_f32();
 
-    *ctx.parent.languages.entry(text.lang).or_insert(0) += text.glyphs.len();
+    *ctx.parent.languages.entry(text.item.lang).or_insert(0) += text.glyph_range.len();
 
-    let glyph_set = ctx.parent.glyph_sets.entry(text.font.clone()).or_default();
-    for g in &text.glyphs {
-        let segment = &text.text[g.range()];
+    let glyph_set = ctx.parent.glyph_sets.entry(text.item.font.clone()).or_default();
+    for g in text.glyphs() {
+        let t = text.text();
+        let segment = &t[g.range()];
         glyph_set.entry(g.id).or_insert_with(|| segment.into());
     }
 
     let fill_transform = ctx.state.transforms(Size::zero(), pos);
-    ctx.set_fill(&text.fill, true, fill_transform);
+    ctx.set_fill(&text.item.fill, true, fill_transform);
 
-    let stroke = text.stroke.as_ref().and_then(|stroke| {
+    let stroke = text.item.stroke.as_ref().and_then(|stroke| {
         if stroke.thickness.to_f32() > 0.0 {
             Some(stroke)
         } else {
@@ -747,8 +827,8 @@ fn write_text(ctx: &mut PageContext, pos: Point, text: &TextItem) {
         ctx.set_text_rendering_mode(TextRenderingMode::Fill);
     }
 
-    ctx.set_font(&text.font, text.size);
-    ctx.set_opacities(text.stroke.as_ref(), Some(&text.fill));
+    ctx.set_font(&text.item.font, text.item.size);
+    ctx.set_opacities(text.item.stroke.as_ref(), Some(&text.item.fill));
     ctx.content.begin_text();
 
     // Position the text.
@@ -760,7 +840,7 @@ fn write_text(ctx: &mut PageContext, pos: Point, text: &TextItem) {
     let mut encoded = vec![];
 
     // Write the glyphs with kerning adjustments.
-    for glyph in &text.glyphs {
+    for glyph in text.glyphs() {
         adjustment += glyph.x_offset;
 
         if !adjustment.is_zero() {
@@ -773,11 +853,11 @@ fn write_text(ctx: &mut PageContext, pos: Point, text: &TextItem) {
             adjustment = Em::zero();
         }
 
-        let cid = crate::font::glyph_cid(&text.font, glyph.id);
+        let cid = crate::font::glyph_cid(&text.item.font, glyph.id);
         encoded.push((cid >> 8) as u8);
         encoded.push((cid & 0xff) as u8);
 
-        if let Some(advance) = text.font.advance(glyph.id) {
+        if let Some(advance) = text.item.font.advance(glyph.id) {
             adjustment += glyph.x_advance - advance;
         }
 
@@ -793,6 +873,46 @@ fn write_text(ctx: &mut PageContext, pos: Point, text: &TextItem) {
     ctx.content.end_text();
 }
 
+// Encodes a text run made only of color glyphs into the content stream
+fn write_color_glyphs(ctx: &mut PageContext, pos: Point, text: TextItemView) {
+    let x = pos.x.to_f32();
+    let y = pos.y.to_f32();
+
+    let mut last_font = None;
+
+    ctx.content.begin_text();
+    ctx.content.set_text_matrix([1.0, 0.0, 0.0, -1.0, x, y]);
+    // So that the next call to ctx.set_font() will change the font to one that
+    // displays regular glyphs and not color glyphs.
+    ctx.state.font = None;
+
+    let glyph_set = ctx.parent.glyph_sets.entry(text.item.font.clone()).or_default();
+
+    for glyph in text.glyphs() {
+        // Retrieve the Type3 font reference and the glyph index in the font.
+        let (font, index) = ctx.parent.color_font_map.get(
+            &mut ctx.parent.alloc,
+            &text.item.font,
+            glyph.id,
+        );
+
+        if last_font != Some(font.get()) {
+            ctx.content.set_font(
+                Name(eco_format!("Cf{}", font.get()).as_bytes()),
+                text.item.size.to_f32(),
+            );
+            last_font = Some(font.get());
+        }
+
+        ctx.content.show(Str(&[index]));
+
+        glyph_set
+            .entry(glyph.id)
+            .or_insert_with(|| text.text()[glyph.range()].into());
+    }
+    ctx.content.end_text();
+}
+
 /// Encode a geometrical shape into the content stream.
 fn write_shape(ctx: &mut PageContext, pos: Point, shape: &Shape) {
     let x = pos.x.to_f32();

crates/typst-render/Cargo.toml

@@ -18,7 +18,6 @@ typst-macros = { workspace = true }
 typst-timing = { workspace = true }
 bytemuck = { workspace = true }
 comemo = { workspace = true }
-flate2 = { workspace = true }
 image = { workspace = true }
 pixglyph = { workspace = true }
 resvg = { workspace = true }

crates/typst-render/src/lib.rs

@@ -1,12 +1,10 @@
 //! Rendering of Typst documents into raster images.
 
-use std::io::Read;
 use std::sync::Arc;
 
 use image::imageops::FilterType;
 use image::{GenericImageView, Rgba};
 use pixglyph::Bitmap;
-use resvg::tiny_skia::IntRect;
 use tiny_skia as sk;
 use ttf_parser::{GlyphId, OutlineBuilder};
 use typst::introspection::Meta;
@@ -14,12 +12,12 @@ use typst::layout::{
     Abs, Axes, Frame, FrameItem, FrameKind, GroupItem, Point, Ratio, Size, Transform,
 };
 use typst::model::Document;
+use typst::text::color::{frame_for_glyph, is_color_glyph};
 use typst::text::{Font, TextItem};
 use typst::visualize::{
     Color, DashPattern, FixedStroke, Geometry, Gradient, Image, ImageKind, LineCap,
-    LineJoin, Paint, Path, PathItem, Pattern, RasterFormat, RelativeTo, Shape,
+    LineJoin, Paint, Path, PathItem, Pattern, RelativeTo, Shape,
 };
-use usvg::TreeParsing;
 
 /// Export a frame into a raster image.
 ///
@@ -115,6 +113,13 @@ impl<'a> State<'a> {
         }
     }
 
+    fn pre_scale(self, scale: Axes<Abs>) -> Self {
+        Self {
+            transform: self.transform.pre_scale(scale.x.to_f32(), scale.y.to_f32()),
+            ..self
+        }
+    }
+
     /// Pre concat the current item's transform.
     fn pre_concat(self, transform: sk::Transform) -> Self {
         Self {
@@ -236,132 +241,27 @@ fn render_text(canvas: &mut sk::Pixmap, state: State, text: &TextItem) {
     for glyph in &text.glyphs {
         let id = GlyphId(glyph.id);
         let offset = x + glyph.x_offset.at(text.size).to_f32();
-        let state = state.pre_translate(Point::new(Abs::raw(offset as _), Abs::raw(0.0)));
 
-        render_svg_glyph(canvas, state, text, id)
-            .or_else(|| render_bitmap_glyph(canvas, state, text, id))
-            .or_else(|| render_outline_glyph(canvas, state, text, id));
+        if is_color_glyph(&text.font, glyph) {
+            let upem = text.font.units_per_em();
+            let text_scale = Abs::raw(text.size.to_raw() / upem);
+            let state = state
+                .pre_translate(Point::new(Abs::raw(offset as _), -text.size))
+                .pre_scale(Axes::new(text_scale, text_scale));
+
+            let glyph_frame = frame_for_glyph(&text.font, glyph.id);
+
+            render_frame(canvas, state, &glyph_frame);
+        } else {
+            let state =
+                state.pre_translate(Point::new(Abs::raw(offset as _), Abs::raw(0.0)));
+            render_outline_glyph(canvas, state, text, id);
+        }
 
         x += glyph.x_advance.at(text.size).to_f32();
     }
 }
 
-/// Render an SVG glyph into the canvas.
-fn render_svg_glyph(
-    canvas: &mut sk::Pixmap,
-    state: State,
-    text: &TextItem,
-    id: GlyphId,
-) -> Option<()> {
-    let ts = &state.transform;
-    let mut data = text.font.ttf().glyph_svg_image(id)?.data;
-
-    // Decompress SVGZ.
-    let mut decoded = vec![];
-    if data.starts_with(&[0x1f, 0x8b]) {
-        let mut decoder = flate2::read::GzDecoder::new(data);
-        decoder.read_to_end(&mut decoded).ok()?;
-        data = &decoded;
-    }
-
-    // Parse XML.
-    let xml = std::str::from_utf8(data).ok()?;
-    let document = roxmltree::Document::parse(xml).ok()?;
-    let root = document.root_element();
-
-    // Parse SVG.
-    let opts = usvg::Options::default();
-    let mut tree = usvg::Tree::from_xmltree(&document, &opts).ok()?;
-    tree.calculate_bounding_boxes();
-    let view_box = tree.view_box.rect;
-
-    // If there's no viewbox defined, use the em square for our scale
-    // transformation ...
-    let upem = text.font.units_per_em() as f32;
-    let (mut width, mut height) = (upem, upem);
-
-    // ... but if there's a viewbox or width, use that.
-    if root.has_attribute("viewBox") || root.has_attribute("width") {
-        width = view_box.width();
-    }
-
-    // Same as for width.
-    if root.has_attribute("viewBox") || root.has_attribute("height") {
-        height = view_box.height();
-    }
-
-    let size = text.size.to_f32();
-    let ts = ts.pre_scale(size / width, size / height);
-
-    // Compute the space we need to draw our glyph.
-    // See https://github.com/RazrFalcon/resvg/issues/602 for why
-    // using the svg size is problematic here.
-    let mut bbox = usvg::BBox::default();
-    if let Some(tree_bbox) = tree.root.bounding_box {
-        bbox = bbox.expand(tree_bbox);
-    }
-
-    // Compute the bbox after the transform is applied.
-    // We add a nice 5px border along the bounding box to
-    // be on the safe size. We also compute the intersection
-    // with the canvas rectangle
-    let bbox = bbox.transform(ts)?.to_rect()?.round_out()?;
-    let bbox = IntRect::from_xywh(
-        bbox.left() - 5,
-        bbox.y() - 5,
-        bbox.width() + 10,
-        bbox.height() + 10,
-    )?;
-
-    let mut pixmap = sk::Pixmap::new(bbox.width(), bbox.height())?;
-
-    // We offset our transform so that the pixmap starts at the edge of the bbox.
-    let ts = ts.post_translate(-bbox.left() as f32, -bbox.top() as f32);
-    resvg::render(&tree, ts, &mut pixmap.as_mut());
-
-    canvas.draw_pixmap(
-        bbox.left(),
-        bbox.top(),
-        pixmap.as_ref(),
-        &sk::PixmapPaint::default(),
-        sk::Transform::identity(),
-        state.mask,
-    );
-
-    Some(())
-}
-
-/// Render a bitmap glyph into the canvas.
-fn render_bitmap_glyph(
-    canvas: &mut sk::Pixmap,
-    state: State,
-    text: &TextItem,
-    id: GlyphId,
-) -> Option<()> {
-    let ts = state.transform;
-    let size = text.size.to_f32();
-    let ppem = size * ts.sy;
-    let raster = text.font.ttf().glyph_raster_image(id, ppem as u16)?;
-    if raster.format != ttf_parser::RasterImageFormat::PNG {
-        return None;
-    }
-    let image = Image::new(raster.data.into(), RasterFormat::Png.into(), None).ok()?;
-
-    // FIXME: Vertical alignment isn't quite right for Apple Color Emoji,
-    // and maybe also for Noto Color Emoji. And: Is the size calculation
-    // correct?
-    let h = text.size;
-    let w = (image.width() / image.height()) * h;
-    let dx = (raster.x as f32) / (image.width() as f32) * size;
-    let dy = (raster.y as f32) / (image.height() as f32) * size;
-    render_image(
-        canvas,
-        state.pre_translate(Point::new(Abs::raw(dx as _), Abs::raw((-size - dy) as _))),
-        &image,
-        Size::new(w, h),
-    )
-}
-
 /// Render an outline glyph into the canvas. This is the "normal" case.
 fn render_outline_glyph(
     canvas: &mut sk::Pixmap,

crates/typst/Cargo.toml

@@ -24,6 +24,7 @@ ciborium = { workspace = true }
 comemo = { workspace = true }
 csv = { workspace = true }
 ecow = { workspace = true }
+flate2 = { workspace = true }
 fontdb = { workspace = true }
 hayagriva = { workspace = true }
 hypher = { workspace = true }
@@ -64,6 +65,7 @@ unicode-bidi = { workspace = true }
 unicode-math-class = { workspace = true }
 unicode-script = { workspace = true }
 unicode-segmentation = { workspace = true }
+unscanny = { workspace = true }
 usvg = { workspace = true }
 wasmi = { workspace = true }
 

crates/typst/src/text/font/color.rs

@@ -0,0 +1,272 @@
+//! Utilities for color font handling
+
+use std::io::Read;
+
+use ecow::EcoString;
+use ttf_parser::GlyphId;
+use usvg::{TreeParsing, TreeWriting};
+
+use crate::layout::{Abs, Axes, Em, Frame, FrameItem, Point, Size};
+use crate::syntax::Span;
+use crate::text::{Font, Glyph, Lang, TextItem};
+use crate::visualize::{Color, Image, Paint, Rgb};
+
+/// Tells if a glyph is a color glyph or not in a given font.
+pub fn is_color_glyph(font: &Font, g: &Glyph) -> bool {
+    let ttf = font.ttf();
+    let glyph_id = GlyphId(g.id);
+    ttf.glyph_raster_image(glyph_id, 160).is_some()
+        || ttf.glyph_svg_image(glyph_id).is_some()
+        || ttf.is_color_glyph(glyph_id)
+}
+
+/// Returns a frame with the glyph drawn inside.
+///
+/// The glyphs are sized in font units, [`text.item.size`] is not taken into
+/// account.
+#[comemo::memoize]
+pub fn frame_for_glyph(font: &Font, glyph_id: u16) -> Frame {
+    let ttf = font.ttf();
+    let upem = Abs::pt(ttf.units_per_em() as f64);
+    let glyph_id = GlyphId(glyph_id);
+
+    let mut frame = Frame::soft(Size::splat(upem));
+
+    if let Some(raster_image) = ttf.glyph_raster_image(glyph_id, u16::MAX) {
+        draw_raster_glyph(&mut frame, font, upem, raster_image);
+    } else if ttf.glyph_svg_image(glyph_id).is_some() {
+        draw_svg_glyph(&mut frame, upem, font, glyph_id);
+    } else if ttf.is_color_glyph(glyph_id) {
+        draw_colr_glyph(&mut frame, font, glyph_id);
+    }
+
+    frame
+}
+
+/// Draws a raster glyph in a frame.
+fn draw_raster_glyph(
+    frame: &mut Frame,
+    font: &Font,
+    upem: Abs,
+    raster_image: ttf_parser::RasterGlyphImage,
+) {
+    let image = Image::new(
+        raster_image.data.into(),
+        typst::visualize::ImageFormat::Raster(typst::visualize::RasterFormat::Png),
+        None,
+    )
+    .unwrap();
+
+    // Apple Color emoji doesn't provide offset information (or at least
+    // not in a way ttf-parser understands), so we artificially shift their
+    // baseline to make it look good.
+    let y_offset = if font.info().family.to_lowercase() == "apple color emoji" {
+        20.0
+    } else {
+        -(raster_image.y as f64)
+    };
+
+    let position = Point::new(
+        upem * raster_image.x as f64 / raster_image.pixels_per_em as f64,
+        upem * y_offset / raster_image.pixels_per_em as f64,
+    );
+    let aspect_ratio = image.width() / image.height();
+    let size = Axes::new(upem, upem * aspect_ratio);
+    frame.push(position, FrameItem::Image(image, size, Span::detached()));
+}
+
+/// Draws a COLR glyph in a frame.
+fn draw_colr_glyph(frame: &mut Frame, font: &Font, glyph_id: GlyphId) {
+    let mut painter = ColrPainter { font, current_glyph: glyph_id, frame };
+    font.ttf().paint_color_glyph(glyph_id, 0, &mut painter);
+}
+
+/// Draws COLR glyphs in a frame.
+struct ColrPainter<'f, 't> {
+    /// The frame in which to draw.
+    frame: &'f mut Frame,
+    /// The font of the text.
+    font: &'t Font,
+    /// The glyph that will be drawn the next time `ColrPainter::paint` is called.
+    current_glyph: GlyphId,
+}
+
+impl<'f, 't> ColrPainter<'f, 't> {
+    fn paint(&mut self, fill: Paint) {
+        self.frame.push(
+            // With images, the position corresponds to the top-left corner, but
+            // in the case of text it matches the baseline-left point. Here, we
+            // move the glyph one unit down to compensate for that.
+            Point::new(Abs::zero(), Abs::pt(self.font.units_per_em())),
+            FrameItem::Text(TextItem {
+                font: self.font.clone(),
+                size: Abs::pt(self.font.units_per_em()),
+                fill,
+                stroke: None,
+                lang: Lang::ENGLISH,
+                text: EcoString::new(),
+                glyphs: vec![Glyph {
+                    id: self.current_glyph.0,
+                    // Advance is not relevant here as we will draw glyph on top
+                    // of each other anyway
+                    x_advance: Em::zero(),
+                    x_offset: Em::zero(),
+                    range: 0..0,
+                    span: (Span::detached(), 0),
+                }],
+            }),
+        )
+    }
+}
+
+impl<'f, 't> ttf_parser::colr::Painter for ColrPainter<'f, 't> {
+    fn outline(&mut self, glyph_id: GlyphId) {
+        self.current_glyph = glyph_id;
+    }
+
+    fn paint_foreground(&mut self) {
+        // Default to black if no color was specified
+        self.paint(Paint::Solid(Color::BLACK))
+    }
+
+    fn paint_color(&mut self, color: ttf_parser::RgbaColor) {
+        let color = Color::Rgb(Rgb::new(
+            color.red as f32 / 255.0,
+            color.green as f32 / 255.0,
+            color.blue as f32 / 255.0,
+            color.alpha as f32 / 255.0,
+        ));
+        self.paint(Paint::Solid(color));
+    }
+}
+
+/// Draws an SVG glyph in a frame.
+fn draw_svg_glyph(
+    frame: &mut Frame,
+    upem: Abs,
+    font: &Font,
+    glyph_id: GlyphId,
+) -> Option<()> {
+    let mut data = font.ttf().glyph_svg_image(glyph_id)?.data;
+
+    // Decompress SVGZ.
+    let mut decoded = vec![];
+    if data.starts_with(&[0x1f, 0x8b]) {
+        let mut decoder = flate2::read::GzDecoder::new(data);
+        decoder.read_to_end(&mut decoded).ok()?;
+        data = &decoded;
+    }
+
+    // Parse XML.
+    let xml = std::str::from_utf8(data).ok()?;
+    let document = roxmltree::Document::parse(xml).ok()?;
+
+    // Parse SVG.
+    let opts = usvg::Options::default();
+    let mut tree = usvg::Tree::from_xmltree(&document, &opts).ok()?;
+
+    // Compute the space we need to draw our glyph.
+    // See https://github.com/RazrFalcon/resvg/issues/602 for why
+    // using the svg size is problematic here.
+    tree.calculate_bounding_boxes();
+    let mut bbox = usvg::BBox::default();
+    if let Some(tree_bbox) = tree.root.bounding_box {
+        bbox = bbox.expand(tree_bbox);
+    }
+    let bbox = bbox.to_rect()?;
+
+    let mut data = tree.to_string(&usvg::XmlOptions::default());
+
+    let width = bbox.width() as f64;
+    let height = bbox.height() as f64;
+    let left = bbox.left() as f64;
+    let top = bbox.top() as f64;
+
+    // The SVG coordinates and the font coordinates are not the same: the Y axis
+    // is mirrored. But the origin of the axes are the same (which means that
+    // the horizontal axis in the SVG document corresponds to the baseline). See
+    // the reference for more details:
+    // https://learn.microsoft.com/en-us/typography/opentype/spec/svg#coordinate-systems-and-glyph-metrics
+    //
+    // If we used the SVG document as it is, svg2pdf would produce a cropped
+    // glyph (only what is under the baseline would be visible). So we need to
+    // embed the original SVG in another one that has the exact dimensions of
+    // the glyph, with a transform to make it fit. We also need to remove the
+    // viewBox, height and width attributes from the inner SVG, otherwise usvg
+    // takes into account these values to clip the embedded SVG.
+    make_svg_unsized(&mut data);
+    let wrapper_svg = format!(
+        r#"
+        <svg
+            width="{width}"
+            height="{height}"
+            viewBox="0 0 {width} {height}"
+            xmlns="http://www.w3.org/2000/svg">
+            <g transform="matrix(1 0 0 1 {tx} {ty})">
+            {inner}
+            </g>
+        </svg>
+    "#,
+        inner = data,
+        tx = -left,
+        ty = -top,
+    );
+
+    let image = Image::new(
+        wrapper_svg.into_bytes().into(),
+        typst::visualize::ImageFormat::Vector(typst::visualize::VectorFormat::Svg),
+        None,
+    )
+    .unwrap();
+    let position = Point::new(Abs::pt(left), Abs::pt(top) + upem);
+    let size = Axes::new(Abs::pt(width), Abs::pt(height));
+    frame.push(position, FrameItem::Image(image, size, Span::detached()));
+
+    Some(())
+}
+
+/// Remove all size specifications (viewBox, width and height attributes) from a
+/// SVG document.
+fn make_svg_unsized(svg: &mut String) {
+    let mut viewbox_range = None;
+    let mut width_range = None;
+    let mut height_range = None;
+
+    let mut s = unscanny::Scanner::new(svg);
+
+    s.eat_until("<svg");
+    s.eat_if("<svg");
+    while !s.eat_if('>') && !s.done() {
+        s.eat_whitespace();
+        let start = s.cursor();
+        let attr_name = s.eat_until('=').trim();
+        // Eat the equal sign and the quote.
+        s.eat();
+        s.eat();
+        let mut escaped = false;
+        while (escaped || !s.eat_if('"')) && !s.done() {
+            escaped = s.eat() == Some('\\');
+        }
+        match attr_name {
+            "viewBox" => viewbox_range = Some(start..s.cursor()),
+            "width" => width_range = Some(start..s.cursor()),
+            "height" => height_range = Some(start..s.cursor()),
+            _ => {}
+        }
+    }
+
+    // Remove the `viewBox` attribute.
+    if let Some(range) = viewbox_range {
+        svg.replace_range(range.clone(), &" ".repeat(range.len()));
+    }
+
+    // Remove the `width` attribute.
+    if let Some(range) = width_range {
+        svg.replace_range(range.clone(), &" ".repeat(range.len()));
+    }
+
+    // Remove the `height` attribute.
+    if let Some(range) = height_range {
+        svg.replace_range(range, "");
+    }
+}

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

@@ -1,5 +1,7 @@
 //! Font handling.
 
+pub mod color;
+
 mod book;
 mod exceptions;
 mod variant;

crates/typst/src/text/item.rs

@@ -65,3 +65,65 @@ impl Glyph {
         usize::from(self.range.start)..usize::from(self.range.end)
     }
 }
+
+/// A slice of a [`TextItem`].
+pub struct TextItemView<'a> {
+    /// The whole item this is a part of
+    pub item: &'a TextItem,
+    /// The glyphs of this slice
+    pub glyph_range: Range<usize>,
+}
+
+impl<'a> TextItemView<'a> {
+    /// Build a TextItemView for the whole contents of a TextItem.
+    pub fn all_of(text: &'a TextItem) -> Self {
+        Self::from_glyph_range(text, 0..text.glyphs.len())
+    }
+
+    /// Build a new [`TextItemView`] from a [`TextItem`] and a range of glyphs.
+    pub fn from_glyph_range(text: &'a TextItem, glyph_range: Range<usize>) -> Self {
+        TextItemView { item: text, glyph_range }
+    }
+
+    /// Obtains a glyph in this slice, remapping the range that it represents in
+    /// the original text so that it is relative to the start of the slice
+    pub fn glyph_at(&self, index: usize) -> Glyph {
+        let g = &self.item.glyphs[self.glyph_range.start + index];
+        let text_range = self.text_range();
+        Glyph {
+            range: (g.range.start - text_range.start as u16)
+                ..(g.range.end - text_range.start as u16),
+            ..*g
+        }
+    }
+
+    /// Returns an iterator over the glyphs of the slice.
+    ///
+    /// The range of text that each glyph represents is remapped to be relative
+    /// to the start of the slice.
+    pub fn glyphs(&self) -> impl Iterator<Item = Glyph> + '_ {
+        (0..self.glyph_range.len()).map(|index| self.glyph_at(index))
+    }
+
+    /// The plain text that this slice represents
+    pub fn text(&self) -> &str {
+        &self.item.text[self.text_range()]
+    }
+
+    /// The total width of this text slice
+    pub fn width(&self) -> Abs {
+        self.item.glyphs[self.glyph_range.clone()]
+            .iter()
+            .map(|g| g.x_advance)
+            .sum::<Em>()
+            .at(self.item.size)
+    }
+
+    /// The range of text in the original TextItem that this slice corresponds
+    /// to.
+    fn text_range(&self) -> Range<usize> {
+        let text_start = self.item.glyphs[self.glyph_range.start].range().start;
+        let text_end = self.item.glyphs[self.glyph_range.end - 1].range().end;
+        text_start..text_end
+    }
+}

crates/typst/src/visualize/image/svg.rs

@@ -30,7 +30,9 @@ impl SvgImage {
     /// Decode an SVG image without fonts.
     #[comemo::memoize]
     pub fn new(data: Bytes) -> StrResult<SvgImage> {
-        let tree = usvg::Tree::from_data(&data, &options()).map_err(format_usvg_error)?;
+        let mut tree =
+            usvg::Tree::from_data(&data, &options()).map_err(format_usvg_error)?;
+        tree.calculate_bounding_boxes();
         Ok(Self(Arc::new(Repr {
             data,
             size: tree_size(&tree),