Redesign document representation 🧱

src/doc.rs

@@ -1,34 +1,60 @@
-//! Generation of abstract documents from syntax trees.
+//! Abstract representation of a typesetted document.
 
-#![allow(dead_code)]
-
-use std::fmt;
-use crate::parsing::{SyntaxTree, Node};
+use std::ops;
+use crate::font::Font;
 
 
-/// Abstract representation of a complete typesetted document.
-///
-/// This abstract thing can then be serialized into a specific format like _PDF_.
 #[derive(Debug, Clone, PartialEq)]
 pub struct Document {
-    /// The pages of the document.
     pub pages: Vec<Page>,
-    /// The font the document is written in.
-    pub font: String,
+    pub fonts: Vec<Font>,
+}
+
+#[derive(Debug, Clone, PartialEq)]
+pub struct Style {
+    // Paper
+    pub paper_size: [Size; 2],
+    pub margins: [Size; 4],
+
+    // Font handling
+    pub font_families: Vec<String>,
+    pub font_size: f32,
+}
+
+impl Default for Style {
+    fn default() -> Style {
+        Style {
+            // A4 paper with 1.5 cm margins in all directions
+            paper_size: [Size::from_mm(210.0), Size::from_mm(297.0)],
+            margins: [Size::from_cm(2.5); 4],
+
+            // Default font family
+            font_families: (&[
+                "NotoSans", "NotoSansMath"
+            ]).iter().map(ToString::to_string).collect(),
+            font_size: 12.0,
+        }
+    }
 }
 
-/// A page of a document.
 #[derive(Debug, Clone, PartialEq)]
 pub struct Page {
-    /// The width and height of the page.
-    pub size: [Size; 2],
-    /// The contents of the page.
-    pub contents: Vec<Text>,
+    pub width: Size,
+    pub height: Size,
+    pub text: Vec<Text>,
 }
 
-/// Plain text.
-#[derive(Debug, Clone, Eq, PartialEq)]
-pub struct Text(pub String);
+#[derive(Debug, Clone, PartialEq)]
+pub struct Text {
+    pub commands: Vec<TextCommand>,
+}
+
+#[derive(Debug, Clone, PartialEq)]
+pub enum TextCommand {
+    Text(String),
+    Move(Size, Size),
+    SetFont(usize, f32),
+}
 
 /// A general distance type that can convert between units.
 #[derive(Debug, Copy, Clone, PartialEq)]
@@ -40,170 +66,49 @@ pub struct Size {
 impl Size {
     /// Create a size from a number of points.
     #[inline]
-    pub fn from_points(points: f32) -> Size {
-        Size { points }
-    }
+    pub fn from_points(points: f32) -> Size { Size { points } }
 
     /// Create a size from a number of inches.
     #[inline]
-    pub fn from_inches(inches: f32) -> Size {
-        Size { points: 72.0 * inches }
-    }
+    pub fn from_inches(inches: f32) -> Size { Size { points: 72.0 * inches } }
 
     /// Create a size from a number of millimeters.
     #[inline]
-    pub fn from_mm(mm: f32) -> Size {
-        Size { points: 2.83465 * mm  }
-    }
+    pub fn from_mm(mm: f32) -> Size { Size { points: 2.83465 * mm  } }
 
     /// Create a size from a number of centimeters.
     #[inline]
-    pub fn from_cm(cm: f32) -> Size {
-        Size { points: 28.3465 * cm }
-    }
+    pub fn from_cm(cm: f32) -> Size { Size { points: 28.3465 * cm } }
 
     /// Create a size from a number of points.
     #[inline]
-    pub fn to_points(&self) -> f32 {
-        self.points
-    }
+    pub fn to_points(&self) -> f32 { self.points }
 
     /// Create a size from a number of inches.
     #[inline]
-    pub fn to_inches(&self) -> f32 {
-        self.points * 0.0138889
-    }
+    pub fn to_inches(&self) -> f32 { self.points * 0.0138889 }
 
     /// Create a size from a number of millimeters.
     #[inline]
-    pub fn to_mm(&self) -> f32 {
-        self.points * 0.352778
-    }
+    pub fn to_mm(&self) -> f32 { self.points * 0.352778 }
 
     /// Create a size from a number of centimeters.
     #[inline]
-    pub fn to_cm(&self) -> f32 {
-        self.points * 0.0352778
+    pub fn to_cm(&self) -> f32 { self.points * 0.0352778 }
+}
+
+impl ops::Add for Size {
+    type Output = Size;
+
+    fn add(self, other: Size) -> Size {
+        Size { points: self.points + other.points }
     }
 }
 
+impl ops::Sub for Size {
+    type Output = Size;
 
-/// A type that can be generated into a document.
-pub trait Generate {
-    /// Generate a document from self.
-    fn generate(self) -> GenResult<Document>;
-}
-
-impl Generate for SyntaxTree<'_> {
-    fn generate(self) -> GenResult<Document> {
-        Generator::new(self).generate()
-    }
-}
-
-/// Result type used for parsing.
-type GenResult<T> = std::result::Result<T, GenerationError>;
-
-/// A failure when generating.
-#[derive(Debug, Clone, Eq, PartialEq)]
-pub struct GenerationError {
-    /// A message describing the error.
-    message: String,
-}
-
-impl fmt::Display for GenerationError {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "generation error: {}", self.message)
-    }
-}
-
-
-/// Transforms an abstract syntax tree into a document.
-#[derive(Debug, Clone)]
-struct Generator<'s> {
-    tree: SyntaxTree<'s>,
-}
-
-impl<'s> Generator<'s> {
-    /// Create a new generator from a syntax tree.
-    fn new(tree: SyntaxTree<'s>) -> Generator<'s> {
-        Generator { tree }
-    }
-
-    /// Generate the abstract document.
-    fn generate(&mut self) -> GenResult<Document> {
-        let mut text = String::new();
-        for node in &self.tree.nodes {
-            match node {
-                Node::Space if !text.is_empty() => text.push(' '),
-                Node::Space | Node::Newline => (),
-                Node::Word(word) => text.push_str(word),
-
-                Node::ToggleItalics | Node::ToggleBold | Node::ToggleMath => unimplemented!(),
-                Node::Func(_) => unimplemented!(),
-
-            }
-        }
-
-        let page = Page {
-            size: [Size::from_mm(210.0), Size::from_mm(297.0)],
-            contents: vec![ Text(text) ],
-        };
-
-        Ok(Document {
-            pages: vec![page],
-            font: "NotoSans-Regular".to_owned(),
-        })
-    }
-
-    /// Gives a generation error with a message.
-    #[inline]
-    fn err<R, S: Into<String>>(&self, message: S) -> GenResult<R> {
-        Err(GenerationError { message: message.into() })
-    }
-}
-
-
-#[cfg(test)]
-mod generator_tests {
-    use super::*;
-    use crate::parsing::ParseTree;
-
-    /// Test if the source gets generated into the document.
-    fn test(src: &str, doc: Document) {
-        assert_eq!(src.parse_tree().unwrap().generate(), Ok(doc));
-    }
-
-    /// Test if generation gives this error for the source code.
-    fn test_err(src: &str, err: GenerationError) {
-        assert_eq!(src.parse_tree().unwrap().generate(), Err(err));
-    }
-
-    #[test]
-    fn generator_simple() {
-        test("This is an example of a sentence.", Document {
-            pages: vec![
-                Page {
-                    size: [Size::from_mm(210.0), Size::from_mm(297.0)],
-                    contents: vec![
-                        Text("This is an example of a sentence.".to_owned()),
-                    ]
-                }
-            ],
-            font: "NotoSans-Regular".to_owned(),
-        });
-    }
-
-    #[test]
-    fn generate_emoji() {
-        use crate::write::WritePdf;
-        let doc = Document {
-            pages: vec![Page {
-                size: [Size::from_mm(210.0), Size::from_mm(297.0)],
-                contents: vec![Text("🌍".to_owned())]
-            }],
-            font: "NotoEmoji-Regular".to_owned(),
-        };
-        let mut file = std::fs::File::create("../target/typeset-doc-emoji.pdf").unwrap();
-        file.write_pdf(&doc).unwrap();
+    fn sub(self, other: Size) -> Size {
+        Size { points: self.points - other.points }
     }
 }

src/engine.rs

@@ -0,0 +1,87 @@
+//! Core typesetting engine.
+
+use std::fmt;
+use crate::parsing::{SyntaxTree, Node};
+use crate::doc::{Document, Style, Page, Text, TextCommand};
+use crate::font::Font;
+
+
+/// A type that can be typesetted into a document.
+pub trait Typeset {
+    /// Generate a document from self.
+    fn typeset(self) -> TypeResult<Document>;
+}
+
+impl Typeset for SyntaxTree<'_> {
+    fn typeset(self) -> TypeResult<Document> {
+        Engine::new(self).typeset()
+    }
+}
+
+/// Result type used for parsing.
+type TypeResult<T> = std::result::Result<T, TypesetError>;
+
+/// Errors occuring in the process of typesetting.
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub struct TypesetError {
+    message: String,
+}
+
+impl fmt::Display for TypesetError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.write_str(&self.message)
+    }
+}
+
+
+/// Transforms an abstract syntax tree into a document.
+#[derive(Debug, Clone)]
+struct Engine<'s> {
+    tree: SyntaxTree<'s>,
+}
+
+impl<'s> Engine<'s> {
+    /// Create a new generator from a syntax tree.
+    fn new(tree: SyntaxTree<'s>) -> Engine<'s> {
+        Engine { tree }
+    }
+
+    /// Generate the abstract document.
+    fn typeset(&mut self) -> TypeResult<Document> {
+        let style = Style::default();
+
+        // Load font defined by style
+        let font_family = style.font_families.first().unwrap();
+        let program = std::fs::read(format!("../fonts/{}-Regular.ttf", font_family)).unwrap();
+        let font = Font::new(program).unwrap();
+
+        let mut text = String::new();
+        for node in &self.tree.nodes {
+            match node {
+                Node::Space if !text.is_empty() => text.push(' '),
+                Node::Space | Node::Newline => (),
+                Node::Word(word) => text.push_str(word),
+
+                Node::ToggleItalics | Node::ToggleBold | Node::ToggleMath => unimplemented!(),
+                Node::Func(_) => unimplemented!(),
+            }
+        }
+
+        let page = Page {
+            width: style.paper_size[0],
+            height: style.paper_size[1],
+            text: vec![Text {
+                commands: vec![
+                    TextCommand::Move(style.margins[0], style.paper_size[1] - style.margins[1]),
+                    TextCommand::SetFont(0, style.font_size),
+                    TextCommand::Text(text)
+                ]
+            }],
+        };
+
+        Ok(Document {
+            pages: vec![page],
+            fonts: vec![font],
+        })
+    }
+}

src/font.rs

@@ -6,18 +6,62 @@ use std::io::{self, Cursor, Seek, SeekFrom};
 use std::collections::HashMap;
 use byteorder::{BE, ReadBytesExt, WriteBytesExt};
 use opentype::{OpenTypeReader, Outlines, TableRecord, Tag};
-use opentype::tables::{Header, CharMap, MaximumProfile, HorizontalMetrics};
+use opentype::tables::{Header, Name, NameEntry, CharMap, MaximumProfile, HorizontalMetrics, OS2};
+use crate::doc::Size;
 
 
 /// An font wrapper which allows to subset a font.
+#[derive(Debug, Clone, PartialEq)]
 pub struct Font {
-    program: Vec<u8>,
+    pub name: String,
+    pub program: Vec<u8>,
+    pub mapping: HashMap<char, u16>,
+    pub widths: Vec<Size>,
+    pub default_glyph: u16,
 }
 
 impl Font {
     /// Create a new font from a font program.
-    pub fn new(program: Vec<u8>) -> Font {
-        Font { program }
+    pub fn new(program: Vec<u8>) -> Result<Font, opentype::Error> {
+        let mut readable = Cursor::new(&program);
+        let mut reader = OpenTypeReader::new(&mut readable);
+
+        let head = reader.read_table::<Header>()?;
+        let name = reader.read_table::<Name>()?;
+        let os2 = reader.read_table::<OS2>()?;
+        let charmap = reader.read_table::<CharMap>()?;
+        let hmtx = reader.read_table::<HorizontalMetrics>()?;
+
+        let unit_ratio = 1.0 / (head.units_per_em as f32);
+        let convert = |x| Size::from_points(unit_ratio * x as f32);
+
+        let base_font = name.get_decoded(NameEntry::PostScriptName);
+        let font_name =  base_font.unwrap_or_else(|| "unknown".to_owned());
+        let widths = hmtx.metrics.iter().map(|m| convert(m.advance_width)).collect();
+
+        Ok(Font {
+            name: font_name,
+            program,
+            mapping: charmap.mapping,
+            widths,
+            default_glyph: os2.us_default_char.unwrap_or(0),
+        })
+    }
+
+    /// Map a character to it's glyph index.
+    pub fn map(&self, c: char) -> u16 {
+        self.mapping.get(&c).map(|&g| g).unwrap_or(self.default_glyph)
+    }
+
+    /// Encode the given text for our font (into glyph ids).
+    pub fn encode(&self, text: &str) -> Vec<u8> {
+        println!("encoding {} with {:?}", text, self.mapping);
+        let mut bytes = Vec::with_capacity(2 * text.len());
+        for glyph in text.chars().map(|c| self.map(c)) {
+            bytes.push((glyph >> 8) as u8);
+            bytes.push((glyph & 0xff) as u8);
+        }
+        bytes
     }
 
     /// Generate a subsetted version of this font including only the chars listed in
@@ -33,7 +77,7 @@ impl Font {
         chars: C,
         needed_tables: I1,
         optional_tables: I2
-    ) -> Result<(Vec<u8>, HashMap<char, u16>), SubsettingError>
+    ) -> Result<Font, SubsettingError>
     where
         C: IntoIterator<Item=char>,
         I1: IntoIterator<Item=S1>, S1: AsRef<str>,
@@ -48,7 +92,7 @@ impl Font {
         tables.sort_by_key(|r| r.tag);
 
         Subsetter {
-            program: &self.program,
+            font: &self,
             reader,
             outlines,
             tables,
@@ -65,7 +109,7 @@ impl Font {
 
 struct Subsetter<'p> {
     // Original font
-    program: &'p [u8],
+    font: &'p Font,
     reader: OpenTypeReader<'p, Cursor<&'p Vec<u8>>>,
     outlines: Outlines,
     tables: Vec<TableRecord>,
@@ -82,7 +126,7 @@ struct Subsetter<'p> {
 
 impl<'p> Subsetter<'p> {
     fn subset<I1, S1, I2, S2>(mut self, needed_tables: I1, optional_tables: I2)
-    -> SubsettingResult<(Vec<u8>, HashMap<char, u16>)>
+    -> SubsettingResult<Font>
     where
         I1: IntoIterator<Item=S1>, S1: AsRef<str>,
         I2: IntoIterator<Item=S2>, S2: AsRef<str>
@@ -117,10 +161,21 @@ impl<'p> Subsetter<'p> {
 
         self.write_header()?;
 
+        let widths = self.glyphs.iter()
+            .map(|&glyph| self.font.widths.get(glyph as usize).map(|&w| w)
+                .take_invalid("missing glyph metrics"))
+            .collect::<SubsettingResult<Vec<_>>>()?;
+
         let mapping = self.chars.into_iter().enumerate().map(|(i, c)| (c, i as u16))
             .collect::<HashMap<char, u16>>();
 
-        Ok((self.body, mapping))
+        Ok(Font {
+            name: self.font.name.clone(),
+            program: self.body,
+            mapping,
+            widths,
+            default_glyph: self.font.default_glyph,
+        })
     }
 
     fn build_glyphs(&mut self) -> SubsettingResult<()> {
@@ -131,6 +186,8 @@ impl<'p> Subsetter<'p> {
             self.glyphs.push(cmap.get(c).ok_or_else(|| SubsettingError::MissingCharacter(c))?)
         }
 
+        self.glyphs.push(self.font.default_glyph);
+
         // Composite glyphs may need additional glyphs we have not yet in our list.
         // So now we have a look at the glyf table to check that and add glyphs
         // we need additionally.
@@ -400,7 +457,7 @@ impl<'p> Subsetter<'p> {
             Err(_) => return Err(SubsettingError::MissingTable(tag.to_string())),
         };
 
-        self.program.get(record.offset as usize .. (record.offset + record.length) as usize)
+        self.font.program.get(record.offset as usize .. (record.offset + record.length) as usize)
             .take_bytes()
     }
 

src/lib.rs

@@ -5,7 +5,7 @@
 //! # Example
 //! This is an example of compiling a really simple document into _PDF_.
 //! ```
-//! use typeset::{parsing::ParseTree, doc::Generate, write::WritePdf};
+//! use typeset::{parsing::ParseTree, engine::Typeset, write::WritePdf};
 //!
 //! // Create an output file.
 //! # /*
@@ -15,7 +15,7 @@
 //!
 //! // Parse the source and then generate the document.
 //! let src = "Hello World from Typeset‼";
-//! let doc = src.parse_tree().unwrap().generate().unwrap();
+//! let doc = src.parse_tree().unwrap().typeset().unwrap();
 //!
 //! // Write the document into file as PDF.
 //! file.write_pdf(&doc).unwrap();
@@ -23,9 +23,10 @@
 
 mod pdf;
 mod utility;
-pub mod font;
 pub mod parsing;
 pub mod doc;
+pub mod engine;
+pub mod font;
 
 /// Writing of documents into supported formats.
 pub mod write {

src/pdf.rs

@@ -2,7 +2,7 @@
 
 use std::fmt;
 use std::io::{self, Write, Cursor};
-use std::collections::{HashMap, HashSet};
+use std::collections::HashSet;
 use pdf::{PdfWriter, Id, Rect, Version, Trailer};
 use pdf::doc::{Catalog, PageTree, Page, Resource, Content};
 use pdf::text::Text;
@@ -10,8 +10,8 @@ use pdf::font::{
     Type0Font, CMapEncoding, CIDFont, CIDFontType, CIDSystemInfo,
     WidthRecord, FontDescriptor, FontFlags, EmbeddedFont, GlyphUnit
 };
-use opentype::{OpenTypeReader, tables::{self, NameEntry, MacStyleFlags}};
-use crate::doc::Document;
+use opentype::{OpenTypeReader, tables::{self, MacStyleFlags}};
+use crate::doc::{self, Document, TextCommand};
 use crate::font::Font;
 
 
@@ -68,7 +68,7 @@ struct PdfCreator<'a, W: Write> {
     writer: PdfWriter<'a, W>,
     doc: &'a Document,
     offsets: Offsets,
-    font: PdfFont,
+    fonts: Vec<PdfFont>,
 }
 
 /// Offsets for the various groups of ids.
@@ -87,33 +87,50 @@ impl<'a, W: Write> PdfCreator<'a, W> {
         let catalog = 1;
         let page_tree = catalog + 1;
         let pages = (page_tree + 1, page_tree + doc.pages.len() as Id);
-        let content_count = doc.pages.iter().flat_map(|p| p.contents.iter()).count() as Id;
+        let content_count = doc.pages.iter().flat_map(|p| p.text.iter()).count() as Id;
         let contents = (pages.1 + 1, pages.1 + content_count);
-        let fonts = (contents.1 + 1, contents.1 + 4);
+        let fonts = (contents.1 + 1, contents.1 + 4 * doc.fonts.len() as Id);
+
+        let offsets = Offsets {
+            catalog,
+            page_tree,
+            pages,
+            contents,
+            fonts,
+        };
+
+        assert!(doc.fonts.len() > 0);
 
         // Find out which chars are used in this document.
-        let mut chars = HashSet::new();
+        let mut char_sets = vec![HashSet::new(); doc.fonts.len()];
+        let mut current_font: usize = 0;
         for page in &doc.pages {
-            for content in &page.contents {
-                chars.extend(content.0.chars());
+            for text in &page.text {
+                for command in &text.commands {
+                    match command {
+                        TextCommand::Text(string) => {
+                            char_sets[current_font].extend(string.chars());
+                        },
+                        TextCommand::SetFont(id, _) => {
+                            assert!(*id < doc.fonts.len());
+                            current_font = *id;
+                        },
+                        _ => {},
+                    }
+                }
             }
         }
 
         // Create a subsetted pdf font.
-        let data = std::fs::read(format!("../fonts/{}.ttf", doc.font))?;
-        let font = PdfFont::new(&doc.font, data, chars)?;
+        let fonts = doc.fonts.iter().enumerate().map(|(i, font)| {
+            PdfFont::new(font, &char_sets[i])
+        }).collect::<PdfResult<Vec<_>>>()?;
 
         Ok(PdfCreator {
             writer: PdfWriter::new(target),
             doc,
-            offsets: Offsets {
-                catalog,
-                page_tree,
-                pages,
-                contents,
-                fonts,
-            },
-            font,
+            offsets,
+            fonts,
         })
     }
 
@@ -154,8 +171,8 @@ impl<'a, W: Write> PdfCreator<'a, W> {
         // The page objects
         let mut id = self.offsets.pages.0;
         for page in &self.doc.pages {
-            let width = page.size[0].to_points();
-            let height = page.size[1].to_points();
+            let width = page.width.to_points();
+            let height = page.height.to_points();
 
             self.writer.write_obj(id, Page::new(self.offsets.page_tree)
                 .media_box(Rect::new(0.0, 0.0, width, height))
@@ -172,77 +189,92 @@ impl<'a, W: Write> PdfCreator<'a, W> {
     fn write_contents(&mut self) -> PdfResult<()> {
         let mut id = self.offsets.contents.0;
         for page in &self.doc.pages {
-            for content in &page.contents {
-                self.writer.write_obj(id, &Text::new()
-                    .set_font(1, 13.0)
-                    .move_line(108.0, 734.0)
-                    .write_text(&self.encode(&content.0))
-                    .to_stream()
-                )?;
+            for text in &page.text {
+                self.write_text(id, text)?;
                 id += 1;
             }
         }
+        Ok(())
+    }
+
+    fn write_text(&mut self, id: u32, text: &doc::Text) -> PdfResult<()> {
+        let mut current_font = 0;
+        let encoded = text.commands.iter().filter_map(|cmd| match cmd {
+            TextCommand::Text(string) => Some(self.fonts[current_font].encode(&string)),
+            TextCommand::SetFont(id, _) => { current_font = *id; None },
+            _ => None,
+        }).collect::<Vec<_>>();
+
+        let mut object = Text::new();
+        let mut nr = 0;
+
+        for command in &text.commands {
+            match command {
+                TextCommand::Text(_) => {
+                    object.write_text(&encoded[nr]);
+                    nr += 1;
+                },
+                TextCommand::SetFont(id, size) => {
+                    object.set_font(*id as u32 + 1, *size);
+                },
+                TextCommand::Move(x, y) => {
+                    object.move_line(x.to_points(), y.to_points());
+                }
+            }
+        }
+
+        self.writer.write_obj(id, &object.to_stream())?;
 
         Ok(())
     }
 
     /// Write the fonts.
     fn write_fonts(&mut self) -> PdfResult<()> {
-        let id = self.offsets.fonts.0;
+        let mut id = self.offsets.fonts.0;
 
-        self.writer.write_obj(id, &Type0Font::new(
-            self.font.name.clone(),
-            CMapEncoding::Predefined("Identity-H".to_owned()),
-            id + 1
-        )).unwrap();
+        for font in &self.fonts {
+            self.writer.write_obj(id, &Type0Font::new(
+                font.name.clone(),
+                CMapEncoding::Predefined("Identity-H".to_owned()),
+                id + 1
+            ))?;
 
-        self.writer.write_obj(id + 1,
-            CIDFont::new(
-                CIDFontType::Type2,
-                self.font.name.clone(),
-                CIDSystemInfo::new("(Adobe)", "(Identity)", 0),
-                id + 2,
-            ).widths(vec![WidthRecord::start(0, self.font.widths.clone())])
-        ).unwrap();
+            self.writer.write_obj(id + 1,
+                CIDFont::new(
+                    CIDFontType::Type2,
+                    font.name.clone(),
+                    CIDSystemInfo::new("(Adobe)", "(Identity)", 0),
+                    id + 2,
+                ).widths(vec![WidthRecord::start(0, font.widths.clone())])
+            )?;
 
-        self.writer.write_obj(id + 2,
-            FontDescriptor::new(
-                self.font.name.clone(),
-                self.font.flags,
-                self.font.italic_angle,
-            )
-            .font_bbox(self.font.bounding_box)
-            .ascent(self.font.ascender)
-            .descent(self.font.descender)
-            .cap_height(self.font.cap_height)
-            .stem_v(self.font.stem_v)
-            .font_file_3(id + 3)
-        ).unwrap();
+            self.writer.write_obj(id + 2,
+                FontDescriptor::new(
+                    font.name.clone(),
+                    font.flags,
+                    font.italic_angle,
+                )
+                .font_bbox(font.bounding_box)
+                .ascent(font.ascender)
+                .descent(font.descender)
+                .cap_height(font.cap_height)
+                .stem_v(font.stem_v)
+                .font_file_3(id + 3)
+            )?;
 
+            self.writer.write_obj(id + 3, &EmbeddedFont::OpenType(&font.program))?;
 
-        self.writer.write_obj(id + 3, &EmbeddedFont::OpenType(&self.font.data)).unwrap();
+            id += 4;
+        }
 
         Ok(())
     }
-
-    /// Encode the given text for our font.
-    fn encode(&self, text: &str) -> Vec<u8> {
-        let mut bytes = Vec::with_capacity(2 * text.len());
-        for glyph in text.chars().map(|c| self.font.map(c)) {
-            bytes.push((glyph >> 8) as u8);
-            bytes.push((glyph & 0xff) as u8);
-        }
-        bytes
-    }
 }
 
 
 /// The data we need from the font.
 struct PdfFont {
-    data: Vec<u8>,
-    mapping: HashMap<char, u16>,
-    default_glyph: u16,
-    name: String,
+    font: Font,
     widths: Vec<GlyphUnit>,
     flags: FontFlags,
     italic_angle: f32,
@@ -256,47 +288,36 @@ struct PdfFont {
 impl PdfFont {
     /// Create a subetted version of the font and calculate some information
     /// needed for creating the _PDF_.
-    pub fn new(font_name: &str, data: Vec<u8>, chars: HashSet<char>) -> PdfResult<PdfFont> {
-        let mut readable = Cursor::new(&data);
+    pub fn new(font: &Font, chars: &HashSet<char>) -> PdfResult<PdfFont> {
+        let mut readable = Cursor::new(&font.program);
         let mut reader = OpenTypeReader::new(&mut readable);
 
         let head = reader.read_table::<tables::Header>()?;
-        let name = reader.read_table::<tables::Name>()?;
         let post = reader.read_table::<tables::Post>()?;
         let os2 = reader.read_table::<tables::OS2>()?;
 
-        let font = Font::new(data);
-        let (subsetted, mapping) = font.subsetted(
-            chars,
+        let subsetted = font.subsetted(
+            chars.iter().cloned(),
             &["head", "hhea", "maxp", "hmtx", "loca", "glyf"],
             &["cvt ", "prep", "fpgm", "OS/2", "cmap", "name", "post"],
         )?;
 
-        let unit_ratio = 1000.0 / (head.units_per_em as f32);
-        let convert = |x| (unit_ratio * x as f32).round() as GlyphUnit;
-
-        let base_font = name.get_decoded(NameEntry::PostScriptName);
-        let font_name =  base_font.unwrap_or_else(|| font_name.to_owned());
-
-
         let mut flags = FontFlags::empty();
         flags.set(FontFlags::FIXED_PITCH, post.is_fixed_pitch);
-        flags.set(FontFlags::SERIF, font_name.contains("Serif"));
+        flags.set(FontFlags::SERIF, font.name.contains("Serif"));
         flags.insert(FontFlags::SYMBOLIC);
         flags.set(FontFlags::ITALIC, head.mac_style.contains(MacStyleFlags::ITALIC));
         flags.insert(FontFlags::SMALL_CAP);
 
-        let mut readable = Cursor::new(&subsetted);
-        let mut reader = OpenTypeReader::new(&mut readable);
-        let hmtx = reader.read_table::<tables::HorizontalMetrics>()?;
-        let widths = hmtx.metrics.iter().map(|m| convert(m.advance_width)).collect();
+        let widths = subsetted.widths.iter()
+            .map(|w| (1000.0 * w.to_points()).round() as GlyphUnit)
+            .collect();
 
+        let unit_ratio = 1.0 / (head.units_per_em as f32);
+        let convert = |x| (unit_ratio * x as f32).round() as GlyphUnit;
 
         Ok(PdfFont {
-            data: subsetted,
-            mapping,
-            default_glyph: os2.us_default_char.unwrap_or(0),
-            name: font_name,
+            font: subsetted,
             widths,
             flags,
             italic_angle: post.italic_angle.to_f32(),
@@ -312,10 +333,13 @@ impl PdfFont {
             stem_v: (10.0 + 220.0 * (os2.us_weight_class as f32 - 50.0) / 900.0) as GlyphUnit,
         })
     }
+}
 
-    /// Map a character to it's glyph index.
-    fn map(&self, c: char) -> u16 {
-        self.mapping.get(&c).map(|&g| g).unwrap_or(self.default_glyph)
+impl std::ops::Deref for PdfFont {
+    type Target = Font;
+
+    fn deref(&self) -> &Font {
+        &self.font
     }
 }
 
@@ -324,20 +348,21 @@ impl PdfFont {
 mod pdf_tests {
     use super::*;
     use crate::parsing::ParseTree;
-    use crate::doc::Generate;
+    use crate::engine::Typeset;
 
     /// Create a pdf with a name from the source code.
     fn test(name: &str, src: &str) {
-        let doc = src.parse_tree().unwrap().generate().unwrap();
+        let doc = src.parse_tree().unwrap().typeset().unwrap();
         let path = format!("../target/typeset-pdf-{}.pdf", name);
         let mut file = std::fs::File::create(path).unwrap();
         file.write_pdf(&doc).unwrap();
     }
 
     #[test]
-    fn pdf_simple() {
+    fn pdf() {
         test("unicode", "∑mbe∂∂ed font with Unicode!");
         test("parentheses", "Text with ) and ( or (enclosed) works.");
+        test("composite-glyph", "Composite character‼");
         test("multiline","
              Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed
              diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed
@@ -345,9 +370,4 @@ mod pdf_tests {
              Stet clita kasd gubergren, no sea takimata sanctus est.
         ");
     }
-
-    #[test]
-    fn pdf_composite_glyph() {
-        test("composite-glyph", "Composite character‼");
-    }
 }