printpdf

printpdf is a Rust library for generating, reading (!), rendering (!!) and optimizing PDF documents.

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[!IMPORTANT]
HTML-to-PDF rendering is still experimental and WIP. In doubt, position PDF elements manually instead.

Features

• Pages, Bookmarks, link annotations (read / write)
• Layers (read / write)
• Graphics: lines, shapes, bezier curves, SVG content (read / write)
• Images encoding / decoding (read support: experimental / write supported with image)
• Embedded fonts, Unicode support (read support: experimental / write)
• Minifying file size (auto-subsetting fonts)
• Rendering PDF pages to SVG files: experimental
• Extracting text from PDF pages (with auto-decoding Unicode, line breaks, text positions: experimental)
• Minimal HTML layouting for simple page layout (using azul-layout + kuchiki HTML parser)
• Advanced graphics - overprint, blending, etc.
• Advanced typography - character / word scaling and spacing, superscript, subscript, etc.
• Embedding SVGs (uses svg2pdf crate internally)

NOT supported are:

• Gradients
• Patterns
• File attachements
• Open Prepress Interface
• Halftoning images
• Conformance / error checking for various PDF standards
• Embedded Javascript

See the WASM32 demo live at: https://fschutt.github.io/printpdf

Writing PDF

Basic example

use printpdf::*;

fn main() {
    let mut doc = PdfDocument::new("My first PDF");
    let page1_contents = vec![Op::Marker { id: "debugging-marker".to_string() }];
    let page1 = PdfPage::new(Mm(10.0), Mm(250.0), page1_contents);
    let pdf_bytes: Vec<u8> = doc
        .with_pages(vec![page1])
        .save(&PdfSaveOptions::default());
}

Graphics

use printpdf::*;

fn main() {
    let mut doc = PdfDocument::new("My first PDF");

    let line = Line {
        // Quadratic shape. The "false" determines if the next (following)
        // point is a bezier handle (for curves)
        // If you want holes, simply reorder the winding of the points to be
        // counterclockwise instead of clockwise.
        points: vec![
            (Point::new(Mm(100.0), Mm(100.0)), false),
            (Point::new(Mm(100.0), Mm(200.0)), false),
            (Point::new(Mm(300.0), Mm(200.0)), false),
            (Point::new(Mm(300.0), Mm(100.0)), false),
        ],
        is_closed: true,
    };
    
    // Triangle shape
    let polygon = Polygon {
        rings: vec![vec![
            (Point::new(Mm(150.0), Mm(150.0)), false),
            (Point::new(Mm(150.0), Mm(250.0)), false),
            (Point::new(Mm(350.0), Mm(250.0)), false),
        ]],
        mode: PaintMode::FillStroke,
        winding_order: WindingOrder::NonZero,
    };
    
    // Graphics config
    let fill_color = Color::Cmyk(Cmyk::new(0.0, 0.23, 0.0, 0.0, None));
    let outline_color = Color::Rgb(Rgb::new(0.75, 1.0, 0.64, None));
    let mut dash_pattern = LineDashPattern::default();
    dash_pattern.dash_1 = Some(20);

    let extgstate = ExtendedGraphicsStateBuilder::new()
        .with_overprint_stroke(true)
        .with_blend_mode(BlendMode::multiply())
        .build();
    
    let page1_contents = vec![
        // add line1 (square)
        Op::SetOutlineColor { col: Color::Rgb(Rgb::new(0.75, 1.0, 0.64, None)) },
        Op::SetOutlineThickness { pt: Pt(10.0) },
        Op::DrawLine { line: line },
    
        // add line2 (triangle)
        Op::SaveGraphicsState,
        Op::LoadGraphicsState { gs: doc.add_graphics_state(extgstate) },
        Op::SetLineDashPattern { dash: dash_pattern },
        Op::SetLineJoinStyle { join: LineJoinStyle::Round },
        Op::SetLineCapStyle { cap: LineCapStyle::Round },
        Op::SetFillColor { col: fill_color },
        Op::SetOutlineThickness { pt: Pt(15.0) },
        Op::SetOutlineColor { col: outline_color },
        Op::DrawPolygon { polygon: polygon },
        Op::RestoreGraphicsState,
    ];
    
    let page1 = PdfPage::new(Mm(10.0), Mm(250.0), page1_contents);
    let pdf_bytes: Vec<u8> = doc
        .with_pages(vec![page1])
        .save(&PdfSaveOptions::default());
}

Images

• Images only get compressed in release mode. You might get huge PDFs (6 or more MB) in debug mode.
• To make this process faster, use BufReader instead of directly reading from the file.
• Scaling of images is implicitly done to fit one pixel = one dot at 300 dpi.

use printpdf::*;

fn main() {
    let mut doc = PdfDocument::new("My first PDF");
    let image_bytes = include_bytes!("assets/img/BMP_test.bmp");
    let image = RawImage::decode_from_bytes(image_bytes).unwrap(); // requires --feature bmp
    
    // In the PDF, an image is an `XObject`, identified by a unique `ImageId`
    let image_xobject_id = doc.add_image(image);

    let page1_contents = vec![
        Op::UseXobject { 
            id: image_xobject_id.clone(), 
            transform: XObjectTransform::default() 
        }
    ];

    let page1 = PdfPage::new(Mm(10.0), Mm(250.0), page1_contents);
    let pdf_bytes: Vec<u8> = doc
        .with_pages(vec![page1])
        .save(&PdfSaveOptions::default());
}

Fonts

use printpdf::*;

fn main() {
    let mut doc = PdfDocument::new("My first PDF");

    let roboto_bytes = include_bytes!("assets/fonts/RobotoMedium.ttf").unwrap()
    let font_index = 0;
    let mut warnings = Vec::new();
    let font = ParsedFont::from_bytes(&roboto_bytes, font_index, &mut warnings).unwrap();

    // If you need custom text shaping (uses the `allsorts` font shaper internally)
    // let glyphs = font.shape(text);

    // printpdf automatically keeps track of which fonts are used in the PDF
    let font_id = doc.add_font(&font);

    let text_pos = Point {
        x: Mm(10.0).into(),
        y: Mm(100.0).into(),
    }; // from bottom left

    let page1_contents = vec![
        Op::SetLineHeight { lh: Pt(33.0) },
        Op::SetWordSpacing { pt: Pt(33.0) },
        Op::SetCharacterSpacing { multiplier: 10.0 },
        Op::SetTextCursor { pos: text_pos },
        // Op::WriteCodepoints { ... }
        // Op::WriteCodepointsWithKerning { ... }
        Op::WriteText {
            items: vec![TextItem::Text("Lorem ipsum".to_string())],
            font: font_id.clone(),
        },
        Op::AddLineBreak,
        Op::WriteText {
            items: vec![TextItem::Text("dolor sit amet".to_string())],
            font: font_id.clone(),
        },
        Op::AddLineBreak,
    ];

    let save_options = PdfSaveOptions {
        subset_fonts: true, // auto-subset fonts on save
        ..Default::default()
    };

    let page1 = PdfPage::new(Mm(10.0), Mm(250.0), page1_contents);
    let mut warnings = Vec::new();
    let pdf_bytes: Vec<u8> = doc
        .with_pages(vec![page1])
        .save(&save_options, &mut warnings);
}

Tables, HTML

For creating tables, etc. printpdf uses a basic layout system, similar to wkhtmltopdf (although more limited in terms of features). It's good enough for basic page layouting, book rendering and reports / forms / etc. Includes automatic page-breaking.

Since printpdf supports WASM, there is an interactive demo at https://fschutt.github.io/printpdf - try playing with the XML.

See SYNTAX.md for the XML syntax description.

// needs --features="html"
use printpdf::*;

fn main() {

    // See https://fschutt.github.io/printpdf for an interactive WASM demo!

    let html = r#"
    <html>

        <!-- printpdf automatically breaks content into pages -->
        <body style="padding:10mm">
            <p style="color: red; font-family: sans-serif;" data-chapter="1" data-subsection="First subsection">Hello!</p>
            <div style="width:200px;height:200px;background:red;" data-chapter="1" data-subsection="Second subsection">
                <p>World!</p>
            </div>
        </body>

        <!-- configure header and footer for each page -->
        <head>
            <header>
                <h4 style="color: #2e2e2e;min-height: 8mm;">Chapter {attr:chapter} * {attr:subsection}</h4>
                <p style="position: absolute;top:5mm;left:5mm;">{builtin:pagenum}</p>
            </header>

            <footer>
                <hr/>
            <footer/>
        </head>
    </html>
    "#;

    let options = XmlRenderOptions {
        // named images to be used in the HTML, i.e. ["image1.png" => DecodedImage(image1_bytes)]
        images: BTreeMap::new(),
        // named fonts to be used in the HTML, i.e. ["Roboto" => DecodedImage(roboto_bytes)]
        fonts: BTreeMap::new(),
        // default page width, printpdf will auto-page-break
        page_width: Mm(210.0),
        // default page height
        page_height: Mm(297.0),
    };

    let pdf_bytes = PdfDocument::new("My PDF")
        .with_html(html, &options).unwrap()
        .save(&PdfSaveOptions::default());
}

Roadmap

The goal of printpdf is to be a general-use PDF library, such as libharu or similar. PDFs generated by printpdf should always adhere to a PDF standard, except if you turn it off. Currently, only the standard PDF/X-3:2002 is covered (i.e. valid PDF according to Adobe Acrobat). Over time, there will be more standards supported.

The printpdf wiki is live at: https://github.com/fschutt/printpdf/wiki

Here are some resources I found while working on this library:

• PDFXPlorer, shows the DOM tree of a PDF, needs .NET 2.0
• Official PDF 1.7 reference
• [GERMAN] How to embed unicode fonts in PDF
• PDF X/1-a Validator
• PDF X/3 technical notes

License / Support

Library is licensed MIT.

You can donate (one-time or recurrent) at https://github.com/sponsors/fschutt. Thanks!