VellumPdf.Kernel 2.3.3

VellumPdf.Kernel

The low-level PDF generation kernel of VellumPdf, a dependency-free PDF library for .NET 10 implemented clean-room from ISO 32000. This is the object model and content-stream writer everything else builds on. It has zero runtime dependencies and is AOT- and trim-ready.

• A PdfCanvas for precise drawing: text, paths, images, colour, and graphics state.
• Fonts: the built-in Standard-14 faces plus TrueType and OpenType-CFF embedding and subsetting, with ToUnicode maps so text stays searchable and copy-paste-able.
• Images: JPEG, PNG, BMP, GIF, TIFF, JBIG2, and JPEG 2000.
• AES-256 encryption, object and cross-reference streams, AcroForm fields, a tagged-PDF structure tree, PDF/A-2 metadata, DeviceCMYK and ICC colour with output intents, and opt-in linearization.

Install

dotnet add package VellumPdf.Kernel

Usage

using VellumPdf.Canvas;    // PdfCanvas
using VellumPdf.Document;  // PdfDocument, PageSize
using VellumPdf.Fonts;     // Standard14

using var doc = new PdfDocument();
var page = doc.AddPage(PageSize.A4);
var font = doc.UseFont(Standard14.Helvetica);
var canvas = new PdfCanvas(page);

canvas
    .BeginText()
    .SetFont(font, 12)
    .SetTextMatrix(1, 0, 0, 1, 72, 720)
    .ShowText("Hello from the Kernel API!")
    .EndText();

canvas.Finish();

using var stream = File.OpenWrite("kernel-hello.pdf");
doc.Save(stream);

For most documents the high-level VellumPdf.Layout builder is easier; reach for the Kernel when you need direct control of the content stream.

Documentation

Kernel walkthrough: https://github.com/Tim81/VellumPDF/blob/main/docs/kernel-guide.md

The VellumPdf family

Roadmap

Planned direction, tracked as GitHub milestones. These are scopes, not commitments — the milestones carry no due dates. 2.3.3 is the latest published release.

Scope past 2.5 runs as two parallel tracks, because auditing the layout engine turned up more work than the PDF 2.0 conformance gap did. Both ship from the same version numbers.

Kernel and conformance

Layout

Editing existing documents. The only breaking milestone is 3.0.

What this library implements of ISO 32000-2 today is inventoried, reference by reference, in PDF 2.0 conformance. It emits a %PDF-2.0 header, which is not the same as conformance, and the table says which is which. The Reader guide and Layout guide each carry a capability table doing the same job for their own package, checked against the code and test suite rather than against this roadmap.

VellumPdf.Reader is marked Preview in the table above; expect its public surface to settle as these milestones land. VellumPdf.Conformance graduated to Stable in 2.0.

License

Apache-2.0. Source and issues: https://github.com/Tim81/VellumPDF

The Graphics Interchange Format(c) is the Copyright property of CompuServe Incorporated. GIF(sm) is a Service Mark property of CompuServe Incorporated. This package reads and writes GIF under the royalty-free licence granted in the GIF89a specification, which requires acknowledging that ownership and offers this wording for it. The NOTICE file shipped in this package carries the full text, alongside every other attribution this product owes.