PanoramicData.Render

A high-fidelity rendering engine for OpenXML (DOCX) documents, producing paginated SVG and PDF output.

What It Does

PanoramicData.Render is a virtual layout engine that reads .docx files and produces visually faithful SVG pages (one per document page) and PDF files. Unlike semantic converters that map document tags to HTML, this library calculates exact glyph positions, line breaks, and object anchors — acting as a layout engine comparable to a word processor's print path.

What It Is Not

• Not a DOCX editor. This is read-only, one-way conversion.
• Not an HTML converter. Output is SVG and PDF only; there is no HTML mapping.
• Not pixel-perfect. The goal is "visually indistinguishable at normal zoom." Sub-pixel identity with Microsoft Word is not claimed.
• Not a UI component. This is a library that produces files/strings. Visualization is the consumer's responsibility.

Quick Start

using PanoramicData.Render;

var options = new RenderOptions
{
    FontDirectories = ["/usr/share/fonts", "C:\\Windows\\Fonts"],
    FallbackFontFamily = "Liberation Sans",
    TargetDpi = 96
};

await using var stream = File.OpenRead("document.docx");
var renderer = new DocxRenderer(options);
var result = await renderer.RenderAsync(stream);

// Get SVG for each page
for (var i = 0; i < result.Pages.Count; i++)
{
    var svg = result.Pages[i].ToSvg();
    await File.WriteAllTextAsync($"page-{i + 1}.svg", svg);
}

// Or export as a single PDF
await using var pdfStream = File.Create("output.pdf");
await result.ToPdfAsync(pdfStream);

// Or get PDF bytes directly
var pdfBytes = result.ToPdf();

Key Design Decisions

Decision	Rationale
SkiaSharp for measurement & PDF	MIT-licensed, cross-platform, includes HarfBuzz for complex script shaping
Knuth-Plass line breaking	Produces paragraph-optimal line breaks matching Word's behaviour more closely than greedy algorithms
Twips as internal unit	Matches Word's internal precision (1/1440 inch), avoiding accumulated rounding errors
Full OOXML style cascade	Document Defaults → Theme → Numbering → Table → Paragraph hierarchy → Character hierarchy → Toggle properties → Direct Formatting

Configuration

RenderOptions supports these settings:

Property	Default	Description
FontDirectories	[]	Directories to search for .ttf/.otf font files
FallbackFontFamily	""	Font to use when the document's font cannot be resolved
TargetDpi	96	Target DPI for SVG output scaling
EmbedFonts	false	Embed fonts as WOFF2 @font-face in SVG output
EmbedImages	true	Embed images as data URIs in SVG output
EnableHyphenation	false	Enable automatic hyphenation using TeX patterns
PageRange	null	Optional Range to render a subset of pages
ShowHiddenText	false	Include runs with w:vanish in the layout

Supported Formats

Input	Output
.docx (OOXML)	SVG (one per page, fonts optionally embedded as WOFF2)
	PDF (single file via SkiaSharp PDF backend)

.doc (binary format) is not supported and never will be. Future versions may add .pptx and .xlsx support.

Requirements

• .NET 10.0+
• Access to .ttf and/or .otf font files used in the source document (system fonts, a directory, or embedded)

Demo App (Local)

The repository includes a Blazor WebAssembly demo app in PanoramicData.Render.Demo.

1) Install WebAssembly tooling

The demo requires the .NET WebAssembly workload:

dotnet workload install wasm-tools

If you have multiple SDK feature bands installed and need to align workloads:

dotnet workload restore PanoramicData.Render.Demo/PanoramicData.Render.Demo.csproj

2) Build and run the demo

From repo root:

dotnet run --project PanoramicData.Render.Demo/PanoramicData.Render.Demo.csproj --configuration Debug --urls "http://localhost:5250"

Then open:

• http://localhost:5250

3) Optional release publish (static output)

dotnet publish PanoramicData.Render.Demo/PanoramicData.Render.Demo.csproj --configuration Release

Published web assets are in:

• PanoramicData.Render.Demo/bin/Release/net10.0/publish/wwwroot

GitHub Pages Deployment (Demo)

CI is configured to publish the demo app to GitHub Pages from GitHub Actions on pushes to main and on semantic version tags.

Triggering a deployment with a tag

git tag 1.0.2
git push origin 1.0.2

Verifying deployment status

Use GitHub UI:

• Actions -> latest CI run -> deploy_pages job

Or with gh CLI:

gh run list --workflow CI --limit 5
gh run view <run-id> --log

Custom Domain: https://render.panoramicdata.com

The repository deploys a CNAME file for render.panoramicdata.com as part of the Pages artifact.

1) DNS

Create a DNS record:

• Type: CNAME
• Host: render
• Target: panoramicdata.github.io

2) GitHub Pages settings

In repo Settings -> Pages:

• Source: GitHub Actions
• Custom domain: render.panoramicdata.com
• Enable Enforce HTTPS after DNS is validated

3) Optional gh commands

Set custom domain via API:

gh api --method PUT repos/panoramicdata/PanoramicData.Render/pages -f cname='render.panoramicdata.com'

Read current Pages config:

gh api repos/panoramicdata/PanoramicData.Render/pages

SSL/TLS certificate notes

You do not upload a certificate manually for GitHub Pages custom domains. After DNS and CNAME are correct, GitHub automatically provisions and renews TLS certificates.

Documentation

• DESIGN.md — Architecture and technical design
• PLAN.md — Phased implementation roadmap
• docs/supported-features.md — Supported features matrix
• docs/known-limitations.md — Known limitations
• docs/plans/ — Detailed per-phase deliverables

License

MIT — Copyright © 2026 Panoramic Data Limited

Contributing

See CONTRIBUTING.md for development setup and coding standards.