Rendering Capabilities

This page summarizes what the current vyuh_docx PDF renderer is designed to handle and where reviewers should look when fidelity questions come up.

Document Structure

Capability	Notes
Sections	Page size, margins, header/footer distance, columns, page borders, and background image metadata.
Paragraphs	Alignment, spacing, indentation, borders, tabs, text wrapping, and explicit page breaks.
Runs	Font family, size, bold, italic, underline, strike, color, highlight, hidden text, baseline alignment.
Lists	Numbered and bulleted structures from DOCX or SFDT list data.
Tables	Grid layout, cell widths, margins, spans, borders, row heights, row splitting, and repeated headers.
Images	Inline and block image nodes with authored extents where available.
Shapes	Modeled drawing and text-box data where represented in the AST.
Headers and footers	Rendered as section furniture with reserved body space.
Comments	Comment metadata and anchors are preserved for round-trip/review surfaces.
Revisions	Tracked-change metadata is preserved in the model.
TOC	Table-of-contents blocks and cached content are represented.
Footnotes/endnotes	Footnote content is represented; PDF placement currently uses end-of-document simplification.
Custom XML	Custom data-store parts are preserved through supported flows.

Layout Behavior

Behavior	Implementation area
Page pagination	PdfLayoutEngine.paginate
Explicit layout model	PdfLayoutDocument, PdfLayoutPage, PdfLayoutBox
Multi-column sections	Section-aware layout engine configuration
Header/footer reserve	PdfExporter measures furniture reserve before paginating body content
Table splitting	Table layout boxes and row continuation logic
Repeated table headers	Table layout metadata
Default tab stops	PdfExporter reads w:defaultTabStop or uses the OOXML default
Watermarks	PdfExporter paints diagonal text on each page
PDF metadata	PdfDocumentWriter receives deterministic creation date when configured

Font Behavior

The renderer has two modes:

Mode	Behavior
Lenient fonts	Missing glyphs fall back where possible. This is the default for general rendering.
strictFonts: true	Missing glyphs throw instead of silently disappearing. Use this for controlled copies.

Hosts can call PdfExporter.registerFont(fontFamily, bytes) before export to make the renderer use supplied fonts.

Source Compatibility

The same DocxBuiltDocument model can come from:

• DocxReader for DOCX;
• SfdtReader for Syncfusion JSON;
• docx() and DocxDocumentBuilder for generated content;
• HtmlParser or MarkdownParser for imported lightweight content.

Renderer features should work from any source that populates the required model fields. If a path loses fidelity, inspect the reader/exporter first to verify the source property reaches the AST.

Not Owned By The Renderer

The renderer does not decide:

• who can view or edit a document;
• whether a PDF is a controlled copy;
• which copy number to allocate;
• whether an electronic signature is valid;
• whether a lifecycle state allows editing;
• where bytes are stored.

Those are docx_editor and host application responsibilities.