Module render_bridge 

XFA layout output to PDF content stream overlay generation.

Converts LayoutDom (from xfa-layout-engine) into PDF content stream operators that can be overlaid on existing PDF pages.

XFA Spec 3.3 §2.6 (p55-56) — Transformations: XFA uses top-left origin (y grows downward), PDF uses bottom-left origin (y grows upward). The CoordinateMapper handles this transformation.

XFA Spec 3.3 §2.7 — Z-Order: objects are rendered in document order. Later objects appear on top of earlier objects (painter’s algorithm).

Structs

CoordinateMapper

Maps XFA coordinates (top-left origin) to PDF coordinates (bottom-left origin).

FontMetricsData

Resolved font metrics for a typeface, used for accurate text measurement.

ImageInfo

Image data collected during rendering for XObject embedding.

PageOverlay

Overlay result for a single page, including content stream and images.

RenderTree

The full intermediate render tree for a document.

XfaRenderConfig

Configuration for PDF overlay rendering.

Enums

RenderNode

A node in the intermediate render representation.

Functions

generate_all_overlays

Generate PDF content stream overlays for all pages in a layout.

generate_field_values_overlays

Generate overlays containing only field value text — no backgrounds, borders, captions, draws, or images. Used by the preserve_static path when widgets lack AP streams.

generate_page_overlay

Generate a PDF content stream overlay for a single page.

layout_dom_to_render_tree

Build a RenderTree from a LayoutDom.