PdfSettings (serde, camelCase) is the Save PDF model: Standard, Compatibility
PDF 1.4-2.0, General (Preserve editing, Thumbnails, Fast web view, View after
saving, Create layers), Compression, Marks and Bleeds, Output, Advanced and
Security. PdfOptions = settings + pages, title and date.
document.exportPdf {path?, preset?, artboard?|artboards?|range?, standard?,
compatibility?, ...sections} -> {path|dataBase64, bytes, warnings} applies the
options over the preset (null keeps the preset's value); PDF/X, passwords,
PDF/A-2b at 2.0 and out-of-range values are refused; options accepted but not
applied yet come back as warnings. document.export {format: pdf} and
document.formats take and list the same options.
The Save PDF dialog (file.export.pdf, ui.savePdfDialog) has Preset,
Standard and Compatibility on top and a section list; it runs the export
before asking for a path, so bad options never open a save dialog.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
On screen, a group (or object) with opacity, a blend mode, an opacity mask or
knockout whose content blends is drawn offscreen over a copy of its backdrop
and mixed back in by its opacity, mask and clip (a group blend mode then
applies to the backdrop-free result, as PDF defines it). Isolate Blending keeps
the content starting from transparency. Clip groups no longer isolate their
children (blending content is clipped per drawing), and non-isolated knockout
groups composite their elements against the art below the group. Groups
without blending inside still render as plain layers.
In PDF, such groups are written as non-isolated transparency groups (a
constant-alpha soft mask instead of the writer's isolated opacity group),
knockout groups included.
doc: Node::blends_through / children_blend.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
color::blend gains blend_rgb (the 16 blend functions, with the 0.3/0.59/0.11
luminance of the non-separable modes), composite (source-over with blending)
and the shared opacity-mask luminance weights. Exported SVG masks take
luminance from sRGB values (color-interpolation="sRGB"), as the canvas does.
Tests: a per-mode table on the canvas (object, fill and group blend modes,
within 1/255; Exclusion 2/255 in the rasteriser's 8-bit pipeline), the same
table through SVG export rendered by resvg, clip and invert masks against the
canvas, and every mode's PDF name read back.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
