When a .ai file, or an EPS with editing data, opened from its editing
data, the reader converted each embedded 8-bit CMYK image to RGB and
stored it as a PNG, so the document lost the image's ink amounts. When
the same .ai opens from its PDF part, the PDF importer keeps them in a
CMYK TIFF.
The reader now stores those samples with ImageBlob::cmyk_tiff, as the
PDF importer does (crates/pdf/src/import_image.rs). An alpha channel
that hides part of the image becomes the image's opacity mask, a
grayscale image over it, as in PDF import. Grayscale, RGB and 1-bit
images still open as RGBA PNGs.
Docs: docs/file-format-parity.md, docs/target-app-parity.md.
A PDF can define spot inks that have different names and the same
alternate space and tint transform, such as Blue1 and Blue2, both RGB
0 0 255. The interpreter drops the ink name, so the importer matches an
interpreted color to the file's Separation and DeviceN spaces by the
tint transform. The spaces of two such inks matched the same color, so
their paths imported as plain RGB and neither ink became a spot swatch.
This happened with both inks on one page, with each on its own page,
and in the PDF part of a .ai file.
The page walk in import_scan.rs, which follows the interpreter's order
for layers and overprint, now also records the ink of each path, from
the color space set by cs and CS or from the shading of the pattern set
by scn and SCN or drawn by sh, and the ink of the color space of the
text between two paths. When the spaces of several inks match a color,
the importer takes the space with the walk's ink names. It applies
these names to a page only when the page uses such an ink and a
counting pass of the interpreter draws as many paths there as the walk
counted. Otherwise the import works as before.
The file now opens with a spot swatch for each ink. Solid fills and
strokes of paths and type, and the stops of gradients on paths, link
to the swatch of their ink, the points of a gradient mesh keep the
ink's color, and PDF export writes each ink as its own separation.
Paint in these inks inside pattern cells, soft masks and type 3 glyphs,
and gradients on type in these inks, still import as RGB. Type in one
of these inks can also import as RGB when type in another Separation or
DeviceN ink is shown with no path drawn between them.
A PDF page's UserUnit (PDF 1.6) sets the size of its user space unit
in multiples of 1/72 inch. The PDF reader has applied it since #1894, so
a page with /UserUnit 10 and a 36 × 50.4 media box opens at 360 × 504
pt. A .ai whose editing data has its artboards in the page's own units
then no longer matched its PDF part. It opened from the PDF part,
without its layers, its hidden objects and the art outside its
artboards, and with its artboards in a row instead of where the
editing data puts them. document.pdfInfo gave such a page's size in
points and its boxes in the file's numbers.
Editing data whose first artboard has the page's size in the page's
units, and not in points, is now compared with the PDF part scaled
down by the UserUnit. The document read from it is then scaled up by
the UserUnit, with its stroke weights, dashes, effects and pattern
tiles. When the layers can't be read, the artboard layout taken from
the editing data is scaled the same way. document.pdfInfo gives the
boxes in points, as it gives the size.
Docs: docs/mcp.md, docs/target-app-parity.md.
BFlat