A colorized image's color channel is the paint's samples repeated once a
pixel, and nothing bounded its size: an image colorized in Registration in
a document with many spot swatches could allocate without limit, and an
overflowing length panicked inside repeat. The length is now computed with
checked arithmetic and refused above MAX_RASTER_ALLOC, the image's own
decode budget, and the export leaves such an image out with the existing
"an image couldn't be decoded" warning instead of drawing it uncolored.
PDF export (and the PDF-compatible .ai it writes) cut each gradient mesh
patch into 8 x 8 flat-coloured quads. Viewers showed colour bands and
hairline seams between them, and files with many meshes became very
large and slow to write.
An opaque mesh is now written as one Type 6 (Coons patch) shading
(ISO 32000-1, 8.7.4.5.7) filling its outline, through the PDF writer's
MeshGradient: each patch blends its corner colours bilinearly, as the
canvas draws it. Colours go through page_color as other fills do, and a
mesh mixing RGB with other models goes through RGB. A mesh with
see-through points, an invalid one, or one past the coordinate range
keeps the quads.
PDF export writes a CMYK image whose opacity mask is a gray image on its
own pixel grid with the mask as the image's soft mask. That path always
asked viewers to smooth the image, so a pixelated piece of an envelope
with Anti-Alias off was still written with /Interpolate when it had such
a mask. It now takes the pixelated flag as images without a mask do, and
caches the smoothed and pixelated versions apart.
Envelope Options stored Anti-Alias and Preserve Shape Using, but nothing that
draws an image read them: a distorted image was always smoothed and always
cut into clip groups.
- With Anti-Alias off, each piece of a distorted image is marked pixelated
(saved as `pixelated`). The renderer draws it with nearest-neighbor
sampling and without mips, SVG export writes `image-rendering: pixelated`,
and PDF export writes it without /Interpolate.
- With Preserve Shape Using Transparency, each piece is the image with a
white opacity mask in the piece's shape instead of a clip group. The
renderer paints an image whose mask is one plain white path straight into
that path, as it does for an image in a clip group, when the path lies
inside the image's frame.
Docs: docs/mcp.md, docs/target-app-parity.md.
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