With undecoded-image marks off, an image in an opacity mask's art that
failed to draw left a hole in the mask. Without Clip, the area outside
the mask art counts as white, so the masked object showed in full.
The renderer now notes an image that fails to draw while mask art is
drawn and leaves the masked object out, as PDF export does since #4765.
This covers images in pattern tiles and in cached effect and shadow
rasters, which remember the failure and report it again when they are
reused. Nested masks pass the failure outward, and View Opacity Mask
shows no coverage for such a mask. An image still waiting to be decoded,
or drawn with the undecoded-image mark, keeps today's behavior.
A knockout element with one opaque Normal solid fill (a path or
compound, no mask, effects or isolation) is drawn once under
AntiAlias::None, including the internal hard-edge frame of Art
Optimized supersampled exports, instead of being erased and added back
through per-element backdrop layers. Analytical antialiasing keeps the
existing compositor and rounding.
Exact-pixel tests compare against the general knockout path for paths
and compound holes across precision, supersampling, translucent parents
and copied backdrops, and check that the backdrop rasters are skipped;
translucent fills keep their knockout compositing.
# Conflicts:
# docs/roadmap.md
# docs/target-app-parity.md
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.