A knockout group that is not isolated, and whose elements blend, is
drawn over a copy of the art below it when the renderer has no layer
open around it. Each element was drawn over the whole copy in a layer,
and the layer was cut to the element's knockout shape with DestIn.
Where the shape covers part of a pixel, the cut counted the element's
coverage a second time. With Page Knockout Group on and Page Isolated
Blending off, the page is drawn this way as soon as an object on it
outside an isolated group has a blend mode other than Normal, on itself
or on a fill or stroke. On a test page, adding a Multiply square
changed the half-covered edge of a blue square over orange from
[115, 115, 141] to [172, 159, 147] on white.
Each element is now drawn over the copy offscreen, over its own
bounds. With the DestOut pass before it, each pixel gets (1 - shape)
times what was below plus shape times the element composited with the
copy at a shape of 1, as ISO 32000-1 section 11.4.6 describes. Pixels
that the shape covers fully or not at all are drawn as before.
Rarely set fields move into one optional boxed NodeExtras, and large NodeKind payloads (images,
live shapes, blends, envelopes) are boxed. Every object, and every undo step that copies it,
shrinks: a 50k-path move keeps ~24.5 MB per step instead of ~40 MB. Files stay byte-identical
(Node keeps its flat JSON through a borrowed Serialize and a from-wire Deserialize, no flatten),
and loading is slightly faster. Undo and redo reuse their step's size estimate instead of
walking the document again (8.3 -> 5.6 ms for a 50k-path move).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VmMmc1J8XeNLxhRihWv9cc
# Conflicts:
# crates/engine/src/cmd/graph.rs
# crates/svg/src/export.rs
New Document.page_isolate / page_knockout, set by
transparency.togglePageIsolatedBlending / togglePageKnockoutGroup {value?}
(one undo step each, saved with the document, reported by
transparency.info) and the Transparency panel menu's check items. The page
renders as an isolated group (top-level blend modes no longer blend with
what lies under the page) and/or a knockout group whose elements are the
layers (neutral layers pass their objects through). PDF and SVG wrap the
page content in an isolated group and write page knockout as soft masks.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
New Node.knockout_shape (transparency.set / object.setProps knockoutShape,
reported by transparency.info). In a knockout group such an object knocks
out only as much as its opacity and mask let through (a 50% object knocks
out 50%); otherwise its full coverage knocks out. The renderer, PDF and
SVG masks honour it, and the panel's checkbox is now live.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Knockout Group is now Knockout {Neutral, Off, On} (old files' true loads as
On, false as Neutral). In a knockout group each child erases what the
children below it drew where it paints, then adds itself, so it composites
against the group's backdrop; neutral plain groups pass their children
through to the enclosing knockout group. transparency.set / object.setProps
take knockout "on"|"off"|"neutral"|bool; transparency.info reports the
state. PDF and SVG write knockout groups as nested soft masks with the same
look (PDF warns); the Transparency panel has a tri-state checkbox.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
dotCooCoo