The walk measured every object's visual box to leave out what is off
the page. A plain group or layer is measured as the union of its
members, and each member then measured itself again when it was
written, so an object in plain groups was measured once for each level
it sits at.
Measuring a plain group or layer now keeps its members' boxes in a
tree, and each member uses its box when it is written. A container
written whatever its box is (a PDF layer's group, placed symbol art) is
not measured. A knockout group's elements are measured for the group's
box and again for the list of elements on the page, and that second box
is used for the element and for its mask. Objects in a live container
(Blend, Envelope, Repeat, Intertwine) are still measured with the
container and again after it is expanded. Node::visual_of_members holds
the formula that Node::visual also uses, so the boxes and every decision
are unchanged.
The output is byte for byte the same on one open path of 200,000
anchors, 20,000 rectangles in 200 groups of 100, and 5,000 point type
objects, and on a document of plain, see-through, clipping and knockout
groups on and off the page, each exported with default settings, with
uncompressed text and with PDF layers.
A projection now counts as invertible when its determinant, or its
adjugate's determinant, is more than 1e-15 times the largest of the six
products that determinant sums. The adjugate of the adjugate is the map
times a number, so the inverse of a projection that inverts also inverts,
is stored and reads back. The adjugate's cofactors are formed with exact
products, so the inverse of that inverse gives back the original map up
to scale, within 1e-6 of each row's largest entry, and a map whose third
row is the sum of its first two is still refused.
Homography::conjugated and Node::transform_projection judged the affine
map by an absolute determinant of 1e-15, so a scale by 1e-8 left type and
symbol instances in perspective with their old projection. Both now use
Homography::affine_is_invertible, which compares the determinant with
the two products it sums at any scale of the map. An affine map whose
determinant or inverse is not finite, such as a scale by 1e200 or
1e-200, is inverted through Homography::inverse. When the direct product
underflows to a map that is not invertible, as for a projection stored
at a subnormal scale, conjugated forms it again with its powers of two
kept apart.
- crates/geom/src/projective.rs: the_inverse_of_an_invertible_map_is_invertible,
conjugating_does_not_depend_on_the_scale_of_the_affine,
conjugating_a_map_at_a_tiny_scale_gives_an_invertible_map
- crates/doc/src/node/tests.rs: a_projection_follows_the_transform_or_is_removed
covers an invertible scale by 1e-8 and a singular map at that size
A compound path was assembled from its members in every frame it was
drawn, and Node::stroke_path grew its buffer by doubling, copying the
path into ever larger buffers for a compound path of many anchors. The
renderer's geometry cache was swept only once it held more than 1,024
entries, so while an object was dragged (a new node, and layer, in
every frame) the old copies stayed alive with all their members.
Now:
- a compound path is drawn from the path the renderer keeps for it in
its geometry cache, as a plain path already was, and is assembled
only when the node changes;
- Node::stroke_path sizes a compound path's buffer up front from its
members' segment counts (the same elements, in the same order);
- unused geometry entries are dropped after a few frames however few
entries there are.
Tests:
- crates/render/src/tests/memory.rs: the second frame draws the kept
path and the same pixels as the first and as a new renderer; after a
five-frame move the renderer no longer holds the compound path drawn
before it. The test fails without the renderer change.
- crates/doc/src/node/tests.rs: a compound path's path is its members'
paths in order (open, closed, empty and single-anchor members).
Not timed; vectorcraft-cli perf was not rerun.
With one Objects on Path group of two or more objects selected, the
Selection and Objects on Path tools show a square Space widget beyond the
last object, ahead along the path. Dragging it moves the last object
along the path, around its bends, as far as the pointer moves along it,
and the objects between follow evenly while the first one stays. With
Alt (Option on macOS) the objects spread from both ends toward or away
from the center of an open path, or of the first anchor of a closed one.
The distance between the objects shows next to the pointer in the
document's units; the drag is one undo step, and Escape cancels it.
- object.objectsOnPath.options takes spacing (points, or "auto", the
default even spread) and start (points from the first anchor). A
spacing the path has no room for is drawn smaller and kept, so a
longer path brings it back. Older files read as Auto.
- Moving the group, Pivot, Rotate, path edits, copies and saving keep
the Space. Scaling, rotating or shearing the group keeps the first
and last objects where the transform takes them on the new path, live
shapes included; a value that cannot be kept that way scales with the
path's length.
- The Rotate All widget follows the first object when Space moves it.
Behavior: https://helpx.adobe.com/illustrator/desktop/manage-objects/arrange-objects/rearrange-and-edit-objects-on-a-path.html
and https://helpx.adobe.com/illustrator/using/objects-on-path.html.
When moving type or a symbol instance in perspective makes the
conjugated projection overflow, Homography::conjugated now forms the
product from factors scaled to a largest entry of 1 and returns it at
that scale, which maps every point to the same place. When even the
scaled result is not invertible, the transform removes the projection
and the art is drawn flat, instead of keeping the old projection while
the flat art moves.
NodeKind's reader buffers the fields that come before `type` as
serde_json::Values. VectorCraft writes `type` first, but a crafted file
can put a long array there: a group whose children held 50M numbers before
its type (a 96 KB gzip) peaked at 1.6 GB, and the cost grows with the
array up to MAX_JSON, before any object in it is counted.
The buffer is read through a counting visitor: each JSON value counts
against MAX_BUFFERED_VALUES (32M, 4M on wasm32) as it is read, and values
replayed from the buffer aren't counted twice. load_file reads within it;
the same file is now refused at a 1.1 GB peak.
Opening a native document now reads at most MAX_READ_NODES objects (4M,
512K on wasm32) and refuses the file past that with a message naming the
budget. Paths already read within MAX_READ_ANCHORS and the web build's JSON
cap is 256 MB, but the number of objects had no bound: a gzip'd document of
empty groups costs about 270 bytes per object once read against some 50 in
its JSON, so 10M groups in a 24 MB file took 2.7 GB to open.
NodeWire's id is read through counted_id, so each object counts once as it
is read. load_file reads through a private load_file_within so a test can
exercise the budget without a 4M-object document.
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