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.
Every click and hover measured each path and compound path along its
curves to cull it (Node::reach_bounds_with), and a compound path was
then assembled whole to test its outline and fill. For a compound path
of thousands of members that took milliseconds per click.
Hit testing now culls paths and compound paths by the box of their
control points (which holds the curves), grown by their strokes' reach,
so the box is never smaller than the reach box it replaces. A compound
path's outline and fill are tested against only the members whose
control box, grown by the tolerance, holds the point: a member outside
that box is farther than the tolerance and winds zero times round the
point. Painted strokes still follow the whole compound path (alignment,
dashes, width profiles) and are measured along all of it, as before.
Tests (crates/doc/src/hit/tests.rs):
- a 2,000-member compound path hits exactly as the whole-path test did,
at random points, on and next to anchors and on the edges of the
members' boxes, for both fill rules, in Outline view and with Object
Selection by Path Only;
- wide strokes painting past the control points are still hit, for a
path and a compound path;
- the cull box holds the reach box for paths and compound paths.
Measured in a debug test build (one run, machine not idle): a click on
a 20,000-member compound path went from about 18 ms to about 1 ms.
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.
BFlat