A sprite sorted by Y stood on the bottom of its box. With a shadow or
empty rows under the feet that is too low, so a figure slipped in
front of a tree it should stand behind. The line belongs to the frame,
not the texture, because one texture can hold several sprite sheets.
- New field `sortLine` on a frame: whole image pixels up from the
frame's bottom edge, 0 to the frame height. 0 is stored as nothing,
so old projects stay the same. Shrinking a frame keeps the line
inside it.
- `feetOf` in drawOrder.ts lifts a sprite by the same share of its
box. Scene view, game view, play and picking all use it. In an
animation the line of the frame shown right now counts.
- The texture tab draws the selected frame's line dashed in yellow
with a knob left of the frame. At 0 the line shares the bottom edge
with the nine-slice border and a resize handle, so the knob is
tested first. A line inside the frame can be dragged directly,
tested after the nine-slice lines.
- The inspector has a new "Sorting" section with a "Sort line"
field. Dragging or typing is one undo step each.
Limit: frames of one walk cycle need the same value, set by hand.
Otherwise the figure changes its place in the order while walking.
Tests:
- ./check.sh: 160 files, 2356 tests, CHECK EXIT 0 (before 2350).
- 6 new unit tests in tests/viewport/sort-by-y.test.ts.
- e2e 37 and 39-43: ALL PASSED, 162 checks. New check 37b-ii drags
the knob up 6 px and undoes it, plus the inspector row.
- Counter checks: if feetOf ignores the line, exactly the 3 order
tests fail. If the knob cannot be grabbed, 37b-ii fails.
- The e2e sum in the README is 1380, counted, not yet seen in CI.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>