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Tommaso Bianchi
1e51b54239
Two user reports from the same session on the deployed build, 2026-08-23.
FIRST: "if I select a shape (es a circle draw in construction lines) and then I
try to toggle contruction to obtain a full line, does not work". Reproduced: Q
converts the selection and so does the offer's Reference > Construction row —
both run m_keys_sketch['Q'] — but the CHECKBOX, the one control actually
labelled Construction, only ever called set_sketch_construction(), which arms
the mode for the NEXT entity. So the obvious control was the one route that
could not convert existing geometry, and it failed silently while also flipping
the draw mode behind the user's back. It now carries Q's meaning.
Scoped to Select mode, and that scoping is not cosmetic: drawing AUTO-SELECTS
what was just drawn (draw-then-edit), so with a draw tool armed "there is a
selection" does not mean the user picked anything — it means they finished a
line. The first version converted there and turned the box into a trap: arm
construction, draw the axis, click the box to go back to real geometry, and
instead of disarming the mode it converted the axis just drawn. The gesture
ladder's C4 rung does exactly that and reported three construction entities
where it wanted one. In Select mode the intent is unambiguous.
SECOND, and this one destroyed work: "after creation of a circle, a round angled
rectangle and a slot, and mirror of those shapes on a vertical line inside a
outer rectangle, preview is ok but application creates errors: the circle is
mirrored, but rectangle and slot are redrawn as pieces of circles screwing both
the original shapes and the copies." A screenshot came with it, and it showed
more than the words did: the ORIGINALS were wrecked too — the rounded rectangle
was drawn as a four-lobed cloud, each corner fillet having gone the long way
round, and the slot had ballooned into two near-full circles.
Measured on the rig, a slot mirrored about a vertical line:
rails 62.873 / 62.873 -> 2.082 / 62.913
caps r=21.554 sweep=-180.00 -> r=32.214 sweep=-237.66
and all four sources moved, the axis line with them
Cause: confirm_op's Mirror branch bound an Arc copy to its source with a
Symmetric constraint on the CENTRE ALONE. An arc has five degrees of freedom;
pinning two of them leaves the endpoints and the sweep free while the shape's
own coincidences still pull on them, and the solver answers with a different,
internally consistent sketch — which is what a reflex cap and a 2 mm rail are.
A circle came through the same code untouched because a circle HAS no endpoints
to leave free, which is exactly why the failure reads as "circles fine, rounded
rectangles and slots destroyed".
Three parts, and each one is here because the measurement caught the previous
one being half a fix:
1. Arcs are bound by BOTH ENDPOINTS. Endpoints before centre in the ladder:
{p0, p1} is four equations against five DoF and pins the sweep, while
{centre, p0, p1} is six and is refused — the refusal is what silently
degraded the batch to a set that left the sweep free.
2. Every copy is reflected from the PRE-BATCH source, so a batch that disturbs
the sketch cannot hand the next copy already-moved geometry.
3. THE APPLIED RESULT IS THE PREVIEW — checked on the sources AND the copies,
and on violation the whole constraint web is dropped and both halves are
restored to the reflection the preview drew. try_add_constraints rolls back
only when a solve FAILS, and every failure here came from a solve that
succeeded at something else. Guarding only the sources fixed the slot and
left the rounded rectangle's copies at a 13.8 mm rail and a 308 degree cap:
the original was safe and the copy was still wrong, which is half a fix.
The parametric link is kept whenever it provably holds the geometry, and dropped
when it does not. A wrong shape is worse than an unlinked one.
WHY NOTHING CAUGHT THIS: the gesture ladder's mirror rung reflects three
straight LINES. It sat green through the whole defect. C4b now mirrors a slot,
so the reflection has arcs in it, and grades the property the user actually
stated: the copy is the source reflected, the source does not move, and no cap
comes back reflex.
VERIFIED against the user's own scene, rebuilt gesture by gesture on the rig —
outer rectangle, circle, rounded rectangle and slot, a vertical CONSTRUCTION
line as the axis, all 17 entities mirrored in one gesture:
ok the mirror axis is a construction line
ok picked the axis and all 17 entities
ok originals unchanged (moved: [])
ok every copy is the exact reflection (worst 0.000000000)
ok no source arc turned reflex — the 'cloud' failure
ok no copied arc turned reflex (6 arcs checked)
One grader correction worth recording, because it cost a round and would cost
the next one too: a reflection REVERSES ORIENTATION, so a copy legitimately
stores p0/p1 the other way round. Comparing p0 to p0 grades the storage order,
not the geometry, and reported a perfect mirror as an 8.98 mm error. Endpoints
are compared as an unordered pair.