engineering/mech/dimension.py collects what the features asked to have
dimensioned, adds the part's own sizes (chain, baseline or ordinate for the
axial lengths, a diameter per segment and per bore, the two overall sizes of a
plate), and removes the duplicates - ISO 129-1 says each dimension appears once,
and a test asserts no measurement is placed twice.
Fits and tolerances are resolved through the modules that already own them:
engineering.fits for an ISO 286 code and engineering.tolerances for an explicit
ISO 129 tolerance, including build_dim_override's sign convention (the lower
deviation is passed as the magnitude of the minus side, exactly as
server.py::_fit_to_tolerances does). A H7 bore at 40 mm resolves to +0.025/0 -
the correctness check the spec names. A fit together with an explicit tolerance,
a fit outside the authored ISO 286 range, and a fit on an intent with no
measurable nominal are each refused by name rather than guessed.
The layout is the part that had to be measured rather than asserted: every
intent's text is turned into a rectangle by the same helper the test uses, and
an intent is placed on the lowest level whose rectangle is free, with the level
pitch clamped to clear the text whatever the caller passed. The test then
asserts the placed rectangles are pairwise disjoint - including on a crowded
plate and with a deliberately too-small step. That is the same property the
repository's dim_overlap critique focus checks on the finished drawing.
The plan's layout clamped that pitch to the text HEIGHT on every axis, which is
only the stacking direction for the row of dimensions under the view. Beside the
view the levels march in x, so the extent they have to clear is the text WIDTH:
measured here, three diameter labels are 9.45 mm wide (9.45, 5.6) at a 8.0 mm
pitch, so a shaft's three segment diameters - all on the y = 0 centreline, hence
all on different levels - overlapped by 1.45 mm. The pitch and the within-level
span are now both taken per axis from the same _text_size helper text_rects
uses, which makes the disjointness a property of the algorithm rather than of
the label lengths that happened to be in the test.
Over hole_table_threshold holes the per-hole diameters leave the view and become
a table instead, grouped by diameter, thread, counterbore and depth, one tag per
group and the quantity on every row.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FKFStjEFzpGyLq5bMpWxTd
