A truncated or hostile file could crash, hang or exhaust memory while
being read. STEP: a last instance without its semicolon no longer runs
the cursor past the end, the complex B-spline forms read their parts
with bounds checks, a knot multiplicity is capped at degree + 1,
parameter lists nest at most 64 deep, and wrapped curves and
conversion-based units follow at most a fixed number of hops so
self-references cannot loop. IGES: spline curve and surface sizes, hole
and boundary counts and list indices are checked against the
parameters the entity actually has, using checked arithmetic;
transformation matrix chains and nested composite curves are cut after
a few links. IGES colour 1 (black) now maps to colour 7 so it shows on a
dark background. WMF: a record whose size claims more than the file has
left is clamped to the remaining bytes. Doc comments describe the
behaviour instead of naming an outside program.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
STEP presentation styles colour what they style: a solid in the standard
index colour its RGB is close to, else in the true colour, and a face
with a style of its own (with the edges round it) through the face and
edge colour attributes. IGES trimmed (144) and bounded (143) surfaces
come in as one SURFACE each in the entry's colour, after the solids,
which now come in last first. Faces show a true colour attribute in
that colour.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
ACIS text files come in one object per body (3DSOLID, REGION or SURFACE).
STEP B-rep models become a block per product with component inserts at
their placements, scaled to the drawing's units; IGES manifold solids come
in as 3DSOLIDs scaled to the drawing's units with their colours. Splines
that are exactly analytic shapes are kept as those shapes. Windows
metafiles become a WMF<n> block of polylines and text fitted to half the
view, placed at its top-left corner or by WMFIN's insertion prompts. The
Import File window lists the four formats as supported.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
