Replaces the start-message TransformationAxis of the previous commit, which was
the wrong shape in two ways.
DetectorTransformation (common/) mirrors a NeXus NXtransformations axis and holds
nothing else: name, type, units, vector, offset, depends_on and the positions
themselves. Deliberately without cleverness - the values are either a single
number for an axis that does not move or one per image, and nothing derives a
position from a start and an increment. That is the point: a producer will later
want to report where a stage actually WENT rather than where it was told to go,
and a structure that stores start+increment cannot express that. A million images
cost 4 MB per axis, which is not a reason to be clever.
Hence also the move to the END message: measured positions are only known once
the run is over.
And hence no metadata version bump, which the previous commit did make. The chain
is optional; when it is absent the writer builds the identical chain from the
start message, exactly as before. Nothing on the wire changes for a producer that
does not send it, so a broker and a writer of different releases still interwork -
the constraint the previous version stated is withdrawn.
The writer transcribes a chain it is given, without recomputing an angle, which
is what makes measured positions possible end to end.
JFJochReader_TransformationChain_SentAndBuilt writes the same run both ways and
checks the two files read back the same, chi/phi included.
CBORSerialize_End_Transformations covers the wire 1:1, asserting the order
survives and that a moving axis keeps one value per image while a stationary one
keeps a single value.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
leonarski_fandClaude Opus 5
e4edcd6fa9