Building a mapping evaluates the geometry of every pixel (resolution, azimuth, solid-angle and
polarization corrections, bin) - about 2 CPU-s and 0.1-0.25 s of wall on a 16 Mpx detector - and a
rotation run built seven, several for a geometry it had already evaluated: the first pass repeats the
pre-scan's, and the canonical pass and the second of two concurrent probes repeat the probes'. None of
it depends on the mask beyond skipping masked pixels, so AzimuthalIntegrationGeometryCache keeps the
unmasked tables of the last geometry (keyed bit for bit on everything SetupPixel reads), and a
mapping for the same geometry copies them and blanks its own masked pixels to what SetupPixel leaves
there. One entry, shared by the run's copies; on myob four of the seven builds now evaluate, three
copy (~40-120 ms against ~240+ ms on a loaded box).
The pre-scan's mapping is only read by the spot measurement, so it is built at the start of that
background task rather than on the main thread ahead of the projection read. It also fills the cache
for the first pass.
Output identical on the three GPU reference sweeps; a new test checks cached against fresh mappings
under different masks and centres.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01D1G8gJVAy6gp1K5Dz3NE5C
leonarski_fandClaude Opus 5.5
4616921087